The Managed Agents events endpoint (`GET /v1/sessions/{id}/events`)
does NOT support filtering by event id. It returns an opaque
`next_page` cursor on each response and accepts it back via the
`page` query parameter; an `after_id=` filter returns 400 Bad
Request, which caused every segment resume to fail backfill (visible
as `{"type":"status","kind":"session_error","message":"Backfill
failed: events.list returned 400 Bad Request"}`).
Caught during testing of commit 8e44de5: resuming from a segment
boundary always returned 400 and the brief silently lost events from
the previous segment.
Changes:
- `listAllEvents` now paginates via `page` / `next_page` and pulls
the full session history (limit=1000). The Anthropic API has no
per-id filter, so the caller is responsible for skipping events
already delivered.
- New `pastInitialId` flag at the top of the body loop: on resume,
mute every event up to and including `initialLastEventId`
(still adding them to `seenEventIds` so the live stream doesn't
re-emit them), then start delivering. On a brand-new session the
flag starts true and is a no-op.
- Safety fallback: if backfill completes without ever seeing
`initialLastEventId` (stale cursor / truncated history), flip
the flag to true so we don't get stuck muting forever — the live
stream will start delivering whatever shows up next.
Co-Authored-By: alex <alex@semipublic.co>
Devin AI
df3c8e7d1c