> ## Documentation Index
> Fetch the complete documentation index at: https://docs.cortex.foundation/llms.txt
> Use this file to discover all available pages before exploring further.

# idempotency_key_reuse

> Idempotency key reused with a different body. HTTP 400.

|           |                                                                 |
| --------- | --------------------------------------------------------------- |
| HTTP      | `400`                                                           |
| `code`    | `idempotency_key_reuse`                                         |
| `type`    | `https://docs.cortex.foundation/problems/idempotency_key_reuse` |
| Retryable | no                                                              |

The `Idempotency-Key` header was reused with a different request body. Replay the original body, or mint a new key.

```json theme={null}
{
  "type": "https://docs.cortex.foundation/problems/idempotency_key_reuse",
  "title": "Idempotency key reused with a different body",
  "status": 400,
  "code": "idempotency_key_reuse",
  "request_id": "req_…"
}
```

## Related

* [Errors](/reference/errors) - how to branch on `code`, and what not to render from `detail`.
* [Problem catalog](/problems) - every code, its status, and whether retrying helps.
* [Troubleshooting](/getting-started/troubleshooting) - what a message in the product means.