much simpler callback approach due to serveStatic with directories !!!

data/input.js

@@ -28,7 +28,7 @@ xhr.onreadystatechange = function(){
 }
 
 function reloadTerminal() {
-  xhr.open("GET", "/terminal", true);
+  xhr.open("POST", "/app=terminal", true);
   xhr.send();
   setTimeout(reloadTerminal, 1000);
 };