CSRF on Grape

auth.rb

# based on http://api.rubyonrails.org/classes/ActionController/RequestForgeryProtection.html

module Auth
  extend ActiveSupport::Concern

  included do
    helpers do
      def session
        env['rack.session']
      end

      def protect_against_forgery
        unless verified_request?
          error!('Unauthorized', 401)
        end
      end

      def verified_request?
        !protect_against_forgery? || request.get? || request.head? ||
          form_authenticity_token == request.headers['X-CSRF-Token'] ||
          form_authenticity_token == request.headers['X-Csrf-Token']
      end

      def form_authenticity_token
        session[:_csrf_token] ||= SecureRandom.base64(32)
      end

      def protect_against_forgery?
        allow_forgery_protection = Rails.configuration.action_controller.allow_forgery_protection
        allow_forgery_protection.nil? || allow_forgery_protection
      end
    end
  end
end

controller.rb

class Controller < Grape::API
  include Auth

  before do
    protect_against_forgery
  end

  resource :something do
    ...
  end
end
 

Thanks @jandudulski we made a gem from your gist : https://github.com/KissKissBankBank/grape-forgery_protection