📩 firebase_notification_helper

A lightweight, easy-to-use Flutter helper package for Firebase Cloud Messaging (FCM), Local Notifications, and Firebase Cloud Function based remote push notification sending.

This package is designed to make notification integration extremely simple — even for beginners.
It includes FCM token fetching, local notification display, foreground notification handling, background handler support, topic subscription, and remote push sending through Firebase Cloud Functions.

✅ Summary of Everything Included in This Package

✔️ Firebase Cloud Messaging setup
✔️ Local notification support
✔️ FCM token fetch
✔️ Android notification channel creation
✔️ Foreground notification listener
✔️ Background message handler support
✔️ Notification tap payload callback
✔️ FCM token refresh callback
✔️ Topic subscribe and unsubscribe
✔️ Remote notification sending through Firebase Cloud Functions
✔️ Send notification to token, multiple tokens, topic, or condition
✔️ Beautiful full-page Flutter example UI
✔️ Example app run instructions
✔️ Security best practices
✔️ Pub.dev-ready consistent formatting

Remote notification sending requires Firebase Cloud Functions or another trusted server environment.

⭐ Features

🔥 Fetch FCM Token
🔔 Show Local Notifications
📨 Send Remote Push Notification using Firebase Cloud Functions
📡 Send Notification to Topic
👥 Send Notification to Multiple Tokens
🎯 Send Notification to Condition
🚀 Foreground Message Handler Support
🌙 Background Message Handler Support
👆 Notification Tap Callback
🔄 Token Refresh Callback
🧪 Full Example App Included
🛡 Safer than client-side server key sending
📦 Clean and beginner-friendly API

🔐 Important Security Note

Do not put your Firebase server key or service account key inside a Flutter app.

Remote push notification sending should be done from a trusted environment, such as:

Firebase Cloud Functions
Your own backend server
Firebase Admin SDK

This package supports remote notification sending through Firebase Cloud Functions.

📦 Installation

Add the package in pubspec.yaml:

dependencies:
  firebase_notification_helper: ^0.0.4

Then run:

flutter pub get

🔥 Firebase Setup

Before using this package, connect your Flutter app with Firebase.

Recommended setup:

dart pub global activate flutterfire_cli
flutterfire configure

For Android, make sure google-services.json exists here:

android/app/google-services.json

For the package example app, make sure google-services.json exists here:

example/android/app/google-services.json

🤖 Android Permission Setup

Add this permission in:

android/app/src/main/AndroidManifest.xml

Add it above the <application> tag:

<uses-permission android:name="android.permission.POST_NOTIFICATIONS" />

⚙️ Upgrade this android part in `/android/build.gradle.kts`

If your project needs manual Firebase setup, add Google Services classpath:

buildscript {
    repositories {
        google()
        mavenCentral()
    }

    dependencies {
        classpath("com.google.gms:google-services:4.4.2")
    }
}

⚙️ Upgrade this android part in `/android/app/build.gradle.kts`

Add Google Services plugin:

plugins {
    id("com.android.application")
    id("org.jetbrains.kotlin.android")
    id("com.google.gms.google-services") // REQUIRED
    id("dev.flutter.flutter-gradle-plugin")
}

If your project needs local notification desugaring support, add this:

android {
    compileOptions {
        sourceCompatibility = JavaVersion.VERSION_11
        targetCompatibility = JavaVersion.VERSION_11
        isCoreLibraryDesugaringEnabled = true
    }

    kotlinOptions {
        jvmTarget = JavaVersion.VERSION_11.toString()
    }
}

dependencies {
    coreLibraryDesugaring("com.android.tools:desugar_jdk_libs:2.1.4")
}

🚀 Initialization

Import the package:

import 'package:flutter/material.dart';
import 'package:firebase_notification_helper/firebase_notification_helper.dart';

Then initialize before runApp():

