Last Updated: August 21, 2017
· sergiotapia

Ruby on Rails 4 - Authentication with Facebook and OmniAuth.

In this article I'm going to teach you how to authenticate your users easily using Facebook. This means a much easier sign up process for your users and you no longer have the responsibility of securing passwords.

This article is written specifically for Ruby on Rails 4. Since I had to cobble together solutions from many sources hopefully this helps people get a working codebase quickly.


Here's a small list of the things we're going to work on. Ideally, you want to follow this progression path to get a working final result.

  • Add Omniauth and Omniauth-Facebook gems.
  • Create User model.
  • Create Sessions controller.
  • Create Omniauth initializer.
  • Add client-side functionality using javascript.
  • Showing the logged in user in the View.

Add Omniauth and Omniauth-Facebook gems.

Open up your Gemfile and add the following gems to it.

gem 'omniauth'
gem 'omniauth-facebook', '1.4.0'

Make sure you run the bundle install command. This configures your Rails application to use those gems.

Create User model.

We need to generate a User model and add in some necessary fields that Omniauth uses for user authentication.

Run the following command from terminal:

rails g model User provider uid name oauth_token oauth_expires_at:datetime

Create a method in the User model that interacts with Omniauth's object.

class User < ActiveRecord::Base
  def self.from_omniauth(auth)
    where(auth.slice(:provider, :uid)).first_or_initialize.tap do |user|
      user.provider = auth.provider
      user.uid = auth.uid =
      user.oauth_token = auth.credentials.token
      user.oauth_expires_at =!

Then we need to create a helper method in our ApplicationController to access whoever is logged in at the moment.

class ApplicationController < ActionController::Base

  def current_user
    @current_user ||= User.find(session[:user_id]) if session[:user_id]
  helper_method :current_user

Create Sessions controller

Next lets create a sessions controller to handle callbacks. This is where we'll actually login our users.

class SessionsController < ApplicationController
  def create
    user = User.from_omniauth(env["omniauth.auth"])
    session[:user_id] =
    redirect_to root_url

  def destroy
    session[:user_id] = nil
    redirect_to root_url

Create a couple of paths in your routes.rb file as well. Otherwise your Rails application won't know what controller to use.

match 'auth/:provider/callback', to: 'sessions#create', via: [:get, :post]
match 'auth/failure', to: redirect('/'), via: [:get, :post]
match 'signout', to: 'sessions#destroy', as: 'signout', via: [:get, :post]

Create Omniauth initializer

We need to create an initializer for Omniauth. Create it in config/initializers/omniauth.rb.

OmniAuth.config.logger = Rails.logger

Rails.application.config.middleware.use OmniAuth::Builder do
  provider :facebook, 'YOUR-APP-ID-HERE', 'YOUR-APP-SECRET-HERE'

Add client-side functionality using Javascript

Create a coffescript file called

jQuery ->
  $('body').prepend('<div id="fb-root"></div>')

    url: "#{window.location.protocol}//"
    dataType: 'script'
    cache: true

window.fbAsyncInit = ->
  FB.init(appId: 'YOUR-APP-ID', cookie: true)

  $('#sign_in').click (e) ->
    FB.login (response) ->
      window.location = '/auth/facebook/callback' if response.authResponse

  $('#sign_out').click (e) ->
    FB.getLoginStatus (response) ->
      FB.logout() if response.authResponse

Showing the logged in user in the View.

In your application.html.erb file, we'll write in some code to display either a sign in link, or the currently logged in user's name.

<div id="user-widget">
  <% if current_user %>
    Welcome <strong><%= %></strong>!
    <%= link_to "Sign out", signout_path, id: "sign_out" %>
  <% else %>
    <%= link_to "Sign in with Facebook", "/auth/facebook", id: "sign_in" %>
  <% end %>

And there you have it.

Quick and painless Facebook authentication in a Ruby on Rails 4 application. Make sure you read Facebook's official documentation on how to request more permissions from users if you need more personal information such as emails and sex.

