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

# Error handling

> HTTP status codes and error response format.

The API uses standard HTTP response codes to indicate success or failure.

| Code  | Description                                     |
| ----- | ----------------------------------------------- |
| `200` | Success                                         |
| `400` | Bad request — invalid parameters                |
| `401` | Unauthorized — missing or invalid API key       |
| `403` | Forbidden — insufficient plan for this endpoint |
| `404` | Not found                                       |
| `429` | Rate limit exceeded                             |
| `500` | Server error                                    |

## Error response format

Validation and client errors typically return:

```json theme={null}
{
  "message": "Error message",
  "status": 400
}
```

When you receive a `429`, check the `Retry-After` header for the number of
seconds to wait before retrying.