gistfile1.txt

var http = require('http');
var httpProxy = require('http-proxy');

var proxyOptions = {
	pathnameOnly: true,
	router: {
		'/app': 'localhost:3000',
		'/accounts': 'localhost:8001'
	}
}

httpProxy.createServer(
	proxyOptions,
	function (req, res, next) {
		console.log('incoming');
		next();
	}
).listen(3001);

Here's what I see with netcat when a request comes in from the web browser:

~|⇒ nc -l 8001
GET / HTTP/1.1
host: localhost:3001
connection: keep-alive
accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
user-agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_2) AppleWebKit/537.22 (KHTML, like Gecko) Chrome/25.0.1364.172 Safari/537.22
accept-encoding: gzip,deflate,sdch
accept-language: en-GB,en;q=0.8,en-US;q=0.6
accept-charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3
cookie: connect.sid=s%3Ag2fuSh4Pph4DJ8GfMK6AcdaN.YuA1sA2N0PT5lvDn4QSwjvKrKLLetzpGaumrBAZn3NY
x-forwarded-for: 127.0.0.1
x-forwarded-port: 55932
x-forwarded-proto: http