Using devise gem sign_in & sign_out API's with sessions

curl.sh

#login
curl -v -H "Accept: application/json" -H "Content-type: application/json" -X POST -d ' {"user":{"email":"<email>","password":"<passwd>"}}' http://localhost:3000/api/v1/sign_in.json
 
#logout
curl -v -H "Accept: application/json" -H "Content-type: application/json" -X DELETE http://localhost:3000/api/v1/sign_out.json?auth_token=<token>

devise.rb

# File config/initializers/devise.rb
# append at the end of devise.rb or add in any initializer file
require 'devise/strategies/token_authenticatable'
module Devise
  module Strategies
    class TokenAuthenticatable < Authenticatable
      def params_auth_hash
        return_params = if params[scope].kind_of?(Hash) && params[scope].has_key?(authentication_keys.first)
            params[scope]
          else
            params
          end
        token = ActionController::HttpAuthentication::Token.token_and_options(request)
        return_params.merge!(:auth_token => token[0]) if token
        return_params
      end
    end
  end
end

routes.rb

# File config/routes.rb
namespace :api do
  namespace :v1 do
    devise_scope :user do
      post   '/sign_in'  => 'sessions#create'
      delete '/sign_out' => 'sessions#destroy'
    end
  end
end

sessions_controller.rb

# File app/controllers/api/v1/sessions_controller.rb
class Api::V1::SessionsController < Devise::SessionsController
  prepend_before_filter :require_no_authentication, :only => [:create ]

  # /api/v1/sign_in.json
  def create
    resource = warden.authenticate!(auth_options)
    sign_in(resource_name, resource)

    render json: {:success => true, auth_token: current_user.authentication_token }.to_json, status: :200
  end

  # /api/v1/sign_out.json
  def destroy
    signed_out = (Devise.sign_out_all_scopes ? sign_out : sign_out(resource_name))
    render json: {:success => true, auth_token: nil }.to_json, status: :200
  end
  
  def failure
    render :json => {:success => false, :errors => ["Login Failed"]}, status: 401
  end
protected
  def auth_options
    { :scope => resource_name, :recall => "#{controller_path}#failure" }
  end
end

user.rb

# File app/models/user.rb
class User < ActiveRecord::Base
  before_save :ensure_authentication_token
  devise :token_authenticatable
end