🪡 refactor: Split useResumableSSE Into Thin Host Bindings

[berry-13]

Pull Request

Before submitting, please review the Contributing Guide.

Documentation changes belong in the LibreChat documentation repository.

Summary

With the resumable run in @librechat/chat core, useResumableSSE was left as one long hook that built everything the run needs from the app: the steer-chip adapter, the query cache adapter, the pane controls and queue-drain markers, and the event and usage handlers. Those are four separate concerns that each read different app state.

This splits it by responsibility into thin bindings in client/src/hooks/SSE/: useResumableSteers (adapts the steer state from useSteerState() in hooks/SSE/steer.ts to the run's steer host, adding queue restore and recovery bookkeeping), useResumableCache (the cache, active jobs and the new chat's optimistic records), useResumablePane (controls, generation epochs, run end and the detached-run markers) and useResumableEvents (the event and usage handlers and the error cards). Each returns one group of the ResumableHost; useResumableSSE composes them and calls mountSubmission, and is now 142 lines (from 4,964 before this stack). No behavior changes. Stacked on #17132.

Type of change

• Refactor

Testing

Tested environments/configuration:

Not applicable: the bindings are moved, not changed.

Automated tests:

• useResumableSSE.spec.ts imports selectLocalSteersForQueue and ABORT_SWEEP_STATUSES from their new home; nothing else in the specs changed.
• In client, the hooks/SSE and hooks/Chat specs plus data-provider/SSE: 1148 pass.
• npx tsc --noEmit in client, eslint, prettier and sort-imports on the changed files: clean.

Screenshots / recordings

No user-facing change.

Risk / compatibility

The host groups are memoized per hook, so a render that changes one handler rebuilds only its group; the host a subscription captured still comes from the render that attached it.

Checklist

• I reviewed my own changes
• 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 2026-10-16T19:41:42.544502Z	d63d52d	New commits
🔒 Security Review	✅ Completed 2026-10-15T07:08:29.207930Z	97c89cf	PR opened

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