When I talk to people about agents interacting with websites, the conversation almost always starts with perception: how does an agent “see” a page? Is it screenshots or the DOM or the accessibility tree? In my previous InfoWorld article, “Accessibility is the first-class interface for AI agents”, I argued that the accessibility tree is becoming an increasingly important interface between websites and AI agents. From there the conversation shifts to actuation, and to ways of making it less brittle, which let a site expose its own actions as callable tools instead of forcing an agent to guess at buttons and forms.

That conversation matters. But it leaves out a more consequential architectural question, one that determines who is accountable when an agent gets something wrong: where does the agent live?

There are three plausible homes for an agent that interacts with your business: on-site, in-browser and off-browser. Each one trades control for reach differently. Right now, much of the industry’s attention is focused on the two homes furthest from the business: browser extensions that co-browse alongside a user, and autonomous agents running in the cloud that talk to your APIs or drive a browser on their own.