Sessions and agents in GitHub Copilot

Recently, I switched from the CLI to the GitHub Copilot desktop app, and some things felt different from how I had been using the CLI. For a complex task or feature, I kept seeing the main session open child sessions to work on different repositories in parallel. I could go straight into a child session and talk to its agent—steer it—without going through the agent in the main session. That was new to me.

The session I can enter is a separate conversation with its own agent, not the same thing as a task subagent that takes an assignment and returns a result.

Then I found that Claude Code’s official documentation also supports subagents spawning subagents, within depth and permission limits. So I did some research. Below are the slides I used for a quick demo with teammates.