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();

  await FirebaseNotificationHelper.initialize(
    config: const NotificationHelperConfig(
      debug: true,
      channelId: 'high_importance_channel',
      channelName: 'High Importance Notifications',
      channelDescription: 'Used for important notifications.',
      cloudFunctionName: 'sendNotification',
      cloudFunctionRegion: 'us-central1',
      requestPermissionOnInit: true,
      enableForegroundLocalNotification: true,
      handleInitialMessage: true,
      emitInitialToken: true,
    ),
    onNotificationTap: (payload) {
      debugPrint('Notification tapped: $payload');
    },
    onTokenChanged: (token) {
      debugPrint('FCM Token Changed: $token');
    },
  );

  runApp(const MyApp());
}

🔑 Get FCM Token

final token = await FirebaseNotificationHelper.getToken();
debugPrint("FCM Token: $token");

🔔 Show Local Notification

await FirebaseNotificationHelper.showLocalNotification(
  title: "Local Test",
  body: "This alert is from your device.",
  payload: {
    "screen": "home",
    "type": "local",
  },
);

await FirebaseNotificationHelper.subscribeToTopic("all_users");

📡 Unsubscribe from Topic

await FirebaseNotificationHelper.unsubscribeFromTopic("all_users");

☁️ Firebase Cloud Function Setup for Remote Notification

Remote push notification sending requires Firebase Cloud Functions.

Flow:

Flutter App
   ↓
firebase_notification_helper
   ↓
Firebase Cloud Function
   ↓
Firebase Admin SDK
   ↓
Firebase Cloud Messaging
   ↓
Receiver Device

Initialize Firebase Functions:

firebase init functions

Choose:

JavaScript

📁 `functions/package.json`

Use this code:

{
  "name": "functions",
  "description": "Cloud Functions for firebase_notification_helper",
  "type": "module",
  "engines": {
    "node": "22"
  },
  "main": "index.js",
  "scripts": {
    "serve": "firebase emulators:start --only functions",
    "deploy": "firebase deploy --only functions",
    "logs": "firebase functions:log"
  },
  "dependencies": {
    "firebase-admin": "^14.0.0",
    "firebase-functions": "^7.2.5"
  },
  "devDependencies": {}
}

📁 `functions/index.js`

Use this Cloud Function code:

import { initializeApp } from "firebase-admin/app";
import { getMessaging } from "firebase-admin/messaging";
import { HttpsError, onCall } from "firebase-functions/v2/https";

initializeApp();

const REGION = "us-central1";

/**
 * For testing: false
 * For production: true
 *
 * If true, user must be logged in with Firebase Auth.
 */
const REQUIRE_AUTH = false;

export const sendNotification = onCall(
  {
    region: REGION
  },
  async (request) => {
    try {
      if (REQUIRE_AUTH && !request.auth) {
        throw new HttpsError(
          "unauthenticated",
          "You must be logged in to send notification."
        );
      }

      const result = await sendFcmMessage(request.data || {});
      return result;
    } catch (error) {
      if (error instanceof HttpsError) {
        throw error;
      }

      throw new HttpsError(
        "internal",
        error?.message || "Failed to send notification."
      );
    }
  }
);

async function sendFcmMessage(input) {
  const target = input.target || {};

  const token = target.token || input.token;
  const tokens = target.tokens || input.tokens;
  const topic = target.topic || input.topic;
  const condition = target.condition || input.condition;

  const title = input.title;
  const body = input.body;
  const data = input.data || {};
  const androidChannelId = input.androidChannelId || "high_importance_channel";

  if (!title || !body) {
    throw new HttpsError(
      "invalid-argument",
      "title and body are required."
    );
  }

  const safeData = stringifyData(data);

  const baseMessage = {
    notification: {
      title: String(title),
      body: String(body)
    },
    data: safeData,
    android: {
      priority: "high",
      notification: {
        channelId: String(androidChannelId),
        sound: "default"
      }
    },
    apns: {
      payload: {
        aps: {
          sound: "default"
        }
      }
    }
  };

  if (token) {
    const response = await getMessaging().send({
      ...baseMessage,
      token: String(token)
    });

    return {
      success: true,
      type: "token",
      message: "Notification sent successfully.",
      response
    };
  }

  if (Array.isArray(tokens) && tokens.length > 0) {
    const cleanTokens = tokens
      .map((item) => String(item).trim())
      .filter((item) => item.length > 0);

    if (cleanTokens.length === 0) {
      throw new HttpsError(
        "invalid-argument",
        "tokens list is empty."
      );
    }

