WARNING: Can't verify CSRF token authenticity rails

I am sending data from view to controller with AJAXand I got this error: >WARNING: Can't verify CSRF token authenticity

I think I have to send this token with data.

Does anyone know how can I do this ?

Edit: My solution

I did this by putting the following code inside the AJAX post:

headers: {
  'X-Transaction': 'POST Example',
  'X-CSRF-Token': $('meta[name="csrf-token"]').attr('content')
},

You should do this:

1. Make sure that you have <%= csrf_meta_tag %> in your layout

2. Add beforeSend to all the ajax request to set the header like below:

---

$.ajax({ url: 'YOUR URL HERE',
  type: 'POST',
  beforeSend: function(xhr) {xhr.setRequestHeader('X-CSRF-Token', $('meta[name="csrf-token"]').attr('content'))},
  data: 'someData=' + someData,
  success: function(response) {
    $('#someDiv').html(response);
  }
});

To send token in all requests you can use:

$.ajaxSetup({
  headers: {
    'X-CSRF-Token': $('meta[name="csrf-token"]').attr('content')
  }
});

The best way to do this is actually just use <%= form_authenticity_token.to_s %> to print out the token directly in your rails code. You dont need to use javascript to search the dom for the csrf token as other posts mention. just add the headers option as below;

$.ajax({
  type: 'post',
  data: $(this).sortable('serialize'),
  headers: {
    'X-CSRF-Token': '<%= form_authenticity_token.to_s %>'
  },
  complete: function(request){},
  url: "<%= sort_widget_images_path(@widget) %>"
})

If I remember correctly, you have to add the following code to your form, to get rid of this problem:

<%= token_tag(nil) %>

Don't forget the parameter.

Indeed simplest way. Don't bother with changing the headers.

Make sure you have:

<%= csrf_meta_tag %> in your layouts/application.html.erb

Just do a hidden input field like so:

<input name="authenticity_token" 
               type="hidden" 
               value="<%= form_authenticity_token %>"/>

Or if you want a jQuery ajax post:

$.ajax({     
    type: 'POST',
    url: "<%= someregistration_path %>",
    data: { "firstname": "text_data_1", "last_name": "text_data2", "authenticity_token": "<%= form_authenticity_token %>" },                                                                                  
    error: function( xhr ){ 
      alert("ERROR ON SUBMIT");
    },
    success: function( data ){ 
      //data response can contain what we want here...
      console.log("SUCCESS, data="+data);
    }
});

Ugrading from an older app to rails 3.1, including the csrf meta tag is still not solving it. On the rubyonrails.org blog, they give some upgrade tips, and specifically this line of jquery which should go in the head section of your layout:

$(document).ajaxSend(function(e, xhr, options) {
 var token = $("meta[name='csrf-token']").attr("content");
  xhr.setRequestHeader("X-CSRF-Token", token);
});

taken from this blog post: http://weblog.rubyonrails.org/2011/2/8/csrf-protection-bypass-in-ruby-on-rails.

In my case, the session was being reset upon each ajax request. Adding the above code solved that issue.

1. Make sure that you have <%= csrf_meta_tag %> in your layout
2. Add a beforeSend to include the csrf-token in the ajax request to set the header. This is only required for post requests.

The code to read the csrf-token is available in the rails/jquery-ujs, so imho it is easiest to just use that, as follows:

$.ajax({
  url: url,
  method: 'post',
  beforeSend: $.rails.CSRFProtection,
  data: {
    // ...
  }
})

The top voted answers here are correct but will not work if you are performing cross-domain requests because the session will not be available unless you explicitly tell jQuery to pass the session cookie. Here's how to do that:

$.ajax({ 
  url: url,
  type: 'POST',
  beforeSend: function(xhr) {
    xhr.setRequestHeader('X-CSRF-Token', $('meta[name="csrf-token"]').attr('content'))
  },
  xhrFields: {
    withCredentials: true
  }
});

I just thought I'd link this here as the article has most of the answer you're looking for and it's also very interesting

http://www.kalzumeus.com/2011/11/17/i-saw-an-extremely-subtle-bug-today-and-i-just-have-to-tell-someone/

oops..

I missed the following line in my application.js

//= require jquery_ujs

I replaced it and its working..

======= UPDATED =========

After 5 years, I am back with Same error, now I have brand new Rails 5.1.6, and I found this post again. Just like circle of life.

Now what was the issue is: Rails 5.1 removed support for jquery and jquery_ujs by default, and added

//= require rails-ujs in application.js

It does the following things:

1. force confirmation dialogs for various actions;
2. make non-GET requests from hyperlinks;
3. make forms or hyperlinks submit data asynchronously with Ajax;
4. have submit buttons become automatically disabled on form submit to prevent double-clicking. (from: https://github.com/rails/rails-ujs/tree/master)

But why is it not including the csrf token for ajax request? If anyone know about this in detail just comment me. I appreciate that.

