Receiving the same token for different users when using firebase messaging

Question

I use the code below to obtain a token from firebase :

const messaging = firebase.messaging();

messaging.requestPermission()
  .then(() =>{
    return fi         


        

Answer 1

Another possible solution to the problem is to add a field called userId in your data that you send as a notification. And at client side, only show notification if the userId == FirebaseAuth.user.id or similar in case you are not using FirebaseAuth.

Answer 2

I have an alternate solution to your problem,

You can use topics for receiving notifications,

1.) Subscribe topic for your registration_token, let the topic name unique for every user like user id.

https://iid.googleapis.com/iid/v1/<REGISTRATION_TOKEN>/rel/topics/<TOPIC_NAME>

Example:

https://iid.googleapis.com/iid/v1/nKctODamlM4:CKrh_PC8kIb7O...clJONHoA/rel/topics/movies
Content-Type:application/json
Authorization:key=AIzaSyZ-1u...0GBYzPu7Udno5aA

2.) Send Notification to topic

https://fcm.googleapis.com/fcm/send
Content-Type:application/json
Authorization:key=AIzaSyZ-1u...0GBYzPu7Udno5aA
{
  "to" : "/topics/movies",
  "priority" : "high",
  "notification" : {
    "body" : "This is a Firebase Cloud Messaging Topic Message!",
    "title" : "FCM Message",
  }
}

3.) Remove registration_id from the topic on logout

https://iid.googleapis.com/iid/v1:batchRemove
Content-Type:application/json
Authorization:key=API_KEY
{
   "to": "/topics/movies",
   "registration_tokens": ["nKctODamlM4:CKrh_PC8kIb7O..."],
}

Replace topic name "movies" with the unique user id or email etc

Answer 3

Firebase Cloud Messaging tokens identify an installation of an app in a specific device. They do not identify a specific user. So in your case, if multiple users access your app in the same browser profile, they will get the same token.

I haven't tried this myself, but I think you can delete the token (typically when the user signs out). Then request permission and get the new token for the new user, as usual.