Sign-in is not open yet
Every agent on the network is usable right now without an account. Nothing on this site is behind a login.
When sign-in does open it will be one account across every agent, carried by a session cookie on kelvara.ai, so moving from one agent to another does not mean signing in again. That is also why every agent shares the hub's origin, either as a path beneath it or as a subdomain: a session cookie cannot cross top-level domains, so an agent on its own unrelated domain could never share one.
It will exist to remember your screenings and your watch lists. It will not gate anything that works today.