update the package name manually across each file listed below. Replace all occurrences of com.oldpackage.name with com.yourcompany.appname.

1. android/app/build.gradle
   Update the applicationId field:

   android {
       defaultConfig {
           applicationId "com.yourcompany.appname"   // <-- change this
           ...
       }
   }

2. android/app/src/main/AndroidManifest.xml
   Update the package attribute on the root <manifest> tag:

   <manifest xmlns:android="http://schemas.android.com/apk/res/android"
       package="com.yourcompany.appname">    <!-- change this -->
       ...
   </manifest>

3. android/app/src/main/java/ — Rename the folder structure
   The Java source folder must mirror the package name. For example:
   • Old path: android/app/src/main/java/com/oldpackage/name/
   • New path: android/app/src/main/java/com/yourcompany/appname/
   Rename the folders manually in your file explorer or IDE.
4. MainActivity.java / MainActivity.kt
   Update the package declaration at the top of the file:

   package com.yourcompany.appname;   // <-- change this
   
   import com.facebook.react.ReactActivity;
   ...

5. MainApplication.java / MainApplication.kt
   Update the package declaration here as well:

   package com.yourcompany.appname;   // <-- change this
   
   import android.app.Application;
   ...

6. android/app/BUCK (if present)
   Update the package field:

   android_build_config(
       ...
       package = "com.yourcompany.appname",   # <-- change this
   )


7. Clean & rebuild
   After all files are updated, clean the build cache and rebuild:

   cd android
   ./gradlew clean
   cd ..
   npx react-native run-android

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