Bitbybit CAD MCP

Official7 toolsLive

by bitbybit-dev · TypeScript

Bitbybit 3D parametric CAD API, version-exact, for coding agents: search, describe, examples, guide

Model Context Protocol (MCP) Server: dev.bitbybit/cad

This MCP server provides access to Bitbybit 3D parametric CAD functionality through a version-exact API aimed at coding agents. Its described capabilities include searching, describing, providing examples, and supplying a guide for the CAD API.

🛠️ Key Features

Bitbybit 3D parametric CAD API
Version-exact API targeting coding agents
Search capability
Description capability
Examples provision
Guide provision

🚀 Use Cases

For agents that need to search CAD API capabilities
For agents that need CAD API descriptions
For agents that require example workflows
For agents that need guidance on using the CAD API

⚡ Developer Benefits

Supports development using a version-exact CAD API
Helps agents find and understand CAD functions via search and descriptions
Provides examples and guidance to support implementation

⚠️ Limitations

No additional tool count or concrete tool list details are provided.

Topics

3d3dmodeling3dprintingaecarchitectureautomotivebabylonjsbitbybitcadcamcreativecodingengineeringgeometryjscadmodelingocctopencascademanifoldthreejsplaycanvas

Captured live from the server via tools/list.

search_api

Find Bitbybit API members (methods, namespaces, cloud operations) by keywords, for example "box solid" or "fillet edges". Returns dotted paths with a one-line summary, the tier (oss on npm, platform-pro only at bitbybit.dev, cloud-pro only on CAD Cloud) and the engines each is published for. Call describe with a path before writing code that uses it.

Parameters4

query	string	required	Keywords, a phrase, or a partial dotted path
engine	string	optional	Only members published for this engine, plus the cloud operations, which run on CAD Cloud rather than in an engine; omit for every engine
limit	integer	optional	How many results, 10 by default
version	string	optional	The API version to search; omit for the version the server holds

Raw schema

{
  "type": "object",
  "properties": {
    "query": {
      "type": "string",
      "minLength": 1,
      "maxLength": 200,
      "description": "Keywords, a phrase, or a partial dotted path"
    },
    "engine": {
      "description": "Only members published for this engine, plus the cloud operations, which run on CAD Cloud rather than in an engine; omit for every engine",
      "type": "string",
      "enum": [
        "babylonjs",
        "threejs",
        "playcanvas"
      ]
    },
    "limit": {
      "description": "How many results, 10 by default",
      "type": "integer",
      "minimum": 1,
      "maximum": 50
    },
    "version": {
      "description": "The API version to search; omit for the version the server holds",
      "type": "string"
    }
  },
  "required": [
    "query"
  ],
  "$schema": "https://json-schema.org/draft/2020-12/schema"
}

describe

The exact contract of one member by dotted path, for example occt.shapes.solid.createBox: signature, every parameter with its type, default and range, the return type, the documentation, examples and where it runs. Answers are for the API version the server holds. An unknown path is reported as not found together with the nearest existing paths; nothing is guessed.

Parameters2

path	string	required	The dotted path of the member, for example occt.shapes.solid.createBox
version	string	optional	The API version to describe; omit for the version the server holds

Raw schema

{
  "type": "object",
  "properties": {
    "path": {
      "type": "string",
      "minLength": 1,
      "maxLength": 256,
      "description": "The dotted path of the member, for example occt.shapes.solid.createBox"
    },
    "version": {
      "description": "The API version to describe; omit for the version the server holds",
      "type": "string"
    }
  },
  "required": [
    "path"
  ],
  "$schema": "https://json-schema.org/draft/2020-12/schema"
}

list_namespace

The members one level below a namespace path, for example occt.shapes, each with its kind and summary. Without a path, the top-level namespaces. Use it to discover what exists before searching for details.

