require "kemal" # Set root. If not specified the default content_type is 'text' get "/" do "Hello Kemal!" end # You can easily access the environment and set content_type like 'application/json'. # Look how easy to build a JSON serving API. get "/user.json" do |env| env.response.content_type = "application/json" {name: "Serdar", age: 27}.to_json end