Grape

Grape is a REST-like API micro-framework for Ruby. It is built to complement existing web application frameworks such as Rails and Sinatra by providing a simple DSL to easily provide APIs. It has built-in support for common conventions such as multiple formats, subdomain/prefix restriction, and versioning.

Installation

Grape is available as a gem, to install it just install the gem:

gem install grape

Basic Usage

Grape APIs are Rack applications that are created by subclassing Grape::API. Below is a simple example showing some of the more common features of Grape in the context of recreating parts of the Twitter API.

class Twitter::API < Grape::API
  version '1'

  helpers do
    def current_user
      @current_user ||= User.authorize!(env)
    end

    def authenticate!
      error!('401 Unauthorized', 401) unless current_user
    end
  end

  resource :statuses do
    get :public_timeline do
      Tweet.limit(20)
    end

    get :home_timeline do
      authenticate!
      current_user.home_timeline
    end

    get '/show/:id' do
      Tweet.find(params[:id])
    end

    post :update do
      authenticate!
      Tweet.create(
        :user => current_user,
        :text => params[:status]
      )
    end
  end
end

This would create a Rack application that could be used like so (in a Rackup config.ru file):

run Twitter::API

And would respond to the following routes:

GET  /1/statuses/public_timeline(.json)
GET  /1/statuses/home_timeline(.json)
GET  /1/statuses/show/:id(.json)
POST /1/statuses/update(.json)

Serialization takes place automatically. For more detailed usage information, please visit the Grape Wiki.

Note on Patches/Pull Requests

  • Fork the project.
  • Make your feature addition or bug fix.
  • Add tests for it. This is important so I don't break it in a future version unintentionally.
  • Commit, do not mess with rakefile, version, or history. (if you want to have your own version, that is fine but bump version in a commit by itself I can ignore when I pull)
  • Send me a pull request. Bonus points for topic branches.

Copyright (c) 2010 Michael Bleigh and Intridea, Inc. See LICENSE for details.