Migration Guide - Transition from GCM to FCM deprecated

Google has officially announced the deprecation of the existing HTTP API for sending push notifications via Firebase Cloud Messaging (FCM), effective from June 20, 2023, with plans to shut it down on June 21, 2024. In response to this, a new FCM API, known as "v1," has been introduced as a replacement.

Firebase Cloud Messaging (FCM) represents the modern successor to Google Cloud Messaging (GCM) and serves as the primary channel for delivering messages to both Android and iOS devices. This comprehensive migration guide is designed to assist you in seamlessly transitioning from GCM to FCM within your deployment infrastructure.


Before embarking on the migration process, it's essential to ensure that the following prerequisites are met:

For On-Premises Deployments: - Creation of a Firebase project through the Firebase Console. - Successful integration of your application with GCM and a prior migration to FCM. Detailed instructions for this step are available in Google's official migration guide.

For OX Cloud Deployments: - Installation or updating of the drive-restricted component to its latest version, inclusive of the FCM keys. - Upgrade of the OX Drive mobile app (for testing purposes) to the latest version, which includes the essential FCM keys.

Database Modifications

As part of the migration, several database changes will be implemented. Specifically, two database update tasks are in place to facilitate the transition. These tasks are responsible for renaming the service identifiers from GCM to FCM for both drive events and the generic PNS transport layer. The two tasks involved are as follows: - com.openexchange.drive.events.fcm.groupware.RenameGCM2FCMUpdateTask - com.openexchange.pns.transport.fcm.groupware.RenameGCM2FCMUpdateTask


In terms of configuration adjustments, there is minimal need for modification beyond the inclusion of the key _type: fcm within each client configuration in the pushClientConfig/*.yml files. These configurations should also be adjusted to point to the appropriate key using the keyPath property. For example:

  _type: fcm
  keyPath: /var/lib/firebase/key-01.json

  _type: fcm
  keyPath: /var/lib/firebase/key-02.json

For further fine-tuning of your FCM configuration, please refer to the Push Notification Service.

This migration guide should enable you to smoothly transition from GCM to FCM and ensure the continued effectiveness of your push notification infrastructure.