tacit-mcp

MCP server that connects AI assistants to Tacit building digital twins. Ask questions about your buildings, equipment, sensors, and zones in natural language.

Works with Claude Desktop, Claude Code, Cursor, Windsurf, and any MCP-compatible client.

What it does

Four read-only tools:

Tool	Purpose
`tacit_list_sites`	List buildings your API key can access
`tacit_graphql`	Query the building knowledge graph (Brick-compliant)
`tacit_timeseries`	Fetch historical sensor data
`tacit_list_files`	List documents and files for a site

The GraphQL tool includes the full schema reference, so the AI model can compose queries without needing separate documentation.

Quick start

git clone https://github.com/ucl-sbde/tacit-mcp.git
cd tacit-mcp
npm install
npm run build

You'll need a Tacit API key. Get one from your dashboard at app.betacit.com under Site Settings > API Keys.

Claude Desktop

Edit ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or %APPDATA%\Claude\claude_desktop_config.json (Windows):

{
  "mcpServers": {
    "tacit": {
      "command": "node",
      "args": ["/path/to/tacit-mcp/dist/index.js"],
      "env": {
        "TACIT_API_KEY": "your-api-key"
      }
    }
  }
}

Claude Code

Add to .mcp.json in your project:

{
  "mcpServers": {
    "tacit": {
      "command": "node",
      "args": ["/path/to/tacit-mcp/dist/index.js"],
      "env": {
        "TACIT_API_KEY": "your-api-key"
      }
    }
  }
}

Cursor

Add to .cursor/mcp.json:

{
  "mcpServers": {
    "tacit": {
      "command": "node",
      "args": ["/path/to/tacit-mcp/dist/index.js"],
      "env": {
        "TACIT_API_KEY": "your-api-key"
      }
    }
  }
}

Try it

Once connected, ask your AI assistant things like:

"List all my building sites"
"What AHUs are in Tower West?"
"Show me temperature sensors on AHU-001"
"Get the last 24 hours of supply air temperature data"
"What equipment feeds the lobby zone?"

Environment variables

Variable	Required	Default	Description
`TACIT_API_KEY`	Yes		Your Tacit API key
`TACIT_API_URL`	No	`https://api.tacit.dev`	API base URL (for self-hosted deployments)

Development

npm run dev     # watch mode with tsx
npm run build   # compile TypeScript
npm start       # run compiled output

License

MIT

Tacit MCP