server.js

var http = require("http");
var url = require('url');
var queryString = require('querystring')

var API_KEY = "THE_API_KEY";
var FEED = "THE_FEED_ID";
var STREAM = "THE_STREAM_NAME";


var NUM_ATTENDEES = 0

http.createServer(function(request, response) {
  var queryURL = url.parse(request.url);
  var pathname = queryURL.pathname;

  // Get event data from
  if (pathname != "/app/casablanca/attendees") {
    response.writeHead(404);
    response.end();
  }

  if(request.method != "POST") {
        response.writeHead(400);
        response.end();
  }
  if(request.headers['content-type'] != 'application/json') {
    response.writeHead(415);
    response.end();
  }
  // Received POST with proper mediatype, process POST
  var data = "";
  request.on("data", function (chunk) {
      data += chunk;
  });
  request.on("end", function () {
    var jdata = JSON.parse(data);
    console.log("Received Payload: " + jdata.attendee);
    if (jdata.attendee == 1) {
        NUM_ATTENDEES += 1;
    } else if (jdata.attendee == -1 && NUM_ATTENDEES > 0
    ) {
        NUM_ATTENDEES -= 1;
    }
  });

  var options = {
    hostname: 'api-m2x.att.com',
    port: 80,
    path: '/v1/feeds/' + FEED + '/streams/' + STREAM,
    method: 'PUT'
  };

  var req = http.request(options, function (resp){
    console.log('STATUS: ' + resp.statusCode);
    var data = '';
    resp.on("data", function (chunk) {
        data += chunk;
    });

    resp.on("end", function () {
        console.log(data);
    });
  });

  var payload = JSON.stringify({value: NUM_ATTENDEES})
  req.setHeader("Content-Type", "application/json");
  req.setHeader("Content-Length", payload.length);
  req.setHeader("X-M2X-KEY", API_KEY);
  req.write(payload);
  req.end();

  response.writeHead(204);
  response.end();

}).listen(8888);