Anubis: One Year to Ship WebAssembly Support
Original: It took a year to ship WebAssembly in Anubis
Why This Matters
WebAssembly support strengthens client-side challenge complexity, raising the bar for AI scraper evasion at scale.
Anubis, a Proof-of-Work bot protection tool developed by Techaro, has shipped WebAssembly support after approximately one year of development. The feature is included in version v1.28.0-pre1, designed to defend websites against aggressive AI scraper bots.
Anubis is an open-source bot mitigation tool built by Techaro, a Canadian company, that uses a Proof-of-Work scheme inspired by Hashcash — originally proposed to reduce email spam — to make mass AI scraping economically costly while keeping the burden negligible for individual users. After roughly one year of development effort, the project has shipped WebAssembly (WASM) support, now available in version v1.28.0-pre1. The tool works by presenting a JavaScript-based challenge to visitors; legitimate users complete it with minimal friction, while large-scale scrapers face compounding computational costs. The project acknowledges this as a transitional solution, with longer-term plans focusing on fingerprinting headless browsers — for example, via font rendering behavior — to reduce the need to challenge likely-legitimate users at all. Anubis requires modern JavaScript and is incompatible with privacy extensions such as JShelter. A no-JavaScript fallback solution is listed as a work in progress. The mascot design is credited to CELPHASE.