chore: document minimum React Native version (>= 0.78)

Set peerDependencies to react-native >= 0.78 and react >= 19.0.0,
add requirements section to package README, add RN version badge to
root README, and downgrade apps/demo to RN 0.78.2 for testing.

Made-with: Cursor

Author: CAMOBAP

README.md

@@ -12,6 +12,8 @@
 [![npm downloads](https://img.shields.io/npm/dm/@callstack/react-native-sandbox.svg?style=for-the-badge)](https://www.npmjs.org/package/@callstack/react-native-sandbox)
 [![check](https://img.shields.io/github/actions/workflow/status/callstackincubator/react-native-sandbox/check.yml?style=for-the-badge)](https://github.com/callstackincubator/react-native-sandbox/actions/workflows/check.yml)
 [![platform: iOS](https://img.shields.io/badge/platform-iOS-blue.svg?style=for-the-badge)](https://img.shields.io/badge/platform-iOS-blue.svg)
+[![react-native >= 0.78](https://img.shields.io/badge/react--native-%3E%3D%200.78-61dafb.svg?style=for-the-badge&logo=react)](https://reactnative.dev/)
+
 
 </div>
 

apps/demo/android/app/src/main/java/com/demo/MainApplication.kt

@@ -4,11 +4,13 @@ import android.app.Application
 import com.facebook.react.PackageList
 import com.facebook.react.ReactApplication
 import com.facebook.react.ReactHost
-import com.facebook.react.ReactNativeApplicationEntryPoint.loadReactNative
 import com.facebook.react.ReactNativeHost
 import com.facebook.react.ReactPackage
+import com.facebook.react.defaults.DefaultNewArchitectureEntryPoint.load
 import com.facebook.react.defaults.DefaultReactHost.getDefaultReactHost
 import com.facebook.react.defaults.DefaultReactNativeHost
+import com.facebook.react.soloader.OpenSourceMergedSoMapping
+import com.facebook.soloader.SoLoader
 
 class MainApplication : Application(), ReactApplication {
 
@@ -33,6 +35,9 @@ class MainApplication : Application(), ReactApplication {
 
   override fun onCreate() {
     super.onCreate()
-    loadReactNative(this)
+    SoLoader.init(this, OpenSourceMergedSoMapping)
+    if (BuildConfig.IS_NEW_ARCHITECTURE_ENABLED) {
+      load()
+    }
   }
 }

apps/demo/android/build.gradle

@@ -5,7 +5,7 @@ buildscript {
         compileSdkVersion = 35
         targetSdkVersion = 35
         ndkVersion = "27.1.12297006"
-        kotlinVersion = "2.1.20"
+        kotlinVersion = "2.0.21"
     }
     repositories {
         google()

apps/demo/android/gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.14.1-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.12-all.zip
 networkTimeout=10000
 validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME

apps/demo/ios/Demo/AppDelegate.swift

@@ -4,36 +4,15 @@ import React_RCTAppDelegate
 import ReactAppDependencyProvider
 
 @main
-class AppDelegate: UIResponder, UIApplicationDelegate {
-  var window: UIWindow?
+class AppDelegate: RCTAppDelegate {
+  override func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey : Any]? = nil) -> Bool {
+    self.moduleName = "Demo"
+    self.dependencyProvider = RCTAppDependencyProvider()
+    self.initialProps = [:]
 
-  var reactNativeDelegate: ReactNativeDelegate?
-  var reactNativeFactory: RCTReactNativeFactory?
-
-  func application(
-    _ application: UIApplication,
-    didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]? = nil
-  ) -> Bool {
-    let delegate = ReactNativeDelegate()
-    let factory = RCTReactNativeFactory(delegate: delegate)
-    delegate.dependencyProvider = RCTAppDependencyProvider()
-
-    reactNativeDelegate = delegate
-    reactNativeFactory = factory
-
-    window = UIWindow(frame: UIScreen.main.bounds)
-
-    factory.startReactNative(
-      withModuleName: "Demo",
-      in: window,
-      launchOptions: launchOptions
-    )
-
-    return true
+    return super.application(application, didFinishLaunchingWithOptions: launchOptions)
   }
-}
 
-class ReactNativeDelegate: RCTDefaultReactNativeFactoryDelegate {
   override func sourceURL(for bridge: RCTBridge) -> URL? {
     self.bundleURL()
   }

apps/demo/ios/Podfile.lock

@@ -2019,7 +2019,7 @@ PODS:
     - React-timing
     - React-utils
     - SocketRocket
-  - React-Sandbox (0.4.0):
+  - React-Sandbox (0.4.1):
     - boost
     - DoubleConversion
     - fast_float
@@ -2451,7 +2451,7 @@ SPEC CHECKSUMS:
   React-runtimeexecutor: 17c70842d5e611130cb66f91e247bc4a609c3508
   React-RuntimeHermes: 3c88e6e1ea7ea0899dcffc77c10d61ea46688cfd
   React-runtimescheduler: 024500621c7c93d65371498abb4ee26d34f5d47d
-  React-Sandbox: e3cf3c955559ed9f0bf014b29dce1e94600cd790
+  React-Sandbox: 9c091813e335735668c62b2d3dbeb1456f93d8a5
   React-timing: c3c923df2b86194e1682e01167717481232f1dc7
   React-utils: 9154a037543147e1c24098f1a48fc8472602c092
   ReactAppDependencyProvider: afd905e84ee36e1678016ae04d7370c75ed539be

bun.lock

@@ -7,6 +7,13 @@
 
 This is the **developer documentation** for installing and using `@callstack/react-native-sandbox` in your React Native application.
 
+## Requirements
+
+- **React Native >= 0.78**
+- **New Architecture** (Fabric) enabled
+
+This library uses `RCTReactNativeFactory`, C++ TurboModules, and Fabric component APIs that are only available starting from React Native 0.78. It does not include an Old Architecture / Bridge fallback.
+
 ## 📦 Installation
 
 ### npm/yarn

packages/react-native-sandbox/README.md

@@ -44,8 +44,8 @@
     ]
   },
   "peerDependencies": {
-    "react": "*",
-    "react-native": "*"
+    "react": ">=19.0.0",
+    "react-native": ">=0.78.0"
   },
   "devDependencies": {
     "react": "19.1.0",