Reliability
Idempotency
Use Idempotency-Key on write requests that can create jobs, purchases, or state changes.
Header
Idempotency-Key: ik_20260511_policy_001
Conflict
Reusing a key with a different payload returns 409 idempotency_conflict.
Where to use it
Use it for extraction, billing checkout, batch creation, and any retryable client workflow.