The device group messaging feature has been deprecated and will stop working after September 29, 2027. The instructions help you migrate off the feature.
Manage your own group-tokens mapping
Because FCM will no longer store your device groups, you must build and maintain your own mapping between your groups (such as a user ID) and their associated FCM registration tokens on your app server. We recommend using a persistent storage solution, like Cloud Firestore, Realtime Database, or a relational database.
When a client app starts up or its token refreshes, it should capture the token and send it to your backend to be stored. Your backend then associates that token with the appropriate user or group.
Retrieve your existing group-tokens mapping
FCM device group management APIs offer a GET method
for retrieving the list of registration tokens that belong to a given
notification_key.
WARNING: The API for retrieving group-tokens mapping will be turned down on September 29, 2027 and the data won't be retained afterwards. Retrieve you group data before September 29, 2027 if you need.
Send messages to each token of a group
To send a message to a group using your newly managed group-tokens mappings, retrieve the list of tokens from your database.
If you are using the Firebase Admin SDK, you can use the multicast messaging API
(sendEachForMulticast) to send a single message payload to multiple tokens at
once.
If you are calling the FCM HTTP v1 API directly, you must make a separate HTTP
request for each token in your group, iterating over the list of registration
tokens and sending a request with the token field explicitly set in the
message payload.
Use topic messaging for large fanout
Topic messaging is not a direct replacement for group messaging. Topics are optimized for throughput rather than latency, and recommended for large fanout. You can learn more about how to manage topic subscriptions and send messages to topics if it works for you.