Seems like most people are using the analogy of agent as an animal, able to migrate from computer to computer and "roam the net".  It may be some time before a significantly useful agent is capable of doing that.

A more realistic short-term goal is to make one more like a plant, and maybe not such a fantastic one.

It may need human assistance to be installed in some vendor's hosting arrangement.

Once there, hopefully it can survive, and become autonomous.  Reproduction, like seed broadcasting in plants, would require help from an outside agent, possibly human, who would propagate a copy of the agent to a new environment.