server.js

var express = require('express'),
	routingProxy = require('http-proxy').RoutingProxy(),
	app = express.createServer();

var apiVersion = 1.0,
	apiHost = my.host.com,
	apiPort = 8080;

function apiProxy(pattern, host, port) {
	return function(req, res, next) {
		if (req.url.match(pattern)) {
			routingProxy.proxyRequest(req, res, {host: host, port: port});
		} else {
			next();
		}
	}
}

app.configure(function () {
	// API proxy middleware
	app.use(apiProxy(new RegExp('\/' + apiVersion + '\/.*'), apiHost, apiPort));

	// Static content middleware
	app.use(express.methodOverride());
	app.use(express.bodyParser());
	app.use(express.static(__dirname));
	app.use(express.errorHandler({
		dumpExceptions: true, 
		showStack: true
	}));
	app.use(app.router);
});

app.listen(3000);