Control FreeCAD from Claude Desktop with This MCP Server

Ever wanted to automate 3D modeling tasks directly from your chat interface? A new open source project called freecad-mcp lets you do exactly that. It’s an MCP (Model Context Protocol) server that bridges Claude Desktop (or any MCP client) with FreeCAD, the popular open source parametric CAD tool.

Instead of manually clicking and dragging in FreeCAD, you can now describe a shape or operation to Claude, and it will generate the FreeCAD Python code to create it for you. Think of it as having a CAD assistant that follows natural language instructions.

What It Does

freecad-mcp exposes FreeCAD’s modeling capabilities through the MCP protocol. It listens for requests from an MCP client (like Claude Desktop) and executes FreeCAD Python scripts. The server can:

• Create 3D primitives like boxes, cylinders, spheres, and cones
• Apply boolean operations (union, cut, intersect)
• Extrude, revolve, sweep, and loft shapes
• Modify existing objects (fillet, chamfer, mirror, pattern)
• Control document and object properties

The interaction is simple: you type a request like “create a cylinder with radius 5mm and height 20mm” into Claude Desktop, and the server runs the corresponding FreeCAD commands. The result appears directly in your FreeCAD document.

Why It’s Cool

Integration with existing workflows. You don’t need a new GUI or custom plugin. If you already use FreeCAD and Claude Desktop, this just works. The MCP protocol is standard, so it could also connect to other AI agents or automation tools.

Removes boilerplate. FreeCAD’s Python API is powerful but verbose. Want a box with filleted edges? Instead of writing 20 lines of scripting, you can just describe it. The server handles the low-level FreeCAD calls.

Ready for experimentation. The repo is MIT licensed, so you can fork it, tweak the server, or extend it with new tools. The code is straightforward Python with minimal dependencies.

Great for parametric exploration. You can ask Claude to generate multiple variations quickly, or combine it with natural language iteration. “Make the base wider, then add a hole through the center” becomes a real chat command.

How to Try It

The repo has clear setup instructions. You’ll need:

• FreeCAD installed (any recent stable version)
• Python 3.10+
• A MCP client like Claude Desktop

Basic steps:

1. Clone the repo:

   git clone https://github.com/neka-nat/freecad-mcp.git
   cd freecad-mcp
   

2. Install dependencies:

   pip install -r requirements.txt
   

3. Configure your MCP client to point to this server (see the repo’s README.md for exact settings).
4. Start FreeCAD and leave it running in the background.
5. Launch the server:

   python server.py
   

6. Now ask Claude Desktop something like “create a cube with side 10mm and then chamfer all edges by 2mm.”

The repo also includes example commands and troubleshooting notes. If you hit issues, check the FreeCAD console output – it logs all script execution.

Final Thoughts

This project is a neat demonstration of how protocol-driven AI integration can make existing tools more accessible. It’s not going to replace careful design or complex parametric modeling, but it’s genuinely useful for quick prototyping, educational demos, or when you want to offload repetitive geometry tasks.

For devs who work with FreeCAD regularly, this could save time on scripting. For AI enthusiasts, it’s a clean example of how to expose a desktop application’s functionality to language models. Either way, it’s worth a quick spin.

If you try it, share what you build. Curious to see what people automate first.

— @githubprojects