Push Notifications in .NET MAUI with FCM

Setting up Firebase Cloud Messaging for iOS in .NET MAUI can be tricky with Apple certificates, provisioning profiles, and various configuration steps. This guide walks you through the entire process step-by-step, helping you avoid the common pitfalls that can cost hours of debugging time.

You’ll learn exactly how to configure Firebase, handle Apple Developer Console setup, implement the .NET MAUI code, and troubleshoot the most frequent issues developers encounter.

Why Firebase Cloud Messaging for .NET MAUI?

Firebase Cloud Messaging provides a reliable and scalable solution for sending push notifications to both iOS and Android devices. For .NET MAUI developers, FCM offers:

- Cross-platform consistency with a unified API
- Free tier supporting millions of messages monthly
- Advanced targeting features for user segmentation
- Built-in analytics for tracking notification performance

Prerequisites

Before implementing push notifications in .NET MAUI with FCM, ensure you have:

- .NET MAUI SDK 8.0 or higher
- Visual Studio 2022 or compatible IDE
- Apple Developer Account (paid membership required)
- Firebase project set up

Estimated implementation time: 2-4 hours

Step 1: Configure Firebase Project

1.1 Register iOS App in Firebase

1. Open the Firebase Console
2. Create a new project or select an existing one
3. Click "Add app" → iOS
4. Enter your Bundle ID exactly as defined in your MAUI project:

<!-- In your .csproj under PropertyGroup -->
<ApplicationId>com.yourcompany.appname</ApplicationId>

1. Download the GoogleService-Info.plist file
2. Skip the additional Firebase setup steps for now

1.2 Add GoogleService-Info.plist to Your Project

Add the file to your project and configure the build action:

<ItemGroup Condition="'$(TargetFramework)' == 'net8.0-ios'">
  <BundleResource Include="GoogleService-Info.plist" />
</ItemGroup>

Step 2: Apple Developer Console Configuration

2.1 Configure App Identifier

1. Go to Apple Developer Console
2. Navigate to Certificates, Identifiers & Profiles
3. Select your App Identifier
4. Enable Push Notifications by checking the checkbox
5. Save changes (this will invalidate existing provisioning profiles)

2.2 Create APNs Authentication Key

- Go to Keys → Add Key
- Enter a name: [YourProject] APNs Key
- Enable: Apple Push Notifications service (APNs)
- Download the key immediately (can only be downloaded once)
- Note down:
  - Key ID (10-character code)
  - Team ID (found in Account overview)

2.3 Update Provisioning Profile

- Download your updated Development/Distribution Provisioning Profile
- Install it in Xcode or via Finder
- Ensure it's used in your build process

Step 3: .NET MAUI Implementation

3.1 Install NuGet Package

Install the Firebase Cloud Messaging package:

dotnet add package Plugin.Firebase.CloudMessaging

3.2 Configure MauiProgram.cs

using Plugin.Firebase.CloudMessaging;

#if ANDROID
using Plugin.Firebase.Core.Platforms.Android;
#elif IOS
using Plugin.Firebase.Core.Platforms.iOS;
#endif

namespace YourMAUIApp
{
    public static class MauiProgram
    {
        public static MauiApp CreateMauiApp()
        {
            var builder = MauiApp.CreateBuilder();
            builder
                .UseMauiApp<App>()
                .RegisterFirebaseServices()
                .ConfigureFonts(fonts =>
                {
                    fonts.AddFont("Nunito-Regular.ttf", "NunitoRegular");
                    fonts.AddFont("Nunito-Semibold.ttf", "NunitoSemibold");
                    fonts.AddFont("Nunito-ExtraBold.ttf", "NunitoExtrabold");
                });

#if DEBUG
    		builder.Logging.AddDebug();
#endif
            return builder.Build();
        }
        /// <summary>
        /// 
        /// 
        ///  Register Firebase Services
        ///  
        /// 
        /// </summary>
        private static MauiAppBuilder RegisterFirebaseServices(this MauiAppBuilder builder)
        {
            builder.ConfigureLifecycleEvents(events => {
#if IOS
                events.AddiOS(iOS => iOS.WillFinishLaunching((_, __) => {
                    CrossFirebase.Initialize();
                    FirebaseCloudMessagingImplementation.Initialize();
                    return false;
                }));
#elif ANDROID
                events.AddAndroid(android => android.OnCreate((activity, _) =>
                CrossFirebase.Initialize(activity)));
#endif
            });

            return builder;
        }    
    }
}

3.3 Create iOS Entitlements

Create Platforms/iOS/Entitlements.plist:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
    <dict>
        <key>aps-environment</key>
        <string>production</string>
    </dict>
</plist>

Choose production or development based on the setting you chose when registering your apns key.

