Connect Nucleus to Cursor

Cursor supports MCP servers via stdio (local) or Streamable HTTP (remote). Two config locations: global and per-project.

Option 1: Settings UI (easiest)

1. Open Cursor → Settings → Tools & MCP
2. Click "Add new MCP server"
3. Name: nucleus
4. Type: streamableHttp
5. URL: https://relay.nucleusos.dev/mcp-readonly
6. Click Install → restart Cursor

Option 2: JSON config (global)

Edit ~/.cursor/mcp.json:

{
  "mcpServers": {
    "nucleus": {
      "url": "https://relay.nucleusos.dev/mcp-readonly",
      "type": "streamableHttp"
    }
  }
}

Option 3: JSON config (per-project)

Create .cursor/mcp.json in your project root:

{
  "mcpServers": {
    "nucleus": {
      "url": "https://relay.nucleusos.dev/mcp-readonly",
      "type": "streamableHttp"
    }
  }
}

Option 4: Local stdio server

{
  "mcpServers": {
    "nucleus": {
      "command": "python3",
      "args": ["-m", "mcp_server_nucleus"],
      "env": {
        "NUCLEAR_BRAIN_PATH": "/path/to/.brain"
      }
    }
  }
}

With OAuth (full server)

{
  "mcpServers": {
    "nucleus": {
      "url": "https://relay.nucleusos.dev/mcp",
      "type": "streamableHttp",
      "headers": {
        "Authorization": "Bearer your-token"
      }
    }
  }
}

Verify

Restart Cursor completely. Open a new session and ask: Search my engrams for "architecture". If connected, you'll get results from your Nucleus brain.

Support: hello@nucleusos.dev · GitHub