Idempotency

Send an Idempotency-Key header (any unique string up to 255 printable ASCII characters) with every POST submit. For 24 hours, the same key with the same body replays the original 202 — same job_id, Idempotent-Replayed: true, and no second charge — so a retry after a timeout is always safe. The same key with a different body is refused with 409 idempotency_key_reuse; a malformed key with 400 idempotency_key_invalid. Keys are scoped to your team.