FreeCAD MCP server

freecad-mcp

What This Does

This is a bridge between your AI agent and FreeCAD — a thinking partner for parametric design, CNC toolpath generation, and mesh work. You bring the design intent and the domain judgment; the agent handles the FreeCAD mechanics. Together: moving faster, co-designing things that would take hours to build by hand, untangling the cryptic error messages that FreeCAD is so good at generating, and hunting down the subtle, knotty modeling problems that are nearly impossible to find alone. Built for personal daily use — designing parts, generating toolpaths, printing and cutting them — not a demo. See TOOLS.md for the full tool reference.

What You Can Work On Together

• Work through a design — "I need a mounting plate — 100x60mm, four M3 holes, rounded corners. What's the right approach?" You bring the requirements and constraints; the agent builds, flags underspecified decisions, and iterates with you.
• Diagnose what went wrong — "I just tried to pad this sketch and got a weird result — what is FreeCAD actually telling me?" The agent can read the Report View, inspect sketch constraints, and explain what's happening in terms you can act on.
• Iterate on an existing part — "This wall feels too thin and the fillet might not survive printing — let's look at it together"
• Plan CNC toolpaths — "I want to mill this pocket — let's work out the right tool and parameters for the material"
• Build something reusable — "I keep doing this same workflow for every bracket — let's write a macro that generates them from a spreadsheet of dimensions"
• Check your work before committing — "Does this model have geometry errors?", "Will these walls survive printing?", "Are any of these parts going to collide?"
• Work with meshes — "I have an STL from the manufacturer — let's get it into FreeCAD and add mounting features"
• Export for manufacturing — "Export this as STEP and generate G-code for my CNC router"

See It In Action

These are a couple of examples of how I've used the MCP.

Debugging a broken external reference — a link FreeCAD can't restore, an error message that seems to contradict what you know about your own model, and a one-line fix found by reading the file directly.

Full story →

Designing a shingles generator — several sessions of back-and-forth to design a parametric generator that tiles any roof surface from a spreadsheet of parameters.

Full story →

Getting Started

FreeCAD version support: All tools except CAM are supported on FreeCAD 1.1.x (current stable). CAM toolpath generation requires a current FreeCAD weekly development build (what used to be called "1.2-dev" before upstream moved to calendar-based versioning, e.g. 26.3.x) — the Path workbench API changed incompatibly between 1.1 and the dev series. This project tracks the latest weekly.

Shortened. The full README is on GitHub.