    if (cleanTokens.length > 500) {
      throw new HttpsError(
        "invalid-argument",
        "Maximum 500 tokens are allowed per request."
      );
    }

    const response = await getMessaging().sendEachForMulticast({
      ...baseMessage,
      tokens: cleanTokens
    });

    return {
      success: response.failureCount === 0,
      type: "tokens",
      message: "Multicast notification request completed.",
      successCount: response.successCount,
      failureCount: response.failureCount,
      responses: response.responses.map((item, index) => ({
        token: cleanTokens[index],
        success: item.success,
        messageId: item.messageId || null,
        error: item.error?.message || null
      }))
    };
  }

  if (topic) {
    const response = await getMessaging().send({
      ...baseMessage,
      topic: normalizeTopic(String(topic))
    });

    return {
      success: true,
      type: "topic",
      message: "Topic notification sent successfully.",
      response
    };
  }

  if (condition) {
    const response = await getMessaging().send({
      ...baseMessage,
      condition: String(condition)
    });

    return {
      success: true,
      type: "condition",
      message: "Condition notification sent successfully.",
      response
    };
  }

  throw new HttpsError(
    "invalid-argument",
    "Provide token, tokens, topic or condition."
  );
}

function stringifyData(data) {
  const safeData = {};

  Object.entries(data || {}).forEach(([key, value]) => {
    if (value === null || value === undefined) {
      safeData[key] = "";
    } else if (typeof value === "object") {
      safeData[key] = JSON.stringify(value);
    } else {
      safeData[key] = String(value);
    }
  });

  return safeData;
}

function normalizeTopic(topic) {
  return topic.trim().replace(/^\/topics\//, "");
}

🚀 Deploy Cloud Function

Run:

firebase deploy --only functions:sendNotification

📨 Send Remote Push Notification to Token

final result = await FirebaseNotificationHelper.sendRemoteNotification(
  target: FcmTarget.token(receiverFcmToken),
  title: "Hello!",
  body: "This is sent using firebase_notification_helper.",
  data: {
    "screen": "chat",
    "id": "123",
  },
);

debugPrint(result.toString());

📨 Send Remote Push Notification to Topic

First subscribe the receiver device:

await FirebaseNotificationHelper.subscribeToTopic("all_users");

Then send:

final result = await FirebaseNotificationHelper.sendRemoteNotification(
  target: const FcmTarget.topic("all_users"),
  title: "New Update",
  body: "A new update is available.",
  data: {
    "screen": "home",
  },
);

debugPrint(result.toString());

📨 Send Remote Push Notification to Multiple Tokens

final result = await FirebaseNotificationHelper.sendRemoteNotification(
  target: FcmTarget.tokens([
    token1,
    token2,
    token3,
  ]),
  title: "Group Notification",
  body: "This notification was sent to multiple devices.",
  data: {
    "type": "group_message",
  },
);

debugPrint(result.rawBody);

📨 Send Remote Push Notification to Condition

final result = await FirebaseNotificationHelper.sendRemoteNotification(
  target: const FcmTarget.condition(
    "'news' in topics || 'updates' in topics",
  ),
  title: "Condition Notification",
  body: "This was sent using a topic condition.",
  data: {
    "screen": "news",
  },
);

debugPrint(result.rawBody);

🧪 Usage Example

Import:

import 'package:flutter/material.dart';
import 'package:firebase_notification_helper/firebase_notification_helper.dart';

Then use this code:

import 'package:flutter/material.dart';
import 'package:firebase_notification_helper/firebase_notification_helper.dart';

class NotificationSenderPage extends StatefulWidget {
  const NotificationSenderPage({super.key});

  @override
  State<NotificationSenderPage> createState() => _NotificationSenderPageState();
}

class _NotificationSenderPageState extends State<NotificationSenderPage> {
  final TextEditingController tokenController = TextEditingController();
  final TextEditingController topicController = TextEditingController(
    text: "all_users",
  );
  final TextEditingController titleController = TextEditingController(
    text: "Test Notification",
  );
  final TextEditingController bodyController = TextEditingController(
    text: "Hello from firebase_notification_helper!",
  );

  bool sendToTopic = false;
  bool loading = false;
  String response = "";

