Removing grape and adding devise

app/helpers/routing_helper.rb

@@ -1,7 +1,6 @@
 module RoutingHelper
   extend ActiveSupport::Concern
   include Rails.application.routes.url_helpers
-  include GrapeRouteHelpers::NamedRouteMatcher
   include ActionView::Helpers::AssetUrlHelper
 
   included do

app/models/user.rb

@@ -1,4 +1,7 @@
 class User < ActiveRecord::Base
+  devise :database_authenticatable, :registerable, :recoverable, :rememberable, :trackable, :validatable
+
   belongs_to :account, inverse_of: :user
+
   validates :account, presence: true
 end