# Yumina > Yumina is an open-source world engine for AI roleplay and AI games: creators define a world with lore, variables and rules, a custom interface, audio and multiple AIs, and players play it in the browser at yumina.io. The engine, editor and player are open source under AGPL-3.0; the hosted site adds the community, publishing and a credit wallet. ## Docs - [Creator docs](https://docs.yumina.io/): building worlds, the editor, publishing - [World spec](https://docs.yumina.io/world-spec/): the world JSON, entries, variables, rules, custom UI ## Blog - [Blog index](https://yumina.io/blog/llms.txt): every post with a one-line description, Markdown links - [Blog full text](https://yumina.io/blog/llms-full.txt): all posts in one file ## Code - [yumina-oss on GitHub](https://github.com/lovetimo0421/yumina-oss): the public repository ## Optional - [Sitemap](https://yumina.io/sitemap.xml) - [RSS](https://yumina.io/blog/feed.xml)