Subagents are one of Claude Code's most powerful features for scaling your work beyond a single conversation. In this lesson, Brian breaks down what subagents actually are — separate context windows that Claude delegates focused work to — and why that matters for keeping your main session clean and efficient. He walks through the three built-in subagents (General-Purpose, Explore, and Plan), explains how Claude automatically chooses when to delegate, and demonstrates the full flow by building a new Tasks feature on a demo project management app.
From there, Brian covers custom subagents — how to create your own specialized agents using the /agents command, where they live in your project, and how they relate to Skills. He shows the agent builder workflow live and explains why committing custom subagents to your repo is part of a solid agent alignment strategy.
- What subagents are and how the delegation chain works
- Why fresh context windows are the key benefit
- The three built-in subagents: General-Purpose (Sonnet), Explore (Haiku), and Plan (Sonnet)
- How Claude automatically delegates without being told
- Live demo: building a Tasks feature using a subagent
- Peeking under the hood with Ctrl+O to see subagent prompts and token usage
- Custom subagents: where they live, how to create them with
/agents - How subagents relate to Skills