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Monban is designed to be a very simple and extensible user authentication library for rails. Its goal is to give all the power to the developer instead of forcing them to make Monban work with their system.

Why use Monban?

Monban makes authentication simple:

  • Easy to use in tests with dependency injection
  • Provides convenient controller helpers
  • Very customizable

Monban doesn't do the following:

  • Doesn't automatically add routes to your application
  • Doesn't force you to use engine based controllers or views
  • Doesn't require you to make changes to your user model


You can read the full documentation at rubydoc


Monban was designed to work with Rails > 4.0. Add this line to your Gemfile:

gem 'monban'

Then inside of your ApplicationController add the following:

include Monban::ControllerHelpers

And you're ready to start designing your authentication system.


If you'd like a good starting point for building an app using Monban, it is suggested to use the monban generators


Monban does currently have some out-of-the-box expectations, but you can configure and change any of these:

  • By default the model should be called User
  • Monban expects your user model to respond to create, id, and find_by
  • You should have an email and password_digest column on your User
  • Passwords will be handled with BCrypt


Console Usage

If you're trying to sign up a User in a console you won't be able to call User#new or User#create because the User model does not know how to encrypt passwords. You should instead use the sign up service in order to create the user: "", password: "password").perform 


Monban doesn't add validations to your user model unless you're using monban generators so it's suggested to add the following validations:

validates :email, presence: true, uniqueness: true
validates :password_digest, presence: true

In addition to that you'll want to add the following to your config/locale/en.yml:

        password_digest: "Password"

Which will generate the error message Password can't be blank instead of Password digest can't be blank.

Layout changes

It is suggested you add something like this to your application layout:

<% if signed_in? %>
  <%= link_to "Sign out", session_path, method: :delete %>
<% else %>
  <%= link_to "Sign in", new_session_path %>
  <%= link_to "Sign up", new_user_path %>
<% end %>

Guest user

If you want to introduce a Guest object when a user is not signed in, you can override Monban's current_user method in your ApplicationController:

def current_user
  super ||

In app/models/, define a Guest class:

class Guest
  def name

This article on the Null Object Pattern provides a good explanation of why you might want to do this.

Controller Additions

Monban provides the following controller methods:

  • sign_in(user)
  • sign_out
  • sign_up(user_params)
  • authenticate(user, password)
  • authenticate_session(session_params)
  • reset_password(user, password)

These helpers:

  • current_user
  • signed_in?

And this filter:

  • require_login

Routing Constraints

To authorize users in config/routes.rb:

require "monban/constraints/signed_in"
require "monban/constraints/signed_out"

Blog::Application.routes.draw do
  constraints do
    root "dashboards#show", as: :dashboard

  constraints do
    root "landings#show"

Usage in Tests

Test mode

Monban provides the following:


Which will change password hashing method to provide plaintext responses instead of using BCrypt. This will allow you to write factories using the password_digest field:

FactoryGirl.define do
  factory :user do
    username 'wombat'
    password_digest 'password'

Spec helpers

A couple of convenience methods are available in your tests. In order to set this up you'll want to add the following to rails_helper.rb or if that doesn't exist spec_helper.rb


RSpec.configure do |config|
  config.include Monban::Test::Helpers, type: :feature
  config.after :each do

Then you can use any of the test helpers in your scenarios

feature "A feature spec" do
  scenario "that requires login" do
    user = create(:user)
    # do something
    # do something else

Monban Backdoor

Similar to clearance's backdoor you can visit a path and sign in quickly via

user = create(:user)
visit dashboard_path(as: user)

To enable this functionality you'll want to add the following to config/environments/test.rb:

config.middleware.insert_after Warden::Manager, Monban::BackDoor

If you'd like to find your User model by a field other than id, insert the middleware with a block that accepts the as query parameter and returns an instance of your User model:

config.middleware.insert_after Warden::Manager, Monban::BackDoor do |user_param|
  User.find_by(username: user_param)

Controller Specs

If you are going to write controller tests, helpers are provided for those as well:


RSpec.configure do |config|
  config.include Monban::Test::ControllerHelpers, type: :controller
  config.after :each do
require 'spec_helper'

describe ProtectedController do

  describe "GET 'index'" do
    it "returns http success when signed in" do
      user = create(:user)
      get 'index'
      response.should be_success

    it "redirects when not signed in" do
      get 'index'
      response.should be_redirect

Advanced Functionality

Authentication with username instead of email

If you want to sign in with username instead of email just change the configuration option

# config/initializers/monban.rb
Monban.configure do |config|
  config.user_lookup_field = :username

If you used the monban:scaffold generator from monban generators you'll have to change the following four references to email.

  • In SessionsController#session_params
  • In UsersController#user_params
  • The email form field on sessions#new
  • The email form field on users#new

Using multiple lookup fields

You may perform a look up on a user using multiple fields by doing something like the following:

class SessionsController < ApplicationController
  def create
    user = authenticate_session(session_params, email_or_username: [:email, :username])

    if (user)
      render :new


  def session_params
    params.require(:session).permit(:email_or_username, :password)


This will allow the user to enter either their username or email to login


Monban::Configuration has lots of options for changing how monban works. Currently the options you can change are as follows:

User values

  • user_lookup_field: (default :email) Field in the database to lookup a user by.
  • user_token_field: (default :password) Field the form submits containing the undigested password.
  • user_token_store_field: (default: :password_digest) Field in the database that stores the user's digested password.
  • user_class: (default: User) The user class.


  • sign_in_notice: (default: You must be signed in) Rails flash message to set when user signs in.
  • sign_in_service: (default: Monban::Services::SignIn) Service for signing a user in.
  • sign_up_service: (default: Monban::Services::SignUp) Service for signing a user up.
  • sign_out_service: (default: Monban::Services::SignOut) Service for signing a user out.
  • authentication_service: (default: Monban::Services::Authentication) Service for authenticated a user.
  • password_reset_service: (default: Monban::Services::PasswordReset) Service for resetting a user's password.

Rails values

  • no_login_handler: A before_action for rails that handles when a user is not signed in.
  • no_login_redirect: Used by the no_login_handler to redirect the user


  • hashing_method: Method to hash an undigested password.
  • token_comparison: Method to compare a digested and undigested password.
  • creation_method: Method for creating a user.
  • find_method: Method for finding a user.

Warden Settings

  • failure_app: Necessary for warden to work. A rack app that handles failures in authentication.


Here are a few of the current limitations of monban:

  • Monban assumes you only have one user model.


  1. Fork it
  2. Create your feature branch (git checkout -b my-new-feature)
  3. Commit your changes (git commit -am 'Add some feature')
  4. Push to the branch (git push origin my-new-feature)
  5. Create new Pull Request