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

# Idempotency key reused

> idempotency_key_reused: HTTP 422, not retryable.

| | |
| - | - |
| Code | `idempotency_key_reused` |
| HTTP status | `422` |
| Retryable | No |
| Python | `vaquill.IdempotencyKeyReusedError` |
| TypeScript | `IdempotencyKeyReusedError` |

## What it means

You sent an `Idempotency-Key` that was already used with a different request.

## What to do

Use a fresh key for each distinct request.
Reuse a key only when you resend the identical request.

## Example response

The `detail` text is illustrative and can differ by endpoint.
`retryAfterSeconds` appears only on a `429` or `503` that carries a `Retry-After` header.

```json theme={"theme":"github-light"}
{
  "type": "https://www.vaquill.ai/docs/errors/idempotency_key_reused",
  "title": "Idempotency key reused",
  "status": 422,
  "detail": "Idempotency key was used with a different request",
  "code": "idempotency_key_reused",
  "retryable": false,
  "requestId": "3f2b8c1e-5a7d-4e9b-9c34-0d6a1b2f7e58"
}
```

## In the SDKs

The Python SDK raises `IdempotencyKeyReusedError` and the TypeScript SDK raises `IdempotencyKeyReusedError`.
Both expose `code`, `retryable`, the request id and the retry hint.
See [Error codes](https://vaquill.ai/docs/errors/index.md) for the full table and attribute names.


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