Packages

PancakeJS is modular — install only what you need. Here's an overview of all available packages.

Core Packages

@pancakeapps/core

Platform-agnostic types, registry, validation, and adapter interfaces. The foundation everything else builds on.

@pancakeapps/server

Server runtime with adapter management, resource store, and tool/widget registration.

@pancakeapps/react

React hooks and components for building widget UIs.

@pancakeapps/cli

CLI for development, building, and running your app.

Adapters

@pancakeapps/adapter-mcp-apps

Adapter for MCP-compatible hosts like Claude Desktop.

@pancakeapps/adapter-chatgpt-apps

Adapter for ChatGPT Apps.

Package Details

@pancakeapps/core

The foundation package containing:

Type definitions for tools, widgets, and adapters
Registry for managing tool/widget definitions
Validation utilities using Zod
Adapter interfaces for building new host adapters

import { 
  ToolDefinition, 
  WidgetDefinition,
  AdapterInterface,
  Registry 
} from '@pancakeapps/core';

@pancakeapps/server

Server-side runtime including:

createUniversalServerApp — Main app factory
Tool/Widget registration — Define your capabilities
Adapter management — Register multiple adapters
Resource store — Serve widget assets

import { 
  createUniversalServerApp,
  textResult,
  htmlResult,
  withData,
  renderWidget 
} from '@pancakeapps/server';

const app = createUniversalServerApp({
  name: 'my-app',
  version: '1.0.0',
});

@pancakeapps/react

React utilities for widgets:

Hook	Purpose
`useToolInvocation`	Access initial data passed to widget
`useWidgetState`	Persist state across renders
`useCallTool`	Call other tools from widget
`useHost`	Access host info and capabilities
`useFollowUp`	Send follow-up prompts
`useTheme`	Get current theme (light/dark)
`useLocale`	Get user's locale
`useCapability`	Check if capability is available

import { 
  UniversalAppProvider,
  useToolInvocation,
  useWidgetState,
  useCallTool,
  useHost 
} from '@pancakeapps/react';

@pancakeapps/cli

Development tools:

# Start development server with hot reload
universal-apps dev

# Build for production
universal-apps build

# Run production server
universal-apps start

@pancakeapps/adapter-mcp-apps

MCP (Model Context Protocol) adapter for Claude Desktop and other MCP-compatible hosts:

import { createMcpAppsServerAdapter } from '@pancakeapps/adapter-mcp-apps';

app.adapter(createMcpAppsServerAdapter());

Features:

JSON-RPC 2.0 communication
Resource serving for widgets
Handshake authentication
Origin validation

@pancakeapps/adapter-chatgpt-apps

ChatGPT Apps adapter:

import { createChatGptServerAdapter } from '@pancakeapps/adapter-chatgpt-apps';

app.adapter(createChatGptServerAdapter());

Features:

window.openai API integration
Output template support
ChatGPT sandbox compatibility

Installation Matrix

Use Case	Packages Needed
Tools only (no UI)	`core`, `server`, `cli`, adapters
Tools + Widgets	All packages
MCP only	`core`, `server`, `react`, `cli`, `adapter-mcp-apps`
ChatGPT only	`core`, `server`, `react`, `cli`, `adapter-chatgpt-apps`
Both platforms	All packages

Version Compatibility

All @pancakeapps/* packages are versioned together. Always use matching versions:

{
  "dependencies": {
    "@pancakeapps/core": "^1.0.0",
    "@pancakeapps/server": "^1.0.0",
    "@pancakeapps/react": "^1.0.0",
    "@pancakeapps/adapter-mcp-apps": "^1.0.0",
    "@pancakeapps/adapter-chatgpt-apps": "^1.0.0",
    "@pancakeapps/cli": "^1.0.0"
  }
}

Peer Dependencies

All packages require:

Package	Version
`zod`	`^3.0.0`
`react`	`^18.0.0` or `^19.0.0`
`react-dom`	`^18.0.0` or `^19.0.0`

Next Steps

Getting Started — Set up your first project
API Reference — Detailed API documentation

@pancakeapps/core

@pancakeapps/server

@pancakeapps/react

@pancakeapps/cli

@pancakeapps/adapter-mcp-apps

@pancakeapps/adapter-chatgpt-apps

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