Carlos Escalante 8f51e33fe0 Assistant: drop mid-run MESSAGES_SNAPSHOT instead of reconciling it ...

Prod bug: earlier assistant replies vanished as new turns completed and
only came back on refresh. Debug capture showed why: with persistence
on, the run-end snapshot rebuilds history under STORE ids while the
client holds it under STREAMED ids (MAF re-mints post-tool-call text
ids, their #3619). ag-ui apply treats the snapshot as authoritative —
matching ids get replaced (streamed text wiped by the store's
empty-content toolCall entry) and the store's text copies were being
filtered out by ReconcileSnapshotMiddleware as presumed duplicates, so
prior answers had no surviving representation.

Reconciling id-mismatched snapshots is unwinnable; skip them instead.
During a normal run the client already built the turn from streamed
events and the snapshot adds nothing. Hydration replays (empty
input.messages) still pass through — there the snapshot IS the
conversation, and every reload converges the client to store ids.
ReconcileSnapshotMiddleware is replaced by the much simpler
DropRunMessagesSnapshotMiddleware.

Verified in dev: multi-turn history persists across runs, one card that
survives follow-ups, reload replays everything, no duplicates.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

2026-07-04 18:56:37 -06:00

22 KiB

Raw Blame History

View Raw