How do I migrate from Firebase Cloud Messaging (FCM) to Pushwoosh without losing my existing subscribers?

Migrating from FCM to Pushwoosh has different implications for Android and iOS platforms. Here is a breakdown for each:

Android

For Android devices, Pushwoosh utilizes FCM as the underlying push notification service. This means you are not completely replacing FCM; instead, the Pushwoosh SDK is designed to work with your existing Firebase project.

When you integrate the Pushwoosh SDK into your app:

• No Replacement: Pushwoosh acts as a layer on top of FCM to provide additional features.
• User Continuity: As long as you configure your Android platform correctly according to our documentation, your existing users who update the application will be registered with Pushwoosh and will continue to receive notifications. There should be no drop in deliverability.
• Multiple FCM Services: If your app uses other services that also rely on FCM, you may need to manage multiple FirebaseMessagingService implementations. Please refer to our guide: Handling Multiple FirebaseMessagingService Implementations.

iOS

The process for iOS is different because Pushwoosh works directly with the Apple Push Notification service (APNs), while Firebase uses its own FCM tokens for iOS devices.

To migrate your existing iOS users:

1. Obtain APNs Tokens: Pushwoosh requires the native APNs device token for each user. Since Firebase uses its own FCM tokens, you will need to get the underlying APNs tokens from your Firebase project.
2. Contact Firebase: You will likely need to contact Firebase support to request an export of the raw APNs tokens for your subscribers.
3. Import to Pushwoosh: Once you have the list of APNs tokens, you can import them into your Pushwoosh application to ensure your existing iOS users can receive notifications.