require 'sass' configure do Tilt.register 'scss', Tilt::SassTemplate set :scss, :syntax => :scss end get '/stylesheets/:file.css' do |file| content_type 'text/css', :charset => 'utf-8' # no #scss method is defined (and #sass only looks for .sass files) # we must call render ourself: render :scss, file.to_sym, :layout => false, :views => './public/stylesheets' end