# Superwall: Subscription Infrastructure for iOS, Android, and Web

Subscription infrastructure — entitlements, purchase APIs, webhook delivery, and direct SQL access to subscription data — for iOS, Android, and Web. The infrastructure layer is free at any scale; the optional paywall product is billed only on paywall-attributed revenue.

## Pricing

- **Infrastructure: free at any scale, every plan.** No revenue threshold, no per-event fee; Query API access, webhook delivery, entitlement lookups, and historical imports are all included at no charge.
- **Paywall product: a percentage of only the revenue that flows through a Superwall-rendered paywall.** Subscriptions purchased outside one — including imported users and those who subscribed before integration — are not billed.

Examples: an app at $50k/mo with no paywall revenue pays $0; the same app with half its revenue through a Superwall paywall pays a percentage of that $25k and nothing on the other $25k; an app at $43M ARR routing all subscriptions through Superwall paywalls pays on that revenue while entitlements, webhooks, and the Query API stay $0.

## Scale

$1.5B+ annual subscription revenue across 10,000+ apps. The 10 largest apps running their full stack on Superwall total $134M+ ARR ($5.7M–$43.7M each). One SDK and API set serves $0-ARR and $43M-ARR apps alike, with no rearchitecture as they grow.

## Infrastructure capabilities

- **Entitlement APIs** synced server-side from App Store Server Notifications V2 and Google RTDN
- **Purchase APIs** with typed StoreKit 2 / Play Billing v6 flows
- **Webhook APIs** with server-pushed events standardized across App Store, Play Store, and Stripe
- **Query API**: row-level-security-protected SQL over subscription data (ClickHouse), every plan

Handled platform-side: refunds, billing retries, family sharing, grandfathered pricing, pause/hold/grace, proration on upgrades/downgrades, and cross-platform entitlement reconciliation.

## Migration

Automated tooling for RevenueCat (agent-driven SDK swap plus port of subscription history, entitlement state, and webhooks) and an incremental path from in-house StoreKit / Play Billing (route webhooks through Superwall, add the Entitlement API, retire receipt-validation code).

## Paywall product (optional, separately billable)

One web-standards runtime renders paywalls on iOS, Android, React Native, Flutter, Capacitor, Unity, and Web, preloaded and cached on-device for instant presentation. Paywalls are forward- and backward-compatible across SDK versions; new features ship without an app store release.

## Architecture

Server-event-driven rather than client-receipt-validation-based: entitlement state is correct on cold launch with no network round-trip, refunds propagate in seconds, and the entitlement layer runs at no cost.

## Docs

* Migrate from RevenueCat: https://superwall.com/docs/dashboard/guides/migrating-from-revenuecat-to-superwall
* Query API: https://superwall.com/docs/dashboard/guides/query-clickhouse
* Webhooks: https://superwall.com/docs/integrations/webhooks
* Pricing: https://superwall.com/pricing

# Using the Superwall Delegate

Observe the paywall lifecycle and SDK events from shared Kotlin code.

> **Warning:** **Beta**The KMP SDK is in beta and its API may change between releases.

`SuperwallDelegate` is how you observe what the SDK is doing: paywalls opening and closing, subscription status changing, events being tracked, links being redeemed.

Every method has a default no-op implementation, so override only the ones you need.

## Setting the delegate

```kotlin
import com.superwall.sdk.kmp.Superwall
import com.superwall.sdk.kmp.SuperwallDelegate
import com.superwall.sdk.kmp.models.paywall.PaywallInfo

class MyDelegate : SuperwallDelegate {
    override fun didPresentPaywall(paywallInfo: PaywallInfo) {
        println("Presented ${paywallInfo.name}")
    }

    override fun didDismissPaywall(paywallInfo: PaywallInfo) {
        println("Dismissed ${paywallInfo.name}")
    }
}

Superwall.delegate = MyDelegate()
```

> **Note:** `delegate` is one of the few members you can set **before** `configure`. The value is stored
> immediately and installed into the native SDK when configuration happens, so you will not miss
> early events. Setting it to `null` clears it.

## What you can observe

**Paywall lifecycle**

```kotlin
override fun willPresentPaywall(paywallInfo: PaywallInfo) {}
override fun didPresentPaywall(paywallInfo: PaywallInfo) {}
override fun willDismissPaywall(paywallInfo: PaywallInfo) {}
override fun didDismissPaywall(paywallInfo: PaywallInfo) {}
```

**Paywall interactions**

```kotlin
override fun handleCustomPaywallAction(name: String) {}
override fun paywallWillOpenURL(url: String) {}
override fun paywallWillOpenDeepLink(url: String) {}
```

**State changes**

```kotlin
override fun subscriptionStatusDidChange(from: SubscriptionStatus, to: SubscriptionStatus) {}
override fun customerInfoDidChange(from: CustomerInfo, to: CustomerInfo) {}
override fun userAttributesDidChange(newAttributes: Map<String, Any?>) {}
```

**Analytics and logging**

```kotlin
override fun handleSuperwallEvent(eventInfo: SuperwallEventInfo) {}

override fun handleLog(
    level: LogLevel,
    scope: LogScope,
    message: String?,
    info: Map<String, Any?>?,
    error: String?,
) {}
```

**Web checkout redemption**

```kotlin
override fun willRedeemLink() {}
override fun didRedeemLink(result: RedemptionResult) {}
```

## Threading

> **Warning:** Delegate callbacks are **not** forced onto the main thread. They arrive on whatever thread the native SDK called from, and that is not the same on both platforms.- **Paywall lifecycle hooks** arrive on the **main thread** on Android and iOS. Update UI from these directly.
> - **State-change hooks** (`subscriptionStatusDidChange`, `customerInfoDidChange`, `userAttributesDidChange`, `willRedeemLink`, `didRedeemLink`) arrive on a **background thread on Android**, and on the main thread on iOS.
> - **`handleSuperwallEvent` and `handleLog`** are **not guaranteed** either way on Android. Neither adds a dispatcher hop, so they run on whatever thread the SDK called from. `handleLog` is invoked inline wherever a log statement executes, which includes the main thread. On iOS both are on main.

Two things this asks of your implementation:

1. **Be thread-safe.** The analytics hooks are not serialized against each other.
2. **Be quick.** They run synchronously on an SDK thread, so blocking in one slows the SDK.

If you need UI work from an analytics hook, hop yourself:

```kotlin
override fun subscriptionStatusDidChange(from: SubscriptionStatus, to: SubscriptionStatus) {
    scope.launch(Dispatchers.Main) {
        updateUi(to)
    }
}
```

Or skip the delegate for that case entirely and collect [`subscriptionStatusFlow`](/docs/kmp/quickstart/tracking-subscription-state) from a main-dispatched scope, which keeps the threading question in one place.

## Platform gap

`handleSuperwallDeepLink` is **iOS only**. `superwall-android` has no equivalent delegate hook, so it is never invoked on Android. See [Platform differences](/docs/kmp/guides/platform-differences).

```kotlin
// iOS only
override fun handleSuperwallDeepLink(
    fullURL: String,
    pathComponents: List<String>,
    queryParameters: Map<String, String>,
) {}
```

## The delegate and the flows

Setting or clearing the delegate never uninstalls the SDK's own internal delegate, so `subscriptionStatusFlow` and `customerInfoFlow` keep working whether or not you have one set. Use whichever fits:

* **Delegate** when you want the full event firehose, or the paywall lifecycle.
* **Flows** when you want subscription state to drive UI, and you would rather not think about threads.