Prevent other people from emitting socket info

I have my node socket server running on the same VPS as my website is. Is there a way I can prevent other "websites" or other node projects from connecting to my socket server and emitting data?

My website and node project have the same IP address.

For example: (client side html)

<script>
  var socket = io.connect('localhost') //localhost as an example
  socket.on('example', function(data) { 
     console.log(data) ;
  });
  socket.emit('sendToServer', 'hello world');
</script>

I want this code right here to only be usable by my website (or IP)

EDIT: If there isnt any to do this within socket.io, is there a way I can authenticate my socket server to make it so only my IP can emit things