Hey @sengming - there is some good documentation on how you can implement headers within API response when using our Ruby API gem here at this link to the GitHub repo for the gem.
I do know that the HTTP REST client that's built into the gem does offer functionality to allow you to retrieve headers associated with a response, but for any further troubleshooting I'd recommend opening an issue in the repo itself, even if it is just to ask a question like this as it is the best place for the most current information on the gem itself. Hope this helps!
