# 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 # Welcome Welcome to the Superwall KMP SDK documentation > **Warning:** **Beta**The KMP SDK is in beta. The API may change between releases, and these docs describe behavior that is still settling. If you hit something that does not match what you see, please [open an issue](https://github.com/superwall/Superwall-KMP/issues). The Superwall KMP SDK brings paywalls, placements, and entitlements to Kotlin Multiplatform. It wraps the native Superwall SDKs (`superwall-android` on Android, SuperwallKit on iOS) behind a single API that lives entirely in `commonMain`. This means there's no `expect`/`actual` of your own, no platform types in your shared code, and an identical `configure` signature on both platforms. There is no `Context` parameter on Android. ```kotlin import com.superwall.sdk.kmp.Superwall Superwall.configure(apiKey = "pk_your_api_key") Superwall.register(placement = "campaign_trigger") { launchTheFeature() } ``` ## Platform support | Platform | Support | Wraps | | -------- | --------------------------------------------------- | ------------------------------------------- | | Android | `minSdk 26` | `com.superwall.sdk:superwall-android` 2.8.0 | | iOS | iOS 14+ (`iosArm64`, `iosSimulatorArm64`, `iosX64`) | SuperwallKit iOS 4.16.1, pinned exactly | Those are the only two targets. There are no JVM, JS, desktop, or watchOS artifacts since the SDK is a wrapper over two native SDKs. > **Note:** Android's `minSdk` here is **26**, higher than the standalone Android SDK's 23. If you are adding > KMP to an existing project, check your `minSdk` before you start. ## How it fits together Your shared Kotlin code calls one API. Underneath, each platform resolves to its own native SDK: * **Android** wraps `superwall-android` directly. One Gradle dependency pulls it in, and an `androidx.startup` initializer captures the `Application` for you. * **iOS** forwards through **SuperwallKMPBridge**, an `@objc` Swift bridging layer over SuperwallKit that flattens Swift-only constructs (enum associated values, structs, `async`) into something Kotlin can consume via cinterop. Your app supplies that bridge as a Swift package. ## Quick Links ## Quickstart /docs/kmp/quickstart/install Install, configure, and present your first paywall ## Platform differences /docs/kmp/guides/platform-differences Where Android and iOS behavior is not one-to-one ## Purchases /docs/kmp/guides/advanced-configuration Own your purchase logic with a `PurchaseController` ## Delegate /docs/kmp/guides/using-superwall-delegate Observe the paywall lifecycle and SDK events ## Example App https://github.com/superwall/Superwall-KMP/tree/main/sample A runnable Compose Multiplatform sample for Android and iOS ## Changelog /docs/kmp/changelog Release notes for the KMP SDK ## Feedback The KMP SDK is actively developed and we want to hear what is missing. If you have feedback on these docs, please leave a rating and message at the bottom of the page. For SDK bugs, [open an issue on GitHub](https://github.com/superwall/Superwall-KMP/issues).