Interesting but not sure if it is what I want about php-sse

[hhxsv5]

This requires a client, whether it is GCM, APN, or your app.

[ugintl]

If I have an app, can I use phpsse to send messages or notifications to the app?

How?

[hhxsv5]

Sure, you need to make sure your app is open in the foreground/background, and this notification is not system level but application level.

If you have high performance requirements, you can use WebSocket, such as Swoole WebSocket Server.

[lbfalvy]

Push notifications also use HTTP, and thus work quite well with PHP. Don't make a mobile app just to use them.

[hhxsv5]

Now there is already a high performance coroutine SSE Server based on Swoole, enjoy the demo.