# @bitbybit-dev/occt OpenCascade Technology (OCCT) CAD kernel integration for [Bitbybit](https://bitbybit.dev) - professional-grade 3D modeling with boolean operations, fillets, chamfers, lofts, sweeps, STEP/IGES import/export, and more. Picture showing bitbybit.dev platform ## Overview This package wraps the [OpenCascade Technology](https://github.com/Open-Cascade-SAS/OCCT) kernel with additional algorithms from Bitbybit. It is **independent of rendering frameworks** - use it with BabylonJS, Three.js, PlayCanvas, or build your own WebGL/WebGPU pipeline. Works in both **Node.js** and **browser** environments. For browser apps, consider using [@bitbybit-dev/occt-worker](https://www.npmjs.com/package/@bitbybit-dev/occt-worker) which wraps this library in a non-blocking WebWorker. ## Quick Start The fastest way to scaffold a project with OCCT pre-configured: ```bash npx @bitbybit-dev/create-app my-project --engine threejs cd my-project npm install npm run dev ``` This creates a complete Vite + TypeScript project with OCCT, JSCAD, and Manifold kernels ready to use. [Learn more about the CLI](https://learn.bitbybit.dev/learn/npm-packages/intro). ### Need Server-Side CAD? The CLI first asks you to choose between a **Frontend** app or a **CAD Cloud** app. Select "cloud" to scaffold a full-stack project with a backend (Hono on Cloudflare Workers, Node.js Express, or ASP.NET Core) and a React + Three.js frontend. Your API key stays on the server and the frontend proxies requests through your backend: ```bash npx @bitbybit-dev/create-app my-cloud-project --type cloud ``` Choose from 5 backend templates: Hono + SDK, Hono + REST, Node.js + SDK, Node.js + REST, or .NET + REST. Each includes ready-to-run examples with model generation, batch operations, and [CAD pipelines](https://learn.bitbybit.dev/api/sdk/typescript/pipelines). [Learn more](https://learn.bitbybit.dev/api/cloud-api). ## Use It With an AI Agent An agent that does not know an API invents plausible names for it, and Bitbybit has more functions across its three CAD kernels than any model holds in memory. The free **[Bitbybit CAD MCP](https://learn.bitbybit.dev/learn/using-ai-with-bitbybit/mcp/bitbybit-mcp)** server removes the guesswork: your agent looks up the exact signature, parameter defaults, return type and examples for the version of `@bitbybit-dev/occt` your project has installed, and writes code that compiles the first time. ```bash claude mcp add --transport http bitbybit https://mcp.bitbybit.dev/mcp ``` Cursor, VS Code, claude.ai, ChatGPT and the Claude API connect to the same endpoint; [`npx -y @bitbybit-dev/mcp`](https://www.npmjs.com/package/@bitbybit-dev/mcp) runs the same server locally, pinned to your installed version. [Every configuration is here](https://learn.bitbybit.dev/learn/using-ai-with-bitbybit/mcp/bitbybit-mcp). With a [CAD Cloud](https://bitbybit.dev/cad-cloud) key, the [Bitbybit CAD Cloud MCP](https://learn.bitbybit.dev/learn/using-ai-with-bitbybit/mcp/cad-cloud-mcp) goes further and lets the agent run the geometry for you - measure a STEP file, run a pipeline, convert to glTF - and hand back the results as files. For assistants that cannot speak MCP, the whole API is also published as [context files](https://learn.bitbybit.dev/learn/using-ai-with-bitbybit/prompt-contexts). The [AI section of the documentation](https://learn.bitbybit.dev/learn/using-ai-with-bitbybit/intro) explains all of it. ## Links | Resource | URL | |----------|-----| | **GitHub** | https://github.com/bitbybit-dev/bitbybit/tree/master/packages/dev/occt | | **Monorepo** | https://github.com/bitbybit-dev/bitbybit | | **NPM** | https://www.npmjs.com/package/@bitbybit-dev/occt | | **Documentation** | https://learn.bitbybit.dev/learn/code/common/occt/what-is-occt | | **API Reference** | https://docs.bitbybit.dev/classes/Bit.OCCT | | **Unit Test Coverage** | https://github.com/bitbybit-dev/bitbybit/actions/workflows/verify.yml | ### API reference Every class, method and input type in this package is documented in the generated TypeScript