# Idempotency (/docs/idempotency)

Retry a batch scrape request without starting it twice.

`POST /v2/batch/scrape` takes an `Idempotency-Key` header, up to 255 printable ASCII characters. Within 1 day, the
same key and body replay the original batch scrape with `Idempotent-Replayed: true`; a different body is a 422.

> [!NOTE]
> The [request headers](/docs/request-headers) are part of the request the key is checked against. A replay costs no
> [credits](/docs/authentication).