Rails (+ devise) + Native-React + FBSDK

I need to authenticate a User on my rails backend.

Originaly, I use Devise/Omniauth + standard FB login pattern. It works very well and I am able to authenticate a new or existing user, to create its session and so to get the devise "current_user" set up with all his FB parameters.

But I am transfering the front part into a React-Native App. I still want to login the user, but, I not only need to save the FB session cookie in the Apps but also to recognize my user on the rails server side.

I was wondering how to do.

I can easily login through the FBSDK with

http://ift.tt/1xPuvww

or http://ift.tt/1IopYD5

I can also easily login on my rails backed with

http://ift.tt/1JQGFcr

But I need do have FB authenticating my user on my rails backend.

Any ideas how to do ?