TecharoHQ/anubis ? reverse-engineered prompt

Build me a small web app or service called Anubis that sits in front of my website and checks incoming visitors before letting them through.

I want it to act like a lightweight firewall for AI crawlers and scraper bots, using one or more simple challenges to decide whether a request should be allowed. It should be easy to run in front of an upstream site, and it should block suspicious traffic while still letting me create exceptions for bots I trust, like the Internet Archive or other known good crawlers.

Please make it practical and polished, with a clear landing page or docs page that explains what it does, how to turn it on, and how to set up allowlists or policy rules. If you need to look up current docs online while building, go ahead. Keep it minimal, fast, and focused on protecting a site without needing a huge cloud provider in front of it.