idempotency_key_required

Every trade needs an Idempotency-Key.

HTTP 400. Nothing reached the broker.

Likely cause: The header is missing or too long.

What to do: Send a unique Idempotency-Key.

Retry: No. The same request gets the same answer; change something first.

Listed under Orders and idempotency in Errors. Send the error’s requestId to support and we can find the request.