Cadex

Free and open source, forever

Software for hardware.

Cadex is an AI-native CAD application. You describe the part. The AI writes a parametric script. Only validated geometry reaches your model. Then the physics engine makes it move.

View on GitHub Demo
The Cadex application: a ducted-fan drone frame in the viewport, parameter sliders below it, and the chat conversation that made it on the right.
A drone frame, its parameters as sliders, and the conversation that built it.

01 How it works

The script is the model. Nothing happens outside it.

  1. 1

    You describe the part

    Dimensions, interfaces, material, constraints. In chat. Click a face in the viewport to pin it — the pin tells the AI which face you mean.

  2. 2

    The AI writes a script

    A declarative Python program called xscript. It runs in a sandboxed headless worker. Only geometry that validates reaches your model.

  3. 3

    You drag the sliders

    Every parameter in the script becomes a slider. Sliders rebuild the model directly — no AI turn, no tokens, no wait for a chat reply.

  4. 4

    The model rebuilds from the script. Always.

    The document is only a cache. Delete it, run the script again, and you get the same model back, byte for byte.

02 What's in the box

Real CAD. Real physics. One application.

Robot software, literally

Dynamics and control are built in on MuJoCo. Your mechanism falls, collides, and is actuated. "Design me a quadruped and teach it to walk" is a sequence of chat turns.

Parametric BREP on OCCT

The same industrial geometry kernel that FreeCAD uses. Exact solids, exact inertias — not convex-hull guesses. Export STEP, STL, and MJCF.

Blender-class UX

Built on a fork of Blender's shell. Left half: viewport. Right half: chat, sliders, model tree, script. That is the whole interface.

Nothing to learn

No fillet button. No extrude button. No workbench to select. You talk, the AI writes the script, the sliders do the rest. One undo step per chat turn.

Works without a screen

The CLI drives the same engine headless. One AI turn writes a parametric script; then a loop sweeps parameters and re-exports for the price of a rebuild.

./cadex -p "a mounting bracket for a NEMA17, 4 mm wall"
./cadex params --set wall=6   # no AI, no tokens

Train it to move

Export the control problem as data, solve it with the bundled PPO trainer on any GPU box, copy one policy file back, and watch the gait play in the viewport.

03 Always free. Always open.

Cadex is not a product. It is a project. There is nothing to buy, no account to make, and no tier to unlock.

Cadex stands on the shoulders of giants, and says so. It is a derivative of FreeCAD and Blender, built on the OCCT geometry kernel and the MuJoCo physics kernel. Every borrowed line is documented — which code came from where, under which license, and what changed.

Cadex is an experimental side project under active development, pre-release. It makes no claims of reliability. It makes one promise: it will forever be free and open source.

Build it yourself

git lfs install
git clone git@github.com:theo-kirby/cadex.git
cd cadex
pixi run setup
pixi run app