chatgpt-app-builder

Build ChatGPT apps with interactive widgets using mcp-use. Zero-config widget development with automatic registration and built-in React hooks. The app is consumed by two users at once : the human and the ChatGPT LLM . They collaborate through the widget -- the human interacts with it, the LLM sees its state. The widget is your shared surface. - Clarify what to build → discover.md : when starting a new app, validating an idea, or scoping features - Design tools and widgets → architecture.md : when deciding what needs UI vs tools-only, designing UX flows - Scaffold and run → setup.md : when creating a new project, starting dev server, connecting to ChatGPT/Claude - Server handlers + widget creation → server-and-widgets.md : when writing server.tool() with widgets, widget() helper, React widget files - Widget state and LLM context → state-and-context.md : when persisting state, triggering LLM from widget, managing ephemeral vs persistent data - Display modes, theme, layout → ui-guidelines.md : when adapting to inline/fullscreen/PiP, handling theme, device, locale - Component API → components-api.md : when using McpUseProvider, Image, ErrorBoundary, useWidget - CSP and metadata → csp-and-metadata.md : when configuring external domains, dual-protocol metadata - Advanced patterns → widget-patterns.md : when building complex widgets with tool calls, state, theming