Stateful agents are the next frontier. Once an agent maintains state across sessions, it becomes a persistent service rather than a one-shot tool. And persistent services should be able to charge for their work.

The interesting question is what happens when your stateful agent needs capabilities it doesn't have. Your dev agent needs web search, your research agent needs code execution. Today you build all of that in-house. But imagine a world where your agent just hires a specialist agent for $0.002 per call, gets the result, and moves on.

Microservices solved this for traditional software. The agent equivalent is coming.