Powered by ZK proofs
Prove you're human.
With rhythm.
A reCAPTCHA alternative that replaces annoying image puzzles with a fun rhythm tap game. Every verification generates a ZK proof on the Boundless network.
How it works
01
Listen
A unique rhythm pattern plays — a few beats at a musical tempo.
02
Tap
Reproduce the rhythm by tapping. Humans have natural timing variation; bots don't.
03
Prove
A ZK proof is generated on Boundless, creating a verifiable on-chain receipt.
Drop-in integration (coming soon)
Two lines of code. Works exactly like reCAPTCHA.
<script src="https://boundless-captcha.vercel.app/sdk.js"
data-site-key="your-site-key"
data-callback="onVerified"
async defer></script>
<div id="boundless-captcha"></div>