d2-mcp

MCP server for the D2 diagram language. Compile, validate, and explore D2 diagrams from any MCP-compatible AI assistant.

Uses the official @terrastruct/d2 WASM package — no CLI binary needed.

Tools

Tool	Description
`compile`	D2 source code → SVG. Supports layout engines, themes, sketch mode, dark themes, multi-board targeting, and more.
`validate`	Check D2 syntax without rendering. Returns validity status and error details.
`list_themes`	List all available D2 themes with IDs (light and dark).
`list_layouts`	List available layout engines (`dagre`, `elk`).
`list_icons`	Browse icons from icons.terrastruct.com by category (AWS, GCP, Azure, K8s, dev, essentials, tech).

Resource	Description
`d2://syntax-reference`	Complete D2 language syntax reference in markdown.

npm install
npm run build
npm start

The server starts on port 3000 by default (override with PORT env var).

This project includes a Dockerfile and render.yaml blueprint for one-click deployment to Render.

Or manually create a Web Service with:

Once deployed, configure your MCP client to connect via Streamable HTTP:

{
  "mcpServers": {
    "d2": {
      "url": "https://your-service.onrender.com/mcp"
    }
  }
}

Replace the URL with your actual Render service URL (or http://localhost:3000/mcp for local).

Parameter	Type	Description
`code`	string	D2 source code (required)
`layout`	`"dagre"` \| `"elk"`	Layout engine (default: dagre)
`sketch`	boolean	Hand-drawn sketch mode
`themeID`	integer	Theme ID (see `list_themes`)
`darkThemeID`	integer	Dark mode theme ID
`pad`	integer	Padding in pixels (default: 100)
`center`	boolean	Center SVG in viewbox
`scale`	number	Scale factor (default: fit to screen)
`target`	string	Target board for multi-board diagrams
`animateInterval`	integer	Animation interval (ms) for multi-board SVGs
`noXMLTag`	boolean	Omit XML declaration for HTML embedding

MIT