Each user is appointed his/her own agent instance. When the user creates his account, an Agent is created and is stored in serialized form as a property of the user in the triple store. Everytime the user makes a request, the agent is loaded from the triple store and unserialized. I thought of storing the agent in a session variable, but when I found out that the session object is unserialized each request I figured this would not form an advantage, especially because I would still have to store the agent in the triple store myself at the end of the session.

This means that I should not make the agent's state too heavy, because it needs to be rebuilt every request.