53 Responses
Add your response


thanks for sharing this. looking forward to implementing it.

over 1 year ago ·

Glad you like it!

over 1 year ago ·

i get this error

undefined local variable or method `current_user' for #<#Class:0x007f5b1c4d0ac0:0x00000003a2be00>

<div data-role="page">
<div id="user-widget">
<% if currentuser %>
Welcome <strong><%= current %></strong>!
<%= linkto "Sign out", signoutpath, id: "sign_out" %>
<% else %>

over 1 year ago ·


Sorry about that! I forgot to mention that you need to create a helper method called current_user.

class ApplicationController < ActionController::Base

  def current_user
    @current_user ||= User.find(session[:user_id]) if session[:user_id]
  helper_method :current_user
over 1 year ago ·

Thanks, really helpful.

over 1 year ago ·

Definitely i will try it!! thanks!

over 1 year ago ·

Don't forget to pass some credits to our friend ryan bates.

over 1 year ago ·

Give Ryan some <3

over 1 year ago ·

I created the app to get the App ID and App Secret code at the facebook developer sections. But after finished all steps as u shown, I got below error. What can it be?

Error Accessing App
We're sorry, but the application you're trying to use doesn't exist or has been disabled.

over 1 year ago ·

@txant: That's probably something wrong on Facebook's end. I've never seen that message but it's pretty straight forward. Your app has been disabled or doesn't exist. Make sure you're using the correct AppID and that your app on isn't disabled.

over 1 year ago ·

@sergiotapia: Thanks for your tutorial and reply message. My error is solved. Because of my careless, I just copied and pasted the and I didn't check the codes which along inside. The AppID need to add at the one of the lines of codes of that file. Now, my rails app works correctly.

over 1 year ago ·

thanks for the tutorial.

I ran into trouble deploying in Heroku because it's required to add in the omniauth.rb initializer :

{:clientoptions => {:ssl => {:capath => "/etc/ssl/certs"}}} # Modify this with your SSL certificates path

over 1 year ago ·

It works! Thanks! How about with Google+? :P?comment=WORKS! THANKS! :P How about google+?

over 1 year ago ·

I have the error of Invalid redirect_uri on calling with ip address from others devices which located in same local network. Its okay at localhost but also have error at Please show me the way to solve. Thanks!

over 1 year ago ·

Thanks a lot!, its working well in rails 4.

over 1 year ago ·

remember to migrate the database! heroku rake db:migrate

over 1 year ago ·

Hi there,

having a problem with creating an initializer for Omniauth. Should you make the file omniauth.rb by yourself or should you generate it by typing in a code in your command prompt with ruby on rails...

Thanks in advance!

over 1 year ago ·

Hi @semvc, you need to create that file manually using your editor of choice. :)

over 1 year ago ·

Thanks sergiotapia for your fast respond, but i have a next question...

I've manually made the omniauth.rb file and placed the correct code into it but when trying to migrate the database --> rake db:migrate, i get the following error:

rake aborted! uninitialized constant OmniAuth::OmniAuth...

Maybe you know the answer?

Thanks in advance!

over 1 year ago ·


I'm trying to implement this tutorial along the app I created following The Rails Tutorial by Michael Hartl however I'm getting an error when I try to join both codes in my create action. This is the part of my session controller which is currently giving a error:

def create
user = User.findby(email: params[:session][:email].downcase) || User.fromomniauth(env["omniauth.auth"])

Any suggestions on how can I manage to solve this problem?

over 1 year ago ·

Hi, solved my previous problem... I'm able to log in with facebook, but when click i get the following error -->


must pass either a code parameter or a signed request (via signed_request parameter or a fbsr_XXX cookie)

Did someone also have this problem? I've searched the internet for some hours but couldn't find any solution... :'(

Hope someone can help me...Thanks!

over 1 year ago ·

Thanks its helped me , And please make file name to

over 1 year ago ·

undefined method `slice' for nil:NilClass

over 1 year ago ·

to fix error reported by @semvc you need to set

window.location = '/auth/facebook' if response.authResponse

in facebook.js.coffescript

over 1 year ago ·

Thanks for the great post, got it working, however I had to remove 'e.preventDefault()' part in '' for it to work :)

over 1 year ago ·

Practical tutorial! Thanks :)

over 1 year ago ·

Koala is also a great gem for fb. Haven't tried it yet on Rails4 apps but it''s worth ckecking out

over 1 year ago ·

Just reading through it now and typing in your code, not tested yet...looks good but could be clearer for the novice user like:

'Create a coffescript file called'

Where? I take it in the App/assets/javascripts folder?

over 1 year ago ·

Succinct, very quick to implement, and most importantly, NO DEVISE!

