Simple username/password authentication for Rails 3.
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Quo Vadis?

Quo Vadis adds simple username/password authentication to Rails 3 applications.

Why bother with yet another authentication gem? Well, I find all the others over-engineered. Code should be easy to use and easy to read. As far as I'm concerned, none of the others ticks both boxes.


  • Minimal effort to add authentication to your app: get up and running in 5 minutes.
  • No surprises: it does what you expect.
  • Easy to customise.
  • Uses BCrypt to encrypt passwords.
  • Sign in, sign out, forgotten password, authenticate actions, remember user between browser sessions.
  • Block accounts.
  • Let you choose which model(s) to authenticate (defaults to User).

Forthcoming features:

  • Generate the views for you (for now, copy the examples given below).
  • Let you choose the identification field (currently username).
  • HTTP basic/digest authentication (probably).
  • Generate model plus migration if it doesn't exist.
  • Detect presence of has_secure_password (see below) and adapt appropriately.

What it doesn't and won't do:

  • Authorisation.
  • Sign up; that's user management, not authentication.
  • Work outside Rails 3.
  • OpenID, OAuth, LDAP, CAS, etc.
  • Separate identity from authentication services (cf OmniAuth).
  • Allow you to have multiple models/scope signed in simultaneously (cf Devise).
  • Offer so much flexibility that it takes more than 10 minutes to wrap your head around it (cf Devise, Authlogic).

Quick Start

If this takes you more than 5 minutes, you can have your money back ;)

Install and run the generator: add gem 'quo_vadis' to your Gemfile, run bundle install, then rails generate quo_vadis:install [MODEL_NAME] (where model name is optional and defaults to User).

Edit and run the generated migration to add the authentication columns: rake db:migrate. Note the migration (currently) assumes you already have a table for your model.

In your User (or whichever) model, add authenticates:

class User < ActiveRecord::Base

Note Quo Vadis validates the presence and uniqueness of the username, and the presence of the password, but it's up to you to add any other validations you want.

Use :authenticate in a before_filter to protect your controllers' actions. For example:

class ArticlesController < ActionController::Base
  before_filter :authenticate, :except => [:index, :show]

Write the sign-in view. Your sign-in form must:

  • be in app/views/sessions/new.html.:format
  • POST the parameters :username and :password to sign_in_url

You have to write the view yourself because you'd inevitably want to change whatever markup I generated for you. You can find an example in the test app.

Remember to serve your sign in form over HTTPS -- to avoid the credentials being stolen.

In your layout, use current_user to retrieve the signed-in user; and sign_in_path, sign_out_path, and forgotten_sign_in_path as appropriate. You can also use authenticated?.

Forgotten Password

Here's the workflow:

  1. [Sign in page] The user clicks the "I've forgotten my password" link.
  2. [Forgotten password page] The user enters their username in the form and submits it.
  3. Quo Vadis emails the user a message with a change-password link. The link is valid for 3 hours.
  4. [The email] The user clicks the link.
  5. [Change password page] The user types in a new password and saves it.
  6. Quo Vadis changes the user's password and signs the user in.

It'll take you about 5 minutes to implement this.

On your sign-in page, link to the forgotten-password view at forgotten_sign_in_url.

Write the forgotten-password view (example). The form must:

  • be in app/views/sessions/forgotten.html.:format
  • POST the parameter :username to forgotten_sign_in_url

Now write the mailer view, i.e. the email which will be sent to your forgetful users (example). The view must:

  • be at app/views/quo_vadis/notifier/change_password.text.erb
  • render @url somewhere (this is the link the user clicks to go to the change-password page)

You can also refer to @username in the email view.

Configure the email's from address in config/initializers/quo_vadis.rb.

Configure the default host so ActionMailer can generate the URL. In config/environments/<env>.rb:

config.action_mailer.default_url_options = {:host => ''}

Finally, write the change-password page (example). The form must:

  • be in app/views/sessions/edit.html.:format
  • PUT the parameter :password to change_password_url(params[:token])


You can customise the flash messages and mailer from/subject in config/locales/quo_vadis.en.yml.

You can customise the sign-in and sign-out redirects in config/initializers/quo_vadis.rb; they both default to the root route. You can also hook into the sign-in and sign-out process if you need to run any other code.

If you want to add other session management type features, go right ahead: create a SessionsController as normal and carry on.

You can skip the validation of authentication attributes (password etc) by overriding should_authenticate? in your model. Perhaps only some of the users should be able to sign in, so you don't want to force them to have a password.

Sign up / user registration

Quo Vadis doesn't offer sign-up because that's user management, not authentication.

However if you have implemented user sign-up yourself, you need to be able to sign in a newly created user. Do this by calling sign_in(user) in your controller. For example:

# In your app
class UsersController < ApplicationController
  def create
    @user = params[:user]
      sign_in @user    # <-- NOTE: sign in your user here
      render 'new'

The sign_in(user) method will redirect the user appropriately (you can configure this in config/initializers/quo_vadis.rb), as well as running any sign-in hook you may have defined in the initializer.

See also

What's up with the name?

Roman sentries used to challenge intruders with, "Halt! Who goes there?"; quo vadis is Latin for "Who goes there?". At least that's what my Latin teacher told us, but I was 8 years old then so I may not be remembering this entirely accurately.

Questions, Problems, Feedback

Please use the GitHub issue tracker or email me.

Intellectual property

Copyright 2011 Andy Stewart (

Released under the MIT licence.