PartCAD

PartCAD is the programming language for manufacturable things.

A package is a Git repository with a partcad.yaml that declares parts (CAD scripts or files), assemblies, materials and requirements. PartCAD renders, tests, simulates, analyses and documents them, and produces the bill of materials, the sourcing and the assembly instructions from that same source. Everything is text, so it is versioned, reviewed and generated like software, by people and by AI agents.

Documentation · Website · Demos · Discord

Install

Pick one. Every option ends up with the same pc command line tool and the same packages.

The standalone command line tools without Python, the snap, the FreeCAD add-on, the MCP server for other AI agents, and the per-OS notes are all in Installation.

Try it

pc init                      # a package in the current directory, with agent skills for Claude Code and Cursor
pc ide view my_part          # show it in the Digital Thread of the IDE or the extension
pc render my_part            # SVG, PNG, DXF... from any angle
pc test                      # the ports, interfaces, physics and simulations the objects declare
pc instructions my_assembly  # the assembly instruction book, PDF or HTML, with the bill of materials

Or, in Claude Code, /pc:gen a mounting bracket with four M4 holes: the agent writes the CAD script, renders it and checks the result against what was asked.

The tutorial walks through a first package, and examples/ has one directory per feature.

What it does

• Parts from CadQuery, build123d, OpenSCAD, Chili3D, SDF, STEP, BREP, STL, 3MF, OBJ, glTF, KiCad EDA PCBs, FreeCAD documents, and any format a plugin package adds (SolidCraft, Rhino, IGES).
• Assemblies and scenes in Assembly YAML, URDF or a STEP file, with interfaces and mating as objects.
• Outputs: STEP, BREP, STL, 3MF, OBJ, IGES, glTF, URDF, Gazebo and MuJoCo worlds, 2D projections, dimensioned drawings, Markdown documentation and PDF or HTML instruction books.
• Engineering: FEA, modal, thermal and CFD analysis (pc cae), simulation in MuJoCo or Gazebo (pc sim), 2.5D toolpaths (pc cam), and materials and manufacturing methods carried into the bill of materials.
• Supply chain: a Build vs Buy decision per line item, stock-based procurement for made parts, and automated purchasing from the command line.
• AI agents: Agent Skills for Claude Code and Cursor, an MCP server (pc mcp), and plain-text --no-ansi output on every command.
• Caching in memory, on disk, in memcached and in S3, so a team or a CI fleet renders each model once.

The full list of what is supported, and what is still in progress, is in Supported formats and features.

Why

PartCAD is not a drawing tool. It is the layer under the drawing tools: the specification of a manufacturable product, kept in a form that a human, a CI job and an AI model can all read, change and verify. Keeping that specification on-prem, in Git, and portable between CAD tools and manufacturers is the point. See Introduction and Use cases.

Community

Questions and feedback go to Discord; bugs and ideas to GitHub issues. Follow LinkedIn, YouTube and Twitter/X for releases. To contribute, start with Contributing.

Licensed under Apache 2.0.