# MCP Setup

> How to connect Claude Desktop or other MCP clients to the Braking Lab Race Engineer.

The Race Engineer connects through the **Model Context Protocol (MCP)** using Streamable HTTP transport with OAuth 2.0 authentication. Setup takes less than 5 minutes.

## Claude Desktop

The recommended client is Claude Desktop, which supports MCP natively.

### Step 1: Open Configuration

In Claude Desktop, go to **Settings > Developer > Edit Config** to open `claude_desktop_config.json`.

### Step 2: Add the Server

Add the following to your configuration:

```json
{
  "mcpServers": {
    "braking-lab": {
      "url": "https://mcp.brakinglab.com/mcp"
    }
  }
}
```

### Step 3: Authenticate

1. Save the config and restart Claude Desktop
2. Claude will detect the Race Engineer tools automatically
3. On first use, a browser window opens for authentication
4. Log in with your Braking Lab account (email/password, Google, or GitHub)
5. Once authenticated, the connection is established

That's it. You can now ask Claude about your telemetry data, request coaching reports, or prepare for races.

### How Authentication Works

Claude Desktop discovers the OAuth endpoints automatically through standard discovery protocols (RFC 9728 and RFC 8414). You don't need to manage tokens or API keys — the client handles everything.

## Cursor

Cursor has built-in MCP support:

1. Open **Settings > MCP**
2. Add a new server with URL: `https://mcp.brakinglab.com/mcp`
3. Save and authenticate when prompted

## Windsurf

Windsurf supports MCP connections:

1. Open the MCP configuration in settings
2. Add the server URL: `https://mcp.brakinglab.com/mcp`
3. Authenticate through the browser when prompted

## Other MCP Clients

Any client that supports **MCP Streamable HTTP transport** and **OAuth 2.0 with PKCE** can connect. The server URL is:

```
https://mcp.brakinglab.com/mcp
```

The server publishes standard discovery endpoints:

- `/.well-known/oauth-protected-resource` — Resource metadata (RFC 9728)
- `/.well-known/oauth-authorization-server` — Authorization server metadata (RFC 8414)

Your client should handle the OAuth flow automatically if it supports these standards.

## OAuth Flow (Technical Reference)

For developers building custom clients, here's the full authentication flow:

```
1. Client → POST /mcp (no token)
   ← 401 + WWW-Authenticate header with resource_metadata URL

2. Client → GET /.well-known/oauth-protected-resource
   ← Returns authorization_servers URL

3. Client → GET /.well-known/oauth-authorization-server
   ← Returns authorization_endpoint, token_endpoint, registration_endpoint

4. Client → POST /oauth/register (dynamic client registration)
   ← Returns client_id and client_secret

5. Client → GET /oauth/authorize (with PKCE code_challenge)
   → Opens browser: user logs in via Supabase auth
   ← Returns authorization code

6. Client → POST /oauth/token (code + code_verifier exchange)
   ← Returns access_token + refresh_token

7. Client → POST /mcp (with Bearer access_token)
   ← MCP response with tool results
```

The access token is a JWT that identifies the user. The refresh token allows silent re-authentication when the access token expires.

## Troubleshooting

### "Connection Failed" or Timeout

- Verify the URL is exactly `https://mcp.brakinglab.com/mcp`
- Check your internet connection
- Restart the MCP client

### Authentication Keeps Asking to Log In

- Clear the client's stored tokens and authenticate again
- Verify your Braking Lab account is active
- Check that browser pop-ups are not blocked

### Tools Not Appearing

- Restart the MCP client after saving the configuration
- Check the client's MCP logs for connection errors
- Verify the server URL doesn't have a trailing slash

## Next Steps

- [Available Tools](/en/docs/race-engineer/tools) — See what the Race Engineer can do
- [Coaching](/en/docs/race-engineer/coaching) — Get AI analysis of your driving