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

# Region behavior

> How regional routing works and how to skip the redirect/retry step.

Streams are regional resources. If your application knows which region owns a stream, you can include a region header to avoid an extra redirect/retry step.

Clients may send:

```http theme={null}
X-Overshoot-Region: us-west1
```

or:

```http theme={null}
X-Overshoot-Region: us-central1
```

If a request reaches the wrong region, the API returns `409` with a `region_error` body that identifies the expected or requested region. Responses expose `X-Overshoot-Region` with the serving region.

<Note>
  One chat-completions request cannot reference streams from multiple regions.
</Note>