From f13d945258eeeca9352a54ddc08e1b3c875ad310 Mon Sep 17 00:00:00 2001
From: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
Date: Wed, 29 Apr 2026 13:33:05 +0000
Subject: [PATCH 1/2] fix(typescript): handle undici timeout errors and retry
 network failures

- Detect Node.js undici timeout errors (UND_ERR_HEADERS_TIMEOUT,
  UND_ERR_BODY_TIMEOUT, ETIMEDOUT) and classify them as reason: timeout
  instead of reason: unknown
- Include full error cause chain in unknown error messages so underlying
  error codes surface to users instead of just 'fetch failed'
- Retry on network-level failures (connection resets, socket errors) in
  addition to retryable HTTP status codes (408, 429, 5xx)

Co-Authored-By: rishabh <rishabh@buildwithfern.com>
---
 .../fix-undici-timeout-handling.yml           | 17 +++++++
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../accept-header/src/core/fetcher/Fetcher.ts | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../alias-extends/src/core/fetcher/Fetcher.ts | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 seed/ts-sdk/alias/src/core/fetcher/Fetcher.ts | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../allof-inline/src/core/fetcher/Fetcher.ts  | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 seed/ts-sdk/allof/src/core/fetcher/Fetcher.ts | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../basic-auth/src/core/fetcher/Fetcher.ts    | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../bytes-upload/src/core/fetcher/Fetcher.ts  | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../content-type/src/core/fetcher/Fetcher.ts  | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../serde-layer/src/core/fetcher/Fetcher.ts   | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../empty-clients/src/core/fetcher/Fetcher.ts | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../enum/serde/src/core/fetcher/Fetcher.ts    | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../union-utils/src/core/fetcher/Fetcher.ts   | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../ts-sdk/errors/src/core/fetcher/Fetcher.ts | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../bigint/src/core/fetcher/Fetcher.ts        | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../local-files/core/fetcher/Fetcher.ts       | 49 ++++++++++++++++++-
 .../core/fetcher/requestWithRetries.ts        | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../node-fetch/src/core/fetcher/Fetcher.ts    | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../output-src-only/core/fetcher/Fetcher.ts   | 49 ++++++++++++++++++-
 .../core/fetcher/requestWithRetries.ts        | 37 +++++++++++---
 .../test-packagePath/core/fetcher/Fetcher.ts  | 49 ++++++++++++++++++-
 .../core/fetcher/requestWithRetries.ts        | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../serde-layer/src/core/fetcher/Fetcher.ts   | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../use-jest/src/core/fetcher/Fetcher.ts      | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../extends/src/core/fetcher/Fetcher.ts       | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../inline/src/core/fetcher/Fetcher.ts        | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../serde/src/core/fetcher/Fetcher.ts         | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../use-jest/src/core/fetcher/Fetcher.ts      | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../wrapper/src/core/fetcher/Fetcher.ts       | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../folders/src/core/fetcher/Fetcher.ts       | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../header-auth/src/core/fetcher/Fetcher.ts   | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../http-head/src/core/fetcher/Fetcher.ts     | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 39 ++++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../license/src/core/fetcher/Fetcher.ts       | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../literal/src/core/fetcher/Fetcher.ts       | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
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 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
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 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
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 .../no-retries/src/core/fetcher/Fetcher.ts    | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../null-type/src/core/fetcher/Fetcher.ts     | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
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 .../nullable/src/core/fetcher/Fetcher.ts      | 49 ++++++++++++++++++-
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 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
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 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../serde/src/core/fetcher/Fetcher.ts         | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../ts-sdk/object/src/core/fetcher/Fetcher.ts | 49 ++++++++++++++++++-
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 .../optional/src/core/fetcher/Fetcher.ts      | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../package-yml/src/core/fetcher/Fetcher.ts   | 49 ++++++++++++++++++-
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 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../no-scripts/src/core/fetcher/Fetcher.ts    | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../oidc-token/src/core/fetcher/Fetcher.ts    | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../use-oxc/src/core/fetcher/Fetcher.ts       | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../use-oxfmt/src/core/fetcher/Fetcher.ts     | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../use-oxlint/src/core/fetcher/Fetcher.ts    | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../use-prettier/src/core/fetcher/Fetcher.ts  | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../use-yarn/src/core/fetcher/Fetcher.ts      | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../simple-fhir/src/core/fetcher/Fetcher.ts   | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../serde-layer/src/core/fetcher/Fetcher.ts   | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../wrapper/src/core/fetcher/Fetcher.ts       | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../exhaustive/src/core/fetcher/Fetcher.ts    | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../trace/serde/src/core/fetcher/Fetcher.ts   | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../inline/src/core/fetcher/Fetcher.ts        | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../no-inline/src/core/fetcher/Fetcher.ts     | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../serde-layer/src/core/fetcher/Fetcher.ts   | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../validation/src/core/fetcher/Fetcher.ts    | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../variables/src/core/fetcher/Fetcher.ts     | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../version/src/core/fetcher/Fetcher.ts       | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../websockets/src/core/fetcher/Fetcher.ts    | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../websockets/src/core/fetcher/Fetcher.ts    | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../no-serde/src/core/fetcher/Fetcher.ts      | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../serde/src/core/fetcher/Fetcher.ts         | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 .../src/core/fetcher/Fetcher.ts               | 49 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 37 +++++++++++---
 425 files changed, 16342 insertions(+), 1909 deletions(-)
 create mode 100644 generators/typescript/sdk/changes/unreleased/fix-undici-timeout-handling.yml

diff --git a/generators/typescript/sdk/changes/unreleased/fix-undici-timeout-handling.yml b/generators/typescript/sdk/changes/unreleased/fix-undici-timeout-handling.yml
new file mode 100644
index 000000000000..a5a9713ceeef
--- /dev/null
+++ b/generators/typescript/sdk/changes/unreleased/fix-undici-timeout-handling.yml
@@ -0,0 +1,17 @@
+- summary: |
+    Detect Node.js undici timeout errors (UND_ERR_HEADERS_TIMEOUT, UND_ERR_BODY_TIMEOUT)
+    and classify them as `reason: "timeout"` instead of `reason: "unknown"`. This fixes
+    an issue where Node's built-in fetch has a hard 300s headersTimeout that fires before
+    the SDK's timeoutInSeconds, causing generic "fetch failed" errors.
+  type: fix
+
+- summary: |
+    Include the full error cause chain in unknown error messages so underlying error codes
+    (e.g., undici error codes, ECONNRESET) surface to users instead of just "fetch failed".
+  type: fix
+
+- summary: |
+    Retry on network-level failures (e.g., connection resets, socket errors) in addition
+    to retryable HTTP status codes (408, 429, 5xx). Previously, thrown errors from the
+    fetch call bypassed retry logic entirely.
+  type: feat
diff --git a/generators/typescript/utils/core-utilities/src/core/fetcher/Fetcher.ts b/generators/typescript/utils/core-utilities/src/core/fetcher/Fetcher.ts
index f59409ce0d3c..b3ff95a7b710 100644
--- a/generators/typescript/utils/core-utilities/src/core/fetcher/Fetcher.ts
+++ b/generators/typescript/utils/core-utilities/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/generators/typescript/utils/core-utilities/src/core/fetcher/requestWithRetries.ts b/generators/typescript/utils/core-utilities/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/generators/typescript/utils/core-utilities/src/core/fetcher/requestWithRetries.ts
+++ b/generators/typescript/utils/core-utilities/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/accept-header/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/accept-header/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/accept-header/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/accept-header/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/accept-header/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/accept-header/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/accept-header/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/accept-header/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/alias-extends/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/alias-extends/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/alias-extends/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/alias-extends/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/alias-extends/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/alias-extends/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/alias-extends/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/alias-extends/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/alias/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/alias/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/alias/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/alias/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/alias/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/alias/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/alias/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/alias/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/allof-inline/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/allof-inline/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/allof-inline/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/allof-inline/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/allof-inline/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/allof-inline/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/allof-inline/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/allof-inline/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/allof/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/allof/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/allof/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/allof/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/allof/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/allof/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/allof/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/allof/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/any-auth/generate-endpoint-metadata/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/any-auth/generate-endpoint-metadata/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/any-auth/generate-endpoint-metadata/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/any-auth/generate-endpoint-metadata/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/any-auth/generate-endpoint-metadata/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/any-auth/generate-endpoint-metadata/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/any-auth/generate-endpoint-metadata/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/any-auth/generate-endpoint-metadata/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/any-auth/no-custom-config/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/any-auth/no-custom-config/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/any-auth/no-custom-config/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/any-auth/no-custom-config/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/any-auth/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/any-auth/no-custom-config/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/any-auth/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/any-auth/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/api-wide-base-path/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/api-wide-base-path/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/api-wide-base-path/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/api-wide-base-path/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/api-wide-base-path/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/api-wide-base-path/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/api-wide-base-path/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/api-wide-base-path/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/audiences/no-custom-config/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/audiences/no-custom-config/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/audiences/no-custom-config/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/audiences/no-custom-config/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/audiences/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/audiences/no-custom-config/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/audiences/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/audiences/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/audiences/with-partner-audience/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/audiences/with-partner-audience/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/audiences/with-partner-audience/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/audiences/with-partner-audience/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/audiences/with-partner-audience/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/audiences/with-partner-audience/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/audiences/with-partner-audience/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/audiences/with-partner-audience/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/basic-auth-environment-variables/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/basic-auth-environment-variables/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/basic-auth-environment-variables/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/basic-auth-environment-variables/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/basic-auth-environment-variables/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/basic-auth-environment-variables/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/basic-auth-environment-variables/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/basic-auth-environment-variables/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/basic-auth-pw-omitted/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/basic-auth-pw-omitted/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/basic-auth-pw-omitted/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/basic-auth-pw-omitted/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/basic-auth-pw-omitted/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/basic-auth-pw-omitted/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/basic-auth-pw-omitted/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/basic-auth-pw-omitted/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/basic-auth/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/basic-auth/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/basic-auth/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/basic-auth/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/basic-auth/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/basic-auth/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/basic-auth/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/basic-auth/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/bearer-token-environment-variable/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/bearer-token-environment-variable/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/bearer-token-environment-variable/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/bearer-token-environment-variable/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/bearer-token-environment-variable/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/bearer-token-environment-variable/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/bearer-token-environment-variable/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/bearer-token-environment-variable/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/bytes-download/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/bytes-download/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/bytes-download/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/bytes-download/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/bytes-download/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/bytes-download/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/bytes-download/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/bytes-download/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/bytes-upload/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/bytes-upload/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/bytes-upload/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/bytes-upload/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/bytes-upload/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/bytes-upload/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/bytes-upload/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/bytes-upload/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/circular-references-advanced/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/circular-references-advanced/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/circular-references-advanced/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/circular-references-advanced/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/circular-references-advanced/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/circular-references-advanced/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/circular-references-advanced/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/circular-references-advanced/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/circular-references-extends/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/circular-references-extends/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/circular-references-extends/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/circular-references-extends/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/circular-references-extends/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/circular-references-extends/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/circular-references-extends/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/circular-references-extends/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/circular-references/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/circular-references/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/circular-references/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/circular-references/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/circular-references/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/circular-references/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/circular-references/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/circular-references/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/client-side-params/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/client-side-params/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/client-side-params/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/client-side-params/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/client-side-params/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/client-side-params/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/client-side-params/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/client-side-params/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/content-type/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/content-type/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/content-type/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/content-type/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/content-type/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/content-type/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/content-type/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/content-type/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/cross-package-type-names/no-custom-config/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/cross-package-type-names/no-custom-config/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/cross-package-type-names/no-custom-config/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/cross-package-type-names/no-custom-config/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/cross-package-type-names/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/cross-package-type-names/no-custom-config/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/cross-package-type-names/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/cross-package-type-names/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/cross-package-type-names/serde-layer/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/cross-package-type-names/serde-layer/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/cross-package-type-names/serde-layer/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/cross-package-type-names/serde-layer/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/cross-package-type-names/serde-layer/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/cross-package-type-names/serde-layer/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/cross-package-type-names/serde-layer/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/cross-package-type-names/serde-layer/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/dollar-string-examples/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/dollar-string-examples/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/dollar-string-examples/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/dollar-string-examples/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/dollar-string-examples/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/dollar-string-examples/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/dollar-string-examples/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/dollar-string-examples/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/empty-clients/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/empty-clients/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/empty-clients/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/empty-clients/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/empty-clients/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/empty-clients/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/empty-clients/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/empty-clients/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/endpoint-security-auth/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/endpoint-security-auth/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/endpoint-security-auth/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/endpoint-security-auth/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/endpoint-security-auth/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/endpoint-security-auth/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/endpoint-security-auth/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/endpoint-security-auth/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/enum/forward-compatible-enums-with-serde/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/enum/forward-compatible-enums-with-serde/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/enum/forward-compatible-enums-with-serde/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/enum/forward-compatible-enums-with-serde/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/enum/forward-compatible-enums-with-serde/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/enum/forward-compatible-enums-with-serde/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/enum/forward-compatible-enums-with-serde/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/enum/forward-compatible-enums-with-serde/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/enum/forward-compatible-enums/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/enum/forward-compatible-enums/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/enum/forward-compatible-enums/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/enum/forward-compatible-enums/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/enum/forward-compatible-enums/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/enum/forward-compatible-enums/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/enum/forward-compatible-enums/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/enum/forward-compatible-enums/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/enum/no-custom-config/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/enum/no-custom-config/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/enum/no-custom-config/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/enum/no-custom-config/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/enum/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/enum/no-custom-config/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/enum/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