Charles Stross' Accelerando <https://en.wikipedia.org/wiki/Accelerando>
Had AI agents running businesses for the principal character Manfred Macx over twenty years ago.
The first part of the book sounded pretty convincing then although I thought it would take a long time to happen. It sounds even more convincing now and much closer.
For a while I named by smartphone "Exocortex" as a tongue-in-cheek recognition of the cognition I offloaded to it...
It's not so funny anymore.