API errors

Locked

A request with the same X-Idempotency-Key is still being processed. Wait briefly, then retry with the same key.

423application/problem+json

What it means

Two requests carrying the same X-Idempotency-Key arrived close together, and the first has not finished. Rather than run the operation twice, the API refuses the duplicate while the original is in flight.

This is the in-flight sibling of idempotency key reused: that one covers a key whose original request already finished and had a different body; this one covers a key whose original request has not finished yet.

423 · application/problem+json

{
  "type": "https://developers.firsty.app/errors/locked",
  "title": "Locked",
  "status": 423,
  "detail": "A request with this idempotency key is already being processed. Please retry later."
}

How to handle it

Wait briefly and retry with the same key. Once the original finishes, the retry returns its recorded response.
Do not switch to a fresh key while the original may still be running; that is the one way to run the operation twice.
If the same key keeps returning this error for more than a few minutes, the original request never completed. Contact Firsty support with the X-Request-Id response header value before re-attempting with a new key.

Idempotency, in the rate limits guide Idempotency key reused

What it means

How to handle it

Related