Grasshopper MCP Bridge is a bridging server that connects Grasshopper and Claude Desktop using the Model Context Protocol (MCP) standard.
- Connects Grasshopper and Claude Desktop through the MCP protocol
- Provides intuitive tool functions for creating and connecting Grasshopper components
- Supports high-level intent recognition, automatically creating complex component patterns from simple descriptions
- Includes a component knowledge base that understands parameters and connection rules for common components
- Provides component guidance resources to help Claude Desktop correctly connect components
The system consists of the following parts:
- Grasshopper MCP Component (GH_MCP.gha): A plugin installed in Grasshopper that provides a TCP server to receive commands
- Python MCP Bridge Server: A bridge server that connects Claude Desktop and the Grasshopper MCP component
- Component Knowledge Base: JSON files containing component information, patterns, and intents
- Rhino 7 or higher
- Grasshopper
- Python 3.8 or higher
- Claude Desktop
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Install the Grasshopper MCP Component
Method 1: Download the pre-compiled GH_MCP.gha file (Recommended)
Download the GH_MCP.gha file directly from the GitHub repository and copy it to the Grasshopper components folder:
%APPDATA%\Grasshopper\Libraries\Method 2: Build from source
If you prefer to build from source, clone the repository and build the C# project using Visual Studio.
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Install the Python MCP Bridge Server
Method 1: Install from PyPI (Recommended)
The simplest method is to install directly from PyPI using pip:
pip install grasshopper-mcpMethod 2: Install from GitHub
You can also install the latest version from GitHub:
pip install git+https://github.com/alfredatnycu/grasshopper-mcp.gitMethod 3: Install from Source Code
If you need to modify the code or develop new features, you can clone the repository and install:
git clone https://github.com/alfredatnycu/grasshopper-mcp.git cd grasshopper-mcp pip install -e .Install a Specific Version
If you need to install a specific version, you can use:
pip install grasshopper-mcp==0.1.0Or install from a specific GitHub tag:
pip install git+https://github.com/alfredatnycu/grasshopper-mcp.git@v0.1.0
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Start Rhino and Grasshopper
Launch Rhino and open Grasshopper.
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Add the GH_MCP Component to Your Canvas
Find the GH_MCP component in the Grasshopper component panel and add it to your canvas.
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Start the Python MCP Bridge Server
Open a terminal and run:
python -m grasshopper_mcp.bridgeNote: The command
grasshopper-mcpmight not work directly due to Python script path issues. Usingpython -m grasshopper_mcp.bridgeis the recommended and more reliable method. -
Connect Claude Desktop to the MCP Bridge
Method 1: Manual Connection
In Claude Desktop, connect to the MCP Bridge server using the following settings:
- Protocol: MCP
- Host: localhost
- Port: 8080
Method 2: Configure Claude Desktop to Auto-Start the Bridge
You can configure Claude Desktop to automatically start the MCP Bridge server by modifying its configuration:
"grasshopper": { "command": "python", "args": ["-m", "grasshopper_mcp.bridge"] }
This configuration tells Claude Desktop to use the command
python -m grasshopper_mcp.bridgeto start the MCP server. -
Start Using Grasshopper with Claude Desktop
You can now use Claude Desktop to control Grasshopper through natural language commands.
Here are some example commands you can use with Claude Desktop:
- "Create a circle with radius 5 at point (0,0,0)"
- "Connect the circle to a extrude component with a height of 10"
- "Create a grid of points with 5 rows and 5 columns"
- "Apply a random rotation to all selected objects"
If you encounter issues, check the following:
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GH_MCP Component Not Loading
- Ensure the .gha file is in the correct location
- In Grasshopper, go to File > Preferences > Libraries and click "Unblock" to unblock new components
- Restart Rhino and Grasshopper
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Bridge Server Won't Start
- If
grasshopper-mcpcommand doesn't work, usepython -m grasshopper_mcp.bridgeinstead - Ensure all required Python dependencies are installed
- Check if port 8080 is already in use by another application
- If
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Claude Desktop Can't Connect
- Ensure the bridge server is running
- Verify you're using the correct connection settings (localhost:8080)
- Check the console output of the bridge server for any error messages
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Commands Not Executing
- Verify the GH_MCP component is on your Grasshopper canvas
- Check the bridge server console for error messages
- Ensure Claude Desktop is properly connected to the bridge server
grasshopper-mcp/
├── grasshopper_mcp/ # Python bridge server
│ ├── __init__.py
│ └── bridge.py # Main bridge server implementation
├── GH_MCP/ # Grasshopper component (C#)
│ └── ...
├── releases/ # Pre-compiled binaries
│ └── GH_MCP.gha # Compiled Grasshopper component
├── setup.py # Python package setup
└── README.md # This file
Contributions are welcome! Please feel free to submit a Pull Request.
This project is licensed under the MIT License - see the LICENSE file for details.
- Thanks to the Rhino and Grasshopper community for their excellent tools
- Thanks to Anthropic for Claude Desktop and the MCP protocol
For questions or support, please open an issue on the GitHub repository.