Add watchOS support

.circleci/config.yml

@@ -233,6 +233,35 @@ jobs:
       - save-kotlin-native-compiler-to-cache
       - save-incremental-gradle-build-to-workspace
 
+  # Self-contained on purpose: no workspace persistence or attachment, so it can run in
+  # parallel to the iOS chain without workspace conflicts.
+  build-and-test-watchos:
+    executor: xcode16
+    steps:
+      - checkout
+      - checkout-submodule
+      - restore-gradle-user-home-directory-from-cache
+      - restore-kotlin-native-compiler-from-cache
+      - run:
+          name: Build libraries and run tests for watchOS
+          command: |
+            tasks=()
+            for module in core result; do
+              for arch in Arm64 DeviceArm64 SimulatorArm64; do
+                tasks+=(":$module:compileKotlinWatchos$arch")
+              done
+            done
+            # either skips DeviceArm64: arrow-core doesn't publish it.
+            for arch in Arm64 SimulatorArm64; do
+              tasks+=(":either:compileKotlinWatchos$arch")
+            done
+            # The commonized (metadata) compilation only runs at publish time otherwise.
+            tasks+=("compileAppleMainKotlinMetadata")
+            tasks+=("watchosSimulatorArm64Test")
+            ./gradlew "${tasks[@]}"
+      - save-gradle-user-home-directory-to-cache
+      - save-kotlin-native-compiler-to-cache
+
   build-sample-android:
     executor: android202409
     steps:
@@ -435,6 +464,7 @@ workflows:
       - unit-tests-build-logic
       - build-libraries-android
       - build-libraries-ios
+      - build-and-test-watchos
       - build-sample-android:
           requires: [build-libraries-android]
       - build-sample-ios:
@@ -478,8 +508,8 @@ workflows:
           outputs: |
             PurchasesErrorCode.kt:models/src/commonMain/kotlin/generated/com/revenuecat/purchases/kmp/models/PurchasesErrorCode.kt
             errors.android.kt:mappings/src/androidMain/kotlin/generated/com/revenuecat/purchases/kmp/mappings/errors.android.kt
-            errors.ios.kt:mappings/src/iosMain/kotlin/generated/com/revenuecat/purchases/kmp/mappings/errors.ios.kt
-          commit_paths: "models/src/commonMain/kotlin/generated/com/revenuecat/purchases/kmp/models/PurchasesErrorCode.kt,mappings/src/androidMain/kotlin/generated/com/revenuecat/purchases/kmp/mappings/errors.android.kt,mappings/src/iosMain/kotlin/generated/com/revenuecat/purchases/kmp/mappings/errors.ios.kt,models/api/models.api,models/api/models.klib.api"
+            errors.ios.kt:mappings/src/appleMain/kotlin/generated/com/revenuecat/purchases/kmp/mappings/errors.apple.kt
+          commit_paths: "models/src/commonMain/kotlin/generated/com/revenuecat/purchases/kmp/models/PurchasesErrorCode.kt,mappings/src/androidMain/kotlin/generated/com/revenuecat/purchases/kmp/mappings/errors.android.kt,mappings/src/appleMain/kotlin/generated/com/revenuecat/purchases/kmp/mappings/errors.apple.kt,models/api/models.api,models/api/models.klib.api"
           context:
             - git-user-ops
             - github-bot-public
@@ -530,6 +560,7 @@ workflows:
       - unit-tests-build-logic
       - build-libraries-android
       - build-libraries-ios
+      - build-and-test-watchos
       - build-sample-android:
           requires: [build-libraries-android]
       - build-sample-ios:
@@ -551,6 +582,7 @@ workflows:
           requires:
             - detekt
             - unit-tests-build-logic
+            - build-and-test-watchos
             - build-sample-android
             - build-sample-ios
             - public-api-tests-android

AGENTS.md

@@ -39,7 +39,7 @@ purchases-kmp/
 │   └── src/
 │       ├── commonMain/       # Shared Kotlin code
 │       ├── androidMain/      # Android-specific implementations
-│       └── iosMain/          # iOS-specific implementations (Swift interop)
+│       └── appleMain/        # Apple-specific implementations (Swift interop), split further into iosMain/watchosMain where needed
 ├── models/                   # Shared data models and domain objects
 ├── mappings/                 # Platform-specific mappings
