Obligatory mention of https://zoo.dev/ who went to extreme lengths on this.

I will say I explored this reasonably deeply and came away with the conclusion that even though we have OpenSCAD and all these examples, LLMs are still very weak at spatial reasoning compared to diffusion models.

You can do all sorts of tricks like have a parts library to get around this and do physics checks but another inconvenient truth is whenever you design a complex assembly, every change to that part needs to be aware of the other parts in the design -- thus you need a global part-aware editing capability from diffusion.

That's getting solved already in china leading labs, and bottlenecked by the lack of good training data, which china is solving with mass labor.

This will be solved overseas first before we will in the US.

p.s. I am not affiliated with zoo or any of these other things FYI was just very curious about this whole area

Or is this capable of generating STEP files directly from an LLM (which I doubt)?

[EDIT]: haha. the answer is hidden in:

.agents/skills/cad/requirements.txt

TL;DR:

    build123d

    ezdxf

    numpy

    trimesh

    vtk

Build123d is a Python-based, parametric (BREP) modeling framework for 2D and 3D CAD. Built on the Open Cascade geometric kernel, it provides a clean, fully Pythonic interface for creating precise models suitable for 3D printing, CNC machining, laser cutting, and other manufacturing processes. Models can be exported to popular CAD tools such as FreeCAD and SolidWorks.

prbly worth mentioning in the README, I can't be the only one wondering out there.

Also: these things seem to be sprouting all over the place these days (a good thing!) ... CAD modeling using LLMs is clearly an idea whose time has come.