RESTCaptcha is a lightweight, privacy-friendly CAPTCHA solution that requires no image puzzles, no third-party tracking, and no persistent server-side sessions.
Instead, it uses proof-of-work to verify human interaction with your form.
Features:
- Stateless challenge using HMAC-signed nonce
- Client-side proof-of-work puzzle (SHA-256 or SHA-512 hash under threshold)
- CDN-ready restcaptcha.js script with pluggable API endpoint
- Optional IP reputation check as an additional security layer
- Fully customisable
- Fully integrable with Node.js, PHP, ASP.NET or any other server technology
- Support for different modes (interactive, auto, invisible, headless)
- Support for multiple languages
- Build with .NET 10 and JavaScript.
- .NET 10
- ASP.NET as web framework
- JavaScript for the restcaptcha.js client script
Starting points for documentation can be found in the GitHub wiki.
Yes, that would be much appreciated. The best way to help is to post a response via the Issue Tracker and/or submit a Pull Request.