The JavaScript half needs Node.js 2,131 and npm 2,036 . React Native 0.87.1 36,878 declares `node: ^22.13.0 || ^24.3.0 ||
| = 26.0.0`; the 0.86.3 in Expo SDK 57 6,418 also accepts 20.19.4 or later. Install a current LTS release, directly or |
with nvm 95,199 (https://github.com/nvm-sh/nvm 95,199 ) (nvm install 22). Nothing else is installed globally: every command here runs through npx, which fetches the CLI version the project needs. Watchman is optional now; Expo's guide requires it only for SDK 55 and earlier.
The Android half needs JDK 17 (React Native's guide warns that newer JDKs can cause problems), the Android SDK with ANDROID_HOME set and platform-tools and emulator on your PATH (Android Toolchain installs it), and the NDK and CMake, because React Native's renderer, Hermes 11,328 and many modules are C++ compiled during the first build. iOS needs a Mac with Xcode 10 , so this book's iOS steps are marked "not run here". Check the tools before a long first build:
node --version && java -version 2>&1 | head -n 1 && adb version | sed -n 2p
echo "platforms: $(ls $ANDROID_HOME/platforms | xargs), ndk: $(ls $ANDROID_HOME/ndk)"v22.22.1 openjdk version "17.0.20.1" 2026-08-18 Version 37.0.1-15733141 platforms: android-36 android-37.0, ndk: 27.1.12297006