FreeCAD does not ship its own MCP (Model Context Protocol) server, but several community projects connect it to Claude Desktop, Claude Code, Cursor and other MCP clients. This page covers how the main ones work, then compares them with SolidCraft, a newer CAD app that has an MCP server built in. FreeCAD is the far more mature program; the comparison is about setup effort and what the AI can do.
What FreeCAD MCP servers exist?
A GitHub search for "freecad mcp" on 18 October 2026, sorted by stars, returned these first:
| Project | Stars | What its README says |
|---|---|---|
| neka-nat/freecad-mcp | about 2,900 | Control FreeCAD from Claude Desktop and other MCP clients: create and edit models, run Python, inspect documents, run FEM analyses |
| bonninr/freecad_mcp | about 230 | Connects FreeCAD to Claude and other MCP clients through a bridge script |
| contextform/freecad-mcp | about 140 | Open-source MCP server for FreeCAD automation |
| blwfish/freecad-mcp | about 60 | A bridge for parametric design, CNC toolpaths and mesh work, with 32 tools |
We read the READMEs of the first, second and fourth. The other entries are listed from their GitHub descriptions only.
How does neka-nat/freecad-mcp work?
It has two parts, according to its README: an addon that runs inside FreeCAD, and an MCP server that your client launches.
- Clone the repository and copy
addon/FreeCADMCPinto your FreeCAD addon directory. - Restart FreeCAD, choose the MCP Addon workbench and click Start RPC Server.
- Add a
freecadentry toclaude_desktop_config.jsonthat runsuvx freecad-mcp(you need uv installed). - Restart Claude Desktop, keep FreeCAD open, and ask for a model.
Its tools include creating, editing and deleting objects, reading a document, taking a screenshot of the active view, running Python on FreeCAD's GUI thread, running a script in a separate freecadcmd process, inserting parts from the FreeCAD parts library, and running a CalculiX FEM analysis. The repository is MIT licensed.
How do the other servers connect?
- bonninr/freecad_mcp describes a client-server design. Its example config launches a Python interpreter on a
freecad_bridge.pyscript stored in FreeCAD'sModfolder. Its tools areget_scene_info(document, objects, sketches, view) andrun_script(arbitrary Python inside FreeCAD). - blwfish/freecad-mcp tells you to give your AI agent a link to its
AGENT-INSTALL.mdand let the agent install it. Its README says all tools except CAM work on FreeCAD 1.1.x, while CAM toolpaths need a weekly development build.
The common pattern is the same: a FreeCAD-side add-on opens a local socket or RPC server, and a small bridge process turns it into MCP tools. Because most tools end in "run Python", the AI is writing FreeCAD scripts for you.
How does SolidCraft's built-in MCP compare?
SolidCraft ships the MCP server inside its command-line tool. There is no add-on and no bridge script: you register solidcraft-cli mcp with your client. Details are on the SolidCraft MCP setup page.
| FreeCAD + community MCP (neka-nat) | SolidCraft built-in MCP | |
|---|---|---|
| Setup steps | Install FreeCAD, copy the addon, start the RPC server in the GUI, install uv, edit the client config | Install SolidCraft and solidcraft-cli, then one line: claude mcp add solidcraft -- solidcraft-cli mcp |
| Needs the GUI running | Yes (plus a headless script tool) | No, a headless session works; the app is optional |
| How the AI works | Mostly creates objects and runs Python in FreeCAD | Runs the app's own modelling commands, in batches that roll back on error |
| Measuring and checking | Read objects and properties; write your own script | Built-in measure and body_topology tools |
| Screenshots | Yes, from the active view | Yes, headless render or the app window |
| File formats | What FreeCAD supports, including STEP and FCStd | STEP, 3MF, STL, OBJ and URDF export; imports STEP, STL, 3MF and FreeCAD .FCStd files in the desktop app |
| Simulation | FEM through CalculiX | None |
| File access limits | Not described in the README | Locked to the design folder by default; --allow-path adds more |
| Maturity | FreeCAD: 20+ years; MCP project: community-maintained | First release October 2026; its README calls it early |
Which one should you use?
- Use FreeCAD with an MCP add-on if you already work in FreeCAD, need drawings, FEM, CAM or large assemblies, or have existing .FCStd files. Expect some setup and some trial and error with scripts.
- Try SolidCraft if you want an AI agent to build simple parts, brackets or enclosures with the least setup, or you want to run the CAD side headless. See SolidCraft vs FreeCAD for the full feature comparison.
- Use both: model in SolidCraft through MCP and move parts to FreeCAD as STEP, or the other way round.
Not verified: we did not install or test any of these servers, and we did not read the READMEs of contextform/freecad-mcp or the smaller projects. Star counts and features change quickly, so check each repository before you commit.