is there anyway to send notification from one devi

问题:

I'm setting up an android apps notification with FCM so it can trigger the app to send notification to other device(receiver) using the same app and receive the notification. I want to use FCM but without Firebase Database but instead using PostGreSQL/other DB. How to do it? also is it possible to implement Firebase in AdonisJS? because I use that for server-side.

回答1:

Firebase Cloud Messaging does not support directly sending messages to a device. Sending a message to a device (known as a downstream message) requires that you specify the FCM server key, and (as its name implies) that key should only be used on a server, or otherwise trusted environment.

The reason for this is that having the FCM server key for a project allows you to send any message to any and all of the devices in that project, so having this available outside of a trusted environment would be a security concern.

But there is no need to use the Firebase Database to send FCM message. The simplest way to verify this is to send a message through a command line curl call, like shown here: How can I send a Firebase Cloud Messaging notification without use the Firebase Console? You can also implement the code to send a message in Cloud Functions or your own favorite server-side environment without a database. You'll just have to pass in the target of where to send the message into the function.