feat(webapp): mollifier API mutations on buffered runs

[d-cs]

Summary

Cancel, replay, reschedule, metadata, tags, and idempotency-key-reset now succeed against a run that's still in the mollifier buffer. Mutations are applied to the buffered snapshot via Lua CAS; the drainer carries the mutation forward when it replays.

Primitives added:

• mutateWithFallback — PG-first / buffer-fallback resolver with bounded-wait safety net for entries that transition mid-mutation.
• applyMetadataMutation — buffered metadata PUT mirroring the PG-side retry loop with CAS atomicity.
• resolveRunForMutation — discriminated-union resolver used by route findResource so the route builder's pre-action 404 check sees buffered runs.

Routes wired (whole files, no GET/POST splits):

• api.v2.runs.\$runParam.cancel.ts
• api.v1.runs.\$runParam.replay.ts
• api.v1.runs.\$runParam.reschedule.ts
• api.v1.runs.\$runId.metadata.ts
• api.v1.runs.\$runId.tags.ts
• resetIdempotencyKey.server.ts

Stacked on the reads PR.

Test plan

• `pnpm run typecheck --filter webapp` passes
• `pnpm run test --filter webapp test/mollifierMutateWithFallback.test.ts` passes
• `pnpm run test --filter webapp test/mollifierApplyMetadataMutation.test.ts` passes
• `pnpm run test --filter webapp test/mollifierResolveRunForMutation.test.ts` passes

[coderabbitai]

Important

Review skipped

Auto reviews are disabled on base/target branches other than the default branch.

Please check the settings in the CodeRabbit UI or the .coderabbit.yaml file in this repository. To trigger a single review, invoke the @coderabbitai review command.

⚙️ Run configuration

Configuration used: Repository UI

Review profile: CHILL

Plan: Pro

Run ID: bfa5943e-9eaf-4d88-bef6-e4d163e9ad3a

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

Use the checkbox below for a quick retry:

• 🔍 Trigger review

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch mollifier-phase-3-mutations

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

[changeset-bot]

🦋 Changeset detected

Latest commit: 63ae447

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 32 packages

Name	Type
@trigger.dev/redis-worker	Patch
@internal/run-engine	Patch
@internal/schedule-engine	Patch
@trigger.dev/build	Patch
@trigger.dev/core	Patch
@trigger.dev/plugins	Patch
@trigger.dev/python	Patch
@trigger.dev/react-hooks	Patch
@trigger.dev/rsc	Patch
@trigger.dev/schema-to-json	Patch
@trigger.dev/sdk	Patch
@trigger.dev/database	Patch
@trigger.dev/otlp-importer	Patch
@trigger.dev/rbac	Patch
trigger.dev	Patch
references-ai-chat	Patch
d3-chat	Patch
references-d3-openai-agents	Patch
@internal/cache	Patch
@internal/clickhouse	Patch
@internal/llm-model-catalog	Patch
@internal/redis	Patch
@internal/replication	Patch
@internal/testcontainers	Patch
@internal/tracing	Patch
@internal/tsql	Patch
@internal/zod-worker	Patch
references-nextjs-realtime	Patch
references-realtime-hooks-test	Patch
references-realtime-streams	Patch
@internal/sdk-compat-tests	Patch
references-telemetry	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[devin-ai-integration]

Devin Review found 3 new potential issues.

View 8 additional findings in Devin Review.

[devin-ai-integration]

🔴 Unhandled error in routeOperationsToRun can crash the request after the primary mutation already succeeded

In the metadata route, after the primary buffered metadata mutation succeeds (line 134), the code fans out parent/root operations via routeOperationsToRun in a Promise.all at lines 168-184. Inside routeOperationsToRun, the applyMetadataMutationToBufferedRun call at line 100 is not wrapped in a try/catch. If Redis is down or throws, the error propagates through Promise.all into the action handler, causing the entire request to return a 500 — even though the caller's own metadata mutation already landed successfully. The comment at lines 88-92 explicitly describes these parent/root operations as "auxiliary" and "best-effort", but the implementation doesn't match that intent.

How to trigger

1. A buffered run has parent/root operations in the metadata PUT body.
2. The primary metadata mutation succeeds on the buffer.
3. The PG service fails for the parent run (e.g., completed run), so routeOperationsToRun falls through to the buffer fallback.
4. applyMetadataMutationToBufferedRun throws (Redis connection error, timeout, etc.).
5. The entire request fails with 500, and the successful primary mutation result at line 186 is never returned.

Suggested change

	await applyMetadataMutationToBufferedRun({
	runId: targetRunId,
	body: { operations },
	});
	}
	await applyMetadataMutationToBufferedRun({
	runId: targetRunId,
	body: { operations },
	}).catch((err) => {
	logger.warn("metadata route: buffer fallback for parent/root op failed", {
	targetRunId,
	error: err instanceof Error ? err.message : String(err),
	});
	});

---

Was this helpful? React with 👍 or 👎 to provide feedback.

[devin-ai-integration]

🚩 Parent metadata routing uses internal ID which won't resolve in the buffer

In routeOperationsToRun at api.v1.runs.$runId.metadata.ts:169, bufferedEntry.parentTaskRunId is documented as an internal CUID (not a friendlyId). When the PG service fails and the code falls back to applyMetadataMutationToBufferedRun at line 100, that function calls buffer.getEntry(input.runId) which indexes by friendlyId. An internal CUID will never match, so getEntry returns null and the function returns { kind: 'not_found' }. This means parent operations can never be routed to a buffered parent via this fallback path. In practice this is likely harmless (parents are typically materialized before children reach the buffer), but it's a silent no-op that could surprise.

---

Was this helpful? React with 👍 or 👎 to provide feedback.

[devin-ai-integration]

🚩 Test file buffer.test.ts has new test block inserted at wrong nesting level

In packages/redis-worker/src/mollifier/buffer.test.ts, lines 1940-1993 insert a new redisTest(...) block between the callback-closing }, (line 1939) and the ) (line 1995) that closes the previous redisTest call. This effectively nests the new test as an extra argument to the outer redisTest, with a semicolon (; from ); at line 1993) appearing inside the argument list. This is likely a syntax error that would prevent the test file from parsing. Not reporting as a bug per review guidelines (would be caught by compiler/CI), but flagging for reviewer awareness since it may block the test suite.

---

Was this helpful? React with 👍 or 👎 to provide feedback.