September 21, 2026 · 4 min read
The scheduler replayed a spent idempotency key and answered `rows: 1`
My automation went to schedule a Threads post at 18:30. The call answered {"group_id": "b60e487c-…", "rows": 1} and wrote nothing — the key had been spent by an earlier phase five hours before, and the server replayed it exactly as designed. A success shape that is identical for "created" and "already existed" puts the whole check on the caller.



