diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 9e88a912d7..3f2c344703 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -3294,6 +3294,21 @@ importers:
         specifier: ^5.5.2
         version: 5.9.3
 
+  ext/test:
+    dependencies:
+      '@hono/node-server':
+        specifier: ^1.14.1
+        version: 1.19.13(hono@4.11.9)
+      '@rivetkit/engine-cli':
+        specifier: workspace:*
+        version: link:../../rivetkit-typescript/packages/engine-cli
+      '@rivetkit/rivetkit-napi':
+        specifier: workspace:*
+        version: link:../../rivetkit-typescript/packages/rivetkit-napi
+      rivetkit:
+        specifier: workspace:*
+        version: link:../../rivetkit-typescript/packages/rivetkit
+
   frontend:
     dependencies:
       '@codemirror/autocomplete':
diff --git a/pnpm-workspace.yaml b/pnpm-workspace.yaml
index 79ccee3944..ec7793b97f 100644
--- a/pnpm-workspace.yaml
+++ b/pnpm-workspace.yaml
@@ -18,6 +18,7 @@ packages:
   - scripts/tests
   - shared/typescript/*
   - website
+  - ext/*
   - website/scripts/typecheck-staging
 
 ignoredBuiltDependencies:
diff --git a/rivetkit-typescript/packages/rivetkit/src/registry/native.ts b/rivetkit-typescript/packages/rivetkit/src/registry/native.ts
index 65d863ba73..02fed166f6 100644
--- a/rivetkit-typescript/packages/rivetkit/src/registry/native.ts
+++ b/rivetkit-typescript/packages/rivetkit/src/registry/native.ts
@@ -54,7 +54,6 @@ import type {
 } from "@/registry/config";
 import {
 	decodeCborCompat,
-	decodeCborJsonCompat,
 	encodeCborCompat,
 } from "@/serde";
 import { getEnvUniversal, VERSION } from "@/utils";
@@ -594,7 +593,7 @@ function decodeValue<T>(value?: RuntimeBytes | null): T {
 		return undefined as T;
 	}
 
-	return decodeCborJsonCompat(value);
+	return decodeCborCompat(value);
 }
 
 function encodeValue(value: unknown): RuntimeBytes {
@@ -931,6 +930,7 @@ function serializeWorkflowEntryKind(
 	}
 }
 
+// TODO: Switch inspector routes to CBOR encoding
 function serializeWorkflowHistoryForJson(data: ArrayBuffer | null): {
 	nameRegistry: string[];
 	entries: Array<{
@@ -964,7 +964,7 @@ function serializeWorkflowHistoryForJson(data: ArrayBuffer | null): {
 
 	const history = decodeWorkflowHistoryTransport(data);
 
-	return {
+	return jsonSafe({
 		nameRegistry: [...history.nameRegistry],
 		entries: history.entries.map((entry) => ({
 			id: entry.id,
@@ -994,7 +994,7 @@ function serializeWorkflowHistoryForJson(data: ArrayBuffer | null): {
 				],
 			),
 		),
-	};
+	});
 }
 
 function toHttpJsonCompatible<T>(value: T): T {