create captcha for api based project

A captcha verification approach for Rails apps, directly integrated into ActiveRecord’s validation mechanism and providing helpers for ActionController and ActionView.

IQ, Math Captcha

Implementation of captcha (Completely Automated Public Turing-Test to Tell Computers and Humans Apart) that is both easy to use and easy to customize/extend.

Death by Captcha Ruby implementation (HTTP API)

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

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

A very simple rack captcha middleware via captchator.com API

NO LONGER MAINTAINED AND NOT RECOMMENDED, AS BOTS ARE ABLE TO RESOLVE CAPTCHAS BETTER THAN HUMANS. Based on Login Attempts check if captcha is necessary. It stores a permanent cookie and uses a table for tracking login requests.

My version of SimpleCaptcha

Merb plugin that provides resource access rate limits and captcha'ing

Form protection with simple captcha calculations.

Helps humankind with simpler captchas

Solve Media CAPTCHA Replacement

这是一个验证码生成器。基于rucaptcha。本人只是将他的源码拉下来。为我的网站进行适配。因为我不使用sesion.id

Captcha based on encyrpting and decrypting user data by mathematical operation

Merb plugin that provides resource access rate limits and captcha'ing

RedisCaptcha provides simple captcha that can be read by human.

Description of TinyCaptcha.

A smart captcha library