Draw.io MCP Server

A Model Context Protocol (MCP) server that enables Claude to create and manipulate Draw.io diagrams directly through conversation.

Features

• Create new Draw.io diagram files
• Add various shapes (rectangles, ellipses, rhombus, cylinders, hexagons, clouds, etc.)
• Add connectors/arrows between shapes
• Multi-line text support - Use \n for line breaks in shape labels (great for class diagrams)
• Customize colors, positions, and sizes
• List and read existing diagrams
• Intelligent path resolution (supports relative, absolute, and ~ paths)
• Automatic path translation for cross-platform compatibility

Installation

1. Clone this repository:

git clone <repository-url>
cd draw-io-mcp

2. Install dependencies:

npm install

3. Build the project:

npm run build

Configuration for Claude Desktop

To use this MCP server with Claude Desktop, add the following configuration to your Claude Desktop config file:

macOS

Edit: ~/Library/Application Support/Claude/claude_desktop_config.json

Windows

Edit: %APPDATA%\Claude\claude_desktop_config.json

Add the following configuration:

{
  "mcpServers": {
    "draw-io": {
      "command": "node",
      "args": ["/absolute/path/to/draw-io-mcp/dist/index.js"]
    }
  }
}

Replace /absolute/path/to/draw-io-mcp with the actual path to this project directory.

After adding the configuration, restart Claude Desktop.

Configuration for Claude Code

To use this MCP server with Claude Code (the CLI), add it via the claude mcp add command or by editing the config file directly.

Option 1: CLI (recommended)

claude mcp add draw-io node /absolute/path/to/draw-io-mcp/dist/index.js

Replace /absolute/path/to/draw-io-mcp with the actual path to this project directory.

Option 2: Edit the config file directly

Claude Code stores MCP configuration in ~/.claude/mcp.json (global) or .claude/mcp.json inside a project (project-scoped). Add the following entry:

{
  "mcpServers": {
    "draw-io": {
      "command": "node",
      "args": ["/absolute/path/to/draw-io-mcp/dist/index.js"]
    }
  }
}

Verify the server is running

After adding the configuration, start or restart Claude Code and run:

claude mcp list

You should see draw-io listed as a connected server. You can also run:

claude mcp get draw-io

to inspect its status and the tools it exposes.

Scope options

Claude Code supports three configuration scopes:

Scope	Flag	Config location	When to use
Local (project-only)	--scope local	.claude/mcp.json in project	Diagrams for a specific repo
User (global)	--scope user	~/.claude/mcp.json	Available in all your projects
Project (shared)	--scope project	.mcp.json in project root	Shared with teammates via git

Example to add with a specific scope:

claude mcp add --scope user draw-io node /absolute/path/to/draw-io-mcp/dist/index.js

Usage Examples

Once configured, you can ask Claude to create diagrams:

Example 1: Simple Flowchart

Create a flowchart at ./flowchart.drawio with:
1. A "Start" rectangle at (100, 50)
2. A "Process Data" rectangle at (100, 150)
3. A "Decision" rhombus at (100, 250)
4. Connect them with arrows

Example 2: Architecture Diagram

Create a system architecture diagram at ./architecture.drawio showing:
- A cloud shape for "Cloud Services"
- A cylinder for "Database"
- Rectangles for different services
- Connect them appropriately

Example 3: Class Diagram with Multi-line Text

Create a class diagram for a Vehicle hierarchy with:
- A Vehicle class with attributes (brand, model) and methods (start, stop)
- A Car subclass with numDoors attribute
- A Motorcycle subclass with engineCC attribute
Use \n for line breaks to separate class name, attributes, and methods

The \n in shape text creates proper line breaks, so text like:

Vehicle\n---\n- brand: String\n+ start(): void

Renders as:

Vehicle
---
- brand: String
+ start(): void

Available Tools

The MCP server provides the following tools:

1. create_diagram - Create a new Draw.io diagram file
2. add_shape - Add shapes (rectangle, ellipse, rhombus, cylinder, hexagon, cloud, step, parallelogram, trapezoid, triangle). Supports multi-line text with \n
3. add_connector - Add connectors between shapes with different styles (straight, curved, orthogonal)
4. read_diagram - Read the raw XML content of a diagram
5. list_shapes - List all shapes in a diagram with their properties

Path Handling

All diagrams are saved to your Desktop by default to make it easy to find them. The server intelligently handles file paths across different platforms:

Default Behavior

• Simple filenames: diagram.drawio → Saved to your Desktop
• Relative paths: ./flowchart.drawio → Saved to your Desktop (subdirectories ignored)
• Claude-suggested paths: /home/claude/test.drawio → Saved to your Desktop

This makes it crystal clear where your files are - they're always on YOUR computer's Desktop, not on any remote machine.

Supported Path Formats

• Desktop (default): diagram.drawio

  • Saved to ~/Desktop/diagram.drawio

• Absolute paths: /Users/username/Documents/diagram.drawio

  • Used as-is (validated for safety)
  • Lets you save to specific locations if needed

• Home directory subdirectories: ~/Documents/diagram.drawio

  • Expands ~ and saves to the specified location
  • Useful for organizing diagrams in specific folders

Automatic Path Translation

When Claude Desktop suggests paths like /home/claude/diagram.drawio, the server automatically translates them to your Desktop:

• /home/claude/diagram.drawio → ~/Desktop/diagram.drawio
• /home/claude/subfolder/test.drawio → ~/Desktop/test.drawio

This ensures you always know where your files are saved.

Safety Features

The server prevents file creation in system directories (/usr, /bin, /etc, etc.) to protect your system.

Development

Build

npm run build

Watch Mode

npm run watch

File Format

Draw.io files (.drawio) are XML-based files that can be opened with:

• Draw.io web app (https://app.diagrams.net)
• Draw.io desktop application
• VS Code with Draw.io extension

License

MIT