How can i integrate Facebook in a Cocos2d-x 3.x?
Umm, Facebook has several API’s: https://developers.facebook.com/docs/reference/apis/
Here is Android: https://developers.facebook.com/docs/android/
We have developed a Facebook sdk for JSB
https://github.com/cocos2d-x/facebook-jsb-sdk
if you are not using Javascript, you can see how we implemented it