Hi HN,I’ve been using anubis (<a href="https:&#x2F;&#x2F;github.com&#x2F;TecharoHQ&#x2F;anubis">https:&#x2F;&#x2F;github.com&#x2F;TecharoHQ&#x2F;anubis</a>) for some time and love its clever use of client-side proof-of-work as an AI firewall. Inspired by that idea, I decided to create an adjacent, self-hostable CAPTCHA system that can be deployed with minimal fuss.The result is Wicketkeeper: <a href="https:&#x2F;&#x2F;github.com&#x2F;a-ve&#x2F;wicketkeeper">https:&#x2F;&#x2F;github.com&#x2F;a-ve&#x2F;wicketkeeper</a>It’s a full-stack CAPTCHA system based on the same proof-of-work logic as anubis - offloading a small, unnoticeable computational task to the user’s browser, making it trivial for humans but costly for simple bots.On the server side:- it&#x27;s a lightweight Go server that issues challenges and verifies solutions.- it implements a time-windowed Redis Bloom filter (via an atomic Lua script) to prevent reuse of solved challenges.- uses short-expiry (10 minutes) Ed25519-signed JWTs for the entire challenge&#x2F;response flow, so no session state is needed.And on the client side:- It includes a simple, dependency-free JavaScript widget.- I&#x27;ve included a complete Express.js example showing exactly how to integrate it into a real web form.Wicketkeeper is open source under the MIT license. I’d love to hear your feedback. Thanks for taking a look!

Show HN: Wicketkeeper - A self-hosted, privacy-friendly proof-of-work captcha