bitbybit

# Bitbybit Monorepo

Open-source 3D CAD algorithms for the web - MIT licensed. This monorepo contains all Bitbybit NPM packages plus example applications.

Written to be used by people and by AI coding agents alike: every function is published in a form an agent can look up while it writes - see [Build It With an AI Agent](#build-it-with-an-ai-agent).

## License

Source code in `packages/`, `languages/`, and `examples/` is [MIT licensed](./LICENSE). Documentation text in `docs/` is [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/). Logos, trademarks, and media assets are **not** open-source - see [CONTENT-LICENSE.md](./CONTENT-LICENSE.md) for details.

# [FULL PLATFORM AT BITBYBIT.DEV](https://bitbybit.dev)   
# [LEARN BITBYBIT](https://learn.bitbybit.dev)   
# [TYPESCRIPT API REFERENCE](https://docs.bitbybit.dev)   

<img src="https://app.bitbybit.dev/assets/git-cover.png" alt="Picture showing bitbybit.dev platform">

## Quick Start

Scaffold a fully-configured 3D CAD project in seconds:

```bash
npx @bitbybit-dev/create-app my-project
```

The CLI first asks you to pick an **app type**:

- **Frontend** - Browser-based 3D/CAD app. Choose a game engine (Three.js, Babylon.js, or PlayCanvas) and OCCT architecture (32-bit, 64-bit, or 64-bit MT). You get a Vite + TypeScript project with all three CAD kernels (OCCT, JSCAD, Manifold) pre-configured.
- **CAD Cloud** - Full-stack project with server-side CAD via our [CAD Cloud API](https://learn.bitbybit.dev/api/cloud-api). Choose a backend template (Hono + SDK, Hono + REST, Node.js + SDK, Node.js + REST, or .NET + REST). You get a React + Three.js frontend that proxies requests through your backend - your API key never leaves the server.

```bash
cd my-project
npm install
npm run dev
```

## Build It With an AI Agent

Bitbybit has 1725 functions across three CAD kernels - more than any model remembers, so an agent working from memory invents plausible names that do not exist. Give it the **[Bitbybit CAD MCP](https://learn.bitbybit.dev/learn/using-ai-with-bitbybit/mcp/bitbybit-mcp)** instead and it looks up the exact signature, defaults, return type and examples for the version you have installed. It is free and needs no account:

```bash
claude mcp add --transport http bitbybit https://mcp.bitbybit.dev/mcp
```

Codex, Cursor, VS Code, Gemini CLI, Windsurf, Zed, the JetBrains IDEs, claude.ai, ChatGPT and the Claude API connect to the same endpoint, and [`npx -y @bitbybit-dev/mcp`](https://www.npmjs.com/package/@bitbybit-dev/mcp) runs it locally against the `@bitbybit-dev` packages in your project - [every configuration is here](https://learn.bitbybit.dev/learn/using-ai-with-bitbybit/mcp/bitbybit-mcp).

[![Add to Cursor](https://cursor.com/deeplink/mcp-install-dark.svg)](https://cursor.com/link/mcp/install?name=bitbybit&config=eyJ1cmwiOiJodHRwczovL21jcC5iaXRieWJpdC5kZXYvbWNwIn0=) [![Install in VS Code](https://img.shields.io/badge/VS_Code-Install_Server-0098FF?style=flat-square&logo=visualstudiocode&logoColor=white)](https://insiders.vscode.dev/redirect/mcp/install?name=bitbybit&config=%7B%22type%22%3A%22http%22%2C%22url%22%3A%22https%3A%2F%2Fmcp.bitbybit.dev%2Fmcp%22%7D) [![Install in VS Code Insiders](https://img.shields.io/badge/VS_Code_Insiders-Install_Server-24bfa5?style=flat-square&logo=visualstudiocode&logoColor=white)](https://insiders.vscode.dev/redirect/mcp/install?name=bitbybit&config=%7B%22type%22%3A%22http%22%2C%22url%22%3A%22https%3A%2F%2Fmcp.bitbybit.dev%2Fmcp%22%7D&quality=insiders)

| | What it gives an agent | Cost |
|---|---|---|
| **[Bitbybit CAD MCP](https://learn.bitbybit.dev/learn/using-ai-with-bitbybit/mcp/bitbybit-mcp)** | The exact API of the version you use: search, full signatures with defaults, examples, and the guide on where geometry should run. Read-only. | Free, no account |
| **[Bitbybit CAD Cloud MCP](https://learn.bitbybit.dev/learn/using-ai-with-bitbybit/mcp/cad-cloud-mcp)** | Hands as well as knowledge: the agent runs operations and pipelines on CAD Cloud, converts STEP to glTF, runs Pro algorithms, and returns the files. | A [CAD Cloud](https://bitbybit.dev/cad-cloud) key |
| **[Context files](https://learn.bitbybit.dev/learn/using-ai-with-bitbybit/prompt-contexts)** and **[Context7](https://learn.bitbybit.dev/learn/using-ai-with-bitbybit/mcp/context-7)** | The whole API as one file to attach, for assistants that cannot speak MCP. | Free |

Every answer carries a tier - `oss` runs in these MIT packages anywhere, `platform-pro` inside the bitbybit.dev editors, `cloud-pro` only on CAD Cloud - so an agent never sends you to a paid service for something the free packages already do. The [AI section of the documentation](https://learn.bitbybit.dev/learn/using-ai-with-bitbybit/intro) covers all of it.

## Support the Mission

⭐ **[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)**

Check out [3D Bits app for Shopify](https://apps.shopify.com/3d-bits-1) - interactive 3D product configurators for e-commerce.

