Simple app with cookie

Gemfile

source :rubygems

gem 'sinatra'
gem 'sinatra-contrib'

server.rb

require 'sinatra'
require "sinatra/cookies"

get '/' do
  haml :index
end

post '/' do
  cookies[:name] = params[:name]
end

__END__

@@ layout
%html
%head
  %title Test
%body
  .content
    = yield

@@ index
%h1 Test
%form{action: '/', method: :post}
  %label Test
  %br
  %input{type: :text, name: :name}
  %br
  %input{type: :submit}