 ├── revenuecatui/             # Jetpack Compose UI components for paywalls
@@ -121,8 +121,8 @@ module/src/
 ├── commonTest/       # Shared tests
 ├── androidMain/      # Android-specific implementations
 ├── androidUnitTest/  # Android unit tests
-├── iosMain/          # iOS-specific implementations
-└── iosTest/          # iOS tests
+├── appleMain/        # Apple-specific implementations (iOS + watchOS)
+└── appleTest/        # Apple platform tests
 ```
 
 ## Constraints / Support Policy
@@ -184,7 +184,7 @@ When creating a pull request, **always add one of these labels** to categorize t
 - **Don't make large refactors** unless explicitly requested
 - **Keep diffs minimal** — only touch what's necessary, preserve existing formatting
 - **Don't break the public API** — binary compatibility validator will catch issues
-- **Follow KMP conventions** — put shared code in `commonMain`, platform-specific in `androidMain`/`iosMain`
+- **Follow KMP conventions** — put shared code in `commonMain`, platform-specific in `androidMain`/`appleMain`
 - **Run Detekt** before committing (`./gradlew detektAll`)
 - **Check both platforms** — changes in `commonMain` affect both iOS and Android
 - **Never commit API keys or secrets** — do not stage or commit credentials or sensitive data

Dangerfile

@@ -3,5 +3,5 @@ danger.import_dangerfile(github: 'RevenueCat/Dangerfile')
 fail_on_generated_edits([
   "models/src/commonMain/kotlin/generated/",
   "mappings/src/androidMain/kotlin/generated/",
-  "mappings/src/iosMain/kotlin/generated/",
+  "mappings/src/appleMain/kotlin/generated/",
 ])

README.md

@@ -31,7 +31,7 @@ our [migration guide](./migrations/KobanKat-MIGRATION.md)
 | --- | --- |
 ✅ | Server-side receipt validation
 ➡️ | [Webhooks](https://docs.revenuecat.com/docs/webhooks) - enhanced server-to-server communication with events for purchases, renewals, cancellations, and more
-📱 | Android and iOS support
+📱 | Android, iOS and watchOS support
 🎯 | Subscription status tracking - know whether a user is subscribed whether they're on iOS, Android or web
 📊 | Analytics - automatic calculation of metrics like conversion, mrr, and churn
 📝 | [Online documentation](https://docs.revenuecat.com/docs) and [SDK Reference](https://revenuecat.github.io/purchases-kmp/) up to date
@@ -66,7 +66,8 @@ This codelab is a step-by-step tutorial designed to help you learn and master th
 - Java 8+
 - Kotlin 2.3.20+
 - Android 6.0+ (API level 23+)
-- iOS 13.0+ 
+- iOS 13.0+
+- watchOS 7.0+ (9.0+ on `watchosDeviceArm64`). Notes: Paywalls and Customer Center (the `-ui` artifact) are iOS only, and the optional `-either` artifact has no `watchosDeviceArm64` variant.
 
 ## SDK Reference
 Our full SDK reference [can be found here](https://revenuecat.github.io/purchases-kmp/).

build-logic/convention/src/main/kotlin/com/revenuecat/purchases/kmp/buildlogic/AppleTargets.kt

@@ -0,0 +1,14 @@
+package com.revenuecat.purchases.kmp.buildlogic
+
+import org.jetbrains.kotlin.gradle.dsl.KotlinMultiplatformExtension
+
+/**
+ * Declares all watchOS compilation targets. The `revenuecat-library` convention plugin declares
+ * Android and iOS targets for every module; modules that also support watchOS call this from
+ * their `kotlin {}` block.
+ */
+fun KotlinMultiplatformExtension.watchosTargets() {
+    watchosArm64()
+    watchosDeviceArm64()
+    watchosSimulatorArm64()
+}

build-logic/convention/src/main/kotlin/com/revenuecat/purchases/kmp/buildlogic/convention/configureKotlin.kt

@@ -35,8 +35,12 @@ internal fun Project.configureKotlin() {
         }
         sourceSets.all {
             languageSettings.apply {
-                if (name.lowercase().startsWith("ios")) {
+                val appleSourceSetPrefixes = listOf("apple", "ios", "watchos", "tvos", "macos")
+                if (appleSourceSetPrefixes.any { name.lowercase().startsWith(it) }) {
                     optIn("kotlinx.cinterop.ExperimentalForeignApi")
+                    // NSInteger and friends commonize to variable-width types (32 bits on
+                    // watchosArm64), which require this opt-in in shared Apple code.
