Parametric modeling
Sketches with a constraint solver and live degrees-of-freedom analysis, a feature tree with expressions and parameters, and persistent naming, so edits upstream don't break features downstream.
Free · Linux · Version 0.1.0
Parametric CAD,
with a co-designer built in.
Brepo is a full parametric CAD application on exact B-rep geometry, with an assistant that reads your model, proposes changes on its own branch and waits for your review. You can sketch, model, assemble, simulate and draw in one app. It's free.
- Kernel
- Open CASCADE 8
- Formats
- STEP AP242, IGES, STL, 3MF, DXF
- Assistant
- Claude or a local model
- Price
- Free
What's inside
A complete CAD workflow, not a demo.
Surfaces and forms
Lofts, sweeps and fillets on exact geometry, plus subdivision Form features for freeform shapes that become real B-rep patches.
Assemblies and motion
Components and joints with a 3D joint solver, motion links, cams, closed loops, contact sets and motion studies. Linked components, flexible sub-assemblies and levels of detail handle large models.
FEA
Linear static analysis of parts and assemblies with bolt preload, contact and adaptive meshing. It produces stress and displacement plots and a PDF report.
Sheet metal
Bends with sourced K-factors, its own unfolder for flat patterns and bend lines, refolding, and DXF / SVG output for the laser.
Technical drawings
Hidden-line views, sections, details and dimensions. GD&T frames, datums, surface texture, weld symbols, parts lists, revision tables, and ISO and ASME templates. Output as PDF, SVG or DXF, with 3D PMI in STEP AP242.
Standard parts
Fasteners, threads and holes (metric, unified, pipe), bearings, profiles, gears, pulleys, sprockets, springs and motors. Every table cites its source.
Design checks
Exact measurements, mass properties and interference, draft and curvature analysis, plus wall thickness, overhang, undercut and clearance checks with colour maps. Plastic design rules with their formulas shown.
Versions, optimisation, scripting
Named versions with geometry diffs, parameter optimisation and sweeps, sandboxed plugin features, and export of the feature tree as a runnable Python script.
The Brepo Assistant
It proposes. You decide.
Select a face, a sketch or a feature and ask. The assistant sees what you see: it gets the model, your selection and rendered pictures of the viewport, and edits through the same typed operations you use.
Every session works on its own branch. When it's done, you review a change set with parameter diffs and before-and-after renders, then accept or discard it. Your main design is never edited behind your back.
- Your choice of model. Claude, with your Claude app sign-in or your own API key, or a local model through Ollama or LM Studio.
- Several sessions at once. A session board shows which ones need you and which are ready for review.
- Open to other agents. Brepo exposes its operations over MCP, so your own agents and tools can drive it too.
- Optional. Brepo is a complete CAD app without the assistant.
Download
Brepo 0.1.0 for Linux
64-bit x86 Linux. Built and tested on Ubuntu 24.04; any recent glibc-based distribution should work. Windows and macOS builds are planned.
AppImage
Any distribution. Make it executable and run it.
.deb package
Ubuntu, Debian, Mint. Adds the menu entry and file type.
AppImage
chmod +x brepo_0.1.0_amd64.AppImage
./brepo_0.1.0_amd64.AppImage.deb
sudo apt install ./brepo_0.1.0_amd64.deb
brepoSHA-256 checksums: SHA256SUMS. Third-party notices and the source offer for the LGPL components are included in the app under File > About Brepo.
Questions
FAQ
Is Brepo really free?
Yes. Download it and use it, including for commercial work, at no cost. If you use Claude through your own API key, Anthropic bills that usage to you directly.
Do I need an account?
No. Brepo runs locally on your machine. Your designs stay on your disk as .brepo files
unless you send them somewhere yourself.
Does my model go to an AI provider?
Only when you start an assistant session, and only to the provider you picked. With a local model through Ollama or LM Studio, nothing leaves your machine.
Can I exchange files with other CAD systems?
Yes. Brepo imports STEP, IGES and DXF, and exports STEP (AP214 and AP242 with PMI), IGES, STL, 3MF, OBJ and GLB, plus PDF, SVG and DXF drawings.
Is it open source?
Brepo itself isn't open source, but it's built on open-source components, most importantly the Open CASCADE Technology kernel (LGPL 2.1). Their licenses, notices and a source offer ship with the app.
What about Windows and macOS?
Linux comes first. Builds for Windows and macOS are planned.