/enum/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/enum/serde/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/enum/serde/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/enum/serde/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/enum/serde/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/enum/serde/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/enum/serde/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/enum/serde/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/enum/serde/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/error-property/no-custom-config/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/error-property/no-custom-config/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/error-property/no-custom-config/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/error-property/no-custom-config/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/error-property/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/error-property/no-custom-config/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/error-property/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/error-property/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/error-property/union-utils/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/error-property/union-utils/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/error-property/union-utils/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/error-property/union-utils/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/error-property/union-utils/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/error-property/union-utils/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/error-property/union-utils/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/error-property/union-utils/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/errors/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/errors/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/errors/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/errors/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/errors/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/errors/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/errors/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/errors/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/examples/examples-with-api-reference/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/examples/examples-with-api-reference/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/examples/examples-with-api-reference/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/examples/examples-with-api-reference/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/examples/examples-with-api-reference/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/examples/examples-with-api-reference/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/examples/examples-with-api-reference/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/examples/examples-with-api-reference/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/examples/retain-original-casing/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/examples/retain-original-casing/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/examples/retain-original-casing/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/examples/retain-original-casing/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/examples/retain-original-casing/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/examples/retain-original-casing/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/examples/retain-original-casing/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/examples/retain-original-casing/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/exhaustive/allow-extra-fields/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/exhaustive/allow-extra-fields/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/exhaustive/allow-extra-fields/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/exhaustive/allow-extra-fields/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/exhaustive/allow-extra-fields/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/allow-extra-fields/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/exhaustive/allow-extra-fields/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/allow-extra-fields/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/exhaustive/bigint-serde-layer/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/exhaustive/bigint-serde-layer/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/exhaustive/bigint-serde-layer/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/exhaustive/bigint-serde-layer/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/exhaustive/bigint-serde-layer/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/bigint-serde-layer/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/exhaustive/bigint-serde-layer/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/bigint-serde-layer/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/exhaustive/bigint/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/exhaustive/bigint/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/exhaustive/bigint/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/exhaustive/bigint/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/exhaustive/bigint/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/bigint/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/exhaustive/bigint/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/bigint/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/exhaustive/consolidate-type-files/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/exhaustive/consolidate-type-files/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/exhaustive/consolidate-type-files/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/exhaustive/consolidate-type-files/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/exhaustive/consolidate-type-files/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/consolidate-type-files/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/exhaustive/consolidate-type-files/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/consolidate-type-files/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/exhaustive/export-all-requests-at-root/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/exhaustive/export-all-requests-at-root/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/exhaustive/export-all-requests-at-root/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/exhaustive/export-all-requests-at-root/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/exhaustive/export-all-requests-at-root/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/export-all-requests-at-root/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/exhaustive/export-all-requests-at-root/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/export-all-requests-at-root/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/exhaustive/local-files/core/fetcher/Fetcher.ts b/seed/ts-sdk/exhaustive/local-files/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/exhaustive/local-files/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/exhaustive/local-files/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/exhaustive/local-files/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/local-files/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/exhaustive/local-files/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/local-files/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/exhaustive/multiple-exports/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/exhaustive/multiple-exports/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/exhaustive/multiple-exports/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/exhaustive/multiple-exports/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/exhaustive/multiple-exports/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/multiple-exports/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/exhaustive/multiple-exports/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/multiple-exports/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/exhaustive/never-throw-errors/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/exhaustive/never-throw-errors/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/exhaustive/never-throw-errors/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/exhaustive/never-throw-errors/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/exhaustive/never-throw-errors/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/never-throw-errors/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/exhaustive/never-throw-errors/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/never-throw-errors/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/exhaustive/no-custom-config/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/exhaustive/no-custom-config/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/exhaustive/no-custom-config/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/exhaustive/no-custom-config/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/exhaustive/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/no-custom-config/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/exhaustive/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/exhaustive/node-fetch/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/exhaustive/node-fetch/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/exhaustive/node-fetch/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/exhaustive/node-fetch/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/exhaustive/node-fetch/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/node-fetch/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/exhaustive/node-fetch/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/node-fetch/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/exhaustive/output-src-only/core/fetcher/Fetcher.ts b/seed/ts-sdk/exhaustive/output-src-only/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/exhaustive/output-src-only/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/exhaustive/output-src-only/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/exhaustive/output-src-only/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/output-src-only/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/exhaustive/output-src-only/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/output-src-only/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/exhaustive/package-path/src/test-packagePath/core/fetcher/Fetcher.ts b/seed/ts-sdk/exhaustive/package-path/src/test-packagePath/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/exhaustive/package-path/src/test-packagePath/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/exhaustive/package-path/src/test-packagePath/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/exhaustive/package-path/src/test-packagePath/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/package-path/src/test-packagePath/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/exhaustive/package-path/src/test-packagePath/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/package-path/src/test-packagePath/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/exhaustive/parameter-naming-camel-case/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/exhaustive/parameter-naming-camel-case/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/exhaustive/parameter-naming-camel-case/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/exhaustive/parameter-naming-camel-case/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/exhaustive/parameter-naming-camel-case/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/parameter-naming-camel-case/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/exhaustive/parameter-naming-camel-case/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/parameter-naming-camel-case/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/exhaustive/parameter-naming-original-name/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/exhaustive/parameter-naming-original-name/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/exhaustive/parameter-naming-original-name/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/exhaustive/parameter-naming-original-name/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/exhaustive/parameter-naming-original-name/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/parameter-naming-original-name/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/exhaustive/parameter-naming-original-name/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/parameter-naming-original-name/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/exhaustive/parameter-naming-snake-case/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/exhaustive/parameter-naming-snake-case/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/exhaustive/parameter-naming-snake-case/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/exhaustive/parameter-naming-snake-case/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/exhaustive/parameter-naming-snake-case/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/parameter-naming-snake-case/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/exhaustive/parameter-naming-snake-case/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/parameter-naming-snake-case/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/exhaustive/parameter-naming-wire-value/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/exhaustive/parameter-naming-wire-value/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/exhaustive/parameter-naming-wire-value/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/exhaustive/parameter-naming-wire-value/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/exhaustive/parameter-naming-wire-value/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/parameter-naming-wire-value/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/exhaustive/parameter-naming-wire-value/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/parameter-naming-wire-value/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/exhaustive/retain-original-casing/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/exhaustive/retain-original-casing/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/exhaustive/retain-original-casing/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/exhaustive/retain-original-casing/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/exhaustive/retain-original-casing/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/retain-original-casing/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/exhaustive/retain-original-casing/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/retain-original-casing/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/exhaustive/serde-layer/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/exhaustive/serde-layer/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/exhaustive/serde-layer/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/exhaustive/serde-layer/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/exhaustive/serde-layer/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/serde-layer/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/exhaustive/serde-layer/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/serde-layer/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/exhaustive/use-jest/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/exhaustive/use-jest/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/exhaustive/use-jest/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/exhaustive/use-jest/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/exhaustive/use-jest/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/use-jest/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/exhaustive/use-jest/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/use-jest/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/exhaustive/web-stream-wrapper/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/exhaustive/web-stream-wrapper/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/exhaustive/web-stream-wrapper/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/exhaustive/web-stream-wrapper/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/exhaustive/web-stream-wrapper/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/web-stream-wrapper/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/exhaustive/web-stream-wrapper/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/web-stream-wrapper/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/exhaustive/with-audiences/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/exhaustive/with-audiences/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/exhaustive/with-audiences/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/exhaustive/with-audiences/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/exhaustive/with-audiences/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/with-audiences/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/exhaustive/with-audiences/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/with-audiences/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/extends/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/extends/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/extends/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/extends/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/extends/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/extends/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/extends/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/extends/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/extra-properties/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/extra-properties/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/extra-properties/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/extra-properties/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/extra-properties/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/extra-properties/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/extra-properties/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/extra-properties/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/file-download/file-download-response-headers/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/file-download/file-download-response-headers/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/file-download/file-download-response-headers/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/file-download/file-download-response-headers/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/file-download/file-download-response-headers/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/file-download/file-download-response-headers/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/file-download/file-download-response-headers/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/file-download/file-download-response-headers/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/file-download/no-custom-config/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/file-download/no-custom-config/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/file-download/no-custom-config/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/file-download/no-custom-config/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/file-download/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/file-download/no-custom-config/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/file-download/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/file-download/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/file-download/stream-wrapper/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/file-download/stream-wrapper/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/file-download/stream-wrapper/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/file-download/stream-wrapper/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/file-download/stream-wrapper/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/file-download/stream-wrapper/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/file-download/stream-wrapper/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/file-download/stream-wrapper/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/file-upload-openapi/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/file-upload-openapi/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/file-upload-openapi/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/file-upload-openapi/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/file-upload-openapi/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/file-upload-openapi/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/file-upload-openapi/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/file-upload-openapi/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/file-upload/form-data-node16/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/file-upload/form-data-node16/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/file-upload/form-data-node16/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/file-upload/form-data-node16/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/file-upload/form-data-node16/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/file-upload/form-data-node16/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/file-upload/form-data-node16/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/file-upload/form-data-node16/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/file-upload/inline/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/file-upload/inline/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/file-upload/inline/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/file-upload/inline/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/file-upload/inline/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/file-upload/inline/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/file-upload/inline/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/file-upload/inline/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/file-upload/no-custom-config/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/file-upload/no-custom-config/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/file-upload/no-custom-config/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/file-upload/no-custom-config/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/file-upload/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/file-upload/no-custom-config/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/file-upload/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/file-upload/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/file-upload/serde/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/file-upload/serde/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/file-upload/serde/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/file-upload/serde/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/file-upload/serde/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/file-upload/serde/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/file-upload/serde/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/file-upload/serde/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/file-upload/use-jest/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/file-upload/use-jest/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/file-upload/use-jest/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/file-upload/use-jest/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/file-upload/use-jest/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/file-upload/use-jest/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/file-upload/use-jest/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/file-upload/use-jest/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/file-upload/wrapper/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/file-upload/wrapper/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/file-upload/wrapper/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/file-upload/wrapper/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/file-upload/wrapper/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/file-upload/wrapper/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/file-upload/wrapper/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/file-upload/wrapper/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/folders/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/folders/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/folders/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/folders/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/folders/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/folders/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/folders/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/folders/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/header-auth-environment-variable/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/header-auth-environment-variable/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/header-auth-environment-variable/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/header-auth-environment-variable/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/header-auth-environment-variable/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/header-auth-environment-variable/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/header-auth-environment-variable/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/header-auth-environment-variable/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/header-auth/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/header-auth/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/header-auth/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/header-auth/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/header-auth/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/header-auth/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/header-auth/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/header-auth/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/http-head/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/http-head/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/http-head/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/http-head/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/http-head/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/http-head/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/http-head/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/http-head/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/idempotency-headers/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/idempotency-headers/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/idempotency-headers/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/idempotency-headers/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/idempotency-headers/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/idempotency-headers/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/idempotency-headers/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/idempotency-headers/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/imdb/branded-string-aliases/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/imdb/branded-string-aliases/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/imdb/branded-string-aliases/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/imdb/branded-string-aliases/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/imdb/branded-string-aliases/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/imdb/branded-string-aliases/src/core/fetcher/requestWithRetries.ts
