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

# HTTP status codes

> Understand common API HTTP status codes and how to handle them.

## Common status codes

| Status  | Meaning                         | What to do                                                                                                    |
| ------- | ------------------------------- | ------------------------------------------------------------------------------------------------------------- |
| **200** | Request succeeded               | Normal response                                                                                               |
| **400** | Invalid request parameters      | Check JSON format, request body, and parameters                                                               |
| **401** | Authentication failed           | Check that the API key is correct and not expired                                                             |
| **403** | Access denied                   | Confirm the API key group can access the requested model and endpoint; check the client protocol and Base URL |
| **404** | Endpoint not found              | Check the request URL                                                                                         |
| **413** | Request body too large          | Reduce the request body size and retry                                                                        |
| **429** | Rate limit reached              | Slow down requests, check console announcements, or inspect current limits                                    |
| **500** | Internal server error           | Retry later and keep the request ID and error message                                                         |
| **503** | Service temporarily unavailable | The model may lack capacity or an upstream provider may be unavailable; retry later or switch models          |
| **524** | Request timeout                 | Check network conditions or reduce request size before retrying                                               |

## Error response format

```json theme={"system"}
{
  "error": {
    "message": "Error description",
    "type": "error_type",
    "code": "error_code"
  }
}
```

## Retry guidance

* **4xx errors**: fix the request before retrying.
* **429**: wait before retrying; use exponential backoff for automation.
* **5xx errors**: wait a few seconds, then retry.