fix(sdk): reset skipToTurnComplete when a new chat turn starts

[wuweiweiwu]

✅ Checklist

• I have followed every step in the contributing guide
• The PR title follows the convention.
• I ran and tested the code works

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Testing

Reproduced with useTriggerChatTransport + useChat and the stop pattern from the ai-chat frontend docs:

1. Send a message so a turn is streaming.
2. Call transport.stopGeneration(chatId), then useChat's stop().
3. Send another message.

Before this change the second turn never renders: no parts arrive, status stays streaming, and the session stays isStreaming: true, so a stop button stays on screen until the page is reloaded. The run itself is fine and everything persists, so a reload shows the full response.

Cause: stopGeneration sets state.skipToTurnComplete = true, and the read loop only clears that when it sees a TURN_COMPLETE record. The abort closes the reader before that record arrives, so the flag survives into the next turn and every record of that turn is skipped, including its own TURN_COMPLETE.

After this change the same sequence streams the second turn normally. Verified against 4.5.11 and 4.5.12 (both affected) with the equivalent patch applied to the built SDK.

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Changelog

Reset skipToTurnComplete when a new chat turn or action is sent, so a message sent after stopGeneration streams normally instead of leaving the chat stuck in a streaming state.

[changeset-bot]

🦋 Changeset detected

Latest commit: 9902a08

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

This PR includes changesets to release 27 packages

Name	Type
@trigger.dev/sdk	Patch
@trigger.dev/python	Patch
@internal/dashboard-agent	Patch
@trigger.dev/build	Patch
@trigger.dev/core	Patch
@trigger.dev/react-hooks	Patch
@trigger.dev/redis-worker	Patch
@trigger.dev/rsc	Patch
@trigger.dev/schema-to-json	Patch
@trigger.dev/database	Patch
@trigger.dev/otlp-importer	Patch
@trigger.dev/rbac	Patch
@trigger.dev/sso	Patch
trigger.dev	Patch
@internal/clickhouse	Patch
@internal/llm-model-catalog	Patch
@internal/metrics-pipeline	Patch
@internal/redis	Patch
@internal/replication	Patch
@internal/run-engine	Patch
@internal/run-store	Patch
@internal/schedule-engine	Patch
@internal/tracing	Patch
@internal/webhook-engine	Patch
@internal/webhook-sources	Patch
@internal/testcontainers	Patch
@internal/cache	Patch

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[github-actions]

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[coderabbitai]

Walkthrough

The chat transport resets skipToTurnComplete before starting a new message or action stream. Tests cover message and action turns after an incomplete stopped turn and verify that pending text streams and turn-completed is emitted. A patch changeset documents the SDK fix.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 1 functions across 2 files.
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.
Title check	✅ Passed	The title clearly and concisely describes the primary SDK fix and follows the repository convention.
Description check	✅ Passed	The description includes a completed checklist, detailed testing steps, and a clear changelog; missing issue and screenshots are non-critical.

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[devin-ai-integration]

✅ Devin Review: No Issues Found

Devin Review analyzed this PR and found no bugs or issues to report.

[github-actions]

Thanks for your contribution! We require all external PRs to be opened in draft status first so you can address CodeRabbit review comments and ensure CI passes before requesting a review. Please re-open this PR as a draft. See CONTRIBUTING.md for details.

[github-actions]

Thanks for your contribution! We require all external PRs to be opened in draft status first so you can address CodeRabbit review comments and ensure CI passes before requesting a review. Please re-open this PR as a draft. See CONTRIBUTING.md for details.

[github-actions]

Thanks for your contribution! We require all external PRs to be opened in draft status first so you can address CodeRabbit review comments and ensure CI passes before requesting a review. Please re-open this PR as a draft. See CONTRIBUTING.md for details.

[wuweiweiwu]

Added regression tests in packages/trigger-sdk/test/chat-transport-events.test.ts: a stop that never sees TURN_COMPLETE, followed by sendMessages and by sendAction. Each asserts the next stream delivers its chunk and a turn-completed event.

The .out stub honours the Last-Event-ID cursor, so a resubscribe cannot replay skipped records. Both tests fail without the reset and pass with it.

Written by Devin

[devin-ai-integration]

Devin Review found 1 new potential issue.

[devin-ai-integration]

🔍 Stopped-turn leftover chunks no longer skipped

Clearing skipToTurnComplete (chat.ts:875, chat.ts:1290) means the new subscription streams every record from its resume cursor. The sinceInSeq guard at chat.ts:1994 filters only stale TURN_COMPLETE records, not leftover text-deltas from the stopped turn. If any remain on .out below the new send, they can now surface in the new turn's UI. Depends on server stop semantics; the author's test streamed cleanly.

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[wuweiweiwu]

Real trade-off, and it is intentional. Some notes for a maintainer who knows the server stop semantics:

• The skip flag exists to drop the tail of a stopped turn, and it clears only on that turn's TURN_COMPLETE. If the stopped turn never writes one, the flag survives every later turn, so the chat is stuck in isStreaming until a reload. That is the bug this PR fixes.
• Leftover deltas cannot be filtered by cursor today: session-in-event-id rides on turn-complete records only (writeTurnCompleteChunk in ai.ts), so the sinceInSeq guard cannot see data records. A per-record turn marker on .out would be needed for exact filtering.
• Scope of the residue: only records written between the abort and the moment the stop lands on the agent, and only if the stopped turn never completes. The cost is a few extra text-deltas in the next turn instead of a chat that no longer streams at all.

If stop does write a TURN_COMPLETE for the stopped turn, the flag clears on the next subscription anyway and this reset changes nothing. Happy to follow a different approach if you want the residue filtered server-side.

Written by Devin