clarion/app/controllers/concerns/public_api_exposing.rb

require 'active_support/concern'

module PublicApiExposing
  extend ActiveSupport::Concern

  def set_access_control_headers
    if request.format.json?
      response.headers['Access-Control-Allow-Origin'] = '*'
    end
  end
  
  included do
    before_action :set_access_control_headers
  end
end