index a45878364e5f..f4f23527c0c3 100644
--- a/seed/ts-sdk/imdb/branded-string-aliases/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/imdb/branded-string-aliases/src/core/fetcher/requestWithRetries.ts
@@ -1,6 +1,6 @@
 const INITIAL_RETRY_DELAY = 1000; // in milliseconds
 const MAX_RETRY_DELAY = 60000; // in milliseconds
-const DEFAULT_MAX_RETRIES = 5;
+const DEFAULT_MAX_RETRIES = 2;
 const JITTER_FACTOR = 0.2; // 20% random jitter
 
 function addPositiveJitter(delay: number): number {
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/imdb/no-custom-config/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/imdb/no-custom-config/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/imdb/no-custom-config/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/imdb/no-custom-config/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/imdb/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/imdb/no-custom-config/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/imdb/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/imdb/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/imdb/omit-undefined/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/imdb/omit-undefined/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/imdb/omit-undefined/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/imdb/omit-undefined/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/imdb/omit-undefined/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/imdb/omit-undefined/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/imdb/omit-undefined/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/imdb/omit-undefined/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/inferred-auth-explicit/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/inferred-auth-explicit/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/inferred-auth-explicit/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/inferred-auth-explicit/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/inferred-auth-explicit/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/inferred-auth-explicit/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/inferred-auth-explicit/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/inferred-auth-explicit/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/inferred-auth-implicit-api-key/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/inferred-auth-implicit-api-key/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/inferred-auth-implicit-api-key/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/inferred-auth-implicit-api-key/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/inferred-auth-implicit-api-key/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/inferred-auth-implicit-api-key/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/inferred-auth-implicit-api-key/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/inferred-auth-implicit-api-key/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/inferred-auth-implicit-no-expiry/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/inferred-auth-implicit-no-expiry/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/inferred-auth-implicit-no-expiry/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/inferred-auth-implicit-no-expiry/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/inferred-auth-implicit-no-expiry/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/inferred-auth-implicit-no-expiry/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/inferred-auth-implicit-no-expiry/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/inferred-auth-implicit-no-expiry/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/inferred-auth-implicit-reference/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/inferred-auth-implicit-reference/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/inferred-auth-implicit-reference/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/inferred-auth-implicit-reference/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/inferred-auth-implicit-reference/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/inferred-auth-implicit-reference/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/inferred-auth-implicit-reference/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/inferred-auth-implicit-reference/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/inferred-auth-implicit/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/inferred-auth-implicit/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/inferred-auth-implicit/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/inferred-auth-implicit/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/inferred-auth-implicit/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/inferred-auth-implicit/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/inferred-auth-implicit/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/inferred-auth-implicit/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/license/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/license/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/license/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/license/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/license/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/license/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/license/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/license/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/literal/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/literal/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/literal/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/literal/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/literal/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/literal/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/literal/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/literal/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/literals-unions/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/literals-unions/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/literals-unions/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/literals-unions/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/literals-unions/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/literals-unions/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/literals-unions/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/literals-unions/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/mixed-case/no-custom-config/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/mixed-case/no-custom-config/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/mixed-case/no-custom-config/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/mixed-case/no-custom-config/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/mixed-case/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/mixed-case/no-custom-config/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/mixed-case/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/mixed-case/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/mixed-case/retain-original-casing/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/mixed-case/retain-original-casing/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/mixed-case/retain-original-casing/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/mixed-case/retain-original-casing/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/mixed-case/retain-original-casing/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/mixed-case/retain-original-casing/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/mixed-case/retain-original-casing/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/mixed-case/retain-original-casing/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/mixed-file-directory/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/mixed-file-directory/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/mixed-file-directory/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/mixed-file-directory/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/mixed-file-directory/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/mixed-file-directory/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/mixed-file-directory/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/mixed-file-directory/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/multi-line-docs/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/multi-line-docs/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/multi-line-docs/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/multi-line-docs/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/multi-line-docs/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/multi-line-docs/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/multi-line-docs/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/multi-line-docs/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/multi-url-environment-no-default/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/multi-url-environment-no-default/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/multi-url-environment-no-default/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/multi-url-environment-no-default/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/multi-url-environment-no-default/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/multi-url-environment-no-default/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/multi-url-environment-no-default/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/multi-url-environment-no-default/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/multi-url-environment-reference/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/multi-url-environment-reference/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/multi-url-environment-reference/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/multi-url-environment-reference/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/multi-url-environment-reference/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/multi-url-environment-reference/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/multi-url-environment-reference/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/multi-url-environment-reference/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/multi-url-environment/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/multi-url-environment/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/multi-url-environment/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/multi-url-environment/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/multi-url-environment/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/multi-url-environment/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/multi-url-environment/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/multi-url-environment/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/multiple-request-bodies/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/multiple-request-bodies/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/multiple-request-bodies/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/multiple-request-bodies/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/multiple-request-bodies/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/multiple-request-bodies/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/multiple-request-bodies/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/multiple-request-bodies/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/no-content-response/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/no-content-response/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/no-content-response/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/no-content-response/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/no-content-response/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/no-content-response/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/no-content-response/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/no-content-response/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/no-environment/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/no-environment/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/no-environment/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/no-environment/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/no-environment/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/no-environment/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/no-environment/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/no-environment/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/no-retries/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/no-retries/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/no-retries/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/no-retries/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/no-retries/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/no-retries/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/no-retries/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/no-retries/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/null-type/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/null-type/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/null-type/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/null-type/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/null-type/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/null-type/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/null-type/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/null-type/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/nullable-allof-extends/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/nullable-allof-extends/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/nullable-allof-extends/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/nullable-allof-extends/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/nullable-allof-extends/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/nullable-allof-extends/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/nullable-allof-extends/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/nullable-allof-extends/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/nullable-optional/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/nullable-optional/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/nullable-optional/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/nullable-optional/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/nullable-optional/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/nullable-optional/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/nullable-optional/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/nullable-optional/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/nullable-request-body/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/nullable-request-body/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/nullable-request-body/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/nullable-request-body/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/nullable-request-body/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/nullable-request-body/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/nullable-request-body/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/nullable-request-body/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/nullable/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/nullable/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/nullable/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/nullable/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/nullable/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/nullable/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/nullable/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/nullable/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/oauth-client-credentials-custom/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/oauth-client-credentials-custom/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/oauth-client-credentials-custom/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/oauth-client-credentials-custom/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/oauth-client-credentials-custom/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/oauth-client-credentials-custom/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/oauth-client-credentials-custom/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/oauth-client-credentials-custom/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/oauth-client-credentials-default/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/oauth-client-credentials-default/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/oauth-client-credentials-default/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/oauth-client-credentials-default/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/oauth-client-credentials-default/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/oauth-client-credentials-default/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/oauth-client-credentials-default/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/oauth-client-credentials-default/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/oauth-client-credentials-environment-variables/no-custom-config/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/oauth-client-credentials-environment-variables/no-custom-config/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/oauth-client-credentials-environment-variables/no-custom-config/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/oauth-client-credentials-environment-variables/no-custom-config/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/oauth-client-credentials-environment-variables/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/oauth-client-credentials-environment-variables/no-custom-config/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/oauth-client-credentials-environment-variables/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/oauth-client-credentials-environment-variables/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/oauth-client-credentials-mandatory-auth/no-custom-config/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/oauth-client-credentials-mandatory-auth/no-custom-config/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/oauth-client-credentials-mandatory-auth/no-custom-config/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/oauth-client-credentials-mandatory-auth/no-custom-config/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/oauth-client-credentials-mandatory-auth/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/oauth-client-credentials-mandatory-auth/no-custom-config/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/oauth-client-credentials-mandatory-auth/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/oauth-client-credentials-mandatory-auth/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/oauth-client-credentials-nested-root/never-throw-errors/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/oauth-client-credentials-nested-root/never-throw-errors/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/oauth-client-credentials-nested-root/never-throw-errors/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/oauth-client-credentials-nested-root/never-throw-errors/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/oauth-client-credentials-nested-root/never-throw-errors/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/oauth-client-credentials-nested-root/never-throw-errors/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/oauth-client-credentials-nested-root/never-throw-errors/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/oauth-client-credentials-nested-root/never-throw-errors/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/oauth-client-credentials-nested-root/no-custom-config/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/oauth-client-credentials-nested-root/no-custom-config/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/oauth-client-credentials-nested-root/no-custom-config/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/oauth-client-credentials-nested-root/no-custom-config/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/oauth-client-credentials-nested-root/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/oauth-client-credentials-nested-root/no-custom-config/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/oauth-client-credentials-nested-root/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/oauth-client-credentials-nested-root/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/oauth-client-credentials-openapi/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/oauth-client-credentials-openapi/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/oauth-client-credentials-openapi/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/oauth-client-credentials-openapi/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/oauth-client-credentials-openapi/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/oauth-client-credentials-openapi/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/oauth-client-credentials-openapi/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/oauth-client-credentials-openapi/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/oauth-client-credentials-reference/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/oauth-client-credentials-reference/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/oauth-client-credentials-reference/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/oauth-client-credentials-reference/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/oauth-client-credentials-reference/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/oauth-client-credentials-reference/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/oauth-client-credentials-reference/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/oauth-client-credentials-reference/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/oauth-client-credentials-with-variables/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/oauth-client-credentials-with-variables/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/oauth-client-credentials-with-variables/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/oauth-client-credentials-with-variables/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/oauth-client-credentials-with-variables/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/oauth-client-credentials-with-variables/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/oauth-client-credentials-with-variables/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/oauth-client-credentials-with-variables/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/oauth-client-credentials/no-custom-config/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/oauth-client-credentials/no-custom-config/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/oauth-client-credentials/no-custom-config/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/oauth-client-credentials/no-custom-config/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/oauth-client-credentials/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/oauth-client-credentials/no-custom-config/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/oauth-client-credentials/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/oauth-client-credentials/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/oauth-client-credentials/serde/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/oauth-client-credentials/serde/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/oauth-client-credentials/serde/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/oauth-client-credentials/serde/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/oauth-client-credentials/serde/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/oauth-client-credentials/serde/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/oauth-client-credentials/serde/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/oauth-client-credentials/serde/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/object/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/object/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/object/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/object/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/object/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/object/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/object/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/object/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/objects-with-imports/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/objects-with-imports/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/objects-with-imports/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/objects-with-imports/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/objects-with-imports/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/objects-with-imports/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/objects-with-imports/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/objects-with-imports/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/openapi-request-body-ref/no-custom-config/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/openapi-request-body-ref/no-custom-config/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/openapi-request-body-ref/no-custom-config/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/openapi-request-body-ref/no-custom-config/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/openapi-request-body-ref/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/openapi-request-body-ref/no-custom-config/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/openapi-request-body-ref/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/openapi-request-body-ref/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/optional/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/optional/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/optional/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/optional/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/optional/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