Content
# MCP Excalidraw Server: Advanced Live Visual Diagramming with AI Integration
A comprehensive **TypeScript-based** system that combines **Excalidraw's powerful drawing capabilities** with **Model Context Protocol (MCP)** integration, enabling AI agents to create and manipulate diagrams in real-time on a live canvas.
## 🚦 Current Status & Version Information
> **📋 Choose Your Installation Method**
| Version | Status | Recommended For |
|---------|--------|----------------|
| **Local Development** | ✅ **FULLY TESTED** | **🎯 RECOMMENDED** |
| **NPM Published** | 🔧 **DEBUGGING IN PROGRESS** | Development testing |
| **Docker Version** | 🔧 **UNDER DEVELOPMENT** | Future deployment |
### **Current Recommendation: Local Development**
For the most stable experience, we recommend using the local development setup. We're actively working on improving the NPM package and Docker deployment options.
### **Development Notes**
- **NPM Package**: Currently debugging MCP tool registration issues
- **Docker Version**: Improving canvas synchronization reliability
- **Local Version**: ✅ All features fully functional
## 🚀 What This System Does
- **🎨 Live Canvas**: Real-time Excalidraw canvas accessible via web browser
- **🤖 AI Integration**: MCP server allows AI agents (like Claude) to create visual diagrams
- **⚡ Real-time Sync**: Elements created via MCP API appear instantly on the canvas
- **🔄 WebSocket Updates**: Live synchronization across multiple connected clients
- **🏗️ Production Ready**: Clean, minimal UI suitable for end users
## 🎥 Demo Video
> **See MCP Excalidraw in Action!**
[](https://youtu.be/RRN7AF7QIew)
*Watch how AI agents create and manipulate diagrams in real-time on the live canvas*
## 🏛️ Architecture Overview
```
┌─────────────────┐ ┌──────────────────┐ ┌─────────────────┐
│ AI Agent │───▶│ MCP Server │───▶│ Canvas Server │
│ (Claude) │ │ (src/index.js) │ │ (src/server.js) │
└─────────────────┘ └──────────────────┘ └─────────────────┘
│
▼
┌─────────────────┐
│ Frontend │
│ (React + WS) │
└─────────────────┘
```
## 🌟 Key Features
### **Modern TypeScript Architecture**
- **Full TypeScript Migration**: Complete type safety for backend and frontend
- **Comprehensive Type Definitions**: Excalidraw elements, API responses, WebSocket messages
- **Strict Type Checking**: Enhanced development experience and compile-time error detection
- **Type-Safe React Components**: TSX components with proper props typing
### **Real-time Canvas Integration**
- Elements created via MCP appear instantly on the live canvas
- WebSocket-based real-time synchronization
- Multi-client support with live updates
### **Production-Ready Interface**
- Clean, minimal UI with connection status
- Simple "Clear Canvas" functionality
- No development clutter or debug information
### **Comprehensive MCP API**
- **Element Creation**: rectangles, ellipses, diamonds, arrows, text, lines
- **Element Management**: update, delete, query with filters
- **Batch Operations**: create multiple elements in one call
- **Advanced Features**: grouping, alignment, distribution, locking
### **Robust Architecture**
- TypeScript-based Express.js backend with REST API + WebSocket
- React frontend with official Excalidraw package and TypeScript
- Dual-path element loading for reliability
- Auto-reconnection and error handling
## 📦 Installation & Setup
### **✅ Recommended: Local Development Setup**
> **Most stable and feature-complete option**
#### **1. Clone the Repository**
```bash
git clone https://github.com/yctimlin/mcp_excalidraw.git
cd mcp_excalidraw
npm install
```
#### **2. Build the Frontend**
```bash
npm run build
```
#### **3. Start the System**
##### **Option A: Production Mode (Recommended)**
```bash
# Start canvas server (serves frontend + API)
npm run canvas
```
##### **Option B: Development Mode**
```bash
# Start both canvas server and Vite dev server
npm run dev
```
#### **4. Access the Canvas**
Open your browser and navigate to:
