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

# Errors

> Handle Fexmetrics error responses and rate limits.

Errors use one JSON shape:

```json theme={null}
{
  "error": {
    "code": "INVALID_REQUEST",
    "message": "Invalid request"
  }
}
```

| HTTP status | Code                    | Meaning                                              |
| ----------- | ----------------------- | ---------------------------------------------------- |
| 400         | `INVALID_REQUEST`       | Invalid parameter, range, body, or server reference. |
| 401         | `RAPIDAPI_UNAUTHORIZED` | Missing or invalid RapidAPI credentials.             |
| 403         | `FEATURE_NOT_AVAILABLE` | Your plan does not include the endpoint or range.    |
| 404         | `SERVER_NOT_FOUND`      | The server is unknown or not public.                 |
| 429         | `RATE_LIMITED`          | A rate or quota limit was reached.                   |
| 500         | `INTERNAL_ERROR`        | An unexpected service error occurred.                |

Retry `429` and `500` with exponential backoff. Fix the request or credentials before retrying other errors.