/optional/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/optional/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/optional/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/package-yml/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/package-yml/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/package-yml/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/package-yml/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/package-yml/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/package-yml/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/package-yml/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/package-yml/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/pagination-custom/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/pagination-custom/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/pagination-custom/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/pagination-custom/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/pagination-custom/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/pagination-custom/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/pagination-custom/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/pagination-custom/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/pagination-uri-path/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/pagination-uri-path/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/pagination-uri-path/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/pagination-uri-path/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/pagination-uri-path/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/pagination-uri-path/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/pagination-uri-path/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/pagination-uri-path/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/pagination/no-custom-config/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/pagination/no-custom-config/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/pagination/no-custom-config/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/pagination/no-custom-config/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/pagination/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/pagination/no-custom-config/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/pagination/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/pagination/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/pagination/page-index-semantics/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/pagination/page-index-semantics/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/pagination/page-index-semantics/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/pagination/page-index-semantics/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/pagination/page-index-semantics/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/pagination/page-index-semantics/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/pagination/page-index-semantics/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/pagination/page-index-semantics/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/path-parameters/no-custom-config/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/path-parameters/no-custom-config/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/path-parameters/no-custom-config/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/path-parameters/no-custom-config/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/path-parameters/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/path-parameters/no-custom-config/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/path-parameters/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/path-parameters/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/path-parameters/no-inline-path-parameters-retain-original-casing/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/path-parameters/no-inline-path-parameters-retain-original-casing/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/path-parameters/no-inline-path-parameters-retain-original-casing/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/path-parameters/no-inline-path-parameters-retain-original-casing/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/path-parameters/no-inline-path-parameters-retain-original-casing/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/path-parameters/no-inline-path-parameters-retain-original-casing/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/path-parameters/no-inline-path-parameters-retain-original-casing/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/path-parameters/no-inline-path-parameters-retain-original-casing/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/path-parameters/no-inline-path-parameters-serde/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/path-parameters/no-inline-path-parameters-serde/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/path-parameters/no-inline-path-parameters-serde/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/path-parameters/no-inline-path-parameters-serde/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/path-parameters/no-inline-path-parameters-serde/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/path-parameters/no-inline-path-parameters-serde/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/path-parameters/no-inline-path-parameters-serde/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/path-parameters/no-inline-path-parameters-serde/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/path-parameters/no-inline-path-parameters/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/path-parameters/no-inline-path-parameters/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/path-parameters/no-inline-path-parameters/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/path-parameters/no-inline-path-parameters/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/path-parameters/no-inline-path-parameters/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/path-parameters/no-inline-path-parameters/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/path-parameters/no-inline-path-parameters/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/path-parameters/no-inline-path-parameters/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/path-parameters/parameter-naming-camel-case/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/path-parameters/parameter-naming-camel-case/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/path-parameters/parameter-naming-camel-case/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/path-parameters/parameter-naming-camel-case/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/path-parameters/parameter-naming-camel-case/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/path-parameters/parameter-naming-camel-case/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/path-parameters/parameter-naming-camel-case/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/path-parameters/parameter-naming-camel-case/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/path-parameters/parameter-naming-original-name/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/path-parameters/parameter-naming-original-name/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/path-parameters/parameter-naming-original-name/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/path-parameters/parameter-naming-original-name/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/path-parameters/parameter-naming-original-name/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/path-parameters/parameter-naming-original-name/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/path-parameters/parameter-naming-original-name/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/path-parameters/parameter-naming-original-name/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/path-parameters/parameter-naming-snake-case/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/path-parameters/parameter-naming-snake-case/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/path-parameters/parameter-naming-snake-case/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/path-parameters/parameter-naming-snake-case/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/path-parameters/parameter-naming-snake-case/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/path-parameters/parameter-naming-snake-case/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/path-parameters/parameter-naming-snake-case/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/path-parameters/parameter-naming-snake-case/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/path-parameters/parameter-naming-wire-value/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/path-parameters/parameter-naming-wire-value/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/path-parameters/parameter-naming-wire-value/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/path-parameters/parameter-naming-wire-value/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/path-parameters/parameter-naming-wire-value/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/path-parameters/parameter-naming-wire-value/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/path-parameters/parameter-naming-wire-value/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/path-parameters/parameter-naming-wire-value/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/path-parameters/retain-original-casing/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/path-parameters/retain-original-casing/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/path-parameters/retain-original-casing/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/path-parameters/retain-original-casing/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/path-parameters/retain-original-casing/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/path-parameters/retain-original-casing/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/path-parameters/retain-original-casing/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/path-parameters/retain-original-casing/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/plain-text/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/plain-text/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/plain-text/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/plain-text/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/plain-text/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/plain-text/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/plain-text/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/plain-text/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/property-access/generate-read-write-only-types/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/property-access/generate-read-write-only-types/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/property-access/generate-read-write-only-types/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/property-access/generate-read-write-only-types/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/property-access/generate-read-write-only-types/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/property-access/generate-read-write-only-types/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/property-access/generate-read-write-only-types/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/property-access/generate-read-write-only-types/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/property-access/no-custom-config/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/property-access/no-custom-config/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/property-access/no-custom-config/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/property-access/no-custom-config/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/property-access/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/property-access/no-custom-config/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/property-access/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/property-access/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/public-object/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/public-object/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/public-object/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/public-object/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/public-object/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/public-object/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/public-object/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/public-object/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/query-param-name-conflict/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/query-param-name-conflict/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/query-param-name-conflict/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/query-param-name-conflict/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/query-param-name-conflict/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/query-param-name-conflict/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/query-param-name-conflict/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/query-param-name-conflict/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/query-parameters-openapi-as-objects/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/query-parameters-openapi-as-objects/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/query-parameters-openapi-as-objects/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/query-parameters-openapi-as-objects/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/query-parameters-openapi-as-objects/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/query-parameters-openapi-as-objects/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/query-parameters-openapi-as-objects/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/query-parameters-openapi-as-objects/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/query-parameters-openapi/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/query-parameters-openapi/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/query-parameters-openapi/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/query-parameters-openapi/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/query-parameters-openapi/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/query-parameters-openapi/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/query-parameters-openapi/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/query-parameters-openapi/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/query-parameters/no-custom-config/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/query-parameters/no-custom-config/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/query-parameters/no-custom-config/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/query-parameters/no-custom-config/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/query-parameters/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/query-parameters/no-custom-config/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/query-parameters/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/query-parameters/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/query-parameters/parameter-naming-camel-case/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/query-parameters/parameter-naming-camel-case/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/query-parameters/parameter-naming-camel-case/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/query-parameters/parameter-naming-camel-case/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/query-parameters/parameter-naming-camel-case/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/query-parameters/parameter-naming-camel-case/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/query-parameters/parameter-naming-camel-case/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/query-parameters/parameter-naming-camel-case/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/query-parameters/parameter-naming-original-name/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/query-parameters/parameter-naming-original-name/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/query-parameters/parameter-naming-original-name/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/query-parameters/parameter-naming-original-name/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/query-parameters/parameter-naming-original-name/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/query-parameters/parameter-naming-original-name/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/query-parameters/parameter-naming-original-name/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/query-parameters/parameter-naming-original-name/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/query-parameters/parameter-naming-snake-case/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/query-parameters/parameter-naming-snake-case/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/query-parameters/parameter-naming-snake-case/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/query-parameters/parameter-naming-snake-case/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/query-parameters/parameter-naming-snake-case/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/query-parameters/parameter-naming-snake-case/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/query-parameters/parameter-naming-snake-case/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/query-parameters/parameter-naming-snake-case/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/query-parameters/parameter-naming-wire-value/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/query-parameters/parameter-naming-wire-value/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/query-parameters/parameter-naming-wire-value/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/query-parameters/parameter-naming-wire-value/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/query-parameters/parameter-naming-wire-value/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/query-parameters/parameter-naming-wire-value/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/query-parameters/parameter-naming-wire-value/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/query-parameters/parameter-naming-wire-value/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/query-parameters/serde/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/query-parameters/serde/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/query-parameters/serde/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/query-parameters/serde/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/query-parameters/serde/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/query-parameters/serde/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/query-parameters/serde/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/query-parameters/serde/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/request-parameters/flatten-request-parameters/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/request-parameters/flatten-request-parameters/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/request-parameters/flatten-request-parameters/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/request-parameters/flatten-request-parameters/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/request-parameters/flatten-request-parameters/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/request-parameters/flatten-request-parameters/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/request-parameters/flatten-request-parameters/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/request-parameters/flatten-request-parameters/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/request-parameters/no-custom-config/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/request-parameters/no-custom-config/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/request-parameters/no-custom-config/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/request-parameters/no-custom-config/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/request-parameters/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/request-parameters/no-custom-config/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/request-parameters/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/request-parameters/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/request-parameters/use-big-int-and-default-request-parameter-values/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/request-parameters/use-big-int-and-default-request-parameter-values/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/request-parameters/use-big-int-and-default-request-parameter-values/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/request-parameters/use-big-int-and-default-request-parameter-values/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/request-parameters/use-big-int-and-default-request-parameter-values/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/request-parameters/use-big-int-and-default-request-parameter-values/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/request-parameters/use-big-int-and-default-request-parameter-values/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/request-parameters/use-big-int-and-default-request-parameter-values/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/request-parameters/use-default-request-parameter-values/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/request-parameters/use-default-request-parameter-values/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/request-parameters/use-default-request-parameter-values/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/request-parameters/use-default-request-parameter-values/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/request-parameters/use-default-request-parameter-values/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/request-parameters/use-default-request-parameter-values/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/request-parameters/use-default-request-parameter-values/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/request-parameters/use-default-request-parameter-values/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/required-nullable/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/required-nullable/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/required-nullable/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/required-nullable/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/required-nullable/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/required-nullable/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/required-nullable/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/required-nullable/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/reserved-keywords/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/reserved-keywords/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/reserved-keywords/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/reserved-keywords/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/reserved-keywords/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/reserved-keywords/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/reserved-keywords/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/reserved-keywords/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/response-property/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/response-property/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/response-property/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/response-property/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/response-property/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/response-property/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/response-property/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/response-property/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/schemaless-request-body-examples/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/schemaless-request-body-examples/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/schemaless-request-body-examples/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/schemaless-request-body-examples/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/schemaless-request-body-examples/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/schemaless-request-body-examples/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/schemaless-request-body-examples/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/schemaless-request-body-examples/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/server-sent-event-examples/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/server-sent-event-examples/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/server-sent-event-examples/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/server-sent-event-examples/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/server-sent-event-examples/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/server-sent-event-examples/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/server-sent-event-examples/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/server-sent-event-examples/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/server-sent-events-openapi/no-custom-config/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/server-sent-events-openapi/no-custom-config/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/server-sent-events-openapi/no-custom-config/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/server-sent-events-openapi/no-custom-config/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/server-sent-events-openapi/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/server-sent-events-openapi/no-custom-config/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/server-sent-events-openapi/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/server-sent-events-openapi/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/server-sent-events/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/server-sent-events/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/server-sent-events/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/server-sent-events/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/server-sent-events/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/server-sent-events/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/server-sent-events/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/server-sent-events/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/server-url-templating/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/server-url-templating/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/server-url-templating/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/server-url-templating/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/server-url-templating/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/server-url-templating/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/server-url-templating/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/server-url-templating/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/simple-api/allow-custom-fetcher/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/simple-api/allow-custom-fetcher/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/simple-api/allow-custom-fetcher/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/simple-api/allow-custom-fetcher/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/simple-api/allow-custom-fetcher/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/simple-api/allow-custom-fetcher/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/simple-api/allow-custom-fetcher/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/simple-api/allow-custom-fetcher/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/simple-api/allow-extra-fields/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/simple-api/allow-extra-fields/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/simple-api/allow-extra-fields/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/simple-api/allow-extra-fields/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/simple-api/allow-extra-fields/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/simple-api/allow-extra-fields/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/simple-api/allow-extra-fields/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/simple-api/allow-extra-fields/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/simple-api/bundle/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/simple-api/bundle/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/simple-api/bundle/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/simple-api/bundle/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/simple-api/bundle/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/simple-api/bundle/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/simple-api/bundle/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/simple-api/bundle/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/simple-api/custom-package-json/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/simple-api/custom-package-json/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/simple-api/custom-package-json/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/simple-api/custom-package-json/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/simple-api/custom-package-json/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/simple-api/custom-package-json/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/simple-api/custom-package-json/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/simple-api/custom-package-json/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/simple-api/jsr/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/simple-api/jsr/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/simple-api/jsr/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/simple-api/jsr/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/simple-api/jsr/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/simple-api/jsr/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/simple-api/jsr/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/simple-api/jsr/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/simple-api/legacy-exports/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/simple-api/legacy-exports/src/core/fetcher/Fetcher.ts
