Mixes in simple per-request authentication

Clearance is built to support authentication and authorization via an email/password sign-in mechanism in applications. It provides some core classes commonly used for these features, along with some opinionated defaults - but is intended to be easy to override.

Omniauth plugin for Artsy authentication.

Use Google Apps as an Authentication Provider

A Ruby client for authentication in Cask CDAP services

Google Apps authentication

An unobtrusive ruby authentication library based on ActiveRecord.

Windows Azure Active Directory authentication client library

Use ClickTale (http://www.clicktale.com/) analytics service with rails sites that require sessions (user authentication for example)

An object-oriented Ruby implementation of the Sender Policy Framework (SPF) e-mail sender authentication system, fully compliant with RFC 4408.

A library for generating signed authentication tokens for use with Firebase. Uses your app secret.

Authentication solution for Rails based on JWT

An authentication library compatible with all Rack-based frameworks

Devise AAF Rapid Connect Authenticatable is an authentication strategy for the Devise[http://github.com/plataformatec/devise] authentication framework.

bridge for supporting multiple google authentication libraries

An engine that provides a basic User model, authentication logic, and remote credential management for G5 applications.

Devise extension to allow authentication via iChain

Simple (but safe) token authentication for Rails apps or API with Devise.

OmniAuth support for multiple providers of an authentication strategy

Library for handling registration and authentication of U2F devices