Authentication via JWT (with encryption)

Auth for your Rails application

Bushido support for Authlogic

Cloudfuji support for Authlogic

AuthNetReceiver is an endpoint and processor for Authorize.Net Silent Post transactions

Rails engine to add IndieAuth authentication endpoint functionality

A description of a really simple authorization plugin for Rails.

A gem for rails giving vast flexibility in authorization management.

Minimalistic authorization library for Ruby on Rails applications.

Authorization that includes basic authorization and 3 social authorization with Latvia social network draugiem.lv, facebook.com and twitter.com.

A simple authentication provider for Ruby/Rails app. Designed for mobile clients and is compatible with the OAuth 2.0 specification.

AutoAdmin: an Admin UI that prefers hints over directions

remove before_action each controller

Auto assign model resource and collection from controller

Automatically add breadcrumbs to each page by using locales

Model-side logic for autocompleting belongs_to associations

Integrate with jQuery UI autocomplete library to provide select by autocomplete input and form helper.

AutoError is a mountable engine for Rails 4.0+ which provides an 'exceptions_app' which helps you catch exceptions (showing the appropriate page to users) and an interface you can mount in your admin panel to display those errors.

automated metareview

Allows you to easily set page titles per view in your Rails 4 app, but also follows Ruby on Rails naming conventions to set sensible default title if none is specified.