Anubis is a free, open-source proof-of-work firewall that blocks AI scrapers and bots before they reach your site. MIT licensed, made by Techaro.
Category
Productivity
Pricing
Freemium, from Free
Verified
Not yet
Last updated
July 18, 2026
Founded
2025
Headquarters
Canada
Free PlanWeb AppOpen SourceFreemiumSelf-Hosted
Overview
Anubis is an open-source proof-of-work firewall that protects websites from AI scraper bots and abusive automated crawlers. It was created by developer Xe Iaso and released on January 19, 2025, after an Amazon web crawler overwhelmed their self-hosted Git server while ignoring robots.txt. The project is now maintained by Techaro, a Canadian company.
Anubis sits as a reverse proxy in front of a web service, forcing incoming clients to solve a SHA-256 proof-of-work challenge, inspired by Hashcash, before reaching the origin server.
Key Features
The core challenge mechanism imposes a small computational cost on each client, intended to be imperceptible for normal browsing but costly at the scale automated scrapers operate. Administrators can configure bot allow/deny policies to whitelist legitimate crawlers, such as search engines, and customize challenge pages. Anubis is released under the MIT license and is written primarily in Go.
Pricing Overview
The core Anubis software is free and open source. Techaro also offers BotStopper, an unbranded, corporate-friendly variant with custom branding and templating support, distributed as a Docker image and made available to GitHub Sponsors at higher contribution tiers rather than through a standard published price list.
Key Features
Proof-of-work challenge gate — Requires clients to solve a SHA-256 computational challenge before reaching the protected site.
Configurable bot policies — Administrators can allowlist or block specific bots and crawlers.
Reverse proxy deployment — Deploys in front of an existing web service without modifying the backend application.
Custom challenge pages — Supports branding and customization of the challenge/error pages shown to visitors.
Open source (MIT licensed) — Fully open-source and self-hostable, with source code on GitHub.
BotStopper commercial variant — An unbranded, enterprise-friendly version available to GitHub Sponsors at higher tiers.
Pros & Cons
Pros
Free and open source under the MIT license
Lightweight and effective against large-scale AI scraper traffic per widespread community adoption
Easy to self-host as a reverse proxy in front of existing infrastructure
Configurable to reduce false positives against legitimate crawlers
Cons
Proof-of-work challenges can add friction or block legitimate automated tools, such as archival crawlers
Requires reverse-proxy setup and some technical familiarity to deploy correctly
BotStopper's commercial pricing isn't published as a standard price list
Pricing
Open Source Free N/A
BotStopper (GitHub Sponsors) Available at higher GitHub Sponsors tiers Monthly
Frequently Asked Questions
Is Anubis free to use?
Yes, the core Anubis software is free and open source under the MIT license.
What does Anubis protect against?
It protects websites from AI scraper bots and abusive automated crawlers using proof-of-work challenges.
Who makes Anubis?
It was created by developer Xe Iaso and is now maintained by Techaro, a Canadian company.
Is there a paid version of Anubis?
Techaro offers BotStopper, an unbranded commercial variant, available to GitHub Sponsors at higher contribution tiers.