api/config/initializers/cors.rb

# Be sure to restart your server when you modify this file.

# Avoid CORS issues when API is called from the frontend app.
# Handle Cross-Origin Resource Sharing (CORS) in order to accept cross-origin Ajax requests.

# Read more: https://github.com/cyu/rack-cors

Rails.application.config.middleware.insert_before 0, Rack::Cors do
  allow do
    origins 'http://localhost:3001'

    resource "*",
      headers: :any,
      methods: [ :get, :post, :put, :patch, :delete, :options, :head ],
      credentials: true
  end
end