Fix MCP init crash on remote connector snapshot timeout

[kentcdodds]

Summary

Sentry KODY-CLOUDFLARE-1D: RemoteConnectorSnapshotTimeoutError for connector "home" was aborting /mcp session setup.

• Capability registry already soft-failed stalled connector snapshots (Bound stalled remote connector snapshot reads #847)
• MCP Durable Object init() still loaded remote-connector instruction summaries without a catch, so a 5s snapshot timeout rejected Promise.all and failed the whole handshake (handleMcpRequest → getServerByName → retryDurableObjectOperation)
• Extract loadRemoteConnectorInstructionSummaries and omit stalled connectors instead of failing init
• Add regression coverage for mixed healthy/stalled connectors

Validation

• npm run validate passed (format, lint, typecheck, 1282 unit tests, 18 Playwright e2e, 2 MCP e2e, primitives, migrations)

Do not merge until CI is green and reviewed.

System recap — extends existing primitives (medium risk)

Mode: recap · Base: main @ 49893e20 · Head: 81982f5f

Classification: extends — MCP session init now soft-fails stalled remote-connector snapshot reads used for instruction summaries.

Primitives touched

Primitive	Group	Impact
mcp-server	surfaces	extends — instruction-summary loading no longer fails MCP DO init when a connector snapshot times out

System map

MCP init loads instruction summaries and the capability registry in parallel; only the registry path was fail-soft before this change.

Legend: green = composes (wiring only) · amber = extended by this PR · red = new primitive · gray = context (unchanged, included only when an edge crosses it).

flowchart LR
	mcpRequest["/mcp request"]:::untouched
	mcpServer["mcp-server<br/>MCP DO init"]:::extended
	snapshotCache["remote connector<br/>snapshot cache"]:::untouched
	registry["capability-registry"]:::untouched
	mcpRequest --> mcpServer
	mcpServer -->|"instruction summaries: catch timeout → omit"| snapshotCache
	mcpServer -->|"already fail-soft (#847)"| registry
	classDef touched fill:#1a7f37,color:#fff
	classDef extended fill:#9a6700,color:#fff
	classDef added fill:#cf222e,color:#fff
	classDef untouched fill:#57606a,color:#fff

Loading

Invariants

Connector snapshot cache keys remain user-scoped; soft-fail omits only the stalled connector's instruction summary and never substitutes another user's connector data.

  

Summary by CodeRabbit

• Bug Fixes

  • Remote connector information now loads more reliably during MCP session initialization.
  • Unavailable or stalled connectors no longer prevent healthy connector information from being included.
  • Connector snapshot failures are handled individually, allowing sessions to continue successfully.

• Tests

  • Added coverage for stalled connector requests and timeout handling.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: 3e075af0-d5b2-4a46-b3f5-9449ef5aad44

📥 Commits

Reviewing files that changed from the base of the PR and between 49893e2 and 81982f5.

📒 Files selected for processing (3)

• packages/worker/src/mcp/index.ts
• packages/worker/src/mcp/remote-connector-instruction-summaries.node.test.ts
• packages/worker/src/mcp/remote-connector-instruction-summaries.ts

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📝 Walkthrough

Walkthrough

The remote connector instruction summary loader moves into a dedicated module. MCP initialization imports the helper, and a new test verifies stalled connector snapshots do not prevent healthy connector summaries from being returned.

Changes

Remote connector summaries

Layer / File(s)	Summary
Implement and validate summary loading packages/worker/src/mcp/remote-connector-instruction-summaries.ts, packages/worker/src/mcp/remote-connector-instruction-summaries.node.test.ts	The extracted helper normalizes references, fetches snapshots concurrently, returns successful summaries, omits failed connectors, and is tested with a stalled snapshot.
Wire the extracted loader into MCP initialization packages/worker/src/mcp/index.ts	MCP initialization imports the dedicated helper and removes the former local implementation and its unused dependencies.

Estimated code review effort: 2 (Simple) | ~10 minutes

Possibly related PRs

• kentcdodds/kody#418: Updates remote connector MCP clients and status APIs to use user-scoped operations.
• kentcdodds/kody#847: Adds timeout-bounded remote connector snapshot reads and cache eviction.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly matches the main change: preventing MCP init crashes when remote connector snapshot requests time out.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch cursor/sentry-triage-kody-cloudflare-1d-83c3

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[github-actions]

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