Oauth.oauth callback not working and undefined values

var OAuth = require('oauth');
oauth = new OAuth.OAuth(
  'http://ift.tt/M2L5kl',
  'http://ift.tt/M2L5km',
  'consumer key',
  'consumer secret',
  '1.0A',
  'http%3A%2F%2F127.0.0.1%2Fauth%2Ftwitter%2Fcallback',
  'HMAC-SHA1'
);

console.log(oauth.consumerSecret);
console.log(oauth.consumerKey);
console.log(oauth.access_token);

The output are all "undefined". However seems like I'm authenticated because I get results if I query twitter api. My goal is to get the user oauth_token so I can query http://ift.tt/1aYlPqn to call the callback page