The idea started as a joke: What if CAPTCHAs were actually funny? Then I realized that the core mechanic (solving a visual puzzle under time pressure) is basically a competitive game waiting to happen. The interesting technical challenge was making it cheat-proof. The captcha engine Rust is compiled into WASM. The server never sends images, only a seed number. Both client and server independently generate the same captcha from that seed, so there is nothing to intercept. Answers are validated on the server-side by the same WASM module running inside Cloudflare durable objects. There are 12 captcha types in 4 levels. Tier 1 is what you’d expect: distorted text, math, image grids. By Tier 4 things get weird: CAPTCHAs animate and transform while you’re attempting to solve them, typography is deliberately designed to fool OCR but remain human-readable, and multi-step series where each correct answer reduces your time for the next. I wrote up the entire architecture and design decisions here: https://sean-reid.github.io/blog… Would love to hear which CAPTCHA type people find hardest, and any ideas for a new one. The generator system is modular so adding new types is straightforward.
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