# idempotency_key_reused

This Idempotency-Key was already used with a different request.

## What it means

The `Idempotency-Key` was used in the last 24 hours with a different method, path or body. Replaying it with different content is refused so a retry can never do something other than the original.

## Why it happens

- The key is derived from something that is not unique per request, like a user id.
- A retry changed the body, for example a new timestamp in `metadata`.

## What to do

1. Generate one key per distinct operation (a UUID), and reuse it only to retry that exact request.
2. Keep retries byte-for-byte identical.

- [Open the dashboard](/app/domains)
- [All limits](/docs/limits-and-pricing)

## In the API

```
HTTP 422

{
  "error": {
    "code": "idempotency_key_reused",
    "message": "This Idempotency-Key was already used with a different request.",
    "fix": "Use a new Idempotency-Key for each distinct request.",
    "docs": "https://apexly.dev/docs/errors/idempotency_key_reused"
  }
}
```