Using Google Apps Script to proxy YouTube Analytics Channel report data http://mashe.hawksey.info/?p=16234

main.js

// instead of var results = YouTubeAnalytics.Reports.query(ids, start-date, end-date, metrics, optionalArgs);
var params = {"method" : "post",
              "payload" : {'ids' : query.ids,
                           "startDate" : startDate,
                           "endDate": endDate,
                           "metrics": query.metrics,
                           "options": JSON.stringify(options)
                          }
             };
var yt_data = UrlFetchApp.fetch("https://script.google.com/macros/s/YOUR_APP_ID/exec", params);
var results = JSON.parse(yt_data.getContentText());

proxy.js

// to enable YouTubeAnalytics you need to go Resources > Advanced services and add YouTube Analytics (remembering to activate in Developer Console)
// Run > doPost to trigger authentication
// Publish > Deploy as web app
//   - Execute as 'me'
//   - Anyone, even anonymously
// Add you web app url to line 10 in main
function doPost(e) {
  var results = YouTubeAnalytics.Reports.query(e.parameters.ids, e.parameters.startDate, e.parameters.endDate, e.parameters.metrics, JSON.parse(e.parameters.options));
  return ContentService.createTextOutput(JSON.stringify(results ))
    .setMimeType(ContentService.MimeType.JSON);
}