GenAI Field Guide

Agents and beyond

Subagents and sessions

A subagent is a fresh model call with its own empty context, given a narrow task by a parent agent. It returns a summary, not its transcript. A session is one running transcript.

≈2 min
Parent conversation Delegates a narrow task Child conversation Fresh context · narrow task ·summary back Check the reported result A confident summary can hide a failure
The parent knows only what the child reported. There is no telepathy between them.

Sessions, hand-offs, and what survives

You want to… Do this
Keep a fact safe across a long session Write it to a file or project. The transcript compacts; files don't.
Resume tomorrow Resume the session if the tool supports it, and expect the early turns to be summarized. Re-supply anything critical.
Try two approaches Fork the session where the tool supports it, so each attempt starts from the same history.
Hand off to another person or agent Hand off the file, not the chat. A written state beats a remembered one.