idempotency_key_required

HTTP status: 400 Bad Request. Retrying the same request unchanged fails the same way.

Why it happens

• Every POST must carry one, so a retry can never create a second payment.

What to do

Send a unique key per operation, 1 to 255 visible ASCII characters: your order ID or a UUID works.

Example

The response is application/problem+json. Branch on code, never on title or detail. See errors for the format.

{
  "type": "https://docs.nowgate.io/errors/idempotency_key_required",
  "title": "Bad Request",
  "status": 400,
  "detail": "What exactly was wrong, in a sentence.",
  "instance": "/v1/payments",
  "code": "idempotency_key_required",
  "request_id": "req_01jc3xb1n6f0q2w8e4r7t5y9v3"
}