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Hey HN! I'm Zach from Adam (https://adam.new/). We're building AI agents for mechanical CAD software. We’ve built the company on two fundamental beliefs:

- AI will be the primary medium for creating mechanical designs just like it is in software today.

- The best paradigm for CAD generation is to generate CAD as code (text -> code -> CAD).

We’re building CADAM, an open source Text to CAD platform. It's a React app (TanStack Start) with a Supabase backend for auth, database, and file storage. Think of it like AI TinkerCAD.

Demo: https://www.youtube.com/watch?v=iESOr7EGWqk Try it: https://adam.new/cadam/

What it does:

- Generates parametric 3D models from natural language, with support for both text prompts and image references.

- Outputs OpenSCAD code with automatically extracted parameters that surface as interactive sliders for instant dimension tweaking

- Exports as .STL or .SCAD (plus OBJ, GLB/GLTF, FBX, and DXF)

Under the hood:

- One agentic endpoint with two modes that swap system prompts and tools: a parametric mode that writes/edits OpenSCAD via a build_parametric_model tool, and a mesh mode that generates 3D textured meshes.

- Simple parameter tweaks bypass the model entirely; adjusting a slider does a deterministic regex update on the SCAD source, requiring no LLM call.

- Model-agnostic via the Vercel AI SDK: Anthropic (Claude), Google (Gemini), and OpenAI/others through OpenRouter, with adaptive thinking auto-enabled on newer models. Surprisingly, in our evals Gemini 3.1 Pro is the top model.

- Runs fully in-browser by compiling OpenSCAD to WebAssembly (in a Web Worker, so the UI never blocks) and rendering with Three.js via React Three Fiber

- Supports BOSL, BOSL2, and MCAD libraries, plus custom font support (Geist) for text in models

Future improvements:

- Support both build123d and CadQuery. This will allow us to move beyond CSG primitives to constraint-driven modeling and provide direct comparisons to other code-as-CAD primitives.

- Better spatial context: UI for face/edge selection and viewport image integration to give LLMs spatial understanding

You can clone the repo and run it locally! Contributions are very welcome.

Comments

jrflo•1h ago

Can you talk more about the UI for face/edge selection that you're working on? Is that only going to be in the OnShape/Fusion plugins?

zachdive•1h ago

It's currently in the plugins and we're working on bringing it to CADAM. Basically you'll be able to use the GUI, and give face/edge selection context to your prompt "extrude a hole through this face". It's directly tied to us adding brep support.

tapia•21m ago

How can this approach be better than just selecting the edge and click the extrude button/write extrude command? Now you have to start writing a prompt and hope that what you want to do is understood by the LLM. I mean, CAD is really not so complicated with the tools we currently have. You just have to learn how to use them.

zachdive•14m ago

That's more of an example to address the point. We've find our users often use this feature in our onshape/fusion extensions in complex assemblies. Being able to select faces and edges as context in addition to prompts can be quite a powerful interface in more complex projects where users need to adjust tolerances or edit multiple objects to prevent interference

paulglx•1h ago

It could be a nice touch to give some examples of what it's possible to ask CADAM!

q3k•1h ago

> A complete V8 internal combustion engine

Yeah, no, that's a lie. This isn't a CAD model. It's a fantasy 3d model that looks like it's straight out of Gearhead Garage (1999).

Any time I see these 'AI CAD' solutions it's always toys, toys, toys. Show me something functional that you've actually manufactured (shitty 3D prints don't count). Or at least show me something that can actually be assembled and isn't just a bunch of boxes with no fasteners to hold them together.

zachdive•1h ago

We could defo update our readme! What do you think of this?: https://x.com/aaronli/status/2064876123109089742?s=20

Fable 5 in our Fusion Extension.

q3k•1h ago

I see cams intersecting eachother and still nothing that is actually ready to be manufactured or even looks like a design that has had any thought put into it. It's the CAD equivalent of idle doodling.

Do you have a single person on your team that's actually a mechanical engineer with practical industry experience?

zachdive•58m ago

Yes and we have a number of mechanical engineers using our extensions! AI in CAD is defo a WIP but when you trace the progress it's not too hard to envisage what the future will look like.

For the Fusion demo we intentionally didn't include the block or any accessories in the visualization as we wanted demonstrate Adam's ability to reason through the mechanical workings of an engine, like how the cams push the valves or the way the the crankshaft drives the connecting rods.

sem4•43m ago

not to say this isn't cool, but it's about as useful as having claude generate a JavaScript illustration of how a v8 works and then expecting someone to manufacturer an engine from that

For anyone doing CAD at a professional level (ie not 3d printed trinkets), the important parts are the physical parameters and tolerances designed into the model. For example I suspect your crankshaft would rip itself apart at engine speeds, not to mention all the plumbing, oil and coolant delivery, and auxiliary pumps and belts are missing