shiny-firebase

name	shiny-firebase
description	Guide for implementing Firebase Cloud Messaging push notifications in .NET MAUI apps using Shiny.Push.FirebaseMessaging on iOS and Android.
auto_invoke	true
triggers	["firebase","FCM","firebase cloud messaging","push notifications firebase","AddPushFirebaseMessaging","FirebaseConfiguration","GoogleService-Info.plist","google-services.json","firebase push","firebase messaging","RequestAccess hangs","FCM token never returns","duplicate FIRApp","Class FIRApp is implemented in both"]

Shiny Firebase Push Notifications Skill

Overview

Shiny.Push.FirebaseMessaging provides Firebase Cloud Messaging (FCM) push notification support for .NET MAUI applications on iOS and Android. It wraps the native Firebase iOS SDK (via a Slim Binding) and Android FCM through the Shiny Push infrastructure.

On iOS everything ships in one binding — Shiny.Firebase.iOS.Binding, pulled in automatically — which embeds a single copy of FirebaseCore alongside the Messaging and Analytics shims. Do not add another Firebase iOS binding package (e.g. AdamE.Firebase.iOS.*) to the same app: a second FirebaseCore means a second FIRApp, and whichever one gets configured is not necessarily the one the token request reads.

NuGet Package

Shiny.Push.FirebaseMessaging

Setup

MauiProgram.cs Configuration

using Shiny;

public static class MauiProgram
{
    public static MauiApp CreateMauiApp()
    {
        var builder = MauiApp.CreateBuilder();
        builder
            .UseMauiApp<App>()
            .UseShiny(); // Required

        // Option 1: Use embedded configuration (GoogleService-Info.plist / google-services.json)
        builder.Services.AddPushFirebaseMessaging();

        // Option 2: Use embedded configuration explicitly
        builder.Services.AddPushFirebaseMessaging(FirebaseConfiguration.Embedded);

        // Option 3: Manual configuration
        builder.Services.AddPushFirebaseMessaging(new FirebaseConfiguration(
            UseEmbeddedConfiguration: false,
            AppId: "your-app-id",
            SenderId: "your-sender-id",
            ProjectId: "your-project-id",
            ApiKey: "your-api-key"
        ));

        // With a custom push delegate
        builder.Services.AddPushFirebaseMessaging<MyPushDelegate>();

        return builder.Build();
    }
}

Custom Push Delegate

public class MyPushDelegate : IPushDelegate
{
    public Task OnReceived(PushNotification notification)
    {
        // Handle incoming push notification
        return Task.CompletedTask;
    }

    public Task OnNewToken(string token)
    {
        // Handle FCM token changes - send to your backend
        return Task.CompletedTask;
    }

    public Task OnUnRegistered(string token)
    {
        // Handle when the device is unregistered from push
        return Task.CompletedTask;
    }

    public Task OnEntry(PushNotification notification)
    {
        // Handle when user taps on a notification
        return Task.CompletedTask;
    }
}

FirebaseConfiguration Record

Parameter	Type	Default	Description
UseEmbeddedConfiguration	bool	true	Use platform config files (GoogleService-Info.plist / google-services.json)
AppId	string?	null	Firebase App ID (required if not using embedded config)
SenderId	string?	null	Firebase Sender ID (required if not using embedded config)
ProjectId	string?	null	Firebase Project ID (required if not using embedded config)
ApiKey	string?	null	Firebase API Key (required if not using embedded config)
DefaultChannel	NotificationChannel?	null	Android only - default notification channel
IntentAction	string?	null	Android only - custom intent action

Platform-Specific Requirements

iOS

• Add GoogleService-Info.plist to your iOS project (if using embedded configuration)
• Set Build Action to BundleResource
• Enable Push Notifications capability in Entitlements.plist
• Enable Remote Notifications background mode

Android

• Add google-services.json to your Android project root (if using embedded configuration)
• The Shiny Push library handles the Android Firebase initialization automatically

Topic Subscriptions (Tags)

The iOS implementation supports topic subscriptions through IPushTagSupport:

// Inject IPushManager
var push = services.GetRequiredService<IPushManager>();

// Cast provider to access tag support
if (push is IPushTagSupport tagSupport)
{
    await tagSupport.AddTag("news");
    await tagSupport.RemoveTag("promotions");
    await tagSupport.SetTags("news", "updates");
    await tagSupport.ClearTags();

    var currentTags = tagSupport.RegisteredTags;
}

Extension Methods

AddPushFirebaseMessaging(FirebaseConfiguration? config = null)

Registers Firebase push notification services. Pass null or omit for embedded configuration.

AddPushFirebaseMessaging<TPushDelegate>(FirebaseConfiguration? config = null)

Registers Firebase push with a custom IPushDelegate implementation that handles notification events.

Troubleshooting

iOS: RequestAccess() never completes — no token, no exception, no OnNewToken

Check the startup log for:

objc[xxxx]: Class FIRApp is implemented in both .../SomeFramework and .../AnotherFramework.
One of the two will be used. Which one is undefined.

The app has two copies of FirebaseCore, so FirebaseApp.configure() configures one FIRApp while the FCM token request reads the other, still-unconfigured one — the native completion block never fires and the await hangs forever.

• On Shiny.Push.FirebaseMessaging 5.0.2 or earlier, this is a library bug — the Core shim shipped in a different framework from the Messaging shim. Upgrade to 5.1.0+, where both live in one framework.
• On 5.1.0+, it means a second Firebase iOS SDK is in the app. Remove the other Firebase binding package, or drop Shiny.Push.FirebaseMessaging and use that SDK's own provider — do not run both.

From 5.1.0 the native shim also fails fast: if Firebase was never configured, RequestAccess() throws Firebase has not been configured instead of hanging.

Key Source Files

• src/Shiny.Push.FirebaseMessaging/FirebaseConfiguration.cs - Configuration record
• src/Shiny.Push.FirebaseMessaging/Platforms/Shared/ServiceCollectionExtensions.cs - DI registration
• src/Shiny.Push.FirebaseMessaging/Platforms/iOS/FirebasePushProvider.cs - iOS FCM provider
• src/Shiny.Firebase.iOS.Binding/ApiDefinitions.cs - the single iOS binding (Core + Messaging + Analytics)