npm install facebook-node-sdk

var Facebook = require('facebook-node-sdk');

var facebook = new Facebook({ appID: 'YOUR_APP_ID', secret: 'YOUR_APP_SECRET' });

facebook.api('/amachang', function(err, data) {
  console.log(data); // => { id: ... }
});

var express = require('express');
var Facebook = require('facebook-node-sdk');

var app = express.createServer();

app.configure(function () {
  app.use(express.bodyParser());
  app.use(express.cookieParser());
  app.use(express.session({ secret: 'foo bar' }));
  app.use(Facebook.middleware({ appId: 'YOUR_APP_ID', secret: 'YOUR_APP_SECRET' }));
});

app.get('/', Facebook.loginRequired(), function (req, res) {
  req.facebook.api('/me', function(err, user) {
    res.writeHead(200, {'Content-Type': 'text/plain'});
    res.end('Hello, ' + user.name + '!');
  });
});