The Browser Selector Your Agent Memorized
Your computer-use agent had a great run last Tuesday. It logged into the vendor portal, clicked through five nested menus, exported the report, attached it to a ticket, and closed out the task in under two minutes. You saved the trace. You praised the model. You shipped the workflow. And somewhere in that successful trace, the agent committed to memory that the "Export CSV" action lives at div.toolbar > div:nth-child(2) > button.btn-secondary:nth-child(4).
By Friday, the vendor pushed a redesign. The toolbar is now a flex container, the secondary buttons are inside a dropdown, and the "Export" verb has been replaced with a download icon. Your agent's memorized path resolves to nothing — or worse, it resolves to a button that now says "Delete Account." The agent has no way to tell the difference. Both are buttons. Both are at the same selector. The trace from Tuesday is no longer a memory; it is a landmine.