+                    optIn("kotlinx.cinterop.UnsafeNumber")
                 }
             }
         }

build-logic/convention/src/main/kotlin/com/revenuecat/purchases/kmp/buildlogic/swift/ConfigureSwiftDependencies.kt

@@ -219,7 +219,6 @@ private fun KonanTarget.isAppleTarget(): Boolean =
         // watchOS
         KonanTarget.WATCHOS_ARM64,
         KonanTarget.WATCHOS_SIMULATOR_ARM64,
-        KonanTarget.WATCHOS_X64,
         KonanTarget.WATCHOS_DEVICE_ARM64,
     )
 
@@ -310,7 +309,6 @@ private fun getTaskSuffix(konanTarget: KonanTarget): String = when (konanTarget)
     // watchOS
     KonanTarget.WATCHOS_ARM64 -> "WatchosArm64"
     KonanTarget.WATCHOS_SIMULATOR_ARM64 -> "WatchosSimulatorArm64"
-    KonanTarget.WATCHOS_X64 -> "WatchosX64"
     KonanTarget.WATCHOS_DEVICE_ARM64 -> "WatchosDeviceArm64"
     else -> error("Unexpected target: $konanTarget")
 }
@@ -376,7 +374,7 @@ private fun KonanTarget.getSdkName(): String = when (this) {
     KonanTarget.TVOS_X64, KonanTarget.TVOS_SIMULATOR_ARM64 -> "appletvsimulator"
     KonanTarget.TVOS_ARM64 -> "appletvos"
     // watchOS
-    KonanTarget.WATCHOS_X64, KonanTarget.WATCHOS_SIMULATOR_ARM64 -> "watchsimulator"
+    KonanTarget.WATCHOS_SIMULATOR_ARM64 -> "watchsimulator"
     KonanTarget.WATCHOS_ARM64, KonanTarget.WATCHOS_DEVICE_ARM64 -> "watchos"
     else -> error("Unsupported target: ${this}")
 }
@@ -394,8 +392,10 @@ private fun KonanTarget.getTriple(): String = when (this) {
     KonanTarget.TVOS_SIMULATOR_ARM64 -> "arm64-apple-tvos-simulator"
     KonanTarget.TVOS_ARM64 -> "arm64-apple-tvos"
     // watchOS
-    KonanTarget.WATCHOS_X64 -> "x86_64-apple-watchos-simulator"
     KonanTarget.WATCHOS_SIMULATOR_ARM64 -> "arm64-apple-watchos-simulator"
-    KonanTarget.WATCHOS_ARM64, KonanTarget.WATCHOS_DEVICE_ARM64 -> "arm64-apple-watchos"
+    // Note: Kotlin/Native's watchosArm64 is arm64_32 (see targetTriple.watchos_arm64 in
+    // konan.properties), while watchosDeviceArm64 is arm64.
+    KonanTarget.WATCHOS_ARM64 -> "arm64_32-apple-watchos"
+    KonanTarget.WATCHOS_DEVICE_ARM64 -> "arm64-apple-watchos"
     else -> error("Unsupported target: $this")
 }

build-logic/convention/src/main/kotlin/com/revenuecat/purchases/kmp/buildlogic/swift/task/GenerateDefFileTask.kt

@@ -78,6 +78,9 @@ abstract class GenerateDefFileTask : DefaultTask() {
             linkerOpts.ios_x64 = -L$toolchain/lib/swift/iphonesimulator/
             linkerOpts.ios_arm64 = -L$toolchain/lib/swift/iphoneos/
             linkerOpts.ios_simulator_arm64 = -L$toolchain/lib/swift/iphonesimulator/
+            linkerOpts.watchos_arm64 = -L$toolchain/lib/swift/watchos/
+            linkerOpts.watchos_device_arm64 = -L$toolchain/lib/swift/watchos/
+            linkerOpts.watchos_simulator_arm64 = -L$toolchain/lib/swift/watchsimulator/
         """.trimIndent()
 
         val content = if (customDeclarations.isPresent) {

core/api/core.klib.api

@@ -1,5 +1,5 @@
 // Klib ABI Dump
-// Targets: [iosArm64, iosSimulatorArm64, iosX64]
+// Targets: [iosArm64, iosSimulatorArm64, iosX64, watchosArm64, watchosDeviceArm64, watchosSimulatorArm64]
 // Rendering settings:
 // - Signature version: 2
 // - Show manifest properties: true

core/build.gradle.kts

@@ -1,4 +1,5 @@
 import com.codingfeline.buildkonfig.compiler.FieldSpec.Type.STRING
+import com.revenuecat.purchases.kmp.buildlogic.watchosTargets
 
 plugins {
