feat: add brownie android

[hurali97]

Summary

This adds support for android to the brownie package. The usage is as simple as after creating the brownfieldstore.brownie.ts:

• Register the Store:

registerStoreIfNeeded(
  storeName = BrownfieldStore.STORE_NAME
) {
  BrownfieldStore(
    counter = 0.0,
    user = User(name = "Username")
  )
}

• Declare the Store:

val store: Store<BrownfieldStore>? = StoreManager.shared.store(BrownfieldStore.STORE_NAME)

• Use the Store:

// Read current state
val current = store?.state

// Update whole state with copy()
store?.set { state ->
  state.copy(counter = state.counter + 1)
}

// Subscribe to full state changes
val unsubscribe = store?.subscribe { newState ->
  println("Counter: ${newState.counter}")
}

// Cleanup subscription
unsubscribe?.invoke()

Test plan

• CI Passes - 🟢
• Tested Locally - 🟢

Screen.Recording.2026-02-26.at.5.18.47.PM.mov

[hurali97]

Should we go with a major release instead? However, then it will not align with react-native-brownfield version as that would still be v3

[thymikee]

We can do it in a point release, no need for major (it’s a new thing). Should align

[hurali97]

Bumped all minors to align.

[Copilot]

Pull request overview

Adds Android support to the @callstack/brownie package by introducing an Android runtime (Kotlin facade + JNI bridge) and updating CLI/docs/examples so stores can be used from Kotlin as well as Swift/JS.

Changes:

• Enable Kotlin codegen (and default to Swift + Kotlin generation) in the CLI.
• Add packages/brownie/android implementation: Kotlin Store/StoreManager, JNI bridge, and RN TurboModule package/module.
• Update docs and example apps to show Android usage and wire up counters.

Reviewed changes

Copilot reviewed 33 out of 33 changed files in this pull request and generated 8 comments.

Show a summary per file

File	Description
packages/cli/src/brownie/commands/codegen.ts	Default codegen now targets Swift + Kotlin.
packages/brownie/react-native.config.js	Removes Android-disable config to allow autolinking.
packages/brownie/package.json	Publishes Android sources in npm package and excludes Android build artifacts.
packages/brownie/cpp/BrownieStore.cpp	Calls change callback outside mutex to reduce lock contention.
packages/brownie/android/src/main/java/com/callstack/brownie/StoreManager.kt	Adds process-wide store registry for Kotlin stores.
packages/brownie/android/src/main/java/com/callstack/brownie/Store.kt	Adds Kotlin typed store wrapper syncing with native snapshot + subscriptions.
packages/brownie/android/src/main/java/com/callstack/brownie/BrownieStoreRegistration.kt	Adds registration helpers including “register once” convenience API.
packages/brownie/android/src/main/java/com/callstack/brownie/BrownieStoreDefinition.kt	Adds serializer/definition APIs with Gson default implementation.
packages/brownie/android/src/main/java/com/callstack/brownie/BrownieStoreBridge.kt	Adds Kotlin/JNI bridge to C++ runtime and change listener fanout.
packages/brownie/android/src/main/java/com/callstack/brownie/BrowniePackage.kt	Registers Android TurboModule package.
packages/brownie/android/src/main/java/com/callstack/brownie/BrownieModule.kt	Android TurboModule: installs JSI + forwards store-change events to JS.
packages/brownie/android/src/main/cpp/JNIBrownieStoreBridge.cpp	JNI glue for store operations + store-change emission into Kotlin.
packages/brownie/android/src/main/cpp/CMakeLists.txt	Builds Android libbrownie.so and links ReactAndroid/fbjni/folly.
packages/brownie/android/src/main/AndroidManifest.xml	Declares Android package manifest for the library.
packages/brownie/android/build.gradle	Android library Gradle config (SDKs, CMake, dependencies).
packages/brownie/.gitignore	Ignores Android build output for the package.
docs/docs/docs/api-reference/brownie/swift-usage.mdx	Updates Swift page to link to separate Android docs.
docs/docs/docs/api-reference/brownie/overview.mdx	Marks Android as supported and links Android usage docs.
docs/docs/docs/api-reference/brownie/getting-started.mdx	Adds Android setup + packaging/publishing steps.
docs/docs/docs/api-reference/brownie/android-usage.mdx	New Android API guide (easy + advanced serialization paths).
docs/docs/docs/api-reference/brownie/_meta.json	Adds Android usage page to docs nav.
apps/RNApp/src/components/counter/index.tsx	Switches to shared counter using useStore and an increment button.
apps/RNApp/src/components/counter/index.ios.tsx	Removes iOS-specific counter component (now shared).
apps/RNApp/package.json	Adds Brownie Kotlin codegen config.
apps/ExpoApp/package.json	Adds Brownie Kotlin codegen config.
apps/ExpoApp/components/counter/index.tsx	Switches to shared counter using useStore and an increment button.
apps/ExpoApp/components/counter/index.ios.tsx	Removes iOS-specific counter component (now shared).
apps/AndroidApp/app/src/vanilla/java/com/callstack/brownfield/android/example/BrownfieldStore.kt	Adds typealiases to generated store types for the vanilla flavor.
apps/AndroidApp/app/src/main/java/com/callstack/brownfield/android/example/components/GreetingCard.kt	Wires Compose UI to Brownie store updates and increment action.
apps/AndroidApp/app/src/main/java/com/callstack/brownfield/android/example/MainActivity.kt	Registers store once during app startup.
apps/AndroidApp/app/src/expo/java/com/callstack/brownfield/android/example/BrownfieldStore.kt	Adds typealiases to generated store types for the expo flavor.
apps/AndroidApp/app/build.gradle.kts	Bumps JVM target to 17 and adds Gson dependency.
.changeset/red-llamas-love.md	Publishes minor bumps for impacted packages.

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[artus9033]

LGTM! We can address full reuse of the C++ code in CXX modules in the future, as discussed