How to persist session in rails API only app

I am pretty new to ruby on rails, I want to add sessions back to rails 6 API app such that I get the current_cart id in session, if the the id does not exist in session, it goes on to create a new cart and store the id in session.

• I would like to know if there is another better option than adding sessions back? i.e. like using JWT tokens.
• I am following rails agile web development book, but I did it in rails API mode only.

Below is my application.rb

# frozen_string_literal: true

require_relative 'boot'

require 'rails'
# Pick the frameworks you want:
require 'active_model/railtie'
require 'active_job/railtie'
require 'active_record/railtie'
require 'active_storage/engine'
require 'action_controller/railtie'
require 'action_mailer/railtie'
require 'action_mailbox/engine'
require 'action_text/engine'
require 'action_view/railtie'
require 'action_cable/engine'
require 'sprockets/railtie'
# require "rails/test_unit/railtie"

# Require the gems listed in Gemfile, including any gems
# you've limited to :test, :development, or :production.
Bundler.require(*Rails.groups)

module DepotApi
  class Application < Rails::Application
    # Initialize configuration defaults for originally generated Rails version.
    config.load_defaults 6.1

    # skip verifying users on logout
    config.to_prepare do
      Devise::SessionsController.skip_before_action :verify_signed_out_user, only: :destroy
    end
    # Configuration for the application, engines, and railties goes here.
    #
    # These settings can be overridden in specific environments using the files
    # in config/environments, which are processed later.
    #
    # config.time_zone = "Central Time (US & Canada)"
    config.eager_load_paths << Rails.root.join('lib')

    # Only loads a smaller set of middleware suitable for API only apps.
    # Middleware like session, flash, cookies can be added back manually.
    # Skip views, helpers and assets when generating a new resource.
    config.api_only = true
    config.app_generators.scaffold_controller = :scaffold_controller

    # Middleware for ActiveAdmin
    config.middleware.use Rack::MethodOverride
    config.middleware.use ActionDispatch::Flash
    config.middleware.use ActionDispatch::Cookies
    config.middleware.use ActionDispatch::Session::CookieStore
  end
end

Below is my Line_items controller

# frozen_string_literal: true
class LineItemsController < ApiController
include CurrentCart
before_action :set_cart, only: [:create]
before_action :set_line_item, only: %i[show update destroy]
# GET /line_items
# GET /line_items.json
def index
@line_items = LineItem.all
end
# GET /line_items/1
# GET /line_items/1.json
def show; end
# POST /line_items
# POST /line_items.json
def create
product = Product.find(params[:product_id])
@line_item = @cart.add_product(product)
if @line_item.save
render :show, status: :created, location: @line_item
else
render json: @line_item.errors, status: :unprocessable_entity
end
end
# Increasing quantity
def add_quantity
@line_item.quantity += 1
@line_item.save
end
# decreasing  quantity
def reduce_quantity
@line_item.quantity > 1
@line_item.quantity -= 1
@line_item.save
end
# PATCH/PUT /line_items/1
# PATCH/PUT /line_items/1.json
def update
if @line_item.update(line_item_params)
render :show, status: :ok, location: @line_item
else
render json: @line_item.errors, status: :unprocessable_entity
end
end
# DELETE /line_items/1
# DELETE /line_items/1.json
def destroy
@line_item.destroy
end
private
# Use callbacks to share common setup or constraints between actions.
def set_line_item
@line_item = LineItem.find(params[:id])
end
# Only allow a list of trusted parameters through.
def line_item_params
params.require(:line_item).permit(:product_id)
end
end

• The value of @cart is set by the current module I have included.

Below is my Currentcart module where I set the session from

module CurrentCart
private
def set_cart
@cart = Cart.find(session[:cart_id])
rescue ActiveRecord::RecordNotFound
@cart = Cart.create
session[:cart_id] = @cart.id
end
end

All my API controllers are extending from this apiController except activeadmin

class ApiController < ActionController::API
end

Below is my application controller

# frozen_string_literal: true
class ApplicationController < ActionController::Base
# Prevent CSRF attacks by using :null_session
protect_from_forgery with: :null_session
before_action :configure_permitted_parameters, if: :devise_controller?
rescue_from CanCan::AccessDenied do |_exception|
render json: { error: 'Access denied' }, status: :forbidden
end
def authenticate_admin_user!
if admin_user_signed_in?
admin_root_path
else
new_admin_user_session_path
end
end
protected
def configure_permitted_parameters
devise_parameter_sanitizer.permit(:sign_up, keys: %i[user_name email role])
devise_parameter_sanitizer.permit(:sign_in, keys: %i[user_name email role])
end
end

• I finally a solution, for the two apps to connect, the create react app and a rails api i needed to first add back sessions to the rails api

    config.api_only = true
config.app_generators.scaffold_controller = :scaffold_controller
# Middleware for ActiveAdmin
config.middleware.use Rack::MethodOverride
config.middleware.use ActionDispatch::Flash
config.middleware.use ActionDispatch::Cookies
config.middleware.use ActionDispatch::Session::CookieStore

• then in create react app i added this setting in
  package.json
"proxy": "http://127.0.0.1:4000"

• Then all my routes on the front end (create react app) where changed as follow
  http://127.0.0.1.400/products to /products

• Their you can get anything from session on the front end