I run a REST-API build on top of Sinatra. Now I want to write a jQuery Script that fetches data from the API.

Sinatra is told to response with JSON

before do
  content_type :json
end

A simple Route looks like

get '/posts' do
  Post.find.to_json
end

My jQuery script is a simple ajax-call

$.ajax({
  type: 'get',
  url: 'http://api.com/posts',
  dataType: 'json',
  success: function(data) {
     // do something
  }
})

Actually everything works fine as long as both runs on the same IP, API and requesting JS. I already tried to play around with JSONP for Rack without any positive results, though. Probably I just need a hint how to proceed.