loom

An MCP server that lets an agent (e.g. Claude Code) validate, render, and export OpenSCAD models it's editing directly as files, so it can visually verify what it built.

Reading, writing, and listing .scad files is left to the agent's normal file tools (Read, Write, Edit, Glob) — this server only wraps the parts Claude Code can't do on its own: invoking the openscad binary and handling its image/binary output.

Requirements

• Node.js 18+
• openscad on your PATH (or set OPENSCAD_BIN to its full path)

Install

npm install

Run standalone

npm start

Register with Claude Code

claude mcp add loom -- node /absolute/path/to/loom/src/index.js

Tools

• openscad-version — confirm the OpenSCAD CLI is available.
• validate-model — compile a .scad file without producing a visual export, to catch syntax/geometry errors. Fast sanity check before rendering.
• render-preview — render a .scad file to PNG and return it inline for visual inspection. Supports image size, camera, projection, color scheme, render mode (full vs. throwntogether), and view overlays (axes/edges/etc). Defaults to saving next to the source file.
• export-model — export a .scad file to STL/OFF/3MF/AMF/DXF/SVG/CSG/POV. Defaults to saving next to the source file.

All three model tools take a path to the .scad file (any location — no fixed workspace directory) and an optional output path to override where the rendered/exported file is saved.

Environment variables

• OPENSCAD_BIN — path to the openscad executable (default: openscad).