index f59409ce0d3c..b3ff95a7b710 100644
--- a/seed/ts-sdk/simple-api/legacy-exports/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/simple-api/legacy-exports/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/simple-api/legacy-exports/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/simple-api/legacy-exports/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/simple-api/legacy-exports/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/simple-api/legacy-exports/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/simple-api/naming-shorthand/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/simple-api/naming-shorthand/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/simple-api/naming-shorthand/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/simple-api/naming-shorthand/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/simple-api/naming-shorthand/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/simple-api/naming-shorthand/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/simple-api/naming-shorthand/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/simple-api/naming-shorthand/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/simple-api/naming/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/simple-api/naming/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/simple-api/naming/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/simple-api/naming/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/simple-api/naming/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/simple-api/naming/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/simple-api/naming/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/simple-api/naming/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/simple-api/no-custom-config/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/simple-api/no-custom-config/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/simple-api/no-custom-config/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/simple-api/no-custom-config/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/simple-api/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/simple-api/no-custom-config/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/simple-api/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/simple-api/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/simple-api/no-linter-and-formatter/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/simple-api/no-linter-and-formatter/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/simple-api/no-linter-and-formatter/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/simple-api/no-linter-and-formatter/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/simple-api/no-linter-and-formatter/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/simple-api/no-linter-and-formatter/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/simple-api/no-linter-and-formatter/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/simple-api/no-linter-and-formatter/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/simple-api/no-scripts/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/simple-api/no-scripts/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/simple-api/no-scripts/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/simple-api/no-scripts/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/simple-api/no-scripts/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/simple-api/no-scripts/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/simple-api/no-scripts/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/simple-api/no-scripts/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/simple-api/oidc-token/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/simple-api/oidc-token/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/simple-api/oidc-token/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/simple-api/oidc-token/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/simple-api/oidc-token/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/simple-api/oidc-token/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/simple-api/oidc-token/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/simple-api/oidc-token/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/simple-api/omit-fern-headers/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/simple-api/omit-fern-headers/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/simple-api/omit-fern-headers/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/simple-api/omit-fern-headers/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/simple-api/omit-fern-headers/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/simple-api/omit-fern-headers/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/simple-api/omit-fern-headers/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/simple-api/omit-fern-headers/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/simple-api/use-oxc/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/simple-api/use-oxc/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/simple-api/use-oxc/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/simple-api/use-oxc/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/simple-api/use-oxc/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/simple-api/use-oxc/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/simple-api/use-oxc/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/simple-api/use-oxc/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/simple-api/use-oxfmt/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/simple-api/use-oxfmt/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/simple-api/use-oxfmt/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/simple-api/use-oxfmt/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/simple-api/use-oxfmt/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/simple-api/use-oxfmt/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/simple-api/use-oxfmt/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/simple-api/use-oxfmt/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/simple-api/use-oxlint/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/simple-api/use-oxlint/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/simple-api/use-oxlint/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/simple-api/use-oxlint/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/simple-api/use-oxlint/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/simple-api/use-oxlint/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/simple-api/use-oxlint/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/simple-api/use-oxlint/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/simple-api/use-prettier-no-linter/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/simple-api/use-prettier-no-linter/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/simple-api/use-prettier-no-linter/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/simple-api/use-prettier-no-linter/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/simple-api/use-prettier-no-linter/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/simple-api/use-prettier-no-linter/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/simple-api/use-prettier-no-linter/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/simple-api/use-prettier-no-linter/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/simple-api/use-prettier/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/simple-api/use-prettier/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/simple-api/use-prettier/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/simple-api/use-prettier/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/simple-api/use-prettier/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/simple-api/use-prettier/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/simple-api/use-prettier/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/simple-api/use-prettier/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/simple-api/use-yarn/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/simple-api/use-yarn/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/simple-api/use-yarn/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/simple-api/use-yarn/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/simple-api/use-yarn/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/simple-api/use-yarn/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/simple-api/use-yarn/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/simple-api/use-yarn/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/simple-fhir/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/simple-fhir/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/simple-fhir/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/simple-fhir/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/simple-fhir/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/simple-fhir/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/simple-fhir/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/simple-fhir/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/single-url-environment-default/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/single-url-environment-default/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/single-url-environment-default/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/single-url-environment-default/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/single-url-environment-default/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/single-url-environment-default/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/single-url-environment-default/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/single-url-environment-default/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/single-url-environment-no-default/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/single-url-environment-no-default/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/single-url-environment-no-default/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/single-url-environment-no-default/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/single-url-environment-no-default/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/single-url-environment-no-default/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/single-url-environment-no-default/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/single-url-environment-no-default/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/streaming-parameter/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/streaming-parameter/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/streaming-parameter/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/streaming-parameter/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/streaming-parameter/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/streaming-parameter/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/streaming-parameter/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/streaming-parameter/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/streaming/no-custom-config/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/streaming/no-custom-config/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/streaming/no-custom-config/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/streaming/no-custom-config/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/streaming/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/streaming/no-custom-config/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/streaming/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/streaming/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/streaming/serde-layer/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/streaming/serde-layer/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/streaming/serde-layer/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/streaming/serde-layer/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/streaming/serde-layer/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/streaming/serde-layer/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/streaming/serde-layer/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/streaming/serde-layer/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/streaming/wrapper/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/streaming/wrapper/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/streaming/wrapper/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/streaming/wrapper/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/streaming/wrapper/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/streaming/wrapper/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/streaming/wrapper/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/streaming/wrapper/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/trace/exhaustive/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/trace/exhaustive/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/trace/exhaustive/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/trace/exhaustive/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/trace/exhaustive/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/trace/exhaustive/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/trace/exhaustive/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/trace/exhaustive/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/trace/no-custom-config/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/trace/no-custom-config/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/trace/no-custom-config/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/trace/no-custom-config/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/trace/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/trace/no-custom-config/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/trace/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/trace/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/trace/serde-no-throwing/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/trace/serde-no-throwing/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/trace/serde-no-throwing/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/trace/serde-no-throwing/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/trace/serde-no-throwing/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/trace/serde-no-throwing/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/trace/serde-no-throwing/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/trace/serde-no-throwing/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/trace/serde/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/trace/serde/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/trace/serde/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/trace/serde/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/trace/serde/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/trace/serde/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/trace/serde/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/trace/serde/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/ts-express-casing/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/ts-express-casing/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/ts-express-casing/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/ts-express-casing/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/ts-express-casing/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/ts-express-casing/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/ts-express-casing/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/ts-express-casing/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/ts-extra-properties/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/ts-extra-properties/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/ts-extra-properties/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/ts-extra-properties/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/ts-extra-properties/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/ts-extra-properties/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/ts-extra-properties/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/ts-extra-properties/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/ts-inline-types/inline/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/ts-inline-types/inline/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/ts-inline-types/inline/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/ts-inline-types/inline/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/ts-inline-types/inline/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/ts-inline-types/inline/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/ts-inline-types/inline/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/ts-inline-types/inline/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/ts-inline-types/no-inline/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/ts-inline-types/no-inline/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/ts-inline-types/no-inline/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/ts-inline-types/no-inline/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/ts-inline-types/no-inline/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/ts-inline-types/no-inline/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/ts-inline-types/no-inline/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/ts-inline-types/no-inline/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/undiscriminated-union-with-response-property/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/undiscriminated-union-with-response-property/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/undiscriminated-union-with-response-property/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/undiscriminated-union-with-response-property/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/undiscriminated-union-with-response-property/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/undiscriminated-union-with-response-property/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/undiscriminated-union-with-response-property/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/undiscriminated-union-with-response-property/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/undiscriminated-unions/no-custom-config/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/undiscriminated-unions/no-custom-config/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/undiscriminated-unions/no-custom-config/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/undiscriminated-unions/no-custom-config/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/undiscriminated-unions/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/undiscriminated-unions/no-custom-config/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/undiscriminated-unions/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/undiscriminated-unions/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/undiscriminated-unions/skip-response-validation/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/undiscriminated-unions/skip-response-validation/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/undiscriminated-unions/skip-response-validation/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/undiscriminated-unions/skip-response-validation/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/undiscriminated-unions/skip-response-validation/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/undiscriminated-unions/skip-response-validation/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/undiscriminated-unions/skip-response-validation/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/undiscriminated-unions/skip-response-validation/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/union-query-parameters/no-custom-config/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/union-query-parameters/no-custom-config/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/union-query-parameters/no-custom-config/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/union-query-parameters/no-custom-config/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/union-query-parameters/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/union-query-parameters/no-custom-config/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/union-query-parameters/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/union-query-parameters/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/unions-with-local-date/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/unions-with-local-date/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/unions-with-local-date/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/unions-with-local-date/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/unions-with-local-date/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/unions-with-local-date/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/unions-with-local-date/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/unions-with-local-date/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/unions/no-custom-config/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/unions/no-custom-config/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/unions/no-custom-config/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/unions/no-custom-config/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/unions/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/unions/no-custom-config/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/unions/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/unions/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/unions/serde-layer/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/unions/serde-layer/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/unions/serde-layer/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/unions/serde-layer/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/unions/serde-layer/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/unions/serde-layer/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/unions/serde-layer/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/unions/serde-layer/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/unknown/no-custom-config/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/unknown/no-custom-config/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/unknown/no-custom-config/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/unknown/no-custom-config/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/unknown/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/unknown/no-custom-config/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/unknown/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/unknown/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/unknown/unknown-as-any/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/unknown/unknown-as-any/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/unknown/unknown-as-any/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/unknown/unknown-as-any/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/unknown/unknown-as-any/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/unknown/unknown-as-any/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/unknown/unknown-as-any/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/unknown/unknown-as-any/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/url-form-encoded/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/url-form-encoded/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