API reference: - [OCCT](https://docs.bitbybit.dev/classes/Bit.OCCT) - [OCCT shapes](https://docs.bitbybit.dev/classes/Bit.OCCTShapes) - [OCCT booleans](https://docs.bitbybit.dev/classes/Bit.OCCTBooleans) - [OCCT input types](https://docs.bitbybit.dev/modules/Bit.Inputs.OCCT) ## Example Applications | App | Source Code | |-----|-------------| | [Hex Shell](https://learn.bitbybit.dev/learn/npm-packages/threejs/advanced-parametric-3d-model) | [GitHub](https://github.com/bitbybit-dev/bitbybit/tree/master/examples/vite/threejs/hex-shell) | | [Cup Configurator](https://app-store.bitbybit.dev/cup) | [GitHub](https://github.com/bitbybit-dev/bitbybit/tree/master/examples/vite/threejs/cup) | | [Hex House Concept](https://learn.bitbybit.dev/learn/npm-packages/threejs/hex-house-concept) | [GitHub](https://github.com/bitbybit-dev/bitbybit/tree/master/examples/vite/threejs/hex-house-concept) | | [Terrace Furniture](https://app-store.bitbybit.dev/terrace-furniture) (BabylonJS) | Closed source | ## Development ```bash # Build package npm run build-p # Run unit tests with coverage npm run test:coverage # Re-run them as you edit npm run test:watch ``` ## Bitbybit Platform Beyond NPM packages, Bitbybit offers: - **[Visual Programming Editors](https://bitbybit.dev)** - Rete & Blockly drag-and-drop 3D modeling, plus a Monaco TypeScript editor - **[CAD Cloud API](https://learn.bitbybit.dev/api/cloud-api)** - Build full [pipelines](https://learn.bitbybit.dev/api/sdk/typescript/pipelines) that compose all Bitbybit algorithms, where each step can reference outputs of previous steps. Supports parametric model generation, STEP-to-glTF conversion, and complex CAD workflows via HTTP - **[Bitbybit Studio](https://studio.bitbybit.dev)** - A growing visual dashboard where API Key users can generate models, convert files, build [pipelines with a GUI](https://learn.bitbybit.dev/api/studio/intro), inspect tasks, and preview 3D results - **[3D Bits for Shopify](https://apps.shopify.com/3d-bits-1)** - Interactive 3D product configurators for e-commerce - **[Script Runners](https://learn.bitbybit.dev/learn/runners/intro)** - Execute visual scripts directly on your website - **[Built for AI Coding Agents](https://learn.bitbybit.dev/learn/using-ai-with-bitbybit/intro)** - The free [Bitbybit CAD MCP](https://learn.bitbybit.dev/learn/using-ai-with-bitbybit/mcp/bitbybit-mcp) gives Claude Code, Cursor, VS Code, claude.ai and ChatGPT the exact API of the version you use; with a key, the [CAD Cloud MCP](https://learn.bitbybit.dev/learn/using-ai-with-bitbybit/mcp/cad-cloud-mcp) runs the geometry too - **[Business & Enterprise](https://bitbybit.dev/b2b)** - We help businesses and enterprises develop custom applications and spin up optimized CAD tenant workflows on our managed servers ## Support the Project This package is part of the open-source Bitbybit ecosystem. Your subscription helps fund continued development. ⭐ **[Subscribe - Silver or Gold plan](https://bitbybit.dev/auth/pick-plan)** | **[Get API Key for CAD Cloud](https://bitbybit.dev/auth/pick-plan?api-keys=true)** ## Community - [Discord](https://discord.gg/GSe3VMe) - [YouTube](https://www.youtube.com/@bitbybitdev?sub_confirmation=1) - [LinkedIn](https://www.linkedin.com/company/bitbybit-dev) - [X (Twitter)](https://x.com/bitbybit_dev) - [Blog](https://learn.bitbybit.dev/blog) ## Major Dependencies [OpenCascade Technology (OCCT)](https://github.com/Open-Cascade-SAS/OCCT), compiled to WebAssembly together with [Draco](https://github.com/google/draco) for glTF compression. ## License The TypeScript and JavaScript in this package: MIT © [Bit By Bit Developers](https://bitbybit.dev). The WebAssembly kernels it ships embed OCCT (LGPL-2.1 with the Open CASCADE exception) and Draco (Apache-2.0). `NOTICE` lists them and `licenses/` reproduces their license texts. The kernel is a separately replaceable component: it is loaded at runtime through the emscripten `locateFile` hook, so a modified OCCT compiled to WebAssembly can be substituted without relinking this package.