npm install node-wechat

var http = require('http'),
    wechat = require('node-wechat');

http.createServer(function (req, res) {
  //预处理
  wechat.handler(req, res);

  //监听文本信息
  wechat.text(function (data) {
    //console.log(data.ToUserName);
    //console.log(data.FromUserName);
    //console.log(data.CreateTime);
    //console.log(data.MsgType);
    //...
    var msg = {
      FromUserName : data.ToUserName,
      ToUserName : data.FromUserName,
      MsgType : "text",
      Content : "这是文本回复",
      FuncFlag : 0
    }
    //回复信息
    wechat.send(msg);
  });

  //监听图片信息
  //wechat.image(function (data) { ... });

  //监听地址信息
  //wechat.location(function (data) { ... });

  //监听链接信息
  //wechat.link(function (data) { ... });

  //监听事件信息
  //wechat.event(function (data) { ... });

  //监听所有信息
  //wechat.all(function (data) { ... });
}).listen(80);