  @override
  void initState() {
    super.initState();
    _loadToken();
  }

  Future<void> _loadToken() async {
    final token = await FirebaseNotificationHelper.getToken();

    if (!mounted) return;

    setState(() {
      tokenController.text = token ?? "";
    });
  }

  Future<void> _sendNotification() async {
    final title = titleController.text.trim();
    final body = bodyController.text.trim();

    if (title.isEmpty || body.isEmpty) {
      setState(() {
        response = "Title and body are required.";
      });
      return;
    }

    if (sendToTopic && topicController.text.trim().isEmpty) {
      setState(() {
        response = "Topic is required.";
      });
      return;
    }

    if (!sendToTopic && tokenController.text.trim().isEmpty) {
      setState(() {
        response = "Target token is required.";
      });
      return;
    }

    setState(() {
      loading = true;
      response = "";
    });

    try {
      final result = await FirebaseNotificationHelper.sendRemoteNotification(
        target: sendToTopic
            ? FcmTarget.topic(topicController.text.trim())
            : FcmTarget.token(tokenController.text.trim()),
        title: title,
        body: body,
        data: {
          "screen": "home",
          "source": "example_app",
        },
      );

      if (!mounted) return;

      setState(() {
        response = result.rawBody;
      });
    } catch (e) {
      if (!mounted) return;

      setState(() {
        response = e.toString();
      });
    } finally {
      if (!mounted) return;

      setState(() {
        loading = false;
      });
    }
  }

  Future<void> _showLocalNotification() async {
    await FirebaseNotificationHelper.showLocalNotification(
      title: titleController.text.trim().isEmpty
          ? "Local Notification"
          : titleController.text.trim(),
      body: bodyController.text.trim().isEmpty
          ? "This is a local notification."
          : bodyController.text.trim(),
      payload: {
        "type": "local",
        "screen": "home",
      },
    );
  }

  Future<void> _subscribeTopic() async {
    await FirebaseNotificationHelper.subscribeToTopic(
      topicController.text.trim(),
    );

    setState(() {
      response = "Subscribed to topic: ${topicController.text.trim()}";
    });
  }

  @override
  void dispose() {
    tokenController.dispose();
    topicController.dispose();
    titleController.dispose();
    bodyController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text("Notification Sender"),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _showLocalNotification,
        child: const Icon(Icons.notifications),
      ),
      body: ListView(
        padding: const EdgeInsets.all(16),
        children: [
          SwitchListTile(
            value: sendToTopic,
            title: const Text("Send to Topic"),
            onChanged: (value) {
              setState(() {
                sendToTopic = value;
              });
            },
          ),

          const SizedBox(height: 12),

          if (sendToTopic)
            TextField(
              controller: topicController,
              decoration: const InputDecoration(
                labelText: "Topic Name",
                border: OutlineInputBorder(),
              ),
            )
          else
            TextField(
              controller: tokenController,
              maxLines: 4,
              decoration: const InputDecoration(
                labelText: "Target FCM Token",
                border: OutlineInputBorder(),
              ),
            ),

          const SizedBox(height: 12),

          TextField(
            controller: titleController,
            decoration: const InputDecoration(
              labelText: "Notification Title",
              border: OutlineInputBorder(),
            ),
          ),

          const SizedBox(height: 12),

          TextField(
            controller: bodyController,
            maxLines: 2,
            decoration: const InputDecoration(
              labelText: "Notification Body",
              border: OutlineInputBorder(),
            ),
          ),

          const SizedBox(height: 12),

          if (sendToTopic)
            OutlinedButton.icon(
              onPressed: _subscribeTopic,
              icon: const Icon(Icons.add_alert),
              label: const Text("Subscribe This Device To Topic"),
            ),

          const SizedBox(height: 12),

          ElevatedButton.icon(
            onPressed: loading ? null : _sendNotification,
            icon: loading
                ? const SizedBox(
                    width: 18,
                    height: 18,
                    child: CircularProgressIndicator(strokeWidth: 2),
                  )
                : const Icon(Icons.send),
            label: Text(loading ? "Sending..." : "Send Notification"),
          ),

          const SizedBox(height: 16),

          const Text(
            "Response:",
            style: TextStyle(fontWeight: FontWeight.bold),
          ),

          const SizedBox(height: 8),

          SelectableText(
            response.isEmpty ? "No response yet." : response,
          ),
        ],
      ),
    );
  }
}

