> ## Documentation Index
> Fetch the complete documentation index at: https://docs.revoengine.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Run API - HTTP Codes
> Run API does support various HTTP Status codes, but some are reserved for internal reporting e.g. `429` and `502`.
# Default Responses
| Code | Description |
| ----- | ---------------------------------------------------------------------------------------------------- |
| `200` | `OK` - Default response except POST method. |
| `201` | `Created` - Default response of POST method. |
| `401` | `Unauthorized` - Authentication is required. |
| `429` | `Too Many Requests` - Your request has been throttled (check your Run API quota). |
| `502` | `Bad Gateway` - Error during executing Endpoint (most likely misconfiguration or compilation error). |
In case of `429`, we recommend to retry the request using exponential backoff.
# Custom Success
You can customize default success HTTP code, read more there: [Input - httpCode](/run-api/response#httpcode)
# Custom Bad Request
You can customize default Bad Request HTTP code,
which occurs during [Guard](/run-api/guard) bounce read more there:
[Input - validateResponse](/run-api/configuration#validateresponse)
# Custom Error
In case of error response, we allow you to throw any response code excluding `502` which we use to address misconfiguration or compilation error or to expose any other internal issues.
