[sentry-junior]

Adds a Sentry MCP changelog entry for changes deployed to mcp.sentry.dev between 2026-10-01 and 2026-10-19. It picks up where #212 left off. Coverage was extended from 2026-10-12 to the latest production deploy on 2026-10-19, so the next scheduled MCP changelog run starts after 8d3affe.

The entry covers:

• the dataset-specific search tools that replace search_events
• marking of incomplete time-series buckets
• regex log search in search_logs
• find_dropped_events
• delete_monitor_environment
• dashboard URLs in get_sentry_resource
• better query generation: conditional aggregates for spans/logs/metrics, no deprecated attributes, Sentry syntax that runs as written
• fixes in get_issue_details (empty extra context, missing or invalid event dates), search tools (array-type attributes, generic 400s from query validation), and tool-list change capabilities
• Pi setup instructions

It also notes that there was no new @sentry/mcp-server npm release in this period (latest is still 0.42.0).

Left out: Seer search translation, which is still limited to some organizations; #1521 (shared sort resolver, no MCP behavior change); the @modelcontextprotocol/sdk bump (#1428); evals-only work (#1405); formatting-only changes from CLI PRs (#1496); and internal refactors, telemetry, lint and CI changes.

Regex availability: Sentry's organizations:ourlogs-regex-searches flag only exposes the UI; the EAP resolver accepts regex filters on logs for every organization, so the entry doesn't call it limited.

Credits: #1501 and #1273 were opened by Seer autofix and #1253 by Junior, with no human author or co-author in the commit metadata, so those items keep only their links. #1532/#1534 are Junior PRs credited as "With Burak Yigit Kaya" from the commit co-author trailer. Josh's GitHub display name is currently a Halloween variant, so the entry uses his handle.

Links: article links now use github.com instead of linear.review, matching the merged #212 entry.

Slug: renamed to sentry-mcp-2026-10-01-to-2026-10-19 (file renamed to match). The entry was never published, so no existing database row is affected.

Deployment evidence:

• previous endpoint c22fb35: run 38221009030, 2026-10-12
• new endpoint 8d3affe: run 39270735631, 2026-10-19 14:38 UTC. Candidate smoke tests, promotion to production and production smoke tests passed, and the recovery step was skipped. recover-cloudflare-deployment.yml has no runs. GitHub Actions can't rule out a deployment made outside it.

Validation: pnpm changelog:validate passes (15 files). The article body compiles with compileMDX and the app's mdxOptions and renders to static HTML (6 sections, 33 links; inline code with \d, () and > renders correctly). All 17 linked toolkit PRs are merged and fall inside aef89da..8d3affe. Not checked: rendering in the Vercel preview.

The proposed publication date is 2026-10-20. The entry goes live only when this PR is merged.

product=mcp
source_repo=getsentry/toolkit
baseline_exclusive=aef89da
endpoint_inclusive=8d3affe39e7e5f1acd3961a38472663aac7326f4
coverage_utc=2026-10-01..2026-10-19
mcp_commits=43 (28 in aef89da..c22fb35 + 15 in c22fb35..8d3affe)
deploy_run=https://github.com/getsentry/toolkit/actions/runs/39270735631
compare=https://github.com/getsentry/toolkit/compare/aef89da...8d3affe

via bete.

--

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Project	Deployment	Actions	Updated
sentry-changelog	Ready	Preview	Oct 19, 2026 3:49pm UTC

[cursor]

The plan checks that the new article page is reachable. It also checks MDX compile errors and changelog list and detail failures. An issue escalates when the new page stays missing or those failures rise.

Rollout complete

Services: sentry-changelog.

Plan

What changed

Requests to /changelog/sentry-mcp-2026-10-01-to-2026-10-19 start returning a published article. The public list, RSS feed, and changelog API include that article after the post-merge sync writes the database. sentry-changelog must deploy. Production reads the database. The markdown overlay applies only on preview.

This pick is strong. The Production deploy workflow sets service sentry-changelog. The runtime filter key is sentry-changelog.

Risk

Bad MDX fails compile on the detail page. Users then see the fallback paragraph. The list page compiles the summary and can hit the same class of error. Cache revalidation can fail after a successful database write. The new page can stay stale. A sync validation failure aborts the whole file upsert run.

Intended effect

The new slug has no production traces before deploy. That zero is the baseline. Confirmed means GET requests to that path return 200 and the body is not the MDX fallback. Absent means the path stays missing after merge, or changelogDetailMdx errors fire for this slug.

Signal	Baseline	Rule	Source
Production requests to /changelog/sentry-mcp-2026-10-01-to-2026-10-19	0 transactions in 2026-10-17T15:52:00Z to 2026-10-19T15:52:00Z	rise above 0 with HTTP 200	Sentry org sentry, project changelog, environment:production plus that path
changelog_stage:changelogDetailMdx errors for this slug	0 events in 2026-10-17T15:52:00Z to 2026-10-19T15:52:00Z	hold at 0 while the new path has traffic	Sentry org sentry, project changelog, environment:production changelog_stage:changelogDetailMdx

Regression watch

This diff can break MDX compile on the new detail page and on the list summary. It can also stall or fail other changelog detail lookups after the sync writes every file-backed row in one transaction. Put a brief first-boot spike aside. Escalate when failure rate leaves 0 or p95 leaves the measured band.

Signal	Baseline	Rule	Source
GET /changelog/[slug] failure rate	0% in 2026-10-18T15:52:00Z to 2026-10-19T15:52:00Z and in 2026-10-17T15:52:00Z to 2026-10-19T15:52:00Z	hold at 0	Sentry org sentry, project changelog, environment:production is_transaction:true transaction:"GET /changelog/[slug]" failure_rate()
GET /changelog/[slug] p95 duration	873ms in 2026-10-18T15:52:00Z to 2026-10-19T15:52:00Z, 862ms in 2026-10-17T15:52:00Z to 2026-10-19T15:52:00Z	hold in 862-873ms	same query, p95(span.duration)
GET /changelog failure rate	0% in both windows above	hold at 0	Sentry org sentry, project changelog, environment:production is_transaction:true transaction:"GET /changelog" failure_rate()
GET /changelog p95 duration	1007ms in 2026-10-18T15:52:00Z to 2026-10-19T15:52:00Z, 998ms in 2026-10-17T15:52:00Z to 2026-10-19T15:52:00Z	hold in 998-1007ms	same query, p95(span.duration)
changelog_stage:changelogDetailMdx errors	0 events in 2026-10-17T15:52:00Z to 2026-10-19T15:52:00Z	hold at 0	Sentry org sentry, project changelog, environment:production changelog_stage:changelogDetailMdx
Changelog slug lookup errors	14 events in 2026-10-17T15:52:00Z to 2026-10-19T15:52:00Z against 7734 slug-page transactions, about 0.18%	hold near 0.18% of GET /changelog/[slug] volume	Sentry org sentry, project changelog, production errors titled Failed query on Changelog slug

Slug-page volume in those windows was 2.35 TPM over 24h and 2.69 TPM over 48h. List volume was 1.01-1.02 TPM. Use that volume when you read the 0.18% share.

Not observable

The Sync Changelog GitHub Action result is not in Sentry. Direct Neon row state is not connected. POST /api/revalidate had no production traces in 2026-10-17T15:52:00Z to 2026-10-19T15:52:00Z, so cache bust success is unknown. The Sentry What's New broadcast is not measured here. Article factual accuracy for hosted MCP is out of scope.