▶️ Example App Run Instructions

Go to example folder:

cd example

Run:

flutter clean
flutter pub get
flutter run

Before running, make sure this file exists:

example/android/app/google-services.json

❗ Common Issues

google-services.json is missing

Place the file here:

android/app/google-services.json

For example app:

example/android/app/google-services.json

cloud_functions and firebase_core version conflict

Use compatible versions:

dependencies:
  firebase_core: ^3.0.0
  firebase_messaging: ^15.0.0
  flutter_local_notifications: ^17.0.0
  cloud_functions: ^5.6.2
  http: ^1.2.0

Notification not showing in foreground

Initialize with:

enableForegroundLocalNotification: true

Topic notification not received

Subscribe the receiver device first:

await FirebaseNotificationHelper.subscribeToTopic("all_users");

📚 API Overview

FirebaseNotificationHelper.initialize();

FirebaseNotificationHelper.getToken();

FirebaseNotificationHelper.deleteToken();

FirebaseNotificationHelper.requestPermission();

FirebaseNotificationHelper.showLocalNotification(
  title: "Title",
  body: "Body",
);

FirebaseNotificationHelper.subscribeToTopic("all_users");

FirebaseNotificationHelper.unsubscribeFromTopic("all_users");

FirebaseNotificationHelper.sendRemoteNotification(
  target: FcmTarget.token(token),
  title: "Title",
  body: "Body",
);

📄 License

MIT License

👨‍💻 Author

Developed by Nafim Ahmed.

📩 firebase_notification_helper

✅ Summary of Everything Included in This Package

⭐ Features

🔐 Important Security Note

📦 Installation

🔥 Firebase Setup

🤖 Android Permission Setup

⚙️ Upgrade this android part in `/android/build.gradle.kts`

⚙️ Upgrade this android part in `/android/app/build.gradle.kts`

🚀 Initialization

🔑 Get FCM Token

🔔 Show Local Notification

📡 Unsubscribe from Topic

☁️ Firebase Cloud Function Setup for Remote Notification

📁 `functions/package.json`

📁 `functions/index.js`

🚀 Deploy Cloud Function

📨 Send Remote Push Notification to Token

📨 Send Remote Push Notification to Topic

📨 Send Remote Push Notification to Multiple Tokens

📨 Send Remote Push Notification to Condition

🧪 Usage Example

▶️ Example App Run Instructions

❗ Common Issues

google-services.json is missing

cloud_functions and firebase_core version conflict

Notification not showing in foreground

Topic notification not received

📚 API Overview

📄 License

👨‍💻 Author

Libraries

firebase_notification_helper package

📩 firebase_notification_helper

✅ Summary of Everything Included in This Package

⭐ Features

🔐 Important Security Note

📦 Installation

🔥 Firebase Setup

🤖 Android Permission Setup

⚙️ Upgrade this android part in /android/build.gradle.kts

⚙️ Upgrade this android part in /android/app/build.gradle.kts

🚀 Initialization

🔑 Get FCM Token

🔔 Show Local Notification

📡 Subscribe to Topic

📡 Unsubscribe from Topic

☁️ Firebase Cloud Function Setup for Remote Notification

📁 functions/package.json

📁 functions/index.js

🚀 Deploy Cloud Function

📨 Send Remote Push Notification to Token

📨 Send Remote Push Notification to Topic

📨 Send Remote Push Notification to Multiple Tokens

📨 Send Remote Push Notification to Condition

🧪 Usage Example

▶️ Example App Run Instructions

❗ Common Issues

google-services.json is missing

cloud_functions and firebase_core version conflict

Notification not showing in foreground

Topic notification not received

📚 API Overview

📄 License

👨‍💻 Author

Libraries

firebase_notification_helper package

⚙️ Upgrade this android part in `/android/build.gradle.kts`

⚙️ Upgrade this android part in `/android/app/build.gradle.kts`

📁 `functions/package.json`

📁 `functions/index.js`