Cause

Same Idempotency-Key was reused with a different request body.

Partner action

Use a new UUID v4 for a new operation, or replay the exact same body.

Gando action (internal)

Check Redis idempotency store entry for the key.

Example response

{
  "error": {
    "code": "idempotency_key_conflict",
    "message": "Idempotency key already used with a different request body",
    "requestId": "req_abc123"
  }
}