In this november, Paypal released KrakenJS which is web application framework based on Connect, Express.

I had a chance to using this framework at the ending of this year. So I want to inform the facility of this framwork.

This article was written for Node.js advent calendar 24th day. Please read previous articles.

Getting started

Install generator

Kraken uses Yeoman for building the bootstrap of application. So first, you need to install generator.

$ sudo npm install -g generator-kraken

Create skelton

$ yo kraken

    / _  _ \
    |(@)(@)|   Release the Kraken!
    )  __  (
  (( ((  )) ))
   `\ `)(' /'

[?] Application name: MyTestApp
[?] Description: My first kraken application
[?] Author: Kai Sasaki
[?] Use RequireJS? (Y/n) n

Write down simple configurations of your application. RequireJS is a JavaScript file and module loader. If you want to optimize loading of module scripts, this is good option. This command installs dependencies automatically. So you don’t need to type npm install again. After only these commands, you can start your application server.

Start your server

$ cd MyTestApp
$ npm start
npm WARN package.json [email protected] No repository field.

> [email protected] start /Users/sasakiumi/MyTestApp
> node index.js

Multipart body parsing will be disabled by default in future versions. To enable, use `middleware:multipart` configuration.
connect.multipart() will be removed in connect 3.0
visit for alternatives
connect.limit() will be removed in connect 3.0
Listening on 8000

Congratulations!! You can see your application through web browser.

start page


Directory structure is very simple. It is based on MVC framework which you might used to be.

Application and middleware configuration

Routes and logic

Custom developer libraries and other code

Language specific content bundles


Web resources that are publicly available

Server and browser-side templates

Unit and functional test cases

Application entry point 

For a characteristic, locale settings are prepared as default. You can make your app international easily. Because KrakenJS is based on Express, you can develop your own Connect stack as you did before. In the index.js file, some functions which are prepared for each request statuses. These description is easier to understand than original connect framework. For example, requestBeforeRout means that this function will be called after request before rouring logic. It’s simple, isn’t it?

'use strict';
var kraken = require('kraken-js'),
    app = {};
// Fired when an app configures itself
app.configure = function (nconf, next) {
// Fired at the beginning of an incoming request
app.requestStart = function (server) { };
// Fired before routing occurs
app.requestBeforeRoute = function (server) { };
// Fired after routing occurs
app.requestAfterRoute = function requestAfterRoute(server) { };
kraken.create(app).listen(function (err) {
    if (err) { console.error(err); }


KrankenJS can include other utility modules for enterprise use. These are also made by Paypal.

  • Lusca: Application security for express apps.
  • Makara: An i18n module for Dust.js.
  • Dust: A Dust.js view renderer for express
  • Kappa: A hierarchical npm-registry proxy

In this article, I won’t write the detail of these modules. But these might be made for enterprise applications. Lusca and Kappa is necessary for secure and private development environment.


In this one month, the number of examples are increasing. Would you like to add your example to this list?

Try it!

KrakenJS is on the way of development, if anything, is only on the first stage of a thing. I could develop an application by using KrakenJS in 2 weeks. It’s easy to use, user friendly, and it has nice libraries. I’ll bet this framework can accelerate your speed of development.

Let’s try it!!