Draw Flow MCP Server

Next AI Draw.io MCP Server

MCP (Model Context Protocol) server that enables AI agents like Claude Desktop and Cursor to generate and edit draw.io diagrams with real-time browser preview.

Self-contained - includes an embedded HTTP server, no external dependencies required.

Quick Start

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

Installation

Claude Desktop

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

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

Cursor

Add to 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

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

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

3. The diagram appears 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 draw.io UI which loads from embed.diagrams.net by default, configurable via DRAWIO_BASE_URL)

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. MCP Server receives tool calls from Claude via stdio
2. Embedded HTTP Server serves the draw.io UI and handles state
3. 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