autofave.js

var Twit = require('twit');
 var T = new Twit({
    consumer_key:         '...'
  , consumer_secret:      '...'
  , access_token:         '...'
  , access_token_secret:  '...'
});
 
var userid = '...';
 
var stream = T.stream('statuses/filter', { follow: userid })
stream.on('tweet', function (tweet) {
  T.post('favorites/create', {id: tweet.id_str}, function(err, reply){
    if (err) console.log(err);
  });
});