Parameters2

path	string	optional	A namespace path such as occt or occt.shapes; omit for the top level
version	string	optional	The API version to list; omit for the version the server holds

Raw schema

{
  "type": "object",
  "properties": {
    "path": {
      "description": "A namespace path such as occt or occt.shapes; omit for the top level",
      "type": "string",
      "maxLength": 256
    },
    "version": {
      "description": "The API version to list; omit for the version the server holds",
      "type": "string"
    }
  },
  "$schema": "https://json-schema.org/draft/2020-12/schema"
}

get_examples

Working TypeScript examples for a member path, for a namespace, or for a topic given as keywords. Each example names the member it belongs to and links its reference page. Examples are written for the API version the server holds.

Parameters5

path	string	optional	A member or namespace path, for example occt.shapes.solid.createBox or occt.fillets
topic	string	optional	Keywords to find examples by, when no path is known
engine	string	optional	Prefer members published for this engine when searching by topic
limit	integer	optional	How many examples, 5 by default
version	string	optional	The API version; omit for the version the server holds

Raw schema

{
  "type": "object",
  "properties": {
    "path": {
      "description": "A member or namespace path, for example occt.shapes.solid.createBox or occt.fillets",
      "type": "string",
      "maxLength": 256
    },
    "topic": {
      "description": "Keywords to find examples by, when no path is known",
      "type": "string",
      "maxLength": 200
    },
    "engine": {
      "description": "Prefer members published for this engine when searching by topic",
      "type": "string",
      "enum": [
        "babylonjs",
        "threejs",
        "playcanvas"
      ]
    },
    "limit": {
      "description": "How many examples, 5 by default",
      "type": "integer",
      "minimum": 1,
      "maximum": 20
    },
    "version": {
      "description": "The API version; omit for the version the server holds",
      "type": "string"
    }
  },
  "$schema": "https://json-schema.org/draft/2020-12/schema"
}

get_guide

Sections of the public guide on building with Bitbybit: what runs in the browser, on a server, on a lightweight backend, and what needs CAD Cloud. Without a topic it lists the sections. Read "integrate" before recommending where geometry should run: the npm packages are the default, and CAD Cloud is for algorithms that exist only there or compute the caller cannot provide.

Parameters1

topic

string

optional

A section id or a short name such as integrate, browser, backend, server-side, pro, start; omit to list the sections

Raw schema

{
  "type": "object",
  "properties": {
    "topic": {
      "description": "A section id or a short name such as integrate, browser, backend, server-side, pro, start; omit to list the sections",
      "type": "string",
      "maxLength": 128
    }
  },
  "$schema": "https://json-schema.org/draft/2020-12/schema"
}

search

Searches the Bitbybit API documentation and returns a list of results with id, title and url. Each id is a dotted API path that fetch accepts.

Parameters1

query

string

required

Search terms

Raw schema

{
  "type": "object",
  "properties": {
    "query": {
      "type": "string",
      "minLength": 1,
      "maxLength": 200,
      "description": "Search terms"
    }
  },
  "required": [
    "query"
  ],
  "$schema": "https://json-schema.org/draft/2020-12/schema"
}

fetch

Fetches the full documentation of one Bitbybit API member by id (a dotted path returned by search) as text, with its title, url and metadata.

Parameters1

string

required

A dotted API path returned by search

Raw schema

{
  "type": "object",
  "properties": {
    "id": {
      "type": "string",
      "minLength": 1,
      "maxLength": 256,
      "description": "A dotted API path returned by search"
    }
  },
  "required": [
    "id"
  ],
  "$schema": "https://json-schema.org/draft/2020-12/schema"
}

packages/dev/mcp/README.md11 KBView on GitHub

@bitbybit-dev/mcp: the Bitbybit CAD MCP server

An MCP server that documents the Bitbybit 3D CAD API for AI coding agents: every function, its parameters, defaults, return type and examples, for the exact version your project uses. Bitbybit has 1725 functions across three CAD kernels - more than any model holds in memory - so an agent working from memory invents plausible names that do not exist. An agent with this server looks each one up instead, and writes code that compiles the first time.

