token_authenticatable.rb

module TokenAuthenticatable
  extend ActiveSupport::Concern

  included do
    before_action :authenticate_request

    attr_reader :current_user

    rescue_from UnauthorizedException, with: ->{ render(json: { error: "Unauthorized"}, status: 403)}
  end

  private

  def authenticate_request
    @current_user = AuthorizeApiRequest.call(request.headers).result
    raise(UnauthorizedException) unless @current_user
  end
end

class UnauthorizedException < StandardError; end