FreeCAD Robust MCP Server
The MCP server connects agents to FreeCAD for part modeling, document edits, macro execution and model export.
- 265 ★ on the repository
- Last commit
- Apache-2.0
Broad access
Why this level
- The agent executes arbitrary Python and macros with FreeCAD permissions, edits documents and writes files to disk.
Install
- Works in
Manual install
pip install freecad-robust-mcpFirst command-based README route. Package and workbench are separate; published 0.6.x does not gain the new pairing workflow described for current source builds.
Access and checks
How we reviewBroad accessThe tool can change data, run commands or handle secrets.
- The agent executes arbitrary Python and macros with FreeCAD permissions, edits documents and writes files to disk.
This is third-party code. Review the repository files before installing.
What it does
FreeCAD Robust MCP Server connects an AI client to running FreeCAD through a separate addon. An agent can create documents, add geometry, edit part parameters and save results. Users inspect the model in FreeCAD or request a viewport image when a GUI is available. Tools cover sketches, STEP and STL export, undo and macros. Arbitrary Python execution in the FreeCAD context extends access beyond geometry, so use trusted tasks in a dedicated working project.
Who it is for. FreeCAD part designers delegating repeatable modeling steps while inspecting the resulting document.
Good fit when
- An agent builds a parametric part from supplied dimensions.
- After an edit, the user needs a viewport image to inspect the model.
- Before downstream processing, a finished part needs export to an agreed format.
- For repeated modeling steps, the user wants a trusted macro.
Not a fit when
- The agent must not execute Python with FreeCAD process permissions.
- A fully headless session is expected to produce viewport screenshots.
- The bridge must be exposed over a network without a supported protected transport.
Example request
Create a blank part in a new document from the supplied dimensions, show a screenshot and object list, and export after model review.MCP
- Transport
- stdio
- Authentication
- not required
Environment variables
FREECAD_MODE- FreeCAD connection mode, xmlrpc by default
Limitations
The external server needs FreeCAD 1.0.2 or newer and Python 3.11 or newer; the author recommends FreeCAD 1.1.4 or newer for security fixes. Published 0.6.x releases described in the README predate the new pairing workflow; pairing requires matching server and workbench builds from one current source checkout. Embedded mode is Linux-only, while macOS and Windows need an external connection. Screenshot and viewport tools are unavailable without a graphical FreeCAD session.
How to disable. Stop the bridge in FreeCAD and remove the server from the AI client. Review saved documents and created macros before removing the addon.
FAQ
Is the Python package enough?
No. FreeCAD and a compatible bridge addon are also required; installing the package does not start the CAD application.
Why is the addon missing from Addon Manager?
The workbench is not yet in the public addon catalog. Follow the repository installation guide and choose a build compatible with your server.
Which button starts the bridge?
Click Start MCP Bridge in the Robust MCP Bridge workbench.
Why did a screenshot request fail?
Screenshots need a graphical FreeCAD session and are unavailable in headless mode.
Can I export a model for printing?
Yes. STL and 3MF export are available; inspect geometry and part parameters first.
Discussion
No questions or reviews yet.
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README in short
The external server supports two local FreeCAD connection modes. Protected remote transport is not implemented; do not expose the bridge on all network interfaces.