/url-form-encoded/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/url-form-encoded/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/url-form-encoded/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/url-form-encoded/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/url-form-encoded/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/url-form-encoded/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/validation/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/validation/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/validation/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/validation/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/validation/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/validation/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/validation/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/validation/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/variables/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/variables/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/variables/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/variables/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/variables/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/variables/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/variables/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/variables/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/version-no-default/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/version-no-default/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/version-no-default/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/version-no-default/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/version-no-default/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/version-no-default/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/version-no-default/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/version-no-default/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/version/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/version/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/version/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/version/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/version/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/version/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/version/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/version/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/webhook-audience/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/webhook-audience/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/webhook-audience/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/webhook-audience/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/webhook-audience/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/webhook-audience/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/webhook-audience/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/webhook-audience/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/webhooks/no-custom-config/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/webhooks/no-custom-config/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/webhooks/no-custom-config/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/webhooks/no-custom-config/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/webhooks/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/webhooks/no-custom-config/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/webhooks/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/webhooks/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/websocket-bearer-auth/websockets/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/websocket-bearer-auth/websockets/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/websocket-bearer-auth/websockets/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/websocket-bearer-auth/websockets/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/websocket-bearer-auth/websockets/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/websocket-bearer-auth/websockets/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/websocket-bearer-auth/websockets/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/websocket-bearer-auth/websockets/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/websocket-inferred-auth/websockets/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/websocket-inferred-auth/websockets/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/websocket-inferred-auth/websockets/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/websocket-inferred-auth/websockets/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/websocket-inferred-auth/websockets/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/websocket-inferred-auth/websockets/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/websocket-inferred-auth/websockets/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/websocket-inferred-auth/websockets/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/websocket-multi-url/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/websocket-multi-url/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/websocket-multi-url/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/websocket-multi-url/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/websocket-multi-url/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/websocket-multi-url/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/websocket-multi-url/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/websocket-multi-url/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/websocket/no-serde/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/websocket/no-serde/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/websocket/no-serde/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/websocket/no-serde/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/websocket/no-serde/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/websocket/no-serde/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/websocket/no-serde/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/websocket/no-serde/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/websocket/no-websocket-clients/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/websocket/no-websocket-clients/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/websocket/no-websocket-clients/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/websocket/no-websocket-clients/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/websocket/no-websocket-clients/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/websocket/no-websocket-clients/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/websocket/no-websocket-clients/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/websocket/no-websocket-clients/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/websocket/serde/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/websocket/serde/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/websocket/serde/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/websocket/serde/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/websocket/serde/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/websocket/serde/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/websocket/serde/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/websocket/serde/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }
diff --git a/seed/ts-sdk/x-fern-default/src/core/fetcher/Fetcher.ts b/seed/ts-sdk/x-fern-default/src/core/fetcher/Fetcher.ts
index 943ec1bfe9c9..95c2411e995c 100644
--- a/seed/ts-sdk/x-fern-default/src/core/fetcher/Fetcher.ts
+++ b/seed/ts-sdk/x-fern-default/src/core/fetcher/Fetcher.ts
@@ -254,6 +254,33 @@ async function getHeaders(args: Fetcher.Args): Promise<Headers> {
     return newHeaders;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isTimeoutError(error: Error): boolean {
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+function getErrorMessageWithCause(error: Error): string {
+    let message = error.message;
+    let current: unknown = "cause" in error ? error.cause : undefined;
+    while (current instanceof Error) {
+        const suffix = "code" in current && typeof (current as Error & { code: unknown }).code === "string"
+            ? ` [${(current as Error & { code: string }).code}]`
+            : "";
+        if (current.message) {
+            message += ` -> ${current.message}${suffix}`;
+        }
+        current = "cause" in current ? current.cause : undefined;
+    }
+    return message;
+}
+
 export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIResponse<R, Fetcher.Error>> {
     let url = args.url;
     if (args.queryString != null && args.queryString.length > 0) {
@@ -370,12 +397,30 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 },
                 rawResponse: abortRawResponse,
             };
+        } else if (error instanceof Error && isTimeoutError(error)) {
+            if (logger.isError()) {
+                const metadata = {
+                    method: args.method,
+                    url: redactUrl(url),
+                    timeoutMs: args.timeoutMs,
+                    errorMessage: getErrorMessageWithCause(error),
+                };
+                logger.error("HTTP request timed out due to runtime timeout", metadata);
+            }
+            return {
+                ok: false,
+                error: {
+                    reason: "timeout",
+                    cause: error,
+                },
+                rawResponse: unknownRawResponse,
+            };
         } else if (error instanceof Error) {
             if (logger.isError()) {
                 const metadata = {
                     method: args.method,
                     url: redactUrl(url),
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                 };
                 logger.error("HTTP request failed with error", metadata);
             }
@@ -383,7 +428,7 @@ export async function fetcherImpl<R = unknown>(args: Fetcher.Args): Promise<APIR
                 ok: false,
                 error: {
                     reason: "unknown",
-                    errorMessage: error.message,
+                    errorMessage: getErrorMessageWithCause(error),
                     cause: error,
                 },
                 rawResponse: unknownRawResponse,
diff --git a/seed/ts-sdk/x-fern-default/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/x-fern-default/src/core/fetcher/requestWithRetries.ts
index 1f689688c4b2..f4f23527c0c3 100644
--- a/seed/ts-sdk/x-fern-default/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/x-fern-default/src/core/fetcher/requestWithRetries.ts
@@ -48,17 +48,40 @@ export async function requestWithRetries(
     requestFn: () => Promise<Response>,
     maxRetries: number = DEFAULT_MAX_RETRIES,
 ): Promise<Response> {
-    let response: Response = await requestFn();
+    let lastError: unknown;
+    let lastResponse: Response | undefined;
+
+    for (let i = 0; i <= maxRetries; i++) {
+        try {
+            const response = await requestFn();
+            lastResponse = response;
+            lastError = undefined;
+
+            if (!([408, 429].includes(response.status) || response.status >= 500)) {
+                return response;
+            }
+
+            if (i === maxRetries) {
+                return response;
+            }
 
-    for (let i = 0; i < maxRetries; ++i) {
-        if ([408, 429].includes(response.status) || response.status >= 500) {
             const delay = getRetryDelayFromHeaders(response, i);
+            await new Promise((resolve) => setTimeout(resolve, delay));
+        } catch (error) {
+            lastError = error;
+            lastResponse = undefined;
+
+            if (i === maxRetries) {
+                throw error;
+            }
 
+            const delay = addSymmetricJitter(Math.min(INITIAL_RETRY_DELAY * 2 ** i, MAX_RETRY_DELAY));
             await new Promise((resolve) => setTimeout(resolve, delay));
-            response = await requestFn();
-        } else {
-            break;
         }
     }
-    return response!;
+
+    if (lastResponse != null) {
+        return lastResponse;
+    }
+    throw lastError;
 }

From 886ee35a71a747855657a3883c0b4eb2c2427784 Mon Sep 17 00:00:00 2001
From: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
Date: Wed, 29 Apr 2026 13:39:10 +0000
Subject: [PATCH 2/2] fix(typescript): don't retry AbortError or undici timeout
 errors

Timeout and abort errors should propagate immediately without retries.
Only transient network errors (ECONNRESET, ECONNREFUSED, etc.) are retried.

Co-Authored-By: rishabh <rishabh@buildwithfern.com>
---
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../core/fetcher/requestWithRetries.ts        | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../core/fetcher/requestWithRetries.ts        | 20 ++++++++++++++++++-
 .../core/fetcher/requestWithRetries.ts        | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
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 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
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 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
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 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
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 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
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 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
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 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
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 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 .../src/core/fetcher/requestWithRetries.ts    | 20 ++++++++++++++++++-
 212 files changed, 4028 insertions(+), 212 deletions(-)

diff --git a/generators/typescript/utils/core-utilities/src/core/fetcher/requestWithRetries.ts b/generators/typescript/utils/core-utilities/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/generators/typescript/utils/core-utilities/src/core/fetcher/requestWithRetries.ts
+++ b/generators/typescript/utils/core-utilities/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/accept-header/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/accept-header/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/accept-header/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/accept-header/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/alias-extends/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/alias-extends/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/alias-extends/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/alias-extends/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/alias/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/alias/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/alias/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/alias/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/allof-inline/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/allof-inline/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/allof-inline/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/allof-inline/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/allof/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/allof/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/allof/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/allof/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/any-auth/generate-endpoint-metadata/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/any-auth/generate-endpoint-metadata/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/any-auth/generate-endpoint-metadata/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/any-auth/generate-endpoint-metadata/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/any-auth/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/any-auth/no-custom-config/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/any-auth/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/any-auth/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/api-wide-base-path/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/api-wide-base-path/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/api-wide-base-path/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/api-wide-base-path/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/audiences/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/audiences/no-custom-config/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/audiences/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/audiences/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/audiences/with-partner-audience/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/audiences/with-partner-audience/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/audiences/with-partner-audience/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/audiences/with-partner-audience/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/basic-auth-environment-variables/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/basic-auth-environment-variables/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/basic-auth-environment-variables/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/basic-auth-environment-variables/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/basic-auth-pw-omitted/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/basic-auth-pw-omitted/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/basic-auth-pw-omitted/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/basic-auth-pw-omitted/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/basic-auth/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/basic-auth/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/basic-auth/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/basic-auth/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/bearer-token-environment-variable/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/bearer-token-environment-variable/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/bearer-token-environment-variable/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/bearer-token-environment-variable/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/bytes-download/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/bytes-download/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/bytes-download/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/bytes-download/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/bytes-upload/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/bytes-upload/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/bytes-upload/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/bytes-upload/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/circular-references-advanced/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/circular-references-advanced/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/circular-references-advanced/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/circular-references-advanced/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/circular-references-extends/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/circular-references-extends/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/circular-references-extends/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/circular-references-extends/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/circular-references/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/circular-references/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/circular-references/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/circular-references/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/client-side-params/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/client-side-params/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/client-side-params/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/client-side-params/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/content-type/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/content-type/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/content-type/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/content-type/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/cross-package-type-names/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/cross-package-type-names/no-custom-config/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/cross-package-type-names/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/cross-package-type-names/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/cross-package-type-names/serde-layer/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/cross-package-type-names/serde-layer/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/cross-package-type-names/serde-layer/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/cross-package-type-names/serde-layer/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/dollar-string-examples/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/dollar-string-examples/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/dollar-string-examples/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/dollar-string-examples/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/empty-clients/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/empty-clients/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/empty-clients/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/empty-clients/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/endpoint-security-auth/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/endpoint-security-auth/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/endpoint-security-auth/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/endpoint-security-auth/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/enum/forward-compatible-enums-with-serde/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/enum/forward-compatible-enums-with-serde/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/enum/forward-compatible-enums-with-serde/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/enum/forward-compatible-enums-with-serde/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/enum/forward-compatible-enums/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/enum/forward-compatible-enums/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/enum/forward-compatible-enums/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/enum/forward-compatible-enums/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/enum/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/enum/no-custom-config/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/enum/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/enum/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/enum/serde/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/enum/serde/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/enum/serde/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/enum/serde/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/error-property/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/error-property/no-custom-config/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/error-property/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/error-property/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/error-property/union-utils/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/error-property/union-utils/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/error-property/union-utils/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/error-property/union-utils/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/errors/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/errors/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/errors/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/errors/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/examples/examples-with-api-reference/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/examples/examples-with-api-reference/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/examples/examples-with-api-reference/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/examples/examples-with-api-reference/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/examples/retain-original-casing/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/examples/retain-original-casing/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/examples/retain-original-casing/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/examples/retain-original-casing/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/exhaustive/allow-extra-fields/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/allow-extra-fields/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/exhaustive/allow-extra-fields/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/allow-extra-fields/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/exhaustive/bigint-serde-layer/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/bigint-serde-layer/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/exhaustive/bigint-serde-layer/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/bigint-serde-layer/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/exhaustive/bigint/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/bigint/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/exhaustive/bigint/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/bigint/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/exhaustive/consolidate-type-files/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/consolidate-type-files/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/exhaustive/consolidate-type-files/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/consolidate-type-files/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/exhaustive/export-all-requests-at-root/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/export-all-requests-at-root/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/exhaustive/export-all-requests-at-root/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/export-all-requests-at-root/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/exhaustive/local-files/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/local-files/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/exhaustive/local-files/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/local-files/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/exhaustive/multiple-exports/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/multiple-exports/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/exhaustive/multiple-exports/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/multiple-exports/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/exhaustive/never-throw-errors/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/never-throw-errors/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/exhaustive/never-throw-errors/