title: Storing "Session Variables" in Facebook Messenger
body: <p>I want to save information about a user (ex postal code, location...) for the duration of the 'session', how could I go about this? From my understanding each time a message is sent, the webhook is hit again, so variables aren't saved on the webhook side. Furthermore, meta data is only available sending from bot to client. I'm looking for a way for the client to influence the flow without the use of a database. </p>
  
  <p>Is this possible given the current iteration of the facebook messenger platform?</p>