Your subscription directly funds continued open-source development of these packages.

## Important Topics

| Topic | Link |
|-------|------|
| Getting Started | https://learn.bitbybit.dev/learn/getting-started/overview |
| TypeScript API Reference | https://docs.bitbybit.dev |
| API Reference - OCCT kernel | https://docs.bitbybit.dev/classes/Bit.OCCT |
| API Reference - JSCAD kernel | https://docs.bitbybit.dev/classes/Bit.JSCAD |
| API Reference - Manifold kernel | https://docs.bitbybit.dev/classes/Bit.Manifold |
| NPM Packages Intro | https://learn.bitbybit.dev/learn/npm-packages/intro |
| Integrate with Three.js | https://learn.bitbybit.dev/learn/npm-packages/threejs/start-with-three-js |
| Integrate with BabylonJS | https://learn.bitbybit.dev/learn/npm-packages/babylonjs/start-with-babylon-js |
| Integrate with PlayCanvas | https://learn.bitbybit.dev/learn/npm-packages/playcanvas/start-with-playcanvas |
| CAD Cloud API | https://learn.bitbybit.dev/api/cloud-api |
| Script Runners | https://learn.bitbybit.dev/learn/runners/intro |
| 3D Bits for Shopify | https://learn.bitbybit.dev/learn/3d-bits/intro |
| AI Coding Agents - Overview | https://learn.bitbybit.dev/learn/using-ai-with-bitbybit/intro |
| Bitbybit CAD MCP - free, version-exact API lookups | https://learn.bitbybit.dev/learn/using-ai-with-bitbybit/mcp/bitbybit-mcp |
| Bitbybit CAD Cloud MCP - let an agent run the geometry | https://learn.bitbybit.dev/learn/using-ai-with-bitbybit/mcp/cad-cloud-mcp |
| Context Files for Assistants Without MCP | https://learn.bitbybit.dev/learn/using-ai-with-bitbybit/prompt-contexts |
| Unit Testing Approach | https://learn.bitbybit.dev/learn/github/unit-tests |
| Live Unit Test Coverage | https://github.com/bitbybit-dev/bitbybit/actions/workflows/verify.yml |
| Blog | https://learn.bitbybit.dev/blog |

## How Bitbybit Fits Into Your Stack

<img src="https://learn.bitbybit.dev/img/bitbybit-dev-cad-platform.webp" alt="Diagram of the Bitbybit platform showing how a website reaches its geometry: script runners, iframe embeds, the NPM packages, the CAD Cloud REST API and AI agents over MCP">

The diagram shows every way a website can reach Bitbybit geometry, and where the NPM packages below sit among them:

- **NPM packages** - this repository. The kernels compile to WebAssembly and run in your users' browsers or in your own Node process, inside your build, MIT licensed and free.
- **[Script runners](https://learn.bitbybit.dev/learn/runners/intro)** - one script file loads the same engine and executes scripts exported from the visual editors, with no build step.
- **Iframe embeds** - a project published on [bitbybit.dev](https://bitbybit.dev) dropped straight into a page.
- **[CAD Cloud REST API](https://learn.bitbybit.dev/api/cloud-api)** - your backend sends the work to our managed kernels and gets results back as files, for the Pro algorithms and for compute you would rather not host.
- **[AI agents](https://learn.bitbybit.dev/learn/using-ai-with-bitbybit/intro)** - the MCP servers above, writing code against any of these paths or running the geometry themselves.

The [full walkthrough of the diagram](https://learn.bitbybit.dev/learn/intro) is on learn.bitbybit.dev.

## NPM Packages

| Package | Description |
|---------|-------------|
| [@bitbybit-dev/babylonjs](https://www.npmjs.com/package/@bitbybit-dev/babylonjs) | BabylonJS engine integration for drawing CAD geometry |
| [@bitbybit-dev/threejs](https://www.npmjs.com/package/@bitbybit-dev/threejs) | Three.js engine integration for drawing CAD geometry |
| [@bitbybit-dev/playcanvas](https://www.npmjs.com/package/@bitbybit-dev/playcanvas) | PlayCanvas engine integration for drawing CAD geometry |
| [@bitbybit-dev/core](https://www.npmjs.com/package/@bitbybit-dev/core) | Core assembly layer combining all CAD kernels |
| [@bitbybit-dev/occt](https://www.npmjs.com/package/@bitbybit-dev/occt) | OpenCascade CAD kernel (works in Node.js & browser) |
| [@bitbybit-dev/occt-worker](https://www.npmjs.com/package/@bitbybit-dev/occt-worker) | OCCT via WebWorker (non-blocking, browser only) |
| [@bitbybit-dev/manifold](https://www.npmjs.com/package/@bitbybit-dev/manifold) | Manifold fast mesh booleans (works in Node.js & browser) |
| [@bitbybit-dev/manifold-worker](https://www.npmjs.com/package/@bitbybit-dev/manifold-worker) | Manifold via WebWorker (non-blocking, browser only) |
| [@bitbybit-dev/jscad](https://www.npmjs.com/package/@bitbybit-dev/jscad) | JSCAD solid modeling (works in Node.js & browser) |
| [@bitbybit-dev/jscad-worker](https://www.npmjs.com/package/@bitbybit-dev/jscad-worker) | JSCAD via WebWorker (non-blocking, browser only) |
| [@bitbybit-dev/base](https://www.npmjs.com/package/@bitbybit-dev/base) | Base math/vector/matrix algorithms used by all packages |
| [@bitbybit-dev/create-app](https://www.npmjs.com/package/@bitbybit-dev/create-app) | CLI tool to scaffold 3D/CAD pr