actionpack-per_form_csrf_tokens

actionpack-per_form_csrf_tokens is a backport of per-form CSRF tokens (introduced in Rails 5) into Rails 4.2.
Note that this gem only adds some patches into ActionController::Base to "accept" new-format tokens, because it's aimed for enabling Rails 4.2 apps to exchange them with Rails 5.x or higher ones.

Add this line to your application's Gemfile:

gem 'actionpack-per_form_csrf_tokens'

And then execute:

$ bundle

You don't need anything other than install.

You should follow the steps below.

1. Fork the repository
2. Create a feature branch: git checkout -b add-new-feature
3. Commit your changes: git commit -am 'Add new feature'
4. Push the branch: git push origin add-new-feature
5. Send us a pull request

The gem is available as open source under the terms of the MIT License.