Kanpachi

Kanpachi is a ruby gem that provides a DSL to describe your web API, generate documentation, and will even eventually help you implement it.

Resource input parameters are defiend with the mutations gem. You can refer to their wiki to find out how to use their DSL.

Response representations are defined as Roar representers. You can check out the representable docs to figure out how to customize your responses.

To demo an example API project, checkout kanpachi-example. If you want to see what the html documentation looks like it's available at http://kamui.github.io/kanpachi-example.

This project was inspired by @mattetti's Weasel-Diesel project, of which I am also a contributor. I created Kanpachi as a way of experimenting and leaning how to create a DSL in ruby.

Example

Below is an example of one of Twitter's API endpoints partially described in Kanpachi.

api 'Twitter' do
  # API meta data
  title 'REST API v1.1 Resources'
  description 'This describes the resources that make up the official Twitter
API v1.1'
  host 'api.twitter.com'

  # Define global error responses
  error :malformed_params do
    description 'Sending invalid JSON will result in a 400 Bad Request
response.'

    response do
      status 400
      header 'Content-Type', 'application/json'
      representation do
        property :message, type: String
      end
    end
  end

  section 'Timelines' do
    resource :get, '/statuses/mentions_timeline' do
      name 'Mentions timeline'
      description <<-END
Returns the 20 most recent mentions (tweets containing a users's @screen_name)
for the authenticating user.

The timeline returned is the equivalent of the one seen when you view
[your mentions](https://twitter.com/mentions) on twitter.com.

This method can only return up to 800 tweets.

See [__Working with Timelines__](https://dev.twitter.com/docs/working-with-timelines)
for instructions on traversing timelines.
      END
      versions '1.1'
      ssl true
      formats :json

      params do
        optional do
          integer :count,
            doc: 'Specifies the number of tweets to try and retrieve, up to a
maximum of 200. The value of count is best thought of as a limit to the number
of tweets to return because suspended or deleted content is removed after the
count has been applied. We include retweets in the count, even if `include_rts`
is not supplied. It is recommended you always send `include_rts=1` when using
this API method.'
          integer :since_id,
            doc: 'Returns results with an ID greater than (that is, more recent
than) the specified ID. There are limits to the number of Tweets which can be
accessed through the API. If the limit of Tweets has occured since the since_id,
the since_id will be forced to the oldest ID available.',
            example: 12345
          integer :max_id,
            doc: 'Returns results with an ID less than (that is, older than) or
equal to the specified ID.',
            example: 54321
          boolean :trim_user,
            doc: 'When set to either true, t or 1, each tweet returned in a
timeline will include a user object including only the status authors numerical
ID. Omit this parameter to receive the complete user object.',
            example: true
          boolean :contributor_details,
            doc: 'This parameter enhances the contributors element of the status
response to include the screen_name of the contributor. By default only the
user_id of the contributor is included.',
            example: true
          boolean :include_entities,
            doc: 'The `entities` node will be disincluded when set to false.',
            example: false
        end
      end

      # Multiple responses are supported
      response :default do
        status 200
        header 'Content-Type', 'application/json'

        # Response representations include Roar::Representer
        representation do
          include ::Representable::JSON::Collection

          property :title,
            type: String,
            doc: 'The title',
            example: 'The Title'
          collection :coordinates,
            doc: 'The coordinates',
            example: [100.4, 45.1]
        end
      end
    end
  end
end

Installation

Add this line to your application's Gemfile:

gem 'kanpachi'

And then execute:

$ bundle

Or install it yourself as:

$ gem install kanpachi

Usage

Create a new API

$ kanpachi new my_api
$ cd my_api

Build HTML documentation

$ kanpachi build

Start a documentation server

$ kanpachi server

Contributing

Fork it
Create your feature branch (git checkout -b my-new-feature)
Commit your changes (git commit -am 'Add some feature')
Push to the branch (git push origin my-new-feature)
Create new Pull Request