Could be run locally or on Heroku
Index.js
var jsforce = require('jsforce');
var username = 'USER_NAME';
var password = 'PASS+TOKEN';
var conn = new jsforce.Connection({});
conn.login(username, password, function(err, userInfo) {
if (err) {
return console.error(err);
}
conn.streaming.topic("/event/ChatterActivity__e").subscribe(function(message) {
console.log(message);
});
});