Push notifications (FCM) in Flutter

Introduction

Push notifications let your app send messages to users even when the app is closed. This helps keep users informed and engaged.

To alert users about new messages or updates instantly.

To remind users about events or tasks.

To send promotional offers or news.

To notify users about app changes or important alerts.

Syntax

Flutter

import 'package:firebase_messaging/firebase_messaging.dart';

FirebaseMessaging messaging = FirebaseMessaging.instance;

// Request permission (iOS)
await messaging.requestPermission();

// Listen for messages
FirebaseMessaging.onMessage.listen((RemoteMessage message) {
  print('Message received: ${message.notification?.title}');
});

Use FirebaseMessaging.instance to access FCM features.

Always request permission on iOS before receiving notifications.

Examples

This gets the unique device token needed to send notifications to this device.

Flutter

FirebaseMessaging messaging = FirebaseMessaging.instance;

// Get the device token
String? token = await messaging.getToken();
print('Device token: $token');

This listens for notifications when the app is running in the foreground.

Flutter

FirebaseMessaging.onMessage.listen((RemoteMessage message) {
  print('Notification received while app is open');
});

This handles what happens when the user taps a notification to open the app.

Flutter

FirebaseMessaging.onMessageOpenedApp.listen((RemoteMessage message) {
  print('User tapped on notification');
});

Sample App

This app initializes Firebase, requests notification permission, and listens for incoming push notifications. When a notification arrives while the app is open, it shows the notification title on screen.

Flutter

import 'package:flutter/material.dart';
import 'package:firebase_core/firebase_core.dart';
import 'package:firebase_messaging/firebase_messaging.dart';

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await Firebase.initializeApp();
  runApp(MyApp());
}

class MyApp extends StatefulWidget {
  @override
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  String _message = 'No message yet';

  @override
  void initState() {
    super.initState();
    FirebaseMessaging.instance.requestPermission();

    FirebaseMessaging.onMessage.listen((RemoteMessage message) {
      setState(() {
        _message = message.notification?.title ?? 'No title';
      });
    });
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(title: Text('FCM Push Notifications')),
        body: Center(child: Text('Latest message: $_message')),
      ),
    );
  }
}

Important Notes

Push notifications require setting up Firebase project and adding config files to your app.

On iOS, users must allow notifications in system settings.

Test notifications using Firebase Console or server APIs.

Summary

Push notifications keep users updated even when app is closed.

Use FirebaseMessaging to get device token and listen for messages.

Always request permission on iOS and handle messages in app.