# 4.x -> 5.0.0

Version 5.x of the Customer.io React Native SDK introduces Firebase wrapper support for FCM users that improves Firebase compatibility and simplifies push notification setup.

## What changed?[](#what-changed)

Version 5.x introduces a Firebase wrapper that improves compatibility with Firebase Cloud Messaging (FCM) and other Firebase services in your app.

## Do you need to update to this version?[](#do-you-need-to-update-to-this-version)

**You need to update to this version if** you use **FCM (Firebase Cloud Messaging)** for push notifications

## Update process[](#update-process)

Add the `CioFirebaseWrapper` import to your Swift files that use `CioMessagingPushFCM`.

Add the Firebase wrapper import to your `AppDelegate.swift` file:

```swift
import UIKit
import CioMessagingPushFCM
import CioFirebaseWrapper  // Add this import for FCM users
import UserNotifications
import Firebase
import FirebaseMessaging

@main
class AppDelegateWithCioIntegration: CioAppDelegateWrapper<AppDelegate> {}
```

## Troubleshooting[](#troubleshooting)

If you see build errors related to Firebase after upgrading:

1.  **Clean your build**: Run `cd ios && pod install && cd ..` then rebuild
2.  **Check imports**: Ensure you’ve added `import CioFirebaseWrapper` to all files that import `CioMessagingPushFCM`