SimpleCADAPI skill
Python SDK for parametric CAD with an agent skill: code-built models, STEP, STL and MJCF export, edits rerun only dependent cells.
- 188 ★ on the repository
- Last commit
Minimal access
Why this level
- `sca addon` extensions run third-party code in their own environment.
Install
- Works in
In your terminal, with SkillFoxx CLI
npx skillfoxx add skills/simplecadapiDetects the agents on your machine, shows the access level and pins the version.
Other ways to install
Access and checks
How we reviewMinimal accessThe tool runs nothing and makes no network calls.
- `sca addon` extensions run third-party code in their own environment.
This is third-party code. Review the repository files before installing.
What it does
SimpleCADAPI is a CAD package written for an agent with no mouse: a functional API with no hidden state, a native OpenCASCADE kernel inside the pip wheel, and errors that carry measured numbers and a fix. Geometry is selected by what it is (`ql`, a stable `scad.ref`) rather than by an index that shifts. The skill installs with `sca skill install` and walks the agent through seven routes: a single part, an assembly with kinematics, rebuilding from STEP, from a mesh or point cloud, from a vector PDF, a GB engineering drawing in DXF, and export to STEP AP242, STL, FreeCAD and MJCF. One skill source compiles for Claude Code, Codex, OpenCode and four more harnesses. The `sca edit` editor shows cells and the live model side by side: clicking a face writes the selection into the notebook and the agent reads it from disk. Add-ons are plugged in as repositories with `sca addon add owner/repo`.
Who it is for. Engineers and designers who hand part and assembly modeling to an agent as code and want to tweak dimensions with a slider instead of rebuilding the file.
Good fit when
- An agent builds an enclosure or articulated mechanism where angles and link lengths are named parameters.
- A part from a STEP file is rebuilt into an editable model with geometry checks.
- A GB-standard drawing is needed as DXF from verified geometry.
- A finished model is handed over as STL for printing or MJCF for simulation.
Not a fit when
- The model is drawn with a mouse in a ready-made CAD and no agent is involved.
- You need standards and formats outside the seven listed routes.
- The environment does not support Python 3.10–3.13.
Example request
Model a bracket with four M4 holes and export it to STEP, checking dimensions against the drawing.Limitations
Python 3.10–3.13 is required. The comparison figures against CadQuery and an industrial CAD come from the author's report, which discloses caveats about run conditions and part mix. Add-ons install from third-party repositories and run code in their own environment, so check the source before `sca addon add`. The description was checked against the 2.2.7 README; newer releases may behave differently.
How to disable. Remove the package with `pip uninstall simplecadapi` and the `sca-*` skill folders from the agent's skills directory. Take out add-ons through `sca addon`.
FAQ
How do I install the SDK and the skill?
Run `pip install "simplecadapi[editor]"`, then `sca skill install`, which compiles the skill for your agent. `sca skill targets` lists the supported harnesses.
Can models run without the editor?
Yes. `sca run model.py` executes a notebook headless and `sca export` writes STEP, STL and OBJ.
Is CadQuery required?
No. The OpenCASCADE kernel ships inside the wheel, with no CadQuery or OCP stack.
How do I add checking or simulation?
Install an add-on with `sca addon add owner/repo`. Its skill lands beside the main one and its code runs in a separate environment.
Which harnesses does the skill support?
One source compiles for Claude Code, Codex, OpenCode, ZCode, OMP, DSH and Kimi Code. `sca skill targets` prints the list.
Discussion
No questions or reviews yet.
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Comparison with similar tools
Cards that share the main search query, and how they differ.
| Tool | Official | Authentication | Repository stars | Main difference |
|---|---|---|---|---|
| SimpleCADAPI (this card) | no | 188 | ||
| FreeCAD MCP | no | not required | 3,310 | drives an installed FreeCAD over MCP; SimpleCADAPI is a standalone SDK with its own kernel and skill |
| OpenSCAD MCP | no | not required | 170 | renders OpenSCAD parts with measurements; SimpleCADAPI builds B-rep models and assemblies with kinematics |
README in short
One skill covering seven CAD routes from part to drawing, compiled for eight harnesses.