Draw Flow MCP Server

🚀 Next AI Draw.io MCP Server

The MCP (Model Context Protocol) server allows AI agents such as Claude Desktop and Cursor to generate and edit draw.io diagrams with a real-time browser preview.

Self-contained - It includes an embedded HTTP server and requires no external dependencies.

🚀 Quick Start

{
  "mcpServers": {
    "drawio": {
      "command": "npx",
      "args": ["@next-ai-drawio/mcp-server@latest"]
    }
  }
}

📦 Installation

Claude Desktop

Add the following to your Claude Desktop config (~/Library/Application Support/Claude/claude_desktop_config.json on macOS):

{
  "mcpServers": {
    "drawio": {
      "command": "npx",
      "args": ["@next-ai-drawio/mcp-server@latest"]
    }
  }
}

VS Code

Add it to your VS Code settings (.vscode/mcp.json in the workspace or user settings):

{
  "mcpServers": {
    "drawio": {
      "command": "npx",
      "args": ["@next-ai-drawio/mcp-server@latest"]
    }
  }
}

Cursor

Add it to the Cursor MCP config (~/.cursor/mcp.json):

{
  "mcpServers": {
    "drawio": {
      "command": "npx",
      "args": ["@next-ai-drawio/mcp-server@latest"]
    }
  }
}

Cline (VS Code Extension)

1. Click the MCP Servers icon in Cline's top menu bar.
2. Select the Configure tab.
3. Click Configure MCP Servers to edit cline_mcp_settings.json.
4. Add the drawio server:

{
  "mcpServers": {
    "drawio": {
      "command": "npx",
      "args": ["@next-ai-drawio/mcp-server@latest"]
    }
  }
}

Claude Code CLI

claude mcp add drawio -- npx @next-ai-drawio/mcp-server@latest

Other MCP Clients

Use the standard MCP configuration with:

• Command: npx
• Args: ["@next-ai-drawio/mcp-server@latest"]

💻 Usage Examples

Basic Usage

1. Restart your MCP client after updating the configuration.
2. Ask the AI to create a diagram:

   "Create a flowchart showing user authentication with login, MFA, and session management"

3. The diagram will appear in your browser in real-time!

✨ Features

• Real-time Preview: Diagrams appear and update in your browser as the AI creates them.
• Version History: Restore previous diagram versions with visual thumbnails - click the clock button (bottom-right) to browse and restore earlier states.
• Natural Language: Describe diagrams in plain text - flowcharts, architecture diagrams, etc.
• Edit Support: Modify existing diagrams with natural language instructions.
• Export: Save diagrams as .drawio files.
• Self-contained: Embedded server, works offline (except the draw.io UI which loads from embed.diagrams.net by default, configurable via DRAWIO_BASE_URL).

📚 Documentation

Available Tools

How It Works

┌─────────────────┐     stdio      ┌─────────────────┐
│  Claude Desktop │ <───────────> │   MCP Server    │
│    (AI Agent)   │               │  (this package) │
└─────────────────┘               └────────┬────────┘
                                          │
                                 ┌────────▼────────┐
                                 │ Embedded HTTP   │
                                 │ Server (:6002)  │
                                 └────────┬────────┘
                                          │
                                 ┌────────▼────────┐
                                 │  User's Browser │
                                 │ (draw.io embed) │
                                 └─────────────────┘

1. The MCP Server receives tool calls from Claude via stdio.
2. The Embedded HTTP Server serves the draw.io UI and handles the state.
3. The Browser shows real-time diagram updates via polling.

Configuration

Private Deployment (Self-hosted draw.io)

For security-sensitive environments that require private deployment of draw.io:

{
  "mcpServers": {
    "drawio": {
      "command": "npx",
      "args": ["@next-ai-drawio/mcp-server@latest"],
      "env": { 
        "DRAWIO_BASE_URL": "https://drawio.your-company.com"
      }
    }
  }
}

You can deploy your own draw.io instance using the official Docker image:

docker run -d -p 8080:8080 jgraph/drawio

Then set DRAWIO_BASE_URL=http://localhost:8080 (or your server's URL).

Troubleshooting

Port already in use

If port 6002 is in use, the server will automatically try the next available port (up to 6020).

Or set a custom port:

{
  "mcpServers": {
    "drawio": {
      "command": "npx",
      "args": ["@next-ai-drawio/mcp-server@latest"],
      "env": { "PORT": "6003" }
    }
  }
}

"No active session"

Call start_session first to open the browser window.

Browser not updating

Check that the browser URL has the ?mcp= query parameter. The MCP session ID connects the browser to the server.

📄 License

Apache-2.0