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Background

Get set up with the Helium SDK for Android. Reach out over your Helium slack channel or email founders@tryhelium.com for any questions.

Installation

Version 4.x of the Android SDK just released. To migrate from v0, view the migration guide. You can also view the v0 guide here.
Add the Helium SDK to your project using Gradle.

Requirements

  • Kotlin Version: 2.0.0 or higher
  • Java Version: 8 or higher
  • Minimum Android SDK: 23 or higher
  • Compile Android SDK: 35 or higher

1. Add repositories to your settings.gradle.kts file:

Ensure you have mavenCentral() and google() in your repositories blocks.
// settings.gradle.kts

pluginManagement {
    repositories {
        gradlePluginPortal()
        google()
        mavenCentral()
    }
}

dependencyResolutionManagement {
    repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS)
    repositories {
        google()
        mavenCentral()
        // You might have other repositories here
    }
}
If you don’t have a dependencyResolutionManagement block, ensure google() and mavenCentral() are present in your pluginManagement { repositories { ... } } block.

2. Add the dependencies to your module-level build.gradle.kts file (e.g., app/build.gradle.kts):

// app/build.gradle.kts

dependencies {
    implementation("com.tryhelium.paywall:core:4.0.0")
}

Initialize Helium

Find your API key here
Initialize the Helium SDK as early as possible in your app’s lifecycle.
Helium.initialize(
    context = this,
    apiKey = "YOUR_API_KEY",
    environment: HeliumEnvironment.PRODUCTION,
)
The supplied environment can be SANDBOX or PRODUCTION. If not sure, use PRODUCTION because Helium will automatically treat debug builds as SANDBOX.
Choose the appropriate location based on your app’s architecture:
class MyApplication : Application() {
    override fun onCreate() {
        super.onCreate()
        // Add this:
        configureHelium()
    }

    // And this:
    private fun configureHelium() {
        // Identify user and adjust Helium.config if needed (see next sections).
        // Then call initialize:
        Helium.initialize(
            context = this,
            apiKey = "YOUR_API_KEY",
            environment = HeliumEnvironment.PRODUCTION,
        )
    }
}
And add necessary imports:
import com.tryhelium.paywall.core.Helium
Helium’s initialization runs on a background thread, so you don’t have to worry about it affecting your app’s launch time.

Identifying Users

Identifying users is optional but can help with targeting and when forwarding events to external analytics platforms. If you are not sure, you probably do not need to identify your users.
Identify users as early as you can to maximize consistency in metrics and targeting. Ideally right before you call Helium.initialize!
Set a custom user ID:
Helium.identity.userId = "custom-user-id"
Set custom user traits for targeting and analytics visibility:
Helium.identity.setUserTraits(HeliumUserTraits(
    traits = mapOf(
        "hasOnboarded" to HeliumUserTraitsArgument.BoolParam(true),
        "accountAge" to HeliumUserTraitsArgument.IntParam(30)
    )
))
// or Helium.identity.addUserTraits() if you don't want to clear existing traits

Presenting Paywalls

You must have a trigger and workflow configured in the dashboard in order to show a paywall.
Call presentPaywall when you want to show a full-screen paywall. For example:
Helium.presentPaywall(
    trigger = "premium",
    onPaywallNotShown = { reason ->
        when (reason) {
            is PaywallNotShownReason.TargetingHoldout -> {
                // User is in holdout group
            }
            is PaywallNotShownReason.AlreadyEntitled -> {
                // User already has access
                // In order for this case to be hit, `config.dontShowIfAlreadyEntitled` must be true
            }
            is PaywallNotShownReason.Error -> {
                // Handle the rare case where a paywall
                // fails to show (see Fallbacks section)
            }
        }
    }
)
Helium.presentPaywall
method
You should now be able to see Helium paywalls in your app! Well done! 🎉
Looking for alternative presentation methods? Check out the guide on Ways to Show a Paywall.

PaywallEventHandlers

The Helium SDK allows you to listen for various paywall-related events. This is useful for tracking analytics, responding to user interactions, or handling the paywall lifecycle. There are two ways to listen for events: using the PaywallEventHandlers class for specific callbacks, or implementing the HeliumEventListener interface to receive all events.

Option 1: Using PaywallEventHandlers

You can create an instance of PaywallEventHandlers and provide lambdas for the events you are interested in. The available handlers are:
  • onOpen: Called when a paywall is displayed to the user.
  • onClose: Called when a paywall is closed for any reason.
  • onDismissed: Called when the user explicitly dismisses a paywall without purchasing.
  • onPurchaseSucceeded: Called when a purchase completes successfully.
  • onCustomPaywallAction: Called when a custom action is triggered from the paywall.
  • onAnyEvent: Called for any of the above events.
To register your handlers, use Helium.shared.addPaywallEventListener. You can either tie the listener to a lifecycle (recommended) or manage it manually. Lifecycle-Aware (Recommended) Pass a LifecycleOwner (like an Activity or Fragment) to have the listener automatically removed when the lifecycle is destroyed.
class MyActivity : AppCompatActivity() {
    private val paywallEventHandlers = PaywallEventHandlers(
        onOpen = { event -> print("Paywall opened: ${event.paywallName}") },
        onClose = { event -> print("Paywall closed: ${event.paywallName}") }
        // ... other event handlers
    )

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        // Add the listener once, it will be cleaned up automatically
        Helium.shared.addPaywallEventListener(this, paywallEventHandlers)
    }
}
If you don’t provide a LifecycleOwner, you are responsible for removing the listener with removeHeliumEventListener() to prevent memory leaks.