Will recommend! Thanks!

over 1 year ago ·

Work as advised. Impressive as this can quickly become complicated stuff. Much appreciated.

over 1 year ago ·

Thanks for the great tutorial! I followed your process to a "T", but I'm getting a similar error as @leovmcosta. I'm getting this error in my SessionsController create function, "syntax error, unexpected end-of-input, expecting keyword_end" (

over 1 year ago ·

@mcmaur: That means that you didn't create the SessionsController. Check above to see what it needs to have.

over 1 year ago ·

Notice "Session" vs. "Sessions" - they're not the same. :) Check your routes.rb file.

over 1 year ago ·

Keep it this way:

class SessionsController < ApplicationController

Create a couple of paths in your routes.rb file as well. Otherwise your Rails application won't know what controller to use.

match 'auth/:provider/callback', to: 'sessions#create', via: [:get, :post]
match 'auth/failure', to: redirect('/'), via: [:get, :post]
match 'signout', to: 'sessions#destroy', as: 'signout', via: [:get, :post]
over 1 year ago ·

Stop and restart your app?

over 1 year ago ·

When the ajax call tries to load the facebook script, I get this error: Given URL is not permitted by the application configuration.: One or more of the given URLs is not allowed by the App's settings. It must match the Website URL or Canvas URL, or the domain must be a subdomain of one of the App's domains.

I wonder why that didn't happen to anyone else. I must have missed something. Configuring the app to allow cross site ajax requests doesnt seem to help

over 1 year ago ·

thanks sergiotapia but when I got to the end of step finish to test the application at localhost:3000/auth/facebook, I got this error:

"error": {
"message": "Invalid redirect_uri: URL \u0111\u00e3 cho kh\u00f4ng \u0111\u01b0\u1ee3c c\u1ea5u h\u00ecnh \u1ee8ng d\u1ee5ng cho ph\u00e9p.",
"type": "OAuthException",
"code": 191

the problem is the URL in the Facebook developer center, but none of the solutions I read works for me

over 1 year ago ·

I'm having routing error ! Can somebody help me ? What to add in the routes.rb so that I can view it

over 1 year ago ·

Is there any i can do with out having to write coffee script and just jqeury?

over 1 year ago ·

it is showing error uninitialized constant OmniAuth can anybody help me with it

over 1 year ago ·

anyone has error free working code for this on github or open source platforms?

over 1 year ago ·

The where on User, would raise a ActiveModel::ForbiddenAttributesError,
so it should be written like this:

where(provider: auth.provider, uid: auth.uid).firstorcreate do |user|

and the controller should had:


def userparams
params.require(:user).permit(:provider, :uid, :name, :oauth
token, :oauthexpiresat)

over 1 year ago ·

After running bundle install when i run user g model .....

it gives me an error.

/home/bishisht/.rvm/gems/ruby-2.1.2/gems/actionpack-4.1.1/lib/actiondispatch/routing/mapper.rb:243:in `defaultcontrollerandaction': Missing :action key on routes definition, please check your routes. (ArgumentError)

and more stuffs. why is this happening?

over 1 year ago ·

it gives me an error :

No route matches [GET] "/user"

over 1 year ago ·

@leovmcosta could it have something to do with using the "||" after you're setting the variable user = User.findby(email: params[:session][:email].downcase) ?

I am assuming that "create" is the method and the first statement contains the "user =" ? If so, there is no setting the setting the omniauth statement to "user =" in the second part if the first evalutes as false.

over 1 year ago ·

Just set this up and I am getting 'ActiveModel::ForbiddenAttributesError'

extracted source -
def sanitizeformassassignment(attributes)
if attributes.respond
to?(:permitted?) && !attributes.permitted?
raise ActiveModel::ForbiddenAttributesError

app trace -

app/models/user.rb:3:in from_omniauth' app/controllers/sessions_controller.rb:3:increate'

over 1 year ago ·
20802 - This is what I'm getting after I click login with facebook link (I can click on "give app access to your profile" on facebook, but it gives me an error when I'm being redirected to callback page in my app)

over 1 year ago ·
20803 - This is what I'm getting after I click login with facebook link (I can click on "give app access to your profile" on facebook, but it gives me an error when I'm being redirected to callback page in my app)

over 1 year ago ·

thanks for your posting.
It was very helpful. but can I ask about the deleting cookie session?
When I log out, then I try to login, without entering facebook ID, Pw, It is logged in.. I hope to entering again.. help me..

over 1 year ago ·

I had a ForbiddenAttributesError, this helped me: The Rails team have added security features.

over 1 year ago ·

Hi, when I do the request it send my a message in the terminal :
(facebook) Authentication failure! invalidcredentials: OAuth2::Error :
and in the browser it show me this :
any idea why it sending thid error??

over 1 year ago ·