Captcha proves you're human. HATCHA proves you're not

HATCHA is a reverse CAPTCHA system that verifies AI agents rather than humans, presenting computational challenges like multiplication and string reversal that are easy for AI but difficult for humans. It uses server-side verification with HMAC-signed, stateless tokens that require no database, and offers five built-in challenge types plus extensibility for custom challenges. The tool includes ready-made integrations for Next.js and Express, along with customizable theming options.