     id("revenuecat-library")
@@ -10,6 +11,8 @@ revenueCat {
 }
 
 kotlin {
+    watchosTargets()
+
     sourceSets {
         commonMain.dependencies {
             api(projects.models)
@@ -19,7 +22,7 @@ kotlin {
             implementation(libs.revenuecat.android)
             implementation(projects.mappings)
         }
-        iosMain.dependencies {
+        appleMain.dependencies {
             implementation(projects.knCore)
             implementation(projects.mappings)
         }

core/src/iosMain/kotlin/com/revenuecat/purchases/kmp/AdTracker.ios.kt → core/src/appleMain/kotlin/com/revenuecat/purchases/kmp/AdTracker.apple.kt

@@ -16,47 +16,52 @@ public actual class AdTracker internal constructor(
     private val iosAdTracker: RCAdTracker
 ) {
     public actual fun trackAdDisplayed(data: AdDisplayedData) {
-        if (!AppleApiAvailability().isAdTrackingAPIAvailable()) {
-            Purchases.logHandler.w("Purchases", "Ad tracking requires iOS 15.0+. Current API is unavailable.")
+        if (!appleApiAvailability.isAdTrackingAPIAvailable()) {
+            Purchases.logHandler.w("Purchases", AD_TRACKING_UNAVAILABLE_MESSAGE)
             return
         }
 
         iosAdTracker.trackAdDisplayed(data.toIos())
     }
 
     public actual fun trackAdOpened(data: AdOpenedData) {
-        if (!AppleApiAvailability().isAdTrackingAPIAvailable()) {
-            Purchases.logHandler.w("Purchases", "Ad tracking requires iOS 15.0+. Current API is unavailable.")
+        if (!appleApiAvailability.isAdTrackingAPIAvailable()) {
+            Purchases.logHandler.w("Purchases", AD_TRACKING_UNAVAILABLE_MESSAGE)
             return
         }
 
         iosAdTracker.trackAdOpened(data.toIos())
     }
 
     public actual fun trackAdRevenue(data: AdRevenueData) {
-        if (!AppleApiAvailability().isAdTrackingAPIAvailable()) {
-            Purchases.logHandler.w("Purchases", "Ad tracking requires iOS 15.0+. Current API is unavailable.")
+        if (!appleApiAvailability.isAdTrackingAPIAvailable()) {
+            Purchases.logHandler.w("Purchases", AD_TRACKING_UNAVAILABLE_MESSAGE)
             return
         }
 
         iosAdTracker.trackAdRevenue(data.toIos())
     }
 
     public actual fun trackAdLoaded(data: AdLoadedData) {
-        if (!AppleApiAvailability().isAdTrackingAPIAvailable()) {
-            Purchases.logHandler.w("Purchases", "Ad tracking requires iOS 15.0+. Current API is unavailable.")
+        if (!appleApiAvailability.isAdTrackingAPIAvailable()) {
+            Purchases.logHandler.w("Purchases", AD_TRACKING_UNAVAILABLE_MESSAGE)
             return
         }
 
         iosAdTracker.trackAdLoaded(data.toIos())
     }
 
     public actual fun trackAdFailedToLoad(data: AdFailedToLoadData) {
-        if (!AppleApiAvailability().isAdTrackingAPIAvailable()) {
-            Purchases.logHandler.w("Purchases", "Ad tracking requires iOS 15.0+. Current API is unavailable.")
+        if (!appleApiAvailability.isAdTrackingAPIAvailable()) {
+            Purchases.logHandler.w("Purchases", AD_TRACKING_UNAVAILABLE_MESSAGE)
             return
         }
 
         iosAdTracker.trackAdFailedToLoad(data.toIos())
     }
 }
+
+private val appleApiAvailability = AppleApiAvailability()
+
+private const val AD_TRACKING_UNAVAILABLE_MESSAGE =
+    "Ad tracking requires iOS 15.0+ or watchOS 8.0+. Current API is unavailable."