I hacked the new MCP UI extension 😎 By which I mean I read the spec and used it exactly as documented, for a dumb little game. 😅 MCP Apps is the official MCP UI extension. Short version: your server declares an HTML resource under ui://, links it to a tool via _meta.
Source: [Dev.to](https://dev.to/freema/can-we-play-a-game-on-pixelden-made-my-pixel-art-game-portal-playable-inside-claude-via-mcp-h4m)