vcad is an open-source parametric CAD system built to replace tools like Fusion 360 and Onshape. It runs a custom BRep kernel written in Rust that compiles to WebAssembly for the browser, meaning exact geometry -- planes, cylinders, NURBS surfaces -- lives right in your tab at vcad.io. There is no cloud meshing step, no seat license, and no feature gating. The entire system is MIT-licensed.
The kernel powers four interfaces: a visual web app, a Rust library, a terminal CLI, and an MCP server that lets AI agents like Claude design parts directly. Pick whichever fits your workflow; the underlying geometry engine is the same everywhere.
Web App
Open vcad.io and start modeling immediately. The app gives you a viewport with orbit/pan/zoom, a feature tree for parametric history, a property panel for dimensions, and a command palette (Cmd+K) for everything else. Sketch on faces, extrude profiles, cut holes, apply fillets, assign materials. Export to STL, GLB, STEP, or DXF when you are done.
No installation, no account required. The WASM kernel runs locally in your browser, so your geometry never leaves your machine unless you choose to enable cloud sync.
Start with the Web App tutorial to build your first part in under five minutes.
Rust
If you prefer code over clicks, cargo add vcad gives you the full kernel as a library. Create geometry programmatically, run boolean operations, query volumes and centers of mass, and export to any format -- all from a Rust binary or script.
use vcad::{centered_cylinder, centered_cube};
let plate = centered_cube("plate", 100.0, 60.0, 5.0);
let hole = centered_cylinder("hole", 4.0, 10.0, 32);
let result = plate - hole;
result.write_stl("plate.stl")?;
This path is ideal for parametric generators, batch exports, CI pipelines, or embedding CAD in a larger Rust application. See Install & Setup for setup, then follow the Rust tutorial.
CLI
The vcad-cli tool brings the kernel to your terminal. Convert between formats, inspect documents, and run headless operations without opening a browser or writing Rust code.
vcad export bracket.vcad bracket.step
vcad info bracket.vcad
vcad import-step housing.step housing.vcad
Install with cargo install vcad-cli, then see the CLI tutorial.
MCP / AI
The MCP server turns vcad into a tool that AI agents can use directly. Configure it in Claude Desktop or Cursor, then describe the part you want in natural language. The agent calls create_cad_document to build geometry, inspect_cad to check dimensions, and export_cad to produce files -- all without you touching the UI.
"Create a 100x60x5mm aluminum plate with four M4 mounting holes
on a 80x40mm bolt pattern, countersunk from the top."
The MCP server also exposes a physics simulation interface for robotics: create environments from assemblies, step simulations with torque or position actions, and train RL policies against real geometry. See MCP Setup to get started.
Whichever path you chose, the next step is Install & Setup to get your environment ready, followed by Core Concepts for the mental model behind every vcad operation.