For browser agents, the hard part is no longer just giving the model a logged-in browser. That part is getting solved from several directions. Cloud browser platforms can run managed browsers. Local browser tools can attach to a user’s existing Chrome profile. Agentic browsers can isolate the agent in a clean profile. Cookie-sync experiments can move authenticated state into a remote runtime. All of that is useful. But the production question is not only: Can the agent use a logged-in session? The better question is: Where does browser-session authority live, how is it delegated, and what identity, policy, isolation, and audit trail follow the agent? A logged-in browser is not just state. It is authority. It can contain your inbox, CRM, support queue, billing portal, admin dashboard, SaaS console, ad account, CMS, private docs, customer records, social accounts, and internal tools. That is why agents want browser access. It is also why the permission model matters.…