riak-js issue

app.js

// Dependencies
var http = require('http');
	express = require('express'),
	path = require('path'),
	db = require('riak-js').getClient({ debug: true }),
	app = express();

// All environments
app.set('port', process.env.PORT || 3000);
app.use(express.logger('dev'));
app.use(express.bodyParser());
app.use(express.methodOverride());
app.use(app.router);
app.use(express.static(path.join(__dirname, 'public')));

// Development only
if ('development' === app.get('env')) {

	app.use(express.errorHandler());

}

// Api index
app.get('/api', function(req, res) {

	db.save('hello', 'test', { works: 'fine' }, function(error, data) {

		console.log(error, data);

	});

	res.end('hey');

});

// Go!
http.createServer(app).listen(app.get('port'), function() {

	console.log('Express server listening on port ' + app.get('port'));

});

When I run this I always get null and undefined returned, is there something I'm missing? I'm pretty new to both node node and riak so I could be being stupid..