MCP Server for Open Brush

This MCP (Model Context Protocol) server exposes the Open Brush API as tools usable by LLMs via the MCP protocol.

📋 Prerequisites

• Python 3.10 or higher
• Open Brush running with API enabled (port 40074)
• Access to an MCP client (like Claude Desktop)

🚀 Installation

1. Clone or download the files

2. Install Python dependencies

pip install -r requirements.txt

3. Make the script executable (optional on Linux/Mac)

chmod +x openbrush_mcp_server.py

⚙️ Configuration

Enable API in Open Brush

1. Launch Open Brush
2. Enable HTTP API in settings
3. API should be accessible at http://localhost:40074/api/v1

Configure in Claude Desktop

Add this configuration to your Claude Desktop MCP configuration file:

On macOS: ~/Library/Application Support/Claude/claude_desktop_config.json

On Windows: %APPDATA%\Claude\claude_desktop_config.json

{
  "mcpServers": {
    "openbrush": {
      "command": "python",
      "args": [
        "/path/to/openbrush_mcp_server.py"
      ]
    }
  }
}

Replace /path/to/ with the absolute path to the file.

📚 Available Tools

The server exposes many tools organized by category:

🎨 Drawing

• draw_paths - Draw multiple paths
• draw_path - Draw a simple path using comma-separated XYZ triplets (e.g. [0,0,0],[0,1,0],[1,1,0], not SVG)
• draw_stroke - Draw a stroke with orientation and pressure
• draw_polygon - Draw a polygon
• draw_text - Draw text
• draw_svg_path - Draw an SVG path

🖌️ Brush

• brush_set_type - Change brush type
• brush_set_size - Set brush size
• brush_add_size - Modify brush size
• brush_set_path_smoothing - Set smoothing
• brush_move - Move brush (absolute position)
• brush_translate - Move brush (relative)
• brush_rotate - Rotate brush (absolute)
• brush_turn - Rotate brush (relative)
• brush_draw - Draw a straight line

🎨 Color

• color_set_rgb - Set color in RGB
• color_set_hsv - Set color in HSV
• color_set_html - Set color with HTML/CSS
• color_add_rgb - Modify color (RGB)
• color_add_hsv - Modify color (HSV)

🧊 3D Models

• model_import - Import local model
• model_web_import - Import from URL
• model_icosa_import - Import from Icosa Gallery
• model_select - Select model
• model_position - Position model
• model_rotation - Rotate model
• model_scale - Scale model
• model_delete - Delete model

💾 Save/Load

• save_overwrite - Save (overwrite)
• save_as - Save as...
• save_new - New save
• load_user - Load user sketch
• load_named - Load by name
• new_scene - New scene

📷 Camera

• camera_move - Move camera (absolute)
• camera_translate - Move camera (relative)
• camera_rotate - Rotate camera (absolute)
• camera_turn - Rotate camera (relative)
• spectator_move - Move spectator view

✂️ Selection

• selection_select_all - Select all
• selection_invert - Invert selection
• selection_delete - Delete selection
• selection_duplicate - Duplicate selection

📑 Layers

• layer_create - Create layer
• layer_set - Set active layer
• layer_show - Show layer
• layer_hide - Hide layer

📐 Guides

• guide_add - Add guide (cube, sphere, etc.)
• guide_position - Position guide
• guide_scale - Scale guide

🔄 Symmetry

• symmetry_mode - Symmetry mode
• symmetry_position - Symmetry widget position

🔧 Utilities

• undo - Undo
• redo - Redo
• show_help - Show API help

💡 Usage Examples

Once the server is configured in Claude Desktop, you can give natural language instructions:

"Draw a red square of size 2 at position 0,0,0"
"Change brush to 'ink' and set color to blue"
"Create a 6-sided polygon with radius 3"
"Import the model 'Andy.glb' and position it at 1,2,3"
"Save the scene as 'my_creation'"

🔍 Testing the Server

To manually test the server:

python openbrush_mcp_server.py

The server should start and wait for commands on stdin/stdout according to the MCP protocol.

🛠️ Troubleshooting

Open Brush API not accessible

• Check that Open Brush is running
• Check that HTTP API is enabled in settings
• Test manually: http://localhost:40074/api/v1?help

MCP server not connecting

• Check the path in Claude Desktop configuration
• Check that Python is in PATH
• Check Claude Desktop logs

Commands failing

• Check provided parameters
• Check Open Brush API documentation
• Check returned error messages

📖 Resources

• Open Brush Documentation
• Model Context Protocol (MCP)
• Complete Open Brush API (when Open Brush is running)

🔒 Security

⚠️ Warning: This server calls a local API. Make sure to:

• Not expose port 40074 on the internet
• Trust sent commands
• Backup your creations regularly

📝 License

This MCP server is provided as-is to facilitate Open Brush usage with LLMs.

🤝 Contribution

Feel free to:

• Report bugs
• Suggest improvements
• Add new tools for missing API commands

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Note: Open Brush is an open-source fork of Google's Tilt Brush. This MCP server is not officially affiliated with Open Brush.