Hello wonderful community! ❤️🌸

Today we're thrilled to announce v2.0.0.alpha1 release 🙌.

A fresh start 😎

Today's release is the beginning of Hanami 2 series. The final 2.0 version will be released later this year.

We decided to start fresh with the development of the framework. The internals needed a cleanup because the code was accumulating techical debt from the old days of Lotus. To evolve it would have required too much effort. Given 1.3 is 4k lines of code, it made a lot of sense for us to start from scratch.

That means this release is not meant to be comparable in terms of features with 1.3, but it's more a preview of Hanami 2.


DRY-up settings

The big change from Hanami 1 is the removal of all the applications (web, admin) as a way to micro-configure areas of your project.

In the past we had:

  • config/enviroment.rb
  • apps/{web,admin,...}/application.rb

To configure where to load files from, which was the default response format for each single app, the sessions, cookies, base URL, just to name a few.

The concept is to unify all these settings at the level of config/application.rb, so they are propagated to the apps. DRY at its finest.

Here's an example of config/application.rb:

# frozen_string_literal: true

module Soundeck
  class Application < Hanami::Application
    config.cookies  = { max_age: 600 }
    config.sessions = :cookie, { secret: ENV["SOUNDECK_SESSIONS_SECRET"] }
    config.middleware.use Middleware::Elapsed, "1.0"

    config.environment(:production) do |c|
      c.base_url = ENV["SOUNDECK_BASE_URL"]
      c.logger = { level: :info, formatter: :json }


We introduced a new syntax for the application configuration based on getters and setters, instead of the DSL we had in Hanami 1.


cookies max_age: 600


config.cookies = { max_age: 600 }

This new syntax helps to simplify the internals, by explicitly separating the intent of reading a value from the intent of setting it.

Hanami::Configuration now performs atomic/thread-safe operations both at the read and write time.


Another difference from the past is that configuration now ships with defaults, instead of making everything explicit in the generated app.

Let me give you an example:


This was an explicit setting of each application configuration.

# apps/web/application.rb
security.x_frame_options = "DENY"


Now the configuration has that value as a default, so the generated code is empty:

In case a developer needs to change the default, they will do it for the whole app:

# config/application.rb
config.security.x_frame_options = "sameorigin"


hanami-router has been rewritten more than a year ago. It's more efficient (+10k req/s for simple Rack benchmark) and it's now based on mustermann path matchers, which powers Sinatra routing as well.

In Hanami 1 we had several places to configure the whole routes of an app: apps/{web,admin,...}/config/routes.rb. Now these files are gone in favor of config/routes.rb at the root of the project.

This change has an impact both on simplification and performance.

Thanks to hanami-router 2, we can define all the routes for all the apps in a single shot in config/routes.rb:

# frozen_string_literal: true

Hanami.application.routes do
  mount :web, at: "/" do
    root to: "home#index"

  mount :admin, at: "/admin" do
    root to: "home#index"

Please note the differences from the past:

  • No more multiple files and multiple routers instances for multiple apps
  • Single router for the whole app 🙌
  • Mounting apps is no longer delegated to the gone Hanami.configure, which was cluttering config/environment.rb
  • Apps as concrete classes are gone (e.g. Web::Application), in favor of symbols
  • The apps registered with mount are the ones that are activated in the internal container


Actions are been redesigned to improve their performance. In Hanami 1, for each incoming HTTP request, we had to create a new action instance, because assigning instance variables (e.g. @book) and using them as exposures, we had to re-create a blank state, with a new action. In the long run, that was putting pressure on Ruby garbage collector.

To remediate to this problem, we made the actions immutable. In order to pass the data from the action to the view, you can use:

response[:book] = Book.new

This also eliminates the need to declare data via the expose DSL, which is now gone.

Another important change from the past is that Hanami::Action is now a superclass to inherit from. In your app you will have a base action class for each sub application (e.g. apps/web/action.rb):

# frozen_string_literal: true

module Web
  class Action < Hanami::Action

This base class is designed to share code with its subclasses. For instance, the action at apps/web/actions/books/show.rb will look like this:

# frozen_string_literal: true

module Web
  module Actions
    module Books
      class Show < Web::Action
        def handle(req, res)
          res[:book] = BookRepository.new.find(req.params[:id])

Code reloading

We extracted code reloading from hanami core to hanami-reloader.

The new implementation is based on guard-rack: this gem watches the file system and restarts the server when it detects a file change. This makes code reloading an external feature of the framework, no longer builtin in its core. The previous builtin implementation based on shotgun was causing compatibility problems (JRuby, Windows, better_errors gem), and it was source of bugs.

The feature is still integrated with hanami server (use --no-code-reloading to skip). The interesting bit is that, if hanami-reloader isn't installed, hanami server won't use code reloading, because it isn't implemented by Hanami. This is useful in production, where you don't need code reloading.

CLI commands

Because this is the first preview of 2.0, only two CLI commands are available for now:

  • hanami version
  • hanami server

We'll re-add all the usual CLI commands from 1.3, as soon we'll implement the related features.

Released Gems 💎

  • hanami-2.0.0.alpha1
  • hanami-cli-1.0.0.alpha1
  • hamami-controller-2.0.0.alpha1
  • hanami-router-2.0.0.alpha1
  • hanami-utils-2.0.0.alpha1
  • hanami-reloader-1.0.0.alpha1

How to try it ⌨️

$ gem install hanami --pre

Please check out https://github.com/jodosha/soundeck if you want to see a working example.

What's next? ⏰

We'll release a new alpha version, in April 2019.

Happy coding! 🌸