Option 2: Implementing HeliumEventListener

For a more centralized approach, your class can implement the HeliumEventListener interface and handle all events in a single onHeliumEvent method.
import com.tryhelium.paywall.core.event.*

class MyActivity : AppCompatActivity(), HeliumEventListener {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        // Add the listener once, it will be cleaned up automatically
        Helium.shared.addPaywallEventListener(this, this)
    }
    override fun onHeliumEvent(event: HeliumEvent) {
        when (event) {
            is PaywallOpen -> {
                // Handle paywall open
            }
            is PaywallClose -> {
                // Handle paywall close
            }
            // ... handle other event types
        }
    }
}

Purchase Handling

By default, Helium will handle purchases for you! The SDK automatically creates a PlayStorePaywallDelegate if you don’t provide one. This section is for those who want to use RevenueCat or implement custom purchase logic.
Use one of our pre-built HeliumPaywallDelegate implementations or create a custom delegate. Set the delegate before calling initialize().
The PlayStorePaywallDelegate handles purchases using Google Play Billing:
// Optional - SDK auto-creates this if heliumPaywallDelegate is not set
Helium.config.heliumPaywallDelegate = PlayStorePaywallDelegate(this)
Want to add some custom behavior but still use the built-in purchase logic? Just subclass PlayStorePaywallDelegate or RevenueCatPaywallDelegate! (Be sure to make a super call for any overridden methods.)

Consumables

This only applies if using the default PlayStorePaywallDelegate for purchase handling. If you are using RevenueCatPaywallDelegate, configure RevenueCat to consume appropriate purchases. If you use a custom HeliumPaywallDelegate, you are responsible for consuming purchases.
If your app sells consumable products (e.g., coins, credits, or tokens) and you want Helium to consume purchases for these products, relay these product IDs to Helium like so:
Helium.config.consumableIds = setOf("coins_100", "gems_50")

Checking Subscription Status & Entitlements

If you use an external payment processor like Stripe, Helium’s entitlement helpers may not be reliable. We recommend implementing your own entitlement checking in that case. If you use Stripe with RevenueCat, we recommend using RevenueCat’s entitlement APIs instead.
The Helium SDK provides multiple ways to check user entitlements and subscription status.
hasAnyEntitlement() Checks if the user has purchased any subscription or non-consumable product.hasAnyActiveSubscription() Checks if the user has any active subscription.hasEntitlementForPaywall(trigger: String) Checks if the user has entitlements for any product in a specific paywall. Returns null if paywall configuration hasn’t been downloaded yet.

Example Usage

Check entitlements before showing paywalls to avoid showing a paywall to a user who should not see it.
Helium.presentPaywall(
    trigger = "my_paywall_trigger",
    config = PaywallPresentationConfig(
        dontShowIfAlreadyEntitled = true,
    ),
    onPaywallNotShown = { paywallNotShownReason ->
        // handle paywall not shown
    }
)

Fallbacks

It is highly recommended that you set up fallbacks in the uncommon case where a paywall fails to display. Please follow the linked guide to do so. Note that if you attempt to display a paywall while it is still being downloaded, a loading state will show. By default, Helium will show this loading state as needed (a shimmer view for up to 7 seconds). You can configure this behavior:
Helium.config.defaultLoadingBudgetInMs = 5000  // 5 seconds
Helium.config.defaultLoadingView = myCustomLoadingView  // optional
If the budget expires before the paywall is ready, a fallback paywall will show if available. Otherwise, the loading state will hide and a PaywallOpenFailed event will be dispatched.
See the Fallbacks Guide for more details on downloading and configuring fallbacks.

Advanced

In most cases there is no need to check download status. Helium will display a loading indication if a paywall is presented before download has completed.
The downloadStatus is a Kotlin Flow that emits HeliumConfigStatus states. The possible states are:
  • HeliumConfigStatus.NotYetDownloaded: The initial state before the download has started.
  • HeliumConfigStatus.Downloading: Indicates that the paywall configuration is currently being downloaded.
  • HeliumConfigStatus.DownloadFailure: Indicates that the paywall configuration download has failed.
  • HeliumConfigStatus.DownloadSuccess: Indicates that the paywall configuration has been successfully downloaded.
Here’s how you can observe the downloadStatus flow in your Activity or Fragment:
// In your Activity or Fragment
lifecycleScope.launch {
    Helium.shared.downloadStatus.collect { status ->
        when (status) {
            is HeliumConfigStatus.NotYetDownloaded -> {
                // Handle not yet downloaded state
            }
            is HeliumConfigStatus.Downloading -> {
                // Handle downloading state
            }
            is HeliumConfigStatus.DownloadFailure -> {
                // Handle download failure
            }
            is HeliumConfigStatus.DownloadSuccess -> {
                // Handle download success
            }
        }
    }
}
You can programmatically hide paywalls using:
// Hide the current paywall
Helium.hidePaywall()

// Hide all currently displayed paywalls
Helium.hideAllPaywalls()
Reset Helium entirely so you can call initialize again. Only for advanced use cases.
Helium.resetHelium()