Agent skill · software engineering · sundial-org
cad-agent
cad-agent — an agent skill for coding agents.
Why this skill is useful
Adds executable commands for CAD modeling and rendering that significantly extend the AI's capabilities in 3D design.
What it needs
Requires docker installed locally. About 2k tokens when loaded. Last updated 2026-03-07. 639 stars on the source repository.
What this skill does
CAD Agent Give your AI agent eyes for CAD work. Description CAD Agent is a rendering server that lets AI agents see what they're building. Send modeling commands → receive rendered images → iterate visually. Use when: designing 3D-printable parts, parametric CAD, mechanical design, build123d modeling Architecture Critical: All CAD logic runs inside the container. You (the agent) only: 1. Send commands via HTTP 2. View the returned images 3. Decide what to do next Never do STL manipulation, mesh processing, or rendering outside the container. The container handles everything — you just command and observe. Setup 1. Clone the Repository 2. Build the Docker Image Or using docker-compose: 3. Run the Server 4. Verify Installation Docker-in-Docker caveat: In nested container environments (e.g., Clawdbot sandbox), host networking may not work—curl localhost:8123 will fail even though the server binds to 0.0.0.0:8123. Use docker exec cad-agent python3 -c "..." commands instead. On a normal Docker host, localhost access works fine. Workflow 1. Create Model 2. Render & View Look at the image. Does it look right? If not, modify and re-render. 3. Iterate 4. Export Endpoints Endpoint What it does ---------- -------------- POST /model/create Run build123d code, create model POST /model/modify Modify existing model GET /model/list List models in session GET /model/{name}/measure Get dimensions POST /render/3d 3D shaded render (VTK) POST /render/2d 2D technical drawing POST /render/multiview 4-view composite POST /export Export STL/STEP/3MF POST /analyze/printability Check if printable build123d Cheatsheet Important Don't bypass the container. No matplotlib, no external STL libraries, no mesh hacking. Renders are your eyes. Always request a render after changes. Iterate visually. The whole point is you can see what you're building. Design File Safety The project has safeguards against accidentally committing CAD outputs: .gitignore blocks .stl, .step, .3mf, etc. …
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills sundial-org/cad-agent