ChatGPT App SDK

The ChatGPT App SDK is the developer framework for building and deploying interactive, full-stack applications with custom UIs directly inside the ChatGPT conversational interface.

This is the official toolkit for transforming ChatGPT from a conversational assistant into an AI-native app platform. The SDK allows developers to create rich, interactive experiences—like a Zillow map or a Canva editor—that render custom HTML/JS UIs within an iframe, all without the user leaving the chat thread. It operates on the Model Context Protocol (MCP), an open standard that enables your MCP server to expose tools (APIs) for the model to call and return structured data, ensuring seamless, context-aware interaction and secure communication. Developers can leverage the SDK's features, including OAuth 2.1 support and the `window.openai` bridge, to deliver powerful, transactional applications to over 800 million ChatGPT users.

https://platform.openai.com/docs/guides/apps-sdk