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/never-throw-errors/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/exhaustive/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/no-custom-config/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/exhaustive/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/exhaustive/node-fetch/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/node-fetch/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/exhaustive/node-fetch/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/node-fetch/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/exhaustive/output-src-only/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/output-src-only/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/exhaustive/output-src-only/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/output-src-only/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/exhaustive/package-path/src/test-packagePath/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/package-path/src/test-packagePath/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/exhaustive/package-path/src/test-packagePath/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/package-path/src/test-packagePath/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/exhaustive/parameter-naming-camel-case/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/parameter-naming-camel-case/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/exhaustive/parameter-naming-camel-case/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/parameter-naming-camel-case/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/exhaustive/parameter-naming-original-name/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/parameter-naming-original-name/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/exhaustive/parameter-naming-original-name/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/parameter-naming-original-name/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/exhaustive/parameter-naming-snake-case/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/parameter-naming-snake-case/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/exhaustive/parameter-naming-snake-case/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/parameter-naming-snake-case/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/exhaustive/parameter-naming-wire-value/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/parameter-naming-wire-value/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/exhaustive/parameter-naming-wire-value/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/parameter-naming-wire-value/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/exhaustive/retain-original-casing/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/retain-original-casing/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/exhaustive/retain-original-casing/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/retain-original-casing/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/exhaustive/serde-layer/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/serde-layer/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/exhaustive/serde-layer/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/serde-layer/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/exhaustive/use-jest/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/use-jest/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/exhaustive/use-jest/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/use-jest/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/exhaustive/web-stream-wrapper/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/web-stream-wrapper/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/exhaustive/web-stream-wrapper/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/web-stream-wrapper/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/exhaustive/with-audiences/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/exhaustive/with-audiences/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/exhaustive/with-audiences/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/exhaustive/with-audiences/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/extends/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/extends/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/extends/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/extends/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/extra-properties/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/extra-properties/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/extra-properties/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/extra-properties/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/file-download/file-download-response-headers/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/file-download/file-download-response-headers/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/file-download/file-download-response-headers/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/file-download/file-download-response-headers/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/file-download/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/file-download/no-custom-config/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/file-download/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/file-download/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/file-download/stream-wrapper/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/file-download/stream-wrapper/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/file-download/stream-wrapper/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/file-download/stream-wrapper/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/file-upload-openapi/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/file-upload-openapi/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/file-upload-openapi/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/file-upload-openapi/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/file-upload/form-data-node16/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/file-upload/form-data-node16/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/file-upload/form-data-node16/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/file-upload/form-data-node16/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/file-upload/inline/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/file-upload/inline/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/file-upload/inline/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/file-upload/inline/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/file-upload/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/file-upload/no-custom-config/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/file-upload/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/file-upload/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/file-upload/serde/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/file-upload/serde/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/file-upload/serde/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/file-upload/serde/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/file-upload/use-jest/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/file-upload/use-jest/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/file-upload/use-jest/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/file-upload/use-jest/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/file-upload/wrapper/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/file-upload/wrapper/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/file-upload/wrapper/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/file-upload/wrapper/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/folders/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/folders/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/folders/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/folders/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/header-auth-environment-variable/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/header-auth-environment-variable/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/header-auth-environment-variable/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/header-auth-environment-variable/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/header-auth/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/header-auth/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/header-auth/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/header-auth/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/http-head/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/http-head/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/http-head/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/http-head/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/idempotency-headers/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/idempotency-headers/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/idempotency-headers/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/idempotency-headers/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/imdb/branded-string-aliases/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/imdb/branded-string-aliases/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/imdb/branded-string-aliases/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/imdb/branded-string-aliases/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/imdb/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/imdb/no-custom-config/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/imdb/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/imdb/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/imdb/omit-undefined/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/imdb/omit-undefined/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/imdb/omit-undefined/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/imdb/omit-undefined/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/inferred-auth-explicit/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/inferred-auth-explicit/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/inferred-auth-explicit/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/inferred-auth-explicit/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/inferred-auth-implicit-api-key/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/inferred-auth-implicit-api-key/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/inferred-auth-implicit-api-key/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/inferred-auth-implicit-api-key/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/inferred-auth-implicit-no-expiry/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/inferred-auth-implicit-no-expiry/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/inferred-auth-implicit-no-expiry/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/inferred-auth-implicit-no-expiry/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/inferred-auth-implicit-reference/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/inferred-auth-implicit-reference/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/inferred-auth-implicit-reference/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/inferred-auth-implicit-reference/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/inferred-auth-implicit/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/inferred-auth-implicit/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/inferred-auth-implicit/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/inferred-auth-implicit/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/license/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/license/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/license/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/license/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/literal/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/literal/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/literal/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/literal/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/literals-unions/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/literals-unions/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/literals-unions/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/literals-unions/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/mixed-case/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/mixed-case/no-custom-config/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/mixed-case/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/mixed-case/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/mixed-case/retain-original-casing/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/mixed-case/retain-original-casing/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/mixed-case/retain-original-casing/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/mixed-case/retain-original-casing/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/mixed-file-directory/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/mixed-file-directory/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/mixed-file-directory/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/mixed-file-directory/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/multi-line-docs/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/multi-line-docs/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/multi-line-docs/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/multi-line-docs/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/multi-url-environment-no-default/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/multi-url-environment-no-default/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/multi-url-environment-no-default/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/multi-url-environment-no-default/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/multi-url-environment-reference/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/multi-url-environment-reference/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/multi-url-environment-reference/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/multi-url-environment-reference/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/multi-url-environment/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/multi-url-environment/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/multi-url-environment/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/multi-url-environment/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/multiple-request-bodies/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/multiple-request-bodies/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/multiple-request-bodies/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/multiple-request-bodies/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/no-content-response/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/no-content-response/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/no-content-response/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/no-content-response/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/no-environment/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/no-environment/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/no-environment/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/no-environment/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/no-retries/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/no-retries/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/no-retries/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/no-retries/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/null-type/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/null-type/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/null-type/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/null-type/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/nullable-allof-extends/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/nullable-allof-extends/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/nullable-allof-extends/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/nullable-allof-extends/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/nullable-optional/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/nullable-optional/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/nullable-optional/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/nullable-optional/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/nullable-request-body/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/nullable-request-body/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/nullable-request-body/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/nullable-request-body/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/nullable/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/nullable/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/nullable/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/nullable/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/oauth-client-credentials-custom/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/oauth-client-credentials-custom/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/oauth-client-credentials-custom/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/oauth-client-credentials-custom/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/oauth-client-credentials-default/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/oauth-client-credentials-default/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/oauth-client-credentials-default/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/oauth-client-credentials-default/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/oauth-client-credentials-environment-variables/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/oauth-client-credentials-environment-variables/no-custom-config/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/oauth-client-credentials-environment-variables/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/oauth-client-credentials-environment-variables/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/oauth-client-credentials-mandatory-auth/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/oauth-client-credentials-mandatory-auth/no-custom-config/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/oauth-client-credentials-mandatory-auth/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/oauth-client-credentials-mandatory-auth/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/oauth-client-credentials-nested-root/never-throw-errors/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/oauth-client-credentials-nested-root/never-throw-errors/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/oauth-client-credentials-nested-root/never-throw-errors/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/oauth-client-credentials-nested-root/never-throw-errors/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/oauth-client-credentials-nested-root/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/oauth-client-credentials-nested-root/no-custom-config/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/oauth-client-credentials-nested-root/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/oauth-client-credentials-nested-root/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/oauth-client-credentials-openapi/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/oauth-client-credentials-openapi/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/oauth-client-credentials-openapi/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/oauth-client-credentials-openapi/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/oauth-client-credentials-reference/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/oauth-client-credentials-reference/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/oauth-client-credentials-reference/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/oauth-client-credentials-reference/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/oauth-client-credentials-with-variables/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/oauth-client-credentials-with-variables/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/oauth-client-credentials-with-variables/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/oauth-client-credentials-with-variables/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/oauth-client-credentials/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/oauth-client-credentials/no-custom-config/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/oauth-client-credentials/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/oauth-client-credentials/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/oauth-client-credentials/serde/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/oauth-client-credentials/serde/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/oauth-client-credentials/serde/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/oauth-client-credentials/serde/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/object/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/object/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/object/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/object/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/objects-with-imports/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/objects-with-imports/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/objects-with-imports/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/objects-with-imports/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/openapi-request-body-ref/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/openapi-request-body-ref/no-custom-config/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/openapi-request-body-ref/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/openapi-request-body-ref/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/optional/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/optional/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/optional/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/optional/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/package-yml/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/package-yml/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/package-yml/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/package-yml/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/pagination-custom/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/pagination-custom/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/pagination-custom/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/pagination-custom/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/pagination-uri-path/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/pagination-uri-path/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/pagination-uri-path/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/pagination-uri-path/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/pagination/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/pagination/no-custom-config/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/pagination/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/pagination/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/pagination/page-index-semantics/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/pagination/page-index-semantics/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/pagination/page-index-semantics/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/pagination/page-index-semantics/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/path-parameters/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/path-parameters/no-custom-config/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/path-parameters/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/path-parameters/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/path-parameters/no-inline-path-parameters-retain-original-casing/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/path-parameters/no-inline-path-parameters-retain-original-casing/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/path-parameters/no-inline-path-parameters-retain-original-casing/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/path-parameters/no-inline-path-parameters-retain-original-casing/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/path-parameters/no-inline-path-parameters-serde/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/path-parameters/no-inline-path-parameters-serde/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/path-parameters/no-inline-path-parameters-serde/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/path-parameters/no-inline-path-parameters-serde/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/path-parameters/no-inline-path-parameters/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/path-parameters/no-inline-path-parameters/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/path-parameters/no-inline-path-parameters/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/path-parameters/no-inline-path-parameters/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/path-parameters/parameter-naming-camel-case/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/path-parameters/parameter-naming-camel-case/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/path-parameters/parameter-naming-camel-case/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/path-parameters/parameter-naming-camel-case/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/path-parameters/parameter-naming-original-name/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/path-parameters/parameter-naming-original-name/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/path-parameters/parameter-naming-original-name/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/path-parameters/parameter-naming-original-name/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/path-parameters/parameter-naming-snake-case/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/path-parameters/parameter-naming-snake-case/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/path-parameters/parameter-naming-snake-case/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/path-parameters/parameter-naming-snake-case/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/path-parameters/parameter-naming-wire-value/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/path-parameters/parameter-naming-wire-value/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/path-parameters/parameter-naming-wire-value/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/path-parameters/parameter-naming-wire-value/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/path-parameters/retain-original-casing/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/path-parameters/retain-original-casing/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/path-parameters