Android push notifications (Kotlin): add the SDK step by step

In the dashboard, open Applications your app SDK Integration and pick Android (Kotlin) ①. Click Download PusherHub.kt ②. Under the button is the folder it goes in ③: your app's package with pusherhub on the end.

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Every step below is on this tab too, with your own keys and package already filled in — copy the code from there.

In Android Studio, switch the file list at the top left to Project.

1. google-services.json ① goes in the app folder, next to the app's build.gradle.kts.
2. PusherHub.kt ② goes in a new pusherhub folder inside your package. Right-click your package (here com.example.myapp), choose New Package , type pusherhub, then drag the file into it.
3. Open PusherHub.kt: its first line ③ already has your own package. The file was made for your app, so don't change anything in it.

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Open the project's build.gradle.kts — the one outside the app folder, shown as build.gradle.kts (MyApp). Inside plugins { }, add ①:

id("com.google.gms.google-services") version "4.4.3" apply false

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Android Studio offers to Sync Now ②. You can wait and sync once, after the next step.

Open the app's build.gradle.kts, shown as build.gradle.kts (:app).

1. Inside plugins { }, add id("com.google.gms.google-services") ①.
2. Inside dependencies { }, add Firebase Cloud Messaging ②. PusherHub needs nothing else.
3. Click Sync Now ③ and wait for it to finish.

implementation(platform("com.google.firebase:firebase-bom:34.4.0"))
implementation("com.google.firebase:firebase-messaging")

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Open app/src/main/AndroidManifest.xml and add these three things to the manifest you already have — don't replace it. The code is in step 3 on your SDK Integration tab.

1. The permissions ①, above <application>. ACCESS_COARSE_LOCATION is only needed if you want each phone's state and city (step 6).
2. A second <intent-filter> ② inside your MainActivity's <activity>. It lets a tap on a notification open your app and be counted. The name says Flutter, but every PusherHub notification uses it, Kotlin apps too.
3. The <service> ③ inside <application>. It's what receives the notifications. Its name is your package plus .pusherhub.PusherHubMessagingService.

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Open MainActivity.kt and add the code from step 4 on your SDK Integration tab — your keys and server are already filled in. (In the picture they're placeholders.)

1. The import ①. Android Studio can add it for you: click on PusherHub and press Alt+Enter (Option+Return on a Mac).
2. PusherHub.initialize(…) ② in onCreate, with your App key and Public key.
3. PusherHub.registerDevice { … } ③ gets the phone's push token, asks the user to allow notifications and adds the phone to PusherHub. collectDeviceMetadata() inside it is optional: it adds the phone's brand, model, language and country, plus state and city if you added the location permission.
4. PusherHub.handleIntent(intent) ④ counts the tap when someone opened the app from a notification.

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Lower down in MainActivity, add these three functions. If you already have one, just add its PusherHub line to it.

1. onNewIntent ① — a notification tapped while the app was open in the background.
2. onRequestPermissionsResult ② — tells PusherHub what the user answered when asked to allow notifications or location.
3. onResume ③ — optional: shows your in-app messages each time the app is opened. Leave it out if you don't use them.

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If your app has its own sign-in, tell PusherHub who's using the phone. Then you can send to one person by your own user ID. It's remembered, even after the app restarts, until logout().

// When someone signs in:
PusherHub.login(currentUserId)

// When they sign out:
PusherHub.logout()

Put your own data in Custom Data when you create a notification — say {"campaign_id": "232"} — and your app gets it back whenever someone taps that notification, whether the app was open, in the background or closed. Add onNotificationOpened to the PusherHub.initialize(…) from step 6:

PusherHub.initialize(
    context = this,
    appKey = "YOUR_APP_KEY",
    publicKey = "YOUR_PUBLIC_KEY",
    baseUrl = "YOUR_SERVER",
    onNotificationOpened = { data ->
        data["campaign_id"]?.let { campaignId ->
            startActivity(Intent(this, CampaignActivity::class.java).putExtra("campaign_id", campaignId))
        }
    },
)

It runs from handleIntent, so keep both of its calls from steps 6 and 7. Every value arrives as text ("232"). This needs PusherHub.kt from 24 October 2026 or later — download it again if yours is older.

Click Run ▶ to open the app on a phone or an emulator with Google Play, and tap Allow when it asks about notifications. Within a few seconds the phone shows up in PusherHub under Devices.

Then send it a test notification.