From The Contingency Market

A session provides authenticated access by an application to the Contingency Market web service.

One creates a new session using the method NewSession().

One can then either register and authenticate a new agent in one go using RegisterSession() or simply authenticate a previously registered agent/session using AuthenticateSession().

The session automatically expires if it hasn't been used to make an API call in 30 minutes. You can call UseSession() to maintain it otherwise, e.g. if the session is otherwise about to expire.

One gracefully terminates a session when one has finished using it with TerminateSession().