/retain-original-casing/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/path-parameters/retain-original-casing/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/plain-text/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/plain-text/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/plain-text/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/plain-text/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/property-access/generate-read-write-only-types/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/property-access/generate-read-write-only-types/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/property-access/generate-read-write-only-types/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/property-access/generate-read-write-only-types/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/property-access/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/property-access/no-custom-config/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/property-access/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/property-access/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/public-object/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/public-object/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/public-object/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/public-object/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/query-param-name-conflict/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/query-param-name-conflict/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/query-param-name-conflict/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/query-param-name-conflict/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/query-parameters-openapi-as-objects/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/query-parameters-openapi-as-objects/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/query-parameters-openapi-as-objects/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/query-parameters-openapi-as-objects/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/query-parameters-openapi/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/query-parameters-openapi/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/query-parameters-openapi/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/query-parameters-openapi/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/query-parameters/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/query-parameters/no-custom-config/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/query-parameters/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/query-parameters/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/query-parameters/parameter-naming-camel-case/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/query-parameters/parameter-naming-camel-case/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/query-parameters/parameter-naming-camel-case/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/query-parameters/parameter-naming-camel-case/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/query-parameters/parameter-naming-original-name/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/query-parameters/parameter-naming-original-name/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/query-parameters/parameter-naming-original-name/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/query-parameters/parameter-naming-original-name/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/query-parameters/parameter-naming-snake-case/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/query-parameters/parameter-naming-snake-case/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/query-parameters/parameter-naming-snake-case/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/query-parameters/parameter-naming-snake-case/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/query-parameters/parameter-naming-wire-value/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/query-parameters/parameter-naming-wire-value/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/query-parameters/parameter-naming-wire-value/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/query-parameters/parameter-naming-wire-value/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/query-parameters/serde/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/query-parameters/serde/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/query-parameters/serde/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/query-parameters/serde/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/request-parameters/flatten-request-parameters/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/request-parameters/flatten-request-parameters/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/request-parameters/flatten-request-parameters/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/request-parameters/flatten-request-parameters/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/request-parameters/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/request-parameters/no-custom-config/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/request-parameters/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/request-parameters/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/request-parameters/use-big-int-and-default-request-parameter-values/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/request-parameters/use-big-int-and-default-request-parameter-values/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/request-parameters/use-big-int-and-default-request-parameter-values/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/request-parameters/use-big-int-and-default-request-parameter-values/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/request-parameters/use-default-request-parameter-values/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/request-parameters/use-default-request-parameter-values/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/request-parameters/use-default-request-parameter-values/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/request-parameters/use-default-request-parameter-values/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/required-nullable/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/required-nullable/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/required-nullable/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/required-nullable/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/reserved-keywords/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/reserved-keywords/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/reserved-keywords/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/reserved-keywords/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/response-property/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/response-property/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/response-property/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/response-property/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/schemaless-request-body-examples/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/schemaless-request-body-examples/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/schemaless-request-body-examples/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/schemaless-request-body-examples/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/server-sent-event-examples/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/server-sent-event-examples/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/server-sent-event-examples/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/server-sent-event-examples/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/server-sent-events-openapi/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/server-sent-events-openapi/no-custom-config/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/server-sent-events-openapi/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/server-sent-events-openapi/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/server-sent-events/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/server-sent-events/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/server-sent-events/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/server-sent-events/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/server-url-templating/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/server-url-templating/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/server-url-templating/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/server-url-templating/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/simple-api/allow-custom-fetcher/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/simple-api/allow-custom-fetcher/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/simple-api/allow-custom-fetcher/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/simple-api/allow-custom-fetcher/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/simple-api/allow-extra-fields/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/simple-api/allow-extra-fields/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/simple-api/allow-extra-fields/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/simple-api/allow-extra-fields/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/simple-api/bundle/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/simple-api/bundle/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/simple-api/bundle/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/simple-api/bundle/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/simple-api/custom-package-json/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/simple-api/custom-package-json/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/simple-api/custom-package-json/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/simple-api/custom-package-json/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/simple-api/jsr/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/simple-api/jsr/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/simple-api/jsr/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/simple-api/jsr/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/simple-api/legacy-exports/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/simple-api/legacy-exports/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/simple-api/legacy-exports/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/simple-api/legacy-exports/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/simple-api/naming-shorthand/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/simple-api/naming-shorthand/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/simple-api/naming-shorthand/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/simple-api/naming-shorthand/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/simple-api/naming/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/simple-api/naming/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/simple-api/naming/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/simple-api/naming/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/simple-api/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/simple-api/no-custom-config/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/simple-api/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/simple-api/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/simple-api/no-linter-and-formatter/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/simple-api/no-linter-and-formatter/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/simple-api/no-linter-and-formatter/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/simple-api/no-linter-and-formatter/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/simple-api/no-scripts/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/simple-api/no-scripts/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/simple-api/no-scripts/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/simple-api/no-scripts/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/simple-api/oidc-token/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/simple-api/oidc-token/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/simple-api/oidc-token/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/simple-api/oidc-token/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/simple-api/omit-fern-headers/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/simple-api/omit-fern-headers/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/simple-api/omit-fern-headers/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/simple-api/omit-fern-headers/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/simple-api/use-oxc/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/simple-api/use-oxc/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/simple-api/use-oxc/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/simple-api/use-oxc/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/simple-api/use-oxfmt/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/simple-api/use-oxfmt/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/simple-api/use-oxfmt/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/simple-api/use-oxfmt/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/simple-api/use-oxlint/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/simple-api/use-oxlint/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/simple-api/use-oxlint/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/simple-api/use-oxlint/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/simple-api/use-prettier-no-linter/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/simple-api/use-prettier-no-linter/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/simple-api/use-prettier-no-linter/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/simple-api/use-prettier-no-linter/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/simple-api/use-prettier/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/simple-api/use-prettier/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/simple-api/use-prettier/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/simple-api/use-prettier/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/simple-api/use-yarn/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/simple-api/use-yarn/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/simple-api/use-yarn/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/simple-api/use-yarn/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/simple-fhir/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/simple-fhir/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/simple-fhir/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/simple-fhir/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/single-url-environment-default/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/single-url-environment-default/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/single-url-environment-default/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/single-url-environment-default/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/single-url-environment-no-default/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/single-url-environment-no-default/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/single-url-environment-no-default/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/single-url-environment-no-default/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/streaming-parameter/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/streaming-parameter/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/streaming-parameter/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/streaming-parameter/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/streaming/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/streaming/no-custom-config/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/streaming/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/streaming/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/streaming/serde-layer/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/streaming/serde-layer/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/streaming/serde-layer/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/streaming/serde-layer/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/streaming/wrapper/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/streaming/wrapper/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/streaming/wrapper/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/streaming/wrapper/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/trace/exhaustive/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/trace/exhaustive/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/trace/exhaustive/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/trace/exhaustive/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/trace/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/trace/no-custom-config/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/trace/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/trace/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/trace/serde-no-throwing/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/trace/serde-no-throwing/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/trace/serde-no-throwing/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/trace/serde-no-throwing/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/trace/serde/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/trace/serde/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/trace/serde/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/trace/serde/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/ts-express-casing/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/ts-express-casing/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/ts-express-casing/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/ts-express-casing/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/ts-extra-properties/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/ts-extra-properties/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/ts-extra-properties/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/ts-extra-properties/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/ts-inline-types/inline/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/ts-inline-types/inline/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/ts-inline-types/inline/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/ts-inline-types/inline/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/ts-inline-types/no-inline/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/ts-inline-types/no-inline/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/ts-inline-types/no-inline/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/ts-inline-types/no-inline/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/undiscriminated-union-with-response-property/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/undiscriminated-union-with-response-property/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/undiscriminated-union-with-response-property/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/undiscriminated-union-with-response-property/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/undiscriminated-unions/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/undiscriminated-unions/no-custom-config/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/undiscriminated-unions/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/undiscriminated-unions/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/undiscriminated-unions/skip-response-validation/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/undiscriminated-unions/skip-response-validation/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/undiscriminated-unions/skip-response-validation/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/undiscriminated-unions/skip-response-validation/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/union-query-parameters/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/union-query-parameters/no-custom-config/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/union-query-parameters/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/union-query-parameters/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/unions-with-local-date/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/unions-with-local-date/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/unions-with-local-date/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/unions-with-local-date/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/unions/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/unions/no-custom-config/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/unions/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/unions/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/unions/serde-layer/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/unions/serde-layer/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/unions/serde-layer/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/unions/serde-layer/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/unknown/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/unknown/no-custom-config/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/unknown/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/unknown/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/unknown/unknown-as-any/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/unknown/unknown-as-any/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/unknown/unknown-as-any/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/unknown/unknown-as-any/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/url-form-encoded/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/url-form-encoded/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/url-form-encoded/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/url-form-encoded/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/validation/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/validation/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/validation/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/validation/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/variables/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/variables/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/variables/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/variables/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/version-no-default/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/version-no-default/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/version-no-default/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/version-no-default/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/version/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/version/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/version/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/version/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/webhook-audience/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/webhook-audience/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/webhook-audience/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/webhook-audience/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/webhooks/no-custom-config/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/webhooks/no-custom-config/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/webhooks/no-custom-config/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/webhooks/no-custom-config/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/websocket-bearer-auth/websockets/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/websocket-bearer-auth/websockets/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/websocket-bearer-auth/websockets/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/websocket-bearer-auth/websockets/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/websocket-inferred-auth/websockets/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/websocket-inferred-auth/websockets/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/websocket-inferred-auth/websockets/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/websocket-inferred-auth/websockets/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/websocket-multi-url/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/websocket-multi-url/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/websocket-multi-url/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/websocket-multi-url/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/websocket/no-serde/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/websocket/no-serde/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/websocket/no-serde/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/websocket/no-serde/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/websocket/no-websocket-clients/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/websocket/no-websocket-clients/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/websocket/no-websocket-clients/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/websocket/no-websocket-clients/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/websocket/serde/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/websocket/serde/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/websocket/serde/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/websocket/serde/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }
 
diff --git a/seed/ts-sdk/x-fern-default/src/core/fetcher/requestWithRetries.ts b/seed/ts-sdk/x-fern-default/src/core/fetcher/requestWithRetries.ts
index f4f23527c0c3..1a840ea11f0d 100644
--- a/seed/ts-sdk/x-fern-default/src/core/fetcher/requestWithRetries.ts
+++ b/seed/ts-sdk/x-fern-default/src/core/fetcher/requestWithRetries.ts
@@ -13,6 +13,24 @@ function addSymmetricJitter(delay: number): number {
     return delay * jitterMultiplier;
 }
 
+const TIMEOUT_ERROR_CODES = new Set(["UND_ERR_HEADERS_TIMEOUT", "UND_ERR_BODY_TIMEOUT", "ETIMEDOUT"]);
+
+function isRetryableError(error: unknown): boolean {
+    if (!(error instanceof Error)) {
+        return true;
+    }
+    if (error.name === "AbortError") {
+        return false;
+    }
+    if ("cause" in error && error.cause instanceof Error && "code" in error.cause) {
+        const { code } = error.cause as Error & { code: unknown };
+        if (typeof code === "string" && TIMEOUT_ERROR_CODES.has(code)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 function getRetryDelayFromHeaders(response: Response, retryAttempt: number): number {
     const retryAfter = response.headers.get("Retry-After");
     if (retryAfter) {
@@ -71,7 +89,7 @@ export async function requestWithRetries(
             lastError = error;
             lastResponse = undefined;
 
-            if (i === maxRetries) {
+            if (i === maxRetries || !isRetryableError(error)) {
                 throw error;
             }