How to enable CORS with gae-boilerplate?

[yoderjen]

I'm trying to use the boilerplate code to hook up a user authentication/login system for an already existing web app. Since they'll have different domains, I need to enable CORS in the appengine handlers.
According to http://enable-cors.org/server_appengine.html , I can do this with the line
self.response.headers.add_header("Access-Control-Allow-Origin", "*")
in the handlers. But I've tried adding it to the end of the base handler (bp_includes/lib/basehandler.py), which didn't work, and also in the handlers for user registration (bp_includes/handlers.py), which also didn't work.

Where should I add the CORS headers?

[kishore-narendran]

If I am not mistaken it has to be added to every single handler?