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

# Quickstart

> Make your first authenticated call to the Locus REST API and MCP server.

You need a Locus API key — a bearer token of the form `lsk_<slug>_<random>`. See
[Authentication](/en/authentication) for how keys work.

<Note>
  Base URL used throughout: `https://core.locusmedical.fr`. Replace it with your
  deployment's URL if different.
</Note>

## 1. Call the REST API

<CodeGroup>
  ```bash cURL theme={null}
  curl -X POST https://core.locusmedical.fr/v1/search \
    -H "Authorization: Bearer $LOCUS_API_KEY" \
    -H "Content-Type: application/json" \
    -d '{"query": "antibioprophylaxie chirurgie colorectale", "limit": 5}'
  ```

  ```python Python theme={null}
  import httpx

  resp = httpx.post(
      "https://core.locusmedical.fr/v1/search",
      headers={"Authorization": f"Bearer {LOCUS_API_KEY}"},
      json={"query": "antibioprophylaxie chirurgie colorectale", "limit": 5},
  )
  resp.raise_for_status()
  print(resp.json()["units"])
  ```

  ```typescript TypeScript theme={null}
  const resp = await fetch("https://core.locusmedical.fr/v1/search", {
    method: "POST",
    headers: {
      Authorization: `Bearer ${process.env.LOCUS_API_KEY}`,
      "Content-Type": "application/json",
    },
    body: JSON.stringify({ query: "antibioprophylaxie chirurgie colorectale", limit: 5 }),
  });
  const { units } = await resp.json();
  ```
</CodeGroup>

Every endpoint returns structured JSON. Explore them all, with a live request
runner, in the **API Reference** tab.

## 2. Try it in the playground

The **API Reference** tab renders each endpoint with an interactive playground.
Click **Authorization**, paste your `lsk_…` key, and run a request without
leaving the docs.

## 3. Connect an MCP client

The same capabilities are exposed as MCP tools over Streamable HTTP at `/mcp`.

```json theme={null}
{
  "mcpServers": {
    "locus": {
      "url": "https://mcp.locusmedical.fr/mcp",
      "headers": { "Authorization": "Bearer ${LOCUS_API_KEY}" }
    }
  }
}
```

See [MCP server](/en/mcp/overview) for the tool catalogue and routing guidance.

## Next steps

<CardGroup cols={2}>
  <Card title="Authentication" icon="key" href="/en/authentication">
    Key format, hashing, rate limits.
  </Card>

  <Card title="Capabilities" icon="layer-group" href="/en/capabilities/overview">
    What each endpoint does and when to use it.
  </Card>
</CardGroup>