Play Store Release — React Native

Prepare a React Native (bare workflow) project to build a signed Android App Bundle (AAB) ready for Google Play Store.

Expo users: If using Expo managed workflow, run eas build --platform android instead. This skill covers the bare React Native workflow.

Workflow Overview

Step 1 — Generate Upload Keystore

keytool -genkeypair \
  -alias upload \
  -keyalg RSA -keysize 2048 \
  -validity 10000 \
  -storetype PKCS12 \
  -keystore upload-keystore.jks

Rules:

• -validity 10000 = ~27 years. Google requires validity beyond Oct 22 2033.
• -storetype PKCS12 — industry standard, avoids JKS migration warnings.
• With PKCS12, store password and key password must be identical.
• Store the .jks outside version control. Recommended: ~/.android/keystores/ or a secrets manager.

Step 2 — Create Credentials

Add signing variables to android/gradle.properties (or ~/.gradle/gradle.properties for global scope):

MYAPP_UPLOAD_STORE_FILE=upload-keystore.jks
MYAPP_UPLOAD_KEY_ALIAS=upload
MYAPP_UPLOAD_STORE_PASSWORD=<your-store-password>
MYAPP_UPLOAD_KEY_PASSWORD=<your-key-password>

Add to .gitignore:

*.jks
*.keystore

If credentials are in android/gradle.properties, ensure that file is in .gitignore or use ~/.gradle/gradle.properties (per-user, never committed).

Step 3 — Configure Signing in Gradle

Edit android/app/build.gradle (Groovy — default for React Native):

android {
    signingConfigs {
        release {
            if (project.hasProperty('MYAPP_UPLOAD_STORE_FILE')) {
                storeFile file(MYAPP_UPLOAD_STORE_FILE)
                storePassword MYAPP_UPLOAD_STORE_PASSWORD
                keyAlias MYAPP_UPLOAD_KEY_ALIAS
                keyPassword MYAPP_UPLOAD_KEY_PASSWORD
            }
        }
    }

    buildTypes {
        release {
            signingConfig signingConfigs.release
            minifyEnabled enableProguardInReleaseBuilds
            shrinkResources enableProguardInReleaseBuilds
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
}

At the top of android/app/build.gradle, set the ProGuard flag:

def enableProguardInReleaseBuilds = true

Version management: set versionCode and versionName in the defaultConfig block of the same file.

Step 4 — ProGuard / R8

Create or edit android/app/proguard-rules.pro:

# React Native Bridge
-keep class com.facebook.react.** { *; }
-keep class com.facebook.hermes.** { *; }
-keep class com.facebook.jni.** { *; }
-dontwarn com.facebook.**

# Hermes engine
-keep class com.facebook.hermes.unicode.** { *; }
-keep class com.facebook.jni.** { *; }

# SoLoader
-keep class com.facebook.soloader.** { *; }
-dontwarn com.facebook.soloader.**

# JNI — native module classes
-keepclassmembers class * {
    @com.facebook.react.uimanager.annotations.ReactProp <methods>;
}
-keepclassmembers class * {
    @com.facebook.react.bridge.ReactMethod <methods>;
}
-keep,includedescriptorclasses class * extends com.facebook.react.bridge.JavaScriptModule { *; }
-keep,includedescriptorclasses class * extends com.facebook.react.bridge.NativeModule { *; }

# OkHttp (used by React Native networking)
-dontwarn okhttp3.**
-dontwarn okio.**
-keep class okhttp3.** { *; }

# Keep native module registrations
-keep class com.facebook.react.PackageList { *; }

Step 5 — Build Release AAB

# Option 1 — React Native CLI
npx react-native build-android --mode=release

# Option 2 — Gradle directly
cd android && ./gradlew bundleRelease

Useful flags:

• ./gradlew bundleRelease --stacktrace — full stack trace on errors.
• ./gradlew clean bundleRelease — clean before building.

Output: android/app/build/outputs/bundle/release/app-release.aab

Step 6 — Verification Checklist

Run these checks before uploading:

# 1. Verify AAB exists
ls -lh android/app/build/outputs/bundle/release/app-release.aab

# 2. Verify signing
jarsigner -verify -verbose -certs android/app/build/outputs/bundle/release/app-release.aab

# 3. Check the signing certificate alias
keytool -printcert -jarfile android/app/build/outputs/bundle/release/app-release.aab

# 4. Verify versionCode (requires bundletool)
bundletool dump manifest --bundle=android/app/build/outputs/bundle/release/app-release.aab \
  | grep -E "versionCode|versionName"

Checklist:

• AAB signed with upload key (not debug)
• versionCode is higher than the previous upload
• versionName matches intended release
• *.jks and *.keystore are in .gitignore
• Credentials not committed (check gradle.properties location)
• enableProguardInReleaseBuilds = true is set
• Hermes is the JS engine (default since RN 0.70)

Common Errors

Gotchas

1. Groovy by default — React Native projects use Groovy DSL (build.gradle, not .gradle.kts). Do not convert to Kotlin DSL unless the entire project has been migrated.

2. project.hasProperty() guard — The signing config uses a guard to avoid build failures when credentials are missing (e.g., on a fresh clone). Without the guard, ./gradlew assembleDebug would fail if credentials aren't set up.

3. Hermes vs JSC — Hermes is the default engine since React Native 0.70. ProGuard rules must match the active engine. If the project uses JSC (legacy), adjust rules accordingly.

4. New Architecture does not change signing — React Native's New Architecture (TurboModules, Fabric) does not affect the signing or release build process. The same Gradle signing config applies.

5. enableProguardInReleaseBuilds — This flag is defined as a variable at the top of build.gradle, not in gradle.properties. Setting it in the wrong place has no effect.

6. Expo managed workflow — If the project uses Expo managed workflow (app.json with expo key, no android/ directory), do NOT follow this skill. Use eas build --platform android instead. This skill is for bare React Native only.

7. App Signing by Google Play — Google re-signs your app with their key. The keystore you generate is the upload key only. If you lose it, you can request a reset through the Play Console.