Using Photoshop generator plugin together with HTML panel. Pseudo-untested-code

generator-plugin.js

exports.init = function (generator, config) {
    var io = require('socket.io').listen(1234); // put your unique port here

    io.sockets.on('connection', function (socket) {
        socket.emit('message', 'i am ready');
        socket.on('doStuff', function (data) {
            generator.getDocumentInfo().then(function (document) {
                socket.emit('message', 'working with document…');
            }, function (err) {
                console.log(err);
            }).done();
        });
    });
};

panel.html

<button>Do stuff</button>
<div></div>

<script src="http://127.0.0.1:1234/socket.io/socket.io.js"></script>
<script>
var socket = io.connect('http://127.0.0.1:1234');

var div = document.querySelector('div');
socket.on('message', function (data) {
    div.innerHTML = data;
});

var button = document.querySelector('button');
button.addEventListener('click', function () {
    socket.emit('doStuff');
});
</script>