external_api_runtime.rb

module ExternalApiRuntime
  extend ActiveSupport::Concern

  module ClassMethods
    def log_process_action(payload)
      messages = super
      api_runtime = payload[:api_runtime]
      messages << (format('ExternalAPI: %.1fms', api_runtime.to_f)) if api_runtime
      messages
    end
  end

  attr_internal :api_runtime

  def initialize(...)
    super
    self.api_runtime = 0
    ActiveSupport::Notifications.subscribe('external_api.call') do |_name, starts, ends, _, _env|
      self.api_runtime += 1000 * (ends - starts)
    end
  end

  def append_info_to_payload(payload)
    super
    payload[:api_runtime] = api_runtime
    self.api_runtime = 0
  end
end

f.use Faraday::Request::Instrumentation, name: 'external_api.call'