```
http://localhost:3000
```
### **🔧 Alternative Installation Methods (In Development)**
#### **NPM Package (Beta)**
```bash
# Currently debugging tool registration - feedback welcome!
npm install -g mcp-excalidraw-server
npx mcp-excalidraw-server
```
#### **Docker Version (Coming Soon)**
```bash
# Canvas sync improvements in progress
docker run -p 3000:3000 mcp-excalidraw-server
```
## 🔧 Available Scripts
| Script | Description |
|--------|-------------|
| `npm start` | Build and start MCP server (`dist/index.js`) |
| `npm run canvas` | Build and start canvas server (`dist/server.js`) |
| `npm run build` | Build both frontend and TypeScript backend |
| `npm run build:frontend` | Build React frontend only |
| `npm run build:server` | Compile TypeScript backend to JavaScript |
| `npm run dev` | Start TypeScript watch mode + Vite dev server |
| `npm run type-check` | Run TypeScript type checking without compilation |
| `npm run production` | Build + start in production mode |
## 🎯 Usage Guide
### **For End Users**
1. Open the canvas at `http://localhost:3000`
2. Check connection status (should show "Connected")
3. AI agents can now create diagrams that appear in real-time
4. Use "Clear Canvas" to remove all elements
### **For AI Agents (via MCP)**
The MCP server provides these tools for creating visual diagrams:
#### **Basic Element Creation**
```javascript
// Create a rectangle
{
"type": "rectangle",
"x": 100,
"y": 100,
"width": 200,
"height": 100,
"backgroundColor": "#e3f2fd",
"strokeColor": "#1976d2",
"strokeWidth": 2
}
```
#### **Create Text Elements**
```javascript
{
"type": "text",
"x": 150,
"y": 125,
"text": "Process Step",
"fontSize": 16,
"strokeColor": "#333333"
}
```
#### **Create Arrows & Lines**
```javascript
{
"type": "arrow",
"x": 300,
"y": 130,
"width": 100,
"height": 0,
"strokeColor": "#666666",
"strokeWidth": 2
}
```
#### **Batch Creation for Complex Diagrams**
```javascript
{
"elements": [
{
"type": "rectangle",
"x": 100,
"y": 100,
"width": 120,
"height": 60,
"backgroundColor": "#fff3e0",
"strokeColor": "#ff9800"
},
{
"type": "text",
"x": 130,
"y": 125,
"text": "Start",
"fontSize": 16
}
]
}
```
## 🔌 Integration with Claude Desktop
### **✅ Recommended: Using Local Installation**
For the **local development version** (most stable), add this configuration to your `claude_desktop_config.json`:
```json
{
"mcpServers": {
"excalidraw": {
"command": "node",
"args": ["/absolute/path/to/mcp_excalidraw/dist/index.js"]
}
}
}
```
**Important**: Replace `/absolute/path/to/mcp_excalidraw` with the actual absolute path to your cloned repository. Note that the path now points to `dist/index.js` (the compiled TypeScript output).
### **🔧 Alternative Configurations (Beta)**
#### **NPM Package (Beta Testing)**
```json
{
"mcpServers": {
"excalidraw": {
"command": "npx",
"args": ["-y", "mcp-excalidraw-server"]
}
}
}
```
*Currently debugging tool registration - let us know if you encounter issues!*
#### **Docker Version (Coming Soon)**
```json
{
"mcpServers": {
"excalidraw": {
"command": "docker",
"args": ["run", "-i", "--rm", "mcp-excalidraw-server"]
}
}
}
```
*Canvas sync improvements in progress.*
## 🔧 Integration with Other Tools
### **Cursor IDE**
Add to your `.cursor/mcp.json`:
```json
{
"mcpServers": {
"excalidraw": {
"command": "node",
"args": ["/absolute/path/to/mcp_excalidraw/dist/index.js"]
}
}
}
```
### **VS Code MCP Extension**
For VS Code MCP extension, add to your settings:
```json
{
"mcp": {
"servers": {
"excalidraw": {
"command": "node",
"args": ["/absolute/path/to/mcp_excalidraw/dist/index.js"]
}
}
}
}
```
## 🛠️ Environment Variables
| Variable | Default | Description |
|----------|---------|-------------|
| `EXPRESS_SERVER_URL` | `http://localhost:3000` | Canvas server URL for MCP sync |
| `ENABLE_CANVAS_SYNC` | `true` | Enable/disable canvas synchronization |
| `DEBUG` | `false` | Enable debug logging |
| `PORT` | `3000` | Canvas server port |
| `HOST` | `localhost` | Canvas server host |
## 📊 API Endpoints
The canvas server provides these REST endpoints:
| Method | Endpoint | Description |
|--------|----------|-------------|
| `GET` | `/api/elements` | Get all elements |
| `POST` | `/api/elements` | Create new element |
| `PUT` | `/api/elements/:id` | Update element |
| `DELETE` | `/api/elements/:id` | Delete element |
| `POST` | `/api/elements/batch` | Create multiple elements |
| `GET` | `/health` | Server health check |
## 🎨 MCP Tools Available
### **Element Management**
- `create_element` - Create any type of Excalidraw element
- `update_element` - Modify existing elements
- `delete_element` - Remove elements
- `query_elements` - Search elements with filters
### **Batch Operations**
- `batch_create_elements` - Create complex diagrams in one call
### **Element Organization**
- `group_elements` - Group multiple elements
