Create Sign In / Sign Out API using Devise

devise.rb

# Find this line config.navigational_formats = ['*/*', :html] in devise.rb file and replace it with this line inorder to accept JSON request and give JSON response.
  
config.navigational_formats =  ["*/*", :html, :json]

routes.rb

# Define devise routes under version of the api

namespace :v1 do
  devise_for :users, :controllers => { sessions: 'api/v1/sessions' }
end

sessions_controller.rb

# Override create method inorder to use json request and response.
# Accepts params user like email and password.
# After verifying authentication successfully we need to generate one AUTH TOKEN for that user and pass it in response.

class Api::V1::SessionsController < Devise::SessionsController  
  before_action :authenticate_user!, except: [:create]
  respond_to :json

  def create
    resource = User.find_for_database_authentication(email: params[:user][:email])
    return invalid_login_attempt unless resource

    if resource.valid_password?(params[:user][:password])
      render json: { success: true, auth_token: resource.authentication_token, email: resource.email }, status: :created
      return
    end
    invalid_login_attempt
  end

  def destroy
    current_user.reset_authentication_token
    render json: { success: true }, status: :ok
  end

  protected
    def invalid_login_attempt
      render json: { success: false, message: "Error with your login or password"}, status: :unauthorized
    end
end