FCM Push Notifications: Firebase Cloud Messaging Android Guide

FCM Push Notifications: Firebase Cloud Messaging Android Guide Firebase Cloud Messaging (FCM) is Google's service for pushing notifications to Android, iOS, and web apps. This guide covers the core patterns for reliable push notifications in Android. FirebaseMessagingService Setup The entry point for handling FCM tokens and messages is FirebaseMessagingService : class MyFirebaseMessagingService : FirebaseMessagingService () { override fun onNewToken ( token : String ) { super . onNewToken ( token ) // Called when FCM generates a new registration token // Send this token to your backend to enable targeted pushes sendTokenToServer ( token ) Log . d ( "FCM" , "New token: $token" ) } override fun onMessageReceived ( remoteMessage : RemoteMessage ) { super . onMessageReceived ( remoteMessage ) // Called when a message arrives // Handle data payload and notification payload handlePushMessage ( remoteMessage ) } } Handling onNewToken When FCM generates a token (initial startup, token refresh)