idempotency_conflict

HTTP 409 · not retryable

You sent Idempotency-Key: <K> with one body, then resent Idempotency-Key: <K> with a different body. The platform stores a SHA-256 hash of the canonicalized request body for each key and refuses to merge mismatched payloads.

How to fix

• Pick a fresh idempotency key when the payload genuinely changes.
• If the payload is unchanged, ensure your client serializes JSON deterministically (same key order, same number formatting). The server canonicalizes by sorting object keys before hashing, so attribute order does not matter — but added or removed fields do.
• Idempotency keys are retained 7 days after the order reaches a terminal state (completed, cancelled, failed). After cleanup the key can be reused freely.