FreeCAD MCP — Claude Code MCP server: what it does, how to install
Connects AI coding agents to FreeCAD for parametric 3D modeling, CAM toolpath calculations, and sketch diagnostics.
claude mcp add freecad-mcp -- docker run -i --rm ghcr.io/blwfish/freecad-mcp:latestWhat FreeCAD MCP does
The bridge links your agent directly to an active FreeCAD session through the AICopilot addon and local sockets. Instead of editing files blindly, the assistant manipulates PartDesign geometry, inspects constraint errors in the Report View, and tracks down broken external references. It can also export geometry to STEP or write CNC G-code directly from chat prompts.
Running multiple FreeCAD instances side by side is supported out of the box. Every GUI or headless process writes a discovery record to ~/.cache/freecad-mcp/instances/, allowing the agent to target specific instances via select_freecad_instance.
Generating CAM toolpaths requires a recent FreeCAD weekly development build, because Path workbench APIs changed after stable 1.1.x. Standard parametric modeling runs on 1.1.x without issues.
What it helps with
- Build parametric mechanical parts according to specified dimensions
- Diagnose broken sketch constraints and pad failures via the Report View
- Produce CNC toolpaths and G-code for milling operations
- Import STL mesh files and attach mounting features
- Export completed 3D models into STEP files
Example prompts for the agent
- Create a 100x60mm mounting plate with rounded edges and four M3 bolt holes
- Read the FreeCAD Report View to diagnose why this sketch cannot be padded
- Calculate toolpaths for milling this pocket and export the G-code
How to install FreeCAD MCP
Platform CLI
claude mcp add freecad-mcp -- docker run -i --rm ghcr.io/blwfish/freecad-mcp:latestPlatform CLI
codex mcp add freecad-mcp -- docker run -i --rm ghcr.io/blwfish/freecad-mcp:latestConfig file
{
"mcpServers": {
"freecad-mcp": {
"command": "docker",
"args": [
"run",
"-i",
"--rm",
"ghcr.io/blwfish/freecad-mcp:latest"
]
}
}
}Config file
{
"servers": {
"freecad-mcp": {
"type": "stdio",
"command": "docker",
"args": [
"run",
"-i",
"--rm",
"ghcr.io/blwfish/freecad-mcp:latest"
]
}
}
}Platform CLI
gemini mcp add freecad-mcp docker run -i --rm ghcr.io/blwfish/freecad-mcp:latestStep by step, with commands for each platform: How to add an MCP server to Claude Code, Codex, Cursor, VS Code, Gemini CLI and more
Questions about FreeCAD MCP
How to install FreeCAD MCP in Claude Code?
Add the Docker container using claude mcp add freecad-mcp -- docker run -i --rm ghcr.io/blwfish/freecad-mcp:latest. You must also have the AICopilot workbench installed and loaded in FreeCAD.
What does FreeCAD MCP do?
It exposes over 30 tools that enable agents to construct parametric models, edit meshes, resolve constraint problems, and output manufacturing files in FreeCAD.
Which FreeCAD version is required?
General modeling tools function on stable FreeCAD 1.1.x. CAM toolpath features strictly require a weekly development build due to breaking API changes in the Path workbench.
