> ## Documentation Index
> Fetch the complete documentation index at: https://docs.square1.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Base URLs

> Which host serves what

Square1 splits its surfaces across several origins. **For the API in this
documentation there is exactly one base URL:**

```text theme={null}
https://inference.square1.dev
```

All six documented endpoints (`/v1/chat/completions`, `/v1/embeddings`,
`/v1/models`, `/v1/models/{id}`, `/v1/me`, `/v1/usage`) live on that host
and nowhere else.

## The full origin map

You'll encounter other `square1.dev` hosts as a user of the service. None
of them serve the API in this reference:

| Origin                               | Serves                                                                        |
| ------------------------------------ | ----------------------------------------------------------------------------- |
| `square1.dev`                        | Landing page and public status                                                |
| `dash.square1.dev`                   | The dashboard web app (sign-up, API keys, settings) and its internal `/api/*` |
| `inference.square1.dev`              | **The developer API — everything in this documentation**                      |
| `cdn.square1.dev` / `fs.square1.dev` | Signed binary delivery (image and file features)                              |

<Warning>
  Don't point an OpenAI SDK at `square1.dev` or `dash.square1.dev` — the
  `/v1` chat surface only exists on `inference.square1.dev`. If you get an
  HTML page or a 404 where you expected JSON, check the host first.
</Warning>

## Practical notes

* **SDK base URL** — include the `/v1` prefix:
  `https://inference.square1.dev/v1`.
* **Request body size** — chat and embeddings accept request bodies up to
  20 MB. Other paths on the host have a smaller limit; there's no reason
  to send large bodies to them.
* **Browser clients** — this API is designed for server-side use. Custom
  response headers (the `x-session-*` family and friends) are not exposed
  to cross-origin browser JavaScript; see
  [Quota feedback](/concepts/quota-feedback).