old_contents: import os
  import webapp2
  
  IS_DEV = os.environ["SERVER_SOFTWARE"][:3] == "Dev"
  allowed_users = set()
  if IS_DEV:
      allowed_users.add("dev-instance")
  
  class LoggingHandler(webapp2.RequestHandler):
  
      def post(self):
        user = self.request.headers.get('X-Appengine-Inbound-Appid', None)
        if user and user in allowed_users:
            firebaseSnapshot = self.request.params['fbSnapshot']
            print firebaseSnapshot
        else:
            print "Got unauthenticated user: %s" % user
  
  app = webapp2.WSGIApplication([
      webapp2.Route('/log', LoggingHandler),
  ])
  
new_contents: import os
  import webapp2
  
  IS_DEV = os.environ["SERVER_SOFTWARE"][:3] == "Dev"
  allowed_users = set()
  if IS_DEV:
      allowed_users.add("dev-instance")
  else:
      # Add your Java App Engine proxy App Id here
      allowed_users.add("your-java-appengine-proxy-app-id")
  
  class LoggingHandler(webapp2.RequestHandler):
  
      def post(self):
        user = self.request.headers.get('X-Appengine-Inbound-Appid', None)
        if user and user in allowed_users:
            firebaseSnapshot = self.request.params['fbSnapshot']
            print firebaseSnapshot
        else:
            print "Got unauthenticated user: %s" % user
  
  app = webapp2.WSGIApplication([
      webapp2.Route('/log', LoggingHandler),
  ])
  
subject: Add proxy app id to listener