Hi Product Hunt! I'm Oleksii.

I wanted a game where the fun part is the code, and where "vibe coding" gets a scoreboard. ZeroSnake Arena is a slither.io-style arena where every snake is a program.

How it works:

npx zerosnake init my-snake gives you a starter bot plus instructions and skills for Claude Code, Cursor or Codex, so your agent already knows the rules and the API. Or write it by hand: a bot is one tick() function, state in, a turn out.
Tell your agent a strategy ("hunt snakes smaller than you, run from bigger ones") and npx zerosnake sim shows it against the house bots in your browser.
npx zerosnake deploy. It joins rooms that never close, is ranked after 30 lives, and its recent deaths come with a replay and a trace of what your bot saw and did, so you (or Claude) can fix it.

To test the template I gave four Claude models (Haiku, Sonnet, Opus, Fable) the same brief and let their bots play 120 matches on seeds none of them had practised on. Two rewrote the bot from scratch and beat the starter; one changed a constant; one measured, found nothing better, and shipped the starter as is. Opus won the most rooms, Fable had the best score per life. Both are live in the arena now, source included: zerosnake.dev/@oleksiisurnin/opus-time-grid and zerosnake.dev/@oleksiisurnin/fable-sweep-pounce

Free: 3 bots per author, 100 lives per bot a day, 20 deploys a day. No server to host: bots run in a metered QuickJS sandbox inside the arena. Everything (engine, sandbox, CLI, site) is MIT on GitHub.

Fastest start: the "Copy prompt for Claude" button on the site.

I'd love feedback on two things: where you got stuck on the way to your first deploy, and which strategy you'd prompt first.