It answers from the API index Bitbybit publishes with every release (https://git-cdn.bitbybit.dev/v<version>/ai-context/index.json), never from memory, and never from a moving "latest".

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 what an agent is writing code for. The MIT-licensed npm packages run the CAD kernels in your users' browsers or in your own Node process; script runners load the same engine from one file; the CAD Cloud REST API runs the work on managed servers. This server knows all of them, and every answer carries a tier - oss, platform-pro or cloud-pro - so an agent never sends you to a paid service for something the free packages already do.

Connect it

The same server runs two ways. Hosted at https://mcp.bitbybit.dev/mcp over Streamable HTTP, which needs nothing installed and serves the newest release; or locally over stdio with npx, which needs Node 20 and serves the version your project has installed. Start with the remote.

Claude Code

bash

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

or the local server:

bash

claude mcp add --transport stdio bitbybit -- npx -y @bitbybit-dev/mcp

For a project, commit a .mcp.json at its root so every collaborator's Claude Code finds it:

json

{ "mcpServers": { "bitbybit": { "type": "http", "url": "https://mcp.bitbybit.dev/mcp" } } }

Cursor (.cursor/mcp.json)

json

{ "mcpServers": { "bitbybit": { "url": "https://mcp.bitbybit.dev/mcp" } } }

VS Code (.vscode/mcp.json) - the type is required, or VS Code tries to start the URL as a program:

json

{ "servers": { "bitbybit": { "type": "http", "url": "https://mcp.bitbybit.dev/mcp" } } }

Either form takes the local server instead: { "command": "npx", "args": ["-y", "@bitbybit-dev/mcp"] }, with "type": "stdio" in VS Code.

Codex

bash

codex mcp add bitbybit --url https://mcp.bitbybit.dev/mcp

or codex mcp add bitbybit -- npx -y @bitbybit-dev/mcp for the local server. In ~/.codex/config.toml that is [mcp_servers.bitbybit] with url = "https://mcp.bitbybit.dev/mcp".

Gemini CLI (gemini mcp add -t http bitbybit https://mcp.bitbybit.dev/mcp), Windsurf (serverUrl in ~/.codeium/windsurf/mcp_config.json), Zed (context_servers in its settings) and the JetBrains IDEs (AI Assistant, MCP, a JSON entry with url) take the same address. claude.ai, ChatGPT and the Claude API connect to the remote as a custom connector - every configuration is documented here.

Which version it serves

The server documents one exact version of the API. It picks it in this order:

--version <version> on the command line;
BITBYBIT_VERSION=<version> in the environment;
the version of the @bitbybit-dev packages installed around the working directory (core, then the renderer packages, then occt); packages that disagree are reported on stderr and the first wins;
its own version, which is the newest API version it was released with.

Indexes are cached in $XDG_CACHE_HOME/bitbybit-mcp (or ~/.cache/bitbybit-mcp); --no-cache skips the cache. Everything the program prints goes to stderr; stdout is the protocol.

Tools

Tool	What it answers
`search_api`	members by keywords, with path, summary, tier and engines
`describe`	the full contract of one member by dotted path; an unknown path is reported with the nearest existing ones
`list_namespace`	the members one level below a namespace
`get_examples`	code examples for a member, a namespace or a topic
`get_guide`	sections of the public guide on where geometry should run
`search`, `fetch`	the same lookups in the shape ChatGPT connectors require

Every tool is read-only. Tiers in the answers: oss (in the npm packages, MIT), platform-pro (only when scripting inside bitbybit.dev), cloud-pro (only on CAD Cloud, with an API key).

The companion server

This server answers questions; it never runs geometry. When you want the agent to produce geometry - measure a STEP file, run a pipeline, unfold a sheet-metal part, convert to glTF - connect the Bitbybit CAD Cloud MCP alongside it, with a CAD Cloud API key:

bash

claude mcp add --transport http bitbybit-cloud https://api.bitbybit.dev/mcp --header "X-API-Key: <your key>"

In Codex the same is [mcp_servers.bitbybit-cloud] with url = "https://api.bitbybit.dev/mcp" and env_http_headers = { "X-API-Key" = "BITBYBIT_API_KEY" }, the key read from the environment.