Anyway I added the following in my custom js file to make it work (Thanks for other answers to help me reach this code):

$( document ).ready(function() {
  $.ajaxSetup({
    headers: {
      'X-CSRF-Token': Rails.csrfToken()
    }
  });
  ----
  ----
});

You can write it globally like below.

Normal JS:

$(function(){

    $('#loader').hide()
    $(document).ajaxStart(function() {
        $('#loader').show();
    })
    $(document).ajaxError(function() {
        alert("Something went wrong...")
        $('#loader').hide();
    })
    $(document).ajaxStop(function() {
        $('#loader').hide();
    });
    $.ajaxSetup({
        beforeSend: function(xhr) {xhr.setRequestHeader('X-CSRF-Token', $('meta[name="csrf-token"]').attr('content'))}
    });
});

Coffee Script:

  $('#loader').hide()
  $(document).ajaxStart ->
    $('#loader').show()

  $(document).ajaxError ->
    alert("Something went wrong...")
    $('#loader').hide()

  $(document).ajaxStop ->
    $('#loader').hide()

  $.ajaxSetup {
    beforeSend: (xhr) ->
      xhr.setRequestHeader('X-CSRF-Token', $('meta[name="csrf-token"]').attr('content'))
  }

If you are not using jQuery and using something like fetch API for requests you can use the following to get the csrf-token:

document.querySelector('meta[name="csrf-token"]').getAttribute('content')

fetch('/users', {
  method: 'POST',
  headers: {
    'Accept': 'application/json',
    'Content-Type': 'application/json',
    'X-CSRF-Token': document.querySelector('meta[name="csrf-token"]').getAttribute('content')},
    credentials: 'same-origin',
    body: JSON.stringify( { id: 1, name: 'some user' } )
    })
    .then(function(data) {
      console.log('request succeeded with JSON response', data)
    }).catch(function(error) {
      console.log('request failed', error)
    })

Use jquery.csrf (https://github.com/swordray/jquery.csrf).

• Rails 5.1 or later

   $ yarn add jquery.csrf
  

   //= require jquery.csrf
  

• Rails 5.0 or before

   source 'https://rails-assets.org' do
     gem 'rails-assets-jquery.csrf'
   end
  

   //= require jquery.csrf
  

• Source code

   (function($) {
     $(document).ajaxSend(function(e, xhr, options) {
       var token = $('meta[name="csrf-token"]').attr('content');
       if (token) xhr.setRequestHeader('X-CSRF-Token', token);
     });
   })(jQuery);
  

If you're using javascript with jQuery to generate the token in your form, this works:

<input name="authenticity_token" 
       type="hidden" 
       value="<%= $('meta[name=csrf-token]').attr('content') %>" />

Obviously, you need to have the <%= csrf_meta_tag %> in your Ruby layout.

I struggled with this issue for days. Any GET call was working correctly, but all PUTs would generate a "Can't verify CSRF token authenticity" error. My website was working fine until I had added a SSL cert to nginx.

I finally stumbled on this missing line in my nginx settings:

location @puma { 
	proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; 
	proxy_set_header Host $http_host; 
	proxy_redirect off;
	proxy_set_header X-Forwarded-Proto https;	# Needed to avoid 'WARNING: Can't verify CSRF token authenticity'
	proxy_pass http://puma; 
}

After adding the missing line "proxy_set_header X-Forwarded-Proto https;", all my CSRF token errors quit.

Hopefully this helps someone else who also is beating their head against a wall. haha

For those of you that do need a non jQuery answer you can simple add the following:

xmlhttp.setRequestHeader('X-CSRF-Token', $('meta[name="csrf-token"]').attr('content'));

A very simple example can be sen here:

xmlhttp.open("POST","example.html",true);
xmlhttp.setRequestHeader('X-CSRF-Token', $('meta[name="csrf-token"]').attr('content'));
xmlhttp.send();

if someone needs help related with Uploadify and Rails 3.2 (like me when I googled this post), this sample app may be helpful: https://github.com/n0ne/Uploadify-Carrierwave-Rails-3.2.3/blob/master/app/views/pictures/index.html.erb

also check the controller solution in this app

I'm using Rails 4.2.4 and couldn't work out why I was getting:

Can't verify CSRF token authenticity

I have in the layout:

<%= csrf_meta_tags %>

In the controller:

protect_from_forgery with: :exception

Invoking tcpdump -A -s 999 -i lo port 3000 was showing the header being set ( despite not needing to set the headers with ajaxSetup - it was done already):

X-CSRF-Token: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
Content-Type: application/x-www-form-urlencoded; charset=UTF-8
X-Requested-With: XMLHttpRequest
DNT: 1
Content-Length: 125
authenticity_token=XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

In the end it was failing because I had cookies switched off. CSRF doesn't work without cookies being enabled, so this is another possible cause if you're seeing this error.