- `ungroup_elements` - Ungroup element groups
- `align_elements` - Align elements (left, center, right, top, middle, bottom)
- `distribute_elements` - Distribute elements evenly
- `lock_elements` / `unlock_elements` - Lock/unlock elements
### **Resource Access**
- `get_resource` - Access scene, library, theme, or elements data
## 🏗️ Development Architecture
### **Frontend** (`frontend/src/`)
- **React + TypeScript**: Modern TSX components with full type safety
- **Vite Build System**: Fast development and optimized production builds
- **Official Excalidraw**: `@excalidraw/excalidraw` package with TypeScript types
- **WebSocket Client**: Type-safe real-time element synchronization
- **Clean UI**: Production-ready interface with proper TypeScript typing
### **Canvas Server** (`src/server.ts` → `dist/server.js`)
- **TypeScript + Express.js**: Fully typed REST API + static file serving
- **WebSocket**: Type-safe real-time client communication
- **Element Storage**: In-memory with comprehensive type definitions
- **CORS**: Cross-origin support with proper typing
### **MCP Server** (`src/index.ts` → `dist/index.js`)
- **TypeScript MCP Protocol**: Type-safe Model Context Protocol implementation
- **Canvas Sync**: Strongly typed HTTP requests to canvas server
- **Element Management**: Full CRUD operations with comprehensive type checking
- **Batch Support**: Type-safe complex diagram creation
### **Type System** (`src/types.ts`)
- **Excalidraw Element Types**: Complete type definitions for all element types
- **API Response Types**: Strongly typed REST API interfaces
- **WebSocket Message Types**: Type-safe real-time communication
- **Server Element Types**: Enhanced element types with metadata
## 🐛 Troubleshooting
### **NPM Package Issues**
- **Symptoms**: MCP tools not registering properly
- **Temporary Solution**: Use local development setup
- **Status**: Actively debugging - updates coming soon
### **Docker Version Notes**
- **Symptoms**: Elements may not sync to canvas immediately
- **Temporary Solution**: Use local development setup
- **Status**: Improving synchronization reliability
### **Canvas Not Loading**
- Ensure `npm run build` completed successfully
- Check that `dist/index.html` exists
- Verify canvas server is running on port 3000
### **Elements Not Syncing**
- Confirm MCP server is running (`npm start`)
- Check `ENABLE_CANVAS_SYNC=true` in environment
- Verify canvas server is accessible at `EXPRESS_SERVER_URL`
### **WebSocket Connection Issues**
- Check browser console for WebSocket errors
- Ensure no firewall blocking WebSocket connections
- Try refreshing the browser page
### **Build Errors**
- Delete `node_modules` and run `npm install`
- Check Node.js version (requires 16+)
- Ensure all dependencies are installed
- Run `npm run type-check` to identify TypeScript issues
- Verify `dist/` directory is created after `npm run build:server`
## 📋 Project Structure
```
mcp_excalidraw/
├── frontend/
│ ├── src/
│ │ ├── App.tsx # Main React component (TypeScript)
│ │ └── main.tsx # React entry point (TypeScript)
│ └── index.html # HTML template
├── src/ (TypeScript Source)
│ ├── index.ts # MCP server (TypeScript)
│ ├── server.ts # Canvas server (Express + WebSocket, TypeScript)
│ ├── types.ts # Comprehensive type definitions
│ └── utils/
│ └── logger.ts # Logging utility (TypeScript)
├── dist/ (Compiled Output)
│ ├── index.js # Compiled MCP server
│ ├── server.js # Compiled Canvas server
│ ├── types.js # Compiled type definitions
│ ├── utils/
│ │ └── logger.js # Compiled logging utility
│ └── frontend/ # Built React frontend
├── tsconfig.json # TypeScript configuration
├── vite.config.js # Vite build configuration
├── package.json # Dependencies and scripts
└── README.md # This file
```
## 🔮 Development Roadmap
- ✅ **TypeScript Migration**: Complete type safety for enhanced development experience
- **NPM Package**: Resolving MCP tool registration issues
- **Docker Deployment**: Improving canvas synchronization
- **Enhanced Features**: Additional MCP tools and capabilities
- **Performance Optimization**: Real-time sync improvements
- **Advanced TypeScript Features**: Stricter type checking and advanced type utilities
## 🤝 Contributing
We welcome contributions! If you're experiencing issues with the NPM package or Docker version, please:
1. Fork the repository
2. Create a feature branch (`git checkout -b feature/amazing-feature`)
3. Commit your changes (`git commit -m 'Add amazing feature'`)
4. Push to the branch (`git push origin feature/amazing-feature`)
5. Open a Pull Request
## 📝 License
This project is licensed under the MIT License - see the [LICENSE](LICENSE) file for details.
## 🙏 Acknowledgments
- **Excalidraw Team** - For the amazing drawing library
- **MCP Community** - For the Model Context Protocol specification
