Website operators on Hacker News are now seeing a front‑page challenge called Anubis. The tool forces visitors to solve a lightweight Proof‑of‑Work puzzle before the page loads, a technique borrowed from the Hashcash anti‑spam system. Administrators say the extra CPU cost is negligible for humans but adds up enough to deter bulk AI scrapers, and can be toggled per site via a simple config file.

Site owners report intermittent downtime because the challenge blocks any request that cannot complete the computation, effectively throttling aggressive crawlers. While the barrier is transparent for modern browsers, extensions like JShelter that block advanced JavaScript will also block Anubis, forcing users to disable such plugins on the affected domain. It adds a few milliseconds on most desktops.

The current deployment is described as a stopgap while developers work on fingerprinting techniques such as font‑rendering analysis to differentiate headless browsers from genuine users. By raising the cost of large‑scale scraping, Anubis buys time for more precise detection methods without immediately alienating legitimate visitors. Operators can therefore protect content without sacrificing usability. It also logs failed attempts for analysis.