OneSignal Help & Documentation

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Xamarin SDK Setup

OneSignal Xamarin SDK Reference. Works with iOS and Android (and derivatives like Amazon).

For Developers

Required For Setup

Generate Credentials

Before setting up the Xamarin SDK, you must generate the appropriate credentials for the platform(s) you are releasing on:

iOS - Generate an iOS Push Certificate

Android - Generate a Google Server API Key

Amazon - Generate an Amazon API Key

The Xamarin OneSignal SDK works for both Xamarin Forms and Xamarin Single View projects.

Setup SDK

1. Add NuGet Package

1.1 Under your Droid and / or iOS targets right click on Packages then select Add Packages....

1.2 Search for OneSignalSDK and press Add Package.

2. Add Code

Xamarin Forms Project

2.1A Add the following to your App.xaml.cs.

using Com.OneSignal;

public App()
  MainPage = new OneSignalXamarinFormsExamplePage();


Xamarin Single View App

2.1B - Android - Add OneSignal to your MainActivity.cs in your OnCreate method.

using Com.OneSignal;

protected override void OnCreate(Bundle savedInstanceState)


2.1B - iOS - Add OneSignal to your AppDelegate.cs in your FinishedLaunching method.

using Com.OneSignal;

public override bool FinishedLaunching(UIApplication application, NSDictionary launchOptions)

  return true;

3. Android Setup

3.1 Add the following permissions to AndroidManifest.xml.

<permission android:name="${manifestApplicationId}.permission.C2D_MESSAGE"
            android:protectionLevel="signature" />
<uses-permission android:name="${manifestApplicationId}.permission.C2D_MESSAGE" />

3.2 In your application tag, add the following.

<application ....>

  <receiver android:name="com.onesignal.GcmBroadcastReceiver"
            android:permission="" >
      <action android:name="" />
      <category android:name="${manifestApplicationId}" />

3.3 Replace all 3 of instances of ${manifestApplicationId} with your package name in AndroidManifest.xml.

4. iOS Setup

4.1 In your application's Info.plist, verify your Bundle Identifier matches you App Settings' Bundle ID, Enable Background Modes, allow Remote notifications.

5. iOS Optional - Add the Notification Extension Service

In order to show rich push notifications (images, buttons, etc), iOS requires a Notification Extension Service.


Recent versions of Visual Studio have introduced a bug where the Notification Extension Service will only work correctly when you run in Release mode. If you follow the following steps and yet images/buttons still do not appear in your push notifications, please make sure you are running in Release mode.

5.1 Right click on your project solution and click Add -> Add New Project

5.2 Click iOS -> Extension -> Notification Service Extension and select Next

5.3 Enter the name OneSignalNotificationServiceExtension and click Next


The Bundle ID for this extension should be the same as the Bundle ID for your main application with .OneSignalNotificationServiceExtension added to the end.

For example, if your primary application's Bundle ID is com.example.test, the Bundle ID for your extension should be com.example.test.OneSignalNotificationServiceExtension.

5.4 Click Create to add the extension service to your project.

5.5 Right click on References for your new OneSignalNotificationServiceExtension and select Edit References

5.6 Select Com.OneSignal.Abstractions and Com.OneSignal.iOS to include them as references for the extension service and click Ok.

5.7 Select the NotificationService.cs source file and replace the contents with this code:

using System;
using Foundation;
using UIKit;
using UserNotifications;
using Com.OneSignal;
using Com.OneSignal.Abstractions;

namespace OneSignalNotificationServiceExtension
  public class NotificationService : UNNotificationServiceExtension
    Action<UNNotificationContent> ContentHandler { get; set; }
    UNMutableNotificationContent BestAttemptContent { get; set; }
    UNNotificationRequest ReceivedRequest { get; set; }

    protected NotificationService(IntPtr handle) : base(handle)
      // Note: this .ctor should not contain any initialization logic.

    public override void DidReceiveNotificationRequest(UNNotificationRequest request, Action<UNNotificationContent> contentHandler)
      ReceivedRequest = request;
      ContentHandler = contentHandler;
      BestAttemptContent = (UNMutableNotificationContent)request.Content.MutableCopy();

      (OneSignal.Current as OneSignalImplementation).DidReceiveNotificationExtensionRequest(request, BestAttemptContent);


    public override void TimeWillExpire()
      // Called just before the extension will be terminated by the system.
      // Use this as an opportunity to deliver your "best attempt" at modified content, otherwise the original push payload will be used.

      (OneSignal.Current as OneSignalImplementation).ServiceExtensionTimeWillExpireRequest(ReceivedRequest, BestAttemptContent);


5.8 Open your extension's Info.plist file, and make sure the deployment target is at least iOS 10 or higher. If your deployment target is higher than the device you attempt to run it on, rich push notifications will not work.

That's it! Now, your application will be able to display push notification images, action buttons, and more.

6. iOS Optional - Only Required for iOS Simulator builds

The following is required to prevent crashes when using the iOS simulator.

6.1 Right click on your iOS project and select Options.

6.2 Select Build > iOS Build, then make sure iPhoneSimulator is selected under "Platform:" at the top.

6.3 Under Additional mtouch arguments: enter --registrar:static.


If run into any issues please see our Troubleshooting section

You're Done!

Next up: Send your first push notification via the OneSignal Dashboard

Xamarin SDK Setup

OneSignal Xamarin SDK Reference. Works with iOS and Android (and derivatives like Amazon).

For Developers