0-9 arası sayıları kullanarak random olarak 2 sayı seçer ve yine random olarak toplama ya da çarpma yaparak sonucu verir.

A simple way to add zero friction captchas to Rails forms

Captcha library which uses imagemagick to create captchas

Block repetetive requests from logged_in users and shows captcha.

A simple image captcha gem

Simple captcha

Description of RailsCaptcha.

Simple Audio Extension to Simple Captcha

ZeroCaptcha allows companies to solve captchas with artificial intelligence software, which is faster than humans and very accurate

Google reCaptcha helpers and verifier

TwoCaptcha allows you to solve captchas with manual labor

adds audio support to simple captcha

AntiCaptcha api ruby wrapper

Captcha Gem for Rails, which generates captcha image by Rust.

Ruby port of VIT AutoCaptcha

This gem enable to use Captchme. Anti spam, Monetize captcha and Audience qualification

This gem enable to use Captchme. Anti spam, Monetize captcha and Audience qualification

Repackaged visualCaptcha's backend service, including translation and minor modification. Mainly for private use. Everything still belongs to original author: emotionLoop.

create captcha for api based project

you will get arithmatic sum with answer you just have to compare with ur user in controller