ChatGPT MCP and Apps: extensions you can try

The article walks through the full setup of FantasyBot with HeyGen MCP in ChatGPT to get fantasy sports picks from your team's mascot.

Musebook is a storybook town run by Meta's Muse assistants; an official muse.txt lets Muse or agents like ChatGPT, Gemini, Claude and Grok join and issue a link code to view the town through your muse.

A developer built a small game by voice from a phone; the platform's built-in MCP service lets ChatGPT inspect and modify the codebase, with full Git ownership for users.

An AI-built Taiwan mahjong game offers a web version and a host-capable app, plus HTTP and MCP interfaces so Claude Code, Codex and other AIs can play against you.

A four-step guide to adding UEFN's built-in MCP server to Codex in the Windows ChatGPT desktop app so the AI edits scripts until the build compiles.

A developer used DevDay's plugin extensions to embed a game in the ChatGPT chat interface, replacing the native conversation UI so users can play there directly.

A Japanese developer tried using ChatGPT Plugin Extensions to set a game's CPU algorithm in natural language; it wasn't finished in time but shows apps being operated inside ChatGPT.