chatgpt-app-builder

# 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. ## Before You Code - **Clarify what to build** → [discover.md](references/discover.md): when starting a new app, validating an idea, or scoping features - **Design tools and widgets** → [architecture.md](references/architecture.md): when deciding what needs UI vs tools-only, designing UX flows ## Setup - **Scaffold and run** → [setup.md](references/setup.md): when creating a new project, starting dev server, connecting to ChatGPT/Claude ## Implementation - **Server handlers + widget creation** → [server-and-widgets.md](references/server-and-widgets.md): when writing server.tool() with widgets, widget() helper, React widget files - **Widget state and LLM context** → [state-and-context.md](references/state-and-context.md): when persisting state, triggering LLM from widget, managing ephemeral vs persistent data - **Display modes, theme, layout** → [ui-guidelines.md](references/ui-guidelines.md): when adapting to inline/fullscreen/PiP, handling theme, device, locale - **Component API** → [components-api.md](references/components-api.md): when using McpUseProvider, Image, ErrorBoundary, useWidget - **C...