OmniCAD
Free parametric 3D CAD in Python on OpenCascade and PySide6, with MCP and CLI for agents.
What it does and how it connects
OmniCAD is a free parametric 3D CAD program written in Python on OpenCascade and PySide6. You design with a history timeline that recalculates only when a measurement changes, as in professional CAD. It covers parametric design with units and expressions, constrained 2D sketches with a solver, solids, surfaces, sheet metal, meshes, a basic assembly mode, and reconstruction of a parametric part with history from an STL, OBJ or 3MF mesh of extrusions, revolutions, holes, fillets and chamfers.
AI agents drive it through an MCP server and a CLI (omnicad) that share one catalog of 386 tools in 17 groups, with a local usage log that is off by default and sends nothing to the network. The app also has a built-in AI assistant. Status is alpha, tested on Windows and on Ubuntu 24.04 under WSL2, and the README lists 32 known open bugs, including cases that can close the app.
OmniCAD is free, built by one person in their spare time, with a Ko-fi donation link on the README; a donation link is not a price. The README is written in Spanish, with an English version linked from it.
Alternatives
Compare side by side- forma-dsl
A declarative DSL for parametric CAD with an MCP server, rather than a full standalone CAD application.
- Sphaire
Browser-native parametric CAD on OpenCascade through WebAssembly, rather than a desktop Python app.
- freecad-chatcad
An AI agent side panel inside FreeCAD, rather than a standalone parametric CAD program.
- freecad-ai (josheeg)
An MCP server that drives FreeCAD 1.1 headlessly, rather than a standalone CAD app with its own kernel.
- Text23D Mechanical
Turns chat prompts into CadQuery or FreeCAD models in a web workbench, rather than a desktop parametric CAD app.
Sources
Not verified
- Pricing: none stated on the repo; a Ko-fi donation link appears on the README, but a donation link is not a price.
- Real user voices: no real linked post read for this page; the repo's open issues are the owner's own bug reports.
- A named individual builder beyond the repository owner handle JerryblackVe.
Last verified November 6, 2026. Listings are informational. The evidence score measures public, verifiable evidence and is not an endorsement or a compatibility claim.