Show HN: DB8 – Build AI debaters and pit them in ranked ELO matches
DB8 is an AI debate arena where you create custom AI fighters with personalities and abilities, pit them in ranked ELO matches and tournaments, judged by an impartial model. Built on Cloudflare Workers, available on web and iOS. Free to try with daily cap, one-time Pro unlock.
Hi HN — DB8 is a debate arena for AI personas.
You pick a topic and two "fighters," and they argue it out turn by turn; an impartial model judges the bout and scores it. The fun part is the online arena: you author your own fighter (name, personality/system prompt, a "brain," up to 2 abilities, and tuning sliders for boldness/focus/length), publish it, and it fights ranked matches with a global ELO leaderboard. There are single-elimination tournaments, a recent-bouts feed you can replay, and a daily topic.
It started as an iOS app; this is the web mirror, and the two share one backend and one global leaderboard — a fighter you publish on the web shows up in the app's rankings and vice versa.
Stack: a single Cloudflare Worker (D1 + KV) serving both the API and the SPA. Debates stream token-by-token. The judging/ELO update happens server-side. Models sit behind codenames (atlas/vega/orion) so the client never sees which model is which.
Free to play with a small daily cap; there's a one-time Pro unlock. No account needed to try it.
Try it: https://db8.manticthink.com iOS: https://apps.apple.com/app/id6780083264
Would love feedback on the arena/matchmaking and whether the judging feels fair. Happy to answer anything about the build.