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

# Auto Router

> clearmaas/auto — let ClearMaas pick the cheapest live model per request.

`clearmaas/auto` is a [named router](/routing/named-routers) we
create for every account on signup. It routes each request to the
cheapest live chat model your account has access to, chosen fresh per
request.

## Usage

<CodeGroup>
  ```python Python theme={null}
  response = client.chat.completions.create(
    model="clearmaas/auto",
    messages=[{"role": "user", "content": "..."}],
  )
  ```

  ```ts TypeScript theme={null}
  const response = await openai.chat.completions.create({
  model: "clearmaas/auto",
  messages: [{ role: "user", content: "..." }],
  });
  ```
</CodeGroup>

No other setup required — the router exists the moment your account is
created.

## Default behavior

The seed configuration:

* **Pattern**: empty — matches **every chat model your account has
  access to**. New models that come online become candidates
  automatically.
* **Strategy**: `cheapest` — picks the model with the lowest per-token
  price among live candidates.
* **Default model**: none. If the pattern resolves to no available
  models, the request fails with a clear error. You can set a default
  in the dashboard if you want a safety net.

You can see and edit your Auto Router in the dashboard under **Routing**.
You can narrow the pattern (e.g. restrict to `openai/*`), swap the
strategy (`balanced` / `quality`), set a `default_model`, or delete the
router entirely — same as any [named router](/routing/named-routers).

## When to prefer Auto Router over explicit model names

* You don't want to pin to a specific model; you want the cheapest live
  chat model at each request.
* You're prototyping and don't want to care about which provider is up.
* You want ClearMaas's routing to "just work" without thinking about it.

## When to prefer explicit model names

* You need deterministic output — picking different models at different
  times will change generation style and quality.
* You're using features specific to one model (e.g. Claude's
  `cache_control`, or a model's native image generation).
* You want predictable per-request cost.

## Seeing what Auto Router picked

Check the `X-Clear-Resolved-Model` response header. See
[Response Headers](/routing/response-headers).

```python theme={null}
res = client.chat.completions.with_raw_response.create(
    model="clearmaas/auto", ...
)
actual_model = res.headers.get("X-Clear-Resolved-Model")
# e.g. "openai/gpt-4o-mini"
```