Is it possible to create a client-side REST API?

Question

Is it possible to set up a JS REST API in the browser?
The idea is that my web server posts data to the client API and that the UI is updated:D
The communication should be encrypted so I figure HTTPS has to enter the mix.

This is probably a silly question and you might wonder why?
The answer is I looked at PHP websockets and read about memory leaks and frequently restarting the server which led me to think websocket in PHP aren't quite there yet.

Answer 1

The server can't request services from a client, but you can send the results from client-side to the server via AJAX for example.