# `IDEMPOTENCY_KEY_INVALID` Invalid Idempotency-Key

Source: https://checkslip.com/en/problems/idempotency-key-invalid

- **HTTP status**: `400`
- **Credit**: No credit taken

## Meaning

`Idempotency-Key` must be 1–255 printable ASCII characters.

## Fix

Use a UUID or a random ASCII string of at most 255 characters.

## Example response

```
{
  "type": "https://checkslip.com/problems/idempotency-key-invalid",
  "title": "Invalid Idempotency-Key",
  "status": 400,
  "code": "IDEMPOTENCY_KEY_INVALID",
  "instance": "01a18600-0000-7000-8000-000000000000"
}
```