excalidraw-mcp

An MCP server that turns Claude Code into an Excalidraw diagram generator.

Ask Claude to draw any architecture and it opens instantly in your browser — fully interactive, editable, and exportable.

"Draw the architecture of a web3 voting system."
        ↓
Claude calls draw_architecture_diagram
        ↓
Python computes layout + generates Excalidraw scene
        ↓
Browser opens with the diagram

Install

pip install claude-excalidraw-mcp

Register with Claude Code

claude mcp add excalidraw excalidraw-mcp

excalidraw-mcp here is the console command installed by the package — not a separate pip package.

Restart Claude Code. That's it.

Usage

Just ask Claude naturally:

Draw the architecture of a food delivery app.
Draw a CI/CD pipeline diagram.
Draw a microservices architecture for an e-commerce platform.

Claude generates the nodes and edges, the server handles layout, shapes, and rendering.

Shapes (auto-detected from label)

Override with "shape": "ellipse" in the node definition.

How it works

Claude Code (MCP Client)
        │  stdio / JSON-RPC 2.0
        ▼
excalidraw-mcp server
        │
        ├── Sugiyama layout (longest-path layers + barycenter crossing reduction)
        ├── Smart arrow routing (straight → S-curve only when crossing detected)
        └── Excalidraw scene JSON → local HTML → browser

Requirements

• Python 3.11+
• Claude Code CLI
• Internet (first load only — Excalidraw loads via CDN)

License

MIT