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OneSignal Example

How to Onesignal push notifications in android via kotlin.

OneSignal is a fast and reliable service to send push notifications, in-app messages, SMS, and emails.

Android SDK Setup

Instructions for adding the OneSignal Android Mobile App SDK to your Android or Amazon Kindle Fire Apps using Android Studio.

Step 1. Requirements

Step 2. Add OneSignal Gradle Plugin and SDK

2.1 Open your root build.gradle (Project: name) file, add the following.

  • Under buildscript > repositories add (before jcenter)
    • mavenCentral()
    • gradlePluginPortal()
  • Under buildscript > dependencies add
    • classpath '[0.12.10, 0.99.99]'
  • Under allprojects > repositories add (before jcenter)
    • mavenCentral()

Newer versions of Android Studio

When creating a new project from Android Studio Artic Fox (or newer) the allprojects{...} is no longer added in the project level gradle. You should only copy the buildscript portion of the code below.


buildscript {
    repositories {
    dependencies {
        classpath '[0.12.10, 0.99.99]'

allprojects {
    repositories {

2.2 Open your App build.gradle (Module: app) file, add the following under buildscript {...} and above ''.


plugins {
    id 'com.onesignal.androidsdk.onesignal-gradle-plugin'
    // Other plugins here if pre-existing

2.3 Add the following to your dependencies section.


dependencies {
    implementation 'com.onesignal:OneSignal:[4.0.0, 4.99.99]'

Sync Gradle

Make sure to press "Sync Now" on the banner that pops up after saving!

Step 3. Add Required Code

3.1 Add the following to the onCreate method in your Application class.

If you don't have an Application class follow our Create Application Class Guide.

Note: The ONESIGNAL_APP_ID can be found in the dashboard Settings > Keys & IDs


import com.onesignal.OneSignal

const val ONESIGNAL_APP_ID = "########-####-####-####-############"

class MainApplication : Application() {
   override fun onCreate() {

      // Logging set to help debug issues, remove before releasing your app.
      OneSignal.setLogLevel(OneSignal.LOG_LEVEL.VERBOSE, OneSignal.LOG_LEVEL.NONE)

      // OneSignal Initialization


import com.onesignal.OneSignal;

public class MainApplication extends Application {
    private static final String ONESIGNAL_APP_ID = "########-####-####-####-############";

    public void onCreate() {

        // Enable verbose OneSignal logging to debug issues if needed.
        OneSignal.setLogLevel(OneSignal.LOG_LEVEL.VERBOSE, OneSignal.LOG_LEVEL.NONE);

        // OneSignal Initialization

By default, notifications will be shown with a small bell icon in the notification shade. Follow the Customize Notification Icons guide to create your own small and large notification icons for your app.

Step 5. Run Your App and Send Yourself a Notification

Run your app on a physical device to make sure it builds correctly.

Your Android device should already be subscribed to push notifications. Check your OneSignal Dashboard Audience > All Users to see your Device Record.

Then head over to Messages > New Push to Send your first Push Notification from OneSignal.

Step 6. Set Custom User Properties

After initialization, OneSignal will automatically collect common user data by default. Use the following methods to set your own custom userIds, emails, phone numbers, and other user-level properties.

Set External User Id

Required if using integrations.
Recommended for messaging across multiple channels (push, email, sms).

OneSignal creates channel-level device records under a unique Id called the player_id. A single user can have multiple player_id records based on how many devices, email addresses, and phone numbers they use to interact with your app.

If your app has its own login system to track users, call setExternalUserId at any time to link all channels to a single user. For more details, see External User Ids.

String externalUserId = "123456789"; // You will supply the external user id to the OneSignal SDK

Let us now look at simple but full examples.

Example 1: Kotlin Android OneSignal

Simple Kotlin Onesignal example.

Step 1: Setup OneSignal

Setup OneSignal as has been described above.

Step 2: Dependencies

Include the following in your app/build.gradle dependencies:

    implementation platform('')
    implementation ''

    implementation 'com.onesignal:OneSignal:[4.0.0, 4.99.99]'

Step 2: Add Permission

Add Internet permission in your AndroidManifest.xml

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

Step 3: Write Code

Here is the full code:


package com.keremturker.kotlin_onesignal

import android.os.Bundle
import com.onesignal.OneSignal

class MainActivity : AppCompatActivity() {

    private val ONESIGNAL_APP_ID = "000b9068-53f6-4210-bc50-ce65b7835c63"

    override fun onCreate(savedInstanceState: Bundle?) {




  • Download code here.
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