You linked to Scripting docs, but your app is WebAPI. Here is a script from those docs:
var http = require('http');
var tropo_webapi = require('tropo-webapi');
var server = http.createServer(function (request, response) {
var tropo = new TropoWebAPI();
// (value, as, name, required, voice)
tropo.say("Hello, how are you?.", null, null, null, "kate");
response.end(TropoJSON(tropo));
}).listen(8000);
https://www.tropo.com/docs/webapi/international_speaking_other_languages.htm
I believe this was resolved in IRC already, but posting the above for any other users checking it out.
Justin Dupree
Director of Customer Experience
Voxeo Labs