Owlcad Plugin

Parametric 3D CAD for 3D printing, for your AI assistant. This plugin connects Claude, Cursor or Gemini CLI to OwlCAD's hosted MCP server, so the assistant can build millimeter-dimensioned parts, check that they will print, and export STL, 3MF or STEP. Everything it makes is a normal OwlCAD project: a tree of named, dimensioned parts you can open in the browser editor at owlcad.com and change afterwards.

What it can do

• Build parts from primitives and booleans, built-in generators (gears, threads, Gridfinity bins and baseplates) and a library of datasheet-dimensioned parts.
• Check them: watertight build, size and volume, overhangs, thinnest wall, collisions between parts, and whether a part fits a given printer's bed. It can also cut an oversized part into printable pieces.
• Export STL, 3MF or OBJ for a slicer, STEP for other CAD tools, or a 2D drawing.
• List, read, edit, organize, share and delete your saved OwlCAD projects.

29 tools in all. The full list, with what each one does, is at owlcad.com/mcp-server.

Requirements

An OwlCAD account on the Pro plan. The first time the assistant uses OwlCAD, a browser opens so you can sign in and approve what it may do. You can revoke the connection at any time from Account settings on owlcad.com.

What it runs, sends and fetches

This plugin contains configuration only. It runs nothing on your machine. It points your assistant at https://mcp.owlcad.com/, OwlCAD's hosted server. Each tool call sends that server the model or project the assistant is working on, and the server reads and writes projects in your OwlCAD account. How that data is handled is described in the privacy policy.

Install

• Claude (web, desktop): Settings → Connectors → Add custom connector, and paste https://mcp.owlcad.com/.

• Claude Code: claude mcp add --transport http owlcad https://mcp.owlcad.com/

• Cursor: add the server to ~/.cursor/mcp.json (or a project's .cursor/mcp.json), then sign in when Cursor asks:

  { "mcpServers": { "owlcad": { "url": "https://mcp.owlcad.com/" } } }
  

• Gemini CLI: gemini extensions install https://github.com/Spare-Matter/owlcad-plugin

Support

owlcad.com/contact · [email protected]

License

The files in this repository (configuration and documentation) are MIT-licensed; see LICENSE. The OwlCAD service they connect to is proprietary.