build123d-mcp
Give your AI CAD eyes.
build123d-mcp is not a standalone chatbot or CAD program. It is a CAD toolbox that an AI/LLM app can use through MCP.
With an LLM app such as Claude, Cursor, VS Code, Continue, Cline, or Codex CLI, build123d-mcp lets the assistant create build123d CAD models, render previews, measure geometry, fix mistakes, and export files such as STEP, STL, SVG, and DXF. Instead of writing a whole CAD script blindly, the assistant can build a part in small steps and check the result as it goes.
On the public CADGenBench leaderboard in June 2026, using build123d-mcp raised the same model's score from 0.360 to 0.457 and CAD validity from 88% to 100%.
Pick Your Setup
Most users should start with the local MCP server setup:
- You use Claude, Cursor, VS Code, Continue, Cline, or Codex CLI on your own machine.
- Your AI app starts
build123d-mcpas a local subprocess. - You do not need to clone this repository.
Use GitHub Codespaces instead if you want a browser-only trial or a ready-made development workspace with Copilot Chat, Python, uv, and the CAD dependencies already installed.






