CADdy

An AI assistant that lives inside FreeCAD — and measures its work instead of guessing.

demo.mp4

You draw. You ask. CADdy continues on the same live document. You keep going. Nothing is exported, nothing is lost, and every AI step is one Ctrl+Z away.

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Why CADdy

• Verified, not eyeballed. After every change CADdy checks the geometry: overlapping parts, open shells, invalid solids, volumes. An AI looking at a screenshot says "looks fine" — CADdy measures.
• One live document. Hand-made and AI-made features sit in the same model tree and stay parametric. Edit either one, any time.
• One step, one undo. However many objects an AI turn creates, a single Ctrl+Z rolls it back.
• Runs on your Claude subscription. It drives the official Claude Code CLI, so there is no separate API key to manage. Usage is drawn from your plan's monthly Agent SDK credit (e.g. $20 on Pro); beyond that, standard API rates apply.

A toy pickup truck, built step by step in one live document.	A sailing ship: measured part by part, not eyeballed.
A 3-part printable figurine, checked for overlaps and fit.	A space elevator concept (below).

Not only parts — ideas too. A visual concept of a space elevator: a cable anchored on Earth's north pole, a climber cabin on its way up, a station in geostationary orbit and a counterweight beyond it, with the Moon, planets and a starfield around them. Asked "what is this", CADdy reads the scene back from the document itself — every part, its size and where it sits.

Requirements

• Windows 10 / 11
• FreeCAD 1.1 (1.0 and older will not work)
• Claude Code CLI, signed in with a Claude Pro or Max plan

If ANTHROPIC_API_KEY is set, the CLI bills that API key instead of your subscription. Unset it unless that is what you want.

Install

git clone https://github.com/furkanbulus123/CADdy.git
cd CADdy
.\install.ps1

The script finds FreeCAD, checks the claude command and links the folder into FreeCAD's Mod directory. No admin rights needed. Restart FreeCAD and pick CADdy from the workbench list.

Usage

Open the CADdy panel and describe what you want:

"Add four M3 mounting holes, 5 mm from each corner."

Button	What it does
New	Start a fresh conversation
Undo / Redo	Step through AI changes
Model	Opus or Sonnet
History	Resume a past chat
Fast / Deep	How much the model thinks

Tests & architecture

See ARCHITECTURE.md.

& "C:\Program Files\FreeCAD 1.1\bin\freecadcmd.exe" tests\test_yukleme_fc.py

License

MIT