Step 4: Firebase APNs Integration

4.1 Upload APNs Authentication Key to Firebase

1. Firebase Console → Project Settings → Cloud Messaging
2. iOS app configuration → APNs Authentication Key
3. Upload your .p8 key file
4. Enter Key ID and Team ID
5. Save the configuration

4.2 Implement Token Retrieval

using Plugin.Firebase.CloudMessaging;

public partial class MainPage : ContentPage
{

    public MainPage()
    {
        InitializeComponent();
    }

    private async void OnCounterClicked(object sender, EventArgs e)
    {
        var status = await CheckAndRequestNotificationPermissionAsync();
        if (status == PermissionStatus.Granted)
        {
            await DisplayAlert("Success", "Notification permission granted!", "OK");
            
            try
            {
                var token = await CrossFirebaseCloudMessaging.Current.GetTokenAsync();
                Console.WriteLine($"FCM token: {token}");
                await Share.RequestAsync(new ShareTextRequest
                {
                    Text = token,
                    Title = "FCM Token"
                });
                    
                // For production: send token to your backend
                await SendTokenToBackend(token);
            }
            catch (Exception ex)
            {
                await DisplayAlert("Error", $"Failed to get FCM token: {ex.Message}", "OK");
            }
        }
        else
        {
            await DisplayAlert("Notice", "Notification permission was not granted.", "OK");
        }
    }

    public async Task<PermissionStatus> CheckAndRequestNotificationPermissionAsync()
    {
        await CrossFirebaseCloudMessaging.Current.CheckIfValidAsync();
        var status = await Permissions.CheckStatusAsync<Permissions.PostNotifications>();
        if (status != PermissionStatus.Granted)
        {
            status = await Permissions.RequestAsync<Permissions.PostNotifications>();
        }
        return status;
    }

    private async Task SendTokenToBackend(string token)
    {
        // Implement your backend integration here
        // Typically POST to /api/devices/register
    }
}

Step 5: Testing Push Notifications in .NET MAUI

Test with iOS Simulator:

1. Build and run your app in the iOS Simulator
2. Launch the app and retrieve the FCM token
3. Firebase Console → Cloud Messaging → Send test message
4. Add the FCM token and send a test notification
5. Verify the notification appears in the simulator

Test with Physical Device:

1. Deploy to a physical device (TestFlight or direct deployment)
2. Launch the app and retrieve the FCM token
3. Use the same Firebase Console process to send test notifications
4. Verify notifications work on the actual device

Both iOS Simulator and physical devices support Firebase push notifications, so you can test your implementation in either environment.

Common Issues and Solutions

"Default FirebaseApp is not initialized" Error

Solution: This occurs when Firebase can't find or load your configuration. Fix it by:

1. First: Verify your ApplicationId in .csproj exactly matches the package name in google-services.json
2. Then: Delete bin and obj folders from your project
3. Finally: Clean and rebuild your project

Issue 2: Token Generated but No Notifications

Solution: Verify APNs Authentication Key is correctly configured in Firebase and check your Entitlements.plist.

Issue 3: NuGet Package Installation Fails (Long Path Issue)

Solution: Firebase iOS libraries can cause path length issues on Windows. The complete workaround is described here: Long Path Issue Solutions

Issue 4: "No valid aps-environment entitlement found"

Solution: Ensure Entitlements.plist is properly included and your provisioning profile is up to date.

Next Steps

You've successfully implemented Firebase push notifications in your .NET MAUI iOS app!

Recommended next steps:

1. Implement Android FCM setup for complete cross-platform coverage
2. Implement rich notifications with media and actions
3. Build backend integration for automated notification campaigns

Conclusion

Push notifications in .NET MAUI with Firebase Cloud Messaging provide a powerful way to engage users across platforms. While the setup requires careful attention to Apple's certificate management, the unified API makes cross-platform notification handling straightforward.

The key to successful implementation is following each configuration step precisely and testing thoroughly on physical devices. With proper setup, you'll have a robust push notification system that scales with your app's growth.

Ready to implement Android push notifications? Check out part 2 of this series covering Android-specific FCM setup in .NET MAUI.

Push Notifications in .NET MAUI with FCM – iOS Part