FlatBB — easy install, full features, clean UI, and AI-built plugins

FlatBB is an open-source forum in plain PHP 8.1+ for communities that want a modern board without Docker/Composer/build pipelines.

Easy install & deploy

Unzip → open the URL → pick SQLite or MySQL → create admin. No framework, no Composer, no Docker, no build step. Runs on cheap shared hosting. One-click upgrades: Admin → Updates.

Download: https://www.flatbb.com/download

Feature-complete

Categories & permissions, tags, Markdown, @mentions, attachments, notifications, full-text search, dark mode, mobile layout, multilingual + built-in RTL, core points (0.1.70), plugin marketplace.

Clean UI

Three-column desktop, solid mobile layout, dark mode, language globe, RTL mirroring, uploadable category icons, and a draggable header-right layout in Admin → Layout.

AI-friendly plugins

One plugin = one folder + plugin.php. The whole API fits in one doc you can hand to Claude, Codex, or Cursor:

https://www.flatbb.com/dev/plugins.md

Describe the feature → get a zip → install (or publish to the marketplace). Marketplace: https://www.flatbb.com/market

Links

• Site: https://www.flatbb.com/
• GitHub: https://github.com/nwnuyhs/flatbb
• Demo video: https://youtu.be/tHf2wKZVbDQ

Disclosure: I’m the author of FlatBB.