The two are designed to work together: the agent learns a member here and calls it there with the same dotted path and the same argument object.

As a library

The package exports the tool registry and the index reader, so another server can serve the same tools:

import { createDocsRegistry, contextForIndex, GUIDES, GUIDE_PAGE_URL } from "@bitbybit-dev/mcp";
import { loadIndex } from "@bitbybit-dev/mcp/index-loader";
import { createMcpServer } from "@bitbybit-dev/mcp/server";

const version = "<a released version>";
const index = await loadIndex({ version });
const context = contextForIndex(index, GUIDES, GUIDE_PAGE_URL);
const server = createMcpServer(createDocsRegistry(), context, { name: "bitbybit", version });

toHttp(registry, context) renders the same tools for a plain HTTP endpoint, and guarded(registry, report) is the error boundary every server puts around a registry: a handler that throws answers a generic error result and the throw goes to report, so no internal message reaches a client. Registry.map(wrap) re-wraps every handler for such concerns of your own. The package root imports no Node built-in, so a bundler can take it into an edge runtime; the loader and the version detector, which read the file system, are the separate index-loader and installed-version entries, and the $ref inliner the tool schemas go through is the dependency-free json-schema entry.

Privacy

The stdio server sends nothing anywhere except one request to the CDN for the index of the version it serves.

Links

Resource	URL
Using AI with Bitbybit	https://learn.bitbybit.dev/learn/using-ai-with-bitbybit/intro
This server, documented	https://learn.bitbybit.dev/learn/using-ai-with-bitbybit/mcp/bitbybit-mcp
CAD Cloud MCP	https://learn.bitbybit.dev/learn/using-ai-with-bitbybit/mcp/cad-cloud-mcp
Agentic CAD - where geometry should run	https://learn.bitbybit.dev/learn/using-ai-with-bitbybit/agentic-cad
Context files, for hosts without MCP	https://learn.bitbybit.dev/learn/using-ai-with-bitbybit/prompt-contexts
GitHub	https://github.com/bitbybit-dev/bitbybit/tree/master/packages/dev/mcp
Monorepo	https://github.com/bitbybit-dev/bitbybit
TypeScript API Reference	https://docs.bitbybit.dev

Bitbybit Platform

Beyond NPM packages, Bitbybit offers:

Visual Programming Editors - Rete & Blockly drag-and-drop 3D modeling, plus a Monaco TypeScript editor
CAD Cloud API - Build full 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 - A growing visual dashboard where API Key users can generate models, convert files, build pipelines with a GUI, inspect tasks, and preview 3D results
3D Bits for Shopify - Interactive 3D product configurators for e-commerce
Script Runners - Execute visual scripts directly on your website
Built for AI Coding Agents - This server, the CAD Cloud MCP for running geometry, and context files for assistants without MCP
Business & Enterprise - 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 | Get API Key for CAD Cloud

Community

License

Install

Tools (7)

search_apidescribelist_namespaceget_examplesget_guidesearchfetch

Add to VS Code Add to Cursor

claude_desktop_config.json

json

{
  "mcpServers": {
    "cad": {
      "command": "npx",
      "args": [
        "-y",
        "@bitbybit-dev/mcp@1.3.2"
      ]
    }
  }
}

Model Context Protocol (MCP) Server: dev.bitbybit/cad

🛠️ Key Features

🚀 Use Cases

⚡ Developer Benefits

⚠️ Limitations

Topics

search_api

describe

list_namespace

get_examples

get_guide

search

fetch

@bitbybit-dev/mcp: the Bitbybit CAD MCP server

Connect it

Which version it serves

Tools

The companion server

As a library

Privacy

Links

Bitbybit Platform

Support the Project

Community

License

Install

Related servers