fix(sdk): re-dispatch a single in-flight user on recovery boot

[claude]

Requested by Matt Aitken · Slack thread

Before: a chat.agent run is killed mid-answer (OOM, crash, eviction) while the message it was answering is the only one still outstanding. The new run boots, puts that message and the half-written reply into its context, and then waits for a message that already arrived. Nobody ever answers the user; the run sits idle until it times out.

After: the new run re-runs that message as a fresh turn and replies to it. The half-written reply is dropped. When two or more messages are outstanding, nothing changes — the interrupted one still goes into context and the newer ones are re-run, exactly as before.

✅ Checklist

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

---

Testing

New regression test in packages/trigger-sdk/test/recovery-boot.test.ts — seeds a partial assistant plus exactly one in-flight user, no onRecoveryBoot, and asserts one turn fires for that user with the orphan partial dropped from the chain. It fails on main (turnCount 0, no turn at all) and passes with this change.

• pnpm exec vitest run in packages/trigger-sdk — 373 passed, 1 skipped (31 files passed, 1 skipped)
• pnpm exec oxfmt --check on the changed files — clean
• pnpm exec oxlint packages/trigger-sdk/src packages/trigger-sdk/test — clean
• pnpm run build --filter @trigger.dev/sdk — clean

What it does: with exactly one in-flight user on a recovery boot, re-dispatch that user as a fresh turn instead of splicing it into the seed chain, where it was never answered.

How: the recovery-boot smart default made one decision in two halves — the seed chain and the recovered-turn list — both gated on partialAssistant !== undefined && inFlightUsers.length > 0. The splice consumes inFlightUsers[0] into the chain as "the question the partial was answering" and dispatches the rest. That only works when there is a rest: at n=1 recoveredTurns came out empty, the boot-injected queue stayed empty, the session.in cursor was advanced past the message anyway, and on a preload or continuation boot (no message on the wire payload) neither dispatch site fired. Both branches now require length > 1, so n=1 falls through to the documented default — chain = settledMessages, re-dispatch every in-flight user. The submit-message boot is unaffected: the existing dedup still drops a queued message identical to the one already on the wire payload.

Also corrected alongside it: the two SDK docstrings and the docs/ai-chat/patterns/recovery-boot.mdx defaults section, which described the default as "re-dispatch every user" and never mentioned the splice.

Follow-up (not in this PR): the webapp e2e OOM helper never streams a token before throwing, so it exercises the no-partial path only and would not have caught this. Worth a variant that emits a token first.

---

Changelog

Fixed a chat agent hanging after an interrupted turn: when a run was killed mid-answer and only the one message it was answering was still outstanding, the new run never replied to it. That message is now re-answered on the new run.

[changeset-bot]

🦋 Changeset detected

Latest commit: c3055c9

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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[devin-ai-integration]

✅ Devin Review: No Issues Found

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

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