Question: In my app.js (server) I need to know from where (URL) the request came.

Currently, I'm passing the URL as parameter from the client:

```
socket.emit('request', window.location.href);

```

and processing it server side

```
socket.on('request', function(url){
    console.log(url);
    ...
});

```

But that's clearly risky and unsecure (clients can send anything to the server). 

So I'm guessing.. is it possible to get the URL parameter only on server side? Maybe from the socket object?

Answer: 
For the entire URL you could use socket.handshake.headers.referer

```
io.on('connect', (socket) => {
     console.log(socket.handshake.headers.referer);
});

```
socket.request.headers.origin
This will return domain connection