fcmappserver
There are 2 repositories under fcmappserver topic.
federicopenin/fcmphp
Class of comunication with server Firebase of google
rajeshkhumanthem/GIMMMAPPSERVER
Example implementation of an FCM App Server using XMPP protocol in C++. If you are looking to build an App Server to serve as a back end for your IOS/Android App, this is what you need. It relies on GIMMM to send/receive messages to/from your mobile application via the Firebase Connection Servers.