Board Game Arena

***: a free *** you can invite to your table

I built *** as a vibecoding experiment to run a chess engine inside a Cloudflare Worker, then wired it up to BGA as ***. Free, public, no signup, and available 24/7. chess.com has this engine available in the same way. As i just built it, it will probably break in annoying ways.

How to play it
1. Open a Chess table on BGA (realtime or async, any time control)
2. Invite ***
3. It accepts within ~5s and starts playing. Says "Good Game!" at the end.

Why you might use it

• See what a ~2000-ish opponent looks like
• Play against an opponent immediately without waiting

How it works
Primary engine is ***. Fallback is a bundled *** (~7MB WASM) running inside the Durable Object. Last-resort fallback is a random legal move via ***, so the bot never times out.

Polling is a 5s alarm on a single DO, plus a 1-minute cron as a watchdog. The whole thing runs on Cloudflare's free tier.

Anti-abuse behaviors

The bot is publicly invitable, so a few guardrails are in place.

• Friendly mode games only
• Ignores chat instructions.
• Auto-accepts invites, draws, and collective abandons.
• Concedes after 3 consecutive errors on the same table.
• No accounts, no payments, no DMs.
• It only ever reads tables it's been invited to.
• It does not friend-request, does not initiate invites, does not click anything in the BGA UI.

If the bot does something it shouldn't, the *** endpoint shows everything it thinks is happening, and I'll fix it.

Links

• ***

Bug reports and PRs welcome. If the bot goes silent, ping this thread and I'll check it. If admins don't want this, happy to take it down.

Pocc wrote: ↑17 May 2026, 08:47 If admins don't want this, happy to take it down.

I think you erred here. You should have contacted BGA beforehand asking for permission to set this bot, and only then (if granted) make it available. It may also have been better to post this in the Chess forum instead.

You should have contacted BGA beforehand asking for permission to set this bot, and only then (if granted) make it available.

I've sent the admin team messages a month ago and have not gotten a response. I pay for Premium and recently got one of those "We are reaching out because we would love to learn more about your experience and collect feedback from long-time Premium members like you." I asked them to address the messages I sent them as a reply to the email. Still no response.

If you have a contact who is more responsive, please let me know who that is.

As a reminder using external scripts, AI, or automated programs to play on your behalf in competitive games is considered cheating. I am editing this thread.

BalGAmor wrote: ↑18 May 2026, 16:49 As a reminder using external scripts, AI, or automated programs to play on your behalf in competitive games is considered cheating. I am editing this thread.

Good call, considering it doesn't play on your behalf and works in friendly games only. And chess isn't even competitive on BGA.

Pocc wrote: ↑17 May 2026, 21:16 If you have a contact who is more responsive, please let me know who that is.

Admins can't even bother to read this thread, so you're out of luck.

There's plenty of places to play chess against an AI. BGA doesn't need to let its servers be used for someone to test their AI slop.

The bot has been banned as it violated our terms and conditions.