Create XML for Twilio to read

app/controllers/alerts_controller.rb

@@ -17,6 +17,7 @@ class AlertsController < ApplicationController
 
     respond_to do |format|
       format.html # show.html.erb
+      format.xml # show.xml.builder
       format.json { render json: @alert }
     end
   end

app/views/alerts/show.xml.builder

@@ -0,0 +1,4 @@
+xml.instruct!
+xml.Response do
+  xml.Say @alert.class_name + ' is now available.', :voice => 'woman'
+end