ncad

ncad is an experimental CAD server and TypeScript playground for building geometry through a small, scriptable API.

The project is centered around analytic sketch geometry: points, planes, curves, composite curves, offsets, joins, sections, and high-level solid operations. The server owns geometry and OpenCascade execution; the TypeScript SDK gives scripts a document/object handle API instead of raw HTTP calls.

Repository Layout

server/              FastAPI CAD server backed by OpenCascade
playground/          Browser playground with Monaco editor and 3D viewer

The reusable TypeScript SDK lives in the separate cad-kitchen/ncad-ts-sdk repository. This repository expects the SDK checkout next to it when regenerating OpenAPI bindings:

cadki/
├── ncad/
└── ncad-ts-sdk/

Requirements

• Conda or micromamba for the Python/OpenCascade server environment.
• Bun for the TypeScript playground.
• Docker is optional; the server also has Docker targets.

Quick Start

First-time setup:

make install

Run the server and playground together:

make dev

The server listens on http://localhost:8080. Swagger UI is available at http://localhost:8080/docs. The playground runs at the Vite URL, usually http://localhost:5173.

You can also run them in separate terminals:

make server-dev
make client-dev

The playground loads local TypeScript examples from playground/public/scripts/. Scripts run against a live document and the viewer renders the resulting scene.glb.

The VS Code remote viewer lives in the sibling ../ncad-vscode-viewer repository and connects to this server by host:port.

Development

Run tests and type checks:

make test

Regenerate the TypeScript OpenAPI bindings after server schema changes:

make gen-api

Check and build the client:

make build

API Shape

Typical playground scripts use the SDK document handle:

const circle = await document.circle([0, 0, 0], [0, 0, 1], 50);
const point = await circle.pointAt(Math.PI / 2);
const tangent = await circle.tangentAt(Math.PI / 2);

const offset = await circle.offset(10);
await offset.setVisual({ color: [0, 0, 0] });

For paths, scripts can build declarative composite curves:

const axis = await document.path()
  .startAt([0, 0, 0])
  .lineTo([100, 0, 0])
  .arcTo([100, 40, 0], { via: [120, 20, 0] })
  .build();

const solid = await axis.pipe(10, { keepAxis: true });

For solid normalization, scripts can fuse caller-selected solids through OCC and optionally split disconnected results into components:

const fused = await document.fuseMany(importedSolids, { tolerance: 0.01 });
const components = await document.fuseMany(importedSolids, {
  tolerance: 0.01,
  splitComponents: true,
});

const exploded = await document.explodeComponents(fused);

The lower-level generated client remains available in the SDK, but scripts should prefer the document/object handle API.

Documentation

• Server setup and runtime notes are documented in server/README.md.
• Playground-specific setup is documented in playground/README.md.

License

The original ncad source code is licensed under the MIT License. See LICENSE.

Third-party code and runtime dependencies keep their own licenses. In particular, Open CASCADE Technology and pythonocc-core are not relicensed by this repository.