FreeCAD MCP (neka-nat)

MCP serverCommunity

A FreeCAD addon plus uvx server that edits documents, runs Python, imports library parts and runs CalculiX FEM. By neka-nat.

3.2k starsUpdated 12 days agoGitHub data from 5 Nov 2026

At a glance

Type: MCP server
Works with: FreeCAD
How it connects: Drives a running copy of the tool
Access: Can modify models
Tool versions: FreeCAD 1.0 and 1.1 (addon paths documented for both); MCP server needs Python 3.12+
Operating systems: Windows, macOS, Linux
Needs a FreeCAD licence: No
Transport: Local (stdio)
AI clients documented: Claude Desktop
Licence: MIT
Language: Python

What it can do

Runs an RPC server inside FreeCAD (127.0.0.1:9875 by default) that the uvx-launched MCP server calls to create, edit, delete and inspect objects and documents.
Executes Python on FreeCAD's GUI thread, as background jobs, or in a separate freecadcmd process so a crashing OpenCascade operation doesn't take the GUI down.
Returns screenshots of the active view after edits, or text only with --only-text-feedback.
Runs CalculiX on an existing FEM analysis and returns peak von Mises stress and displacements.
Inserts parts from the FreeCAD parts library.

Limitations

FreeCAD must be open with the MCP Addon workbench's RPC server started (auto-start is optional).
Code execution runs arbitrary Python with your user's permissions; remote connections are off by default and should use the auth token or an SSH tunnel.
The addon and the PyPI package update separately and warn when their versions don't match.

Install

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

Source: github.com/neka-nat/freecad-mcp#1-install-and-start-the-freecad-addon

Copy addon/FreeCADMCP into your FreeCAD addon directory, restart FreeCAD, select the MCP Addon workbench and click Start RPC Server in the FreeCAD MCP toolbar.

Source: github.com/neka-nat/freecad-mcp#1-install-and-start-the-freecad-addon

{
  "mcpServers": {
    "freecad": {
      "command": "uvx",
      "args": ["freecad-mcp"]
    }
  }
}

Source: github.com/neka-nat/freecad-mcp#2-connect-claude-desktop

MCP servers and skills run code on your computer. Review the source before installing.

AI-generated models, drawings and results must be checked by a qualified engineer before use.