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

# Error Handling

> Understand error types and recovery strategies for reliable Gateway integrations.

Even the best models encounter occasional failures. This guide explains how the Gateway reports errors and how you should respond.

***

## Error categories

Errors can originate from the Gateway, the provider, or your request. The error response will include metadata to help you diagnose the issue.

| Status range | Meaning                                  | Typical action                        |
| ------------ | ---------------------------------------- | ------------------------------------- |
| 400-499      | Invalid request or authentication issues | Fix the payload or credentials.       |
| 429          | Rate limited                             | Retry with backoff and respect limits |
| 500-599      | Gateway or provider failure              | Retry with backoff and log details    |

***

## Retry behavior

* Implement exponential backoff with jitter.
* Use the `Retry-After` header when present.
* Avoid infinite retries by setting a max retry count.

***

## Provider errors

Sometimes errors originate upstream. We will attempt to indicate this in the error response. The router should attempt to navigate you away from that provider if possible, should these errors keep happening.

***

## Next steps

* Review [Rate limits](./rate-limits.mdx) to plan for throttling.
* Learn how [Routing and fallbacks](../guides/routing-and-fallbacks.mdx) work.