# Unknown API key

Resolve unknown API key errors.

The `X-Api-Key` value is a valid UUID but does not match any active [API key](/explanation/application/api-keys).

The key may have been revoked or never existed. [Generate a new key](/explanation/application/api-keys#generate-an-api-key) to continue.

## Response

All error responses follow the [Problem Details (RFC 9457)](/reference/api/overview#errors) format. The `type`, `title`, `status`, and `detail` fields are always present, while `instance` may be omitted depending on the API.

Here is an example of the response returned for this error:

```json
{
  "type": "https://croct.help/api/authentication/unknown-api-key",
  "title": "The API key is unknown.",
  "status": 401,
  "detail": "The provided API key does not exist.",
  "instance": "/client/web/content"
}
```