🔁 fix: Keep the Error Card When a Stream Reattached Without Resume State Fails

[berry-13]

Pull Request

Before submitting, please review the Contributing Guide.

Documentation changes belong in the LibreChat documentation repository.

Summary

When the stream status route answers a running job without resumeState (an older server, or a status that omits it), useResumeOnLoad attaches with a minimal submission whose placeholder response has no isCreatedByUser and no parent. If the reattached stream then reports a failure, building the error turn from that placeholder throws a ZodError (isCreatedByUser is required), so the error card is never written and the pane stays submitted. The placeholder is now a parented assistant row (isCreatedByUser: false, parented under the last user turn), and the fallback user row is marked as the user's, so the failure renders as an error like any other. Fixes berry-13#223.

The fix lands where the resume rules now live: the resume-state helpers (rebuilding a submission from resume state or from a bare status, matching a submission to its resume state, the branch to restore, and the merge of a resumed pair into history) move out of useResumeOnLoad.ts and useResumableSSE.ts into packages/chat/src/core/resumable/resume.ts, and the pending-action appliers they use move from utils/approval.ts to packages/chat/src/core/pending.ts, which utils/approval.ts re-exports. Apart from the fix, no behavior changes. Stacked on #17110.

Type of change

• Bug fix
• Refactor

Testing

Tested environments/configuration:

The failure path needs a status without resumeState, which current servers do not send, so it is covered by the spec below rather than by hand.

Automated tests:

• transport.spec.tsx (resume): reattaches through a status without resumeState, emits an error on the stream, and expects the chat to settle on that error. It fails on the base with the ZodError and passes with the fix.
• Added packages/chat/src/core/__tests__/resume.spec.ts for the moved resume helpers and the minimal submission.
• npx jest src/core in packages/chat, and in client the hooks/SSE, hooks/Chat and hooks/Agents specs, utils/approval.spec.ts and PendingSteers.test.tsx: all pass.
• npx tsc --noEmit in packages/chat and client, eslint, prettier and sort-imports on the changed files: clean.

Screenshots / recordings

No user-facing change.

Risk / compatibility

None. utils/approval.ts keeps exporting the pending-action appliers, now from @librechat/chat.

Checklist

• I reviewed my own changes
• Relevant tests have been added or updated
• Existing relevant tests pass
• The change does not introduce new warnings or errors

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-10-15T15:25:42.602270Z	79364f3	New commits
🔒 Security Review	✅ Completed 2026-10-15T05:51:42.825469Z	d88d6f6	PR opened

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[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Avoid appending the resumed user row twice

When a bare-status reattach finds lastUserMessage, that exact row is already present in messages, but the submission retains the full array and sets isRegenerate: false. If the reattached stream emits the error this change targets, errorHandler calls mergeErrorMessages, whose normal path returns [...messages, userMessage, errorMessage]; this duplicates the prompt (including its messageId) in the rendered and React Query-cached transcript. Exclude the selected user row from the submission prefix, or otherwise use a merge path that appends only the error for this resume case.

AGENTS.md reference: AGENTS.md:L50-L53

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