idempotency_conflict — Idempotency key reused

What causes it

• The same `Idempotency-Key` was sent by this API client with a different `payload`, `execution_mode`, or `external_reference` (trigger), or a different row set (batch). Keys are compared per client, so two clients may reuse a value.
• A key was recycled after the client-side request object changed — for example a retry that regenerated a timestamp inside the payload.

How to fix it

1. Generate a new key (a UUID) for every distinct request; reuse a key only to retry the byte-identical request, which returns the original execution or batch.
2. Store the key alongside the request in your own system before sending, so a crash between send and response can be replayed safely.

Operations that return it

• POST /workflows/{id}/trigger Trigger a workflow
• POST /workflows/{id}/batches Create a batch from N rows

Example response

HTTP/1.1 409 Conflict · Content-Type: application/json

{
  "error": {
    "code": "idempotency_conflict",
    "message": "The Idempotency-Key has already been used with a different request payload.",
    "details": [],
    "request_id": "6f1c2a3e-8d4b-4c5e-9f0a-1b2c3d4e5f60",
    "doc_url": "https://cascades.crscreditapi.com/docs/api/errors/idempotency_conflict"
  }
}

Related

• Concepts › Idempotency