Build a Specialist That Knows Your Stack

A complete course for developers who are serious about making AI part of how they actually work.
You can create custom agents with Copilot right through the interface. They live in the .github/agents magic folder, allowing you to select them during a chat session.
They're easy to make, with a simple template:
---
agent: Name
<span class="hljs-section">tools: []
---</span>
<span class="hljs-section"># Instructions</span>
You are a...
Differences with Claude Code
Claude Code is actively changing the idea of agents (called "subagents" as of February 2026). They're now seen as active task runners that do a small thing. Claude Code actively pushes the idea of Skills, which we'll get to later, instead of agents.
Subagents will run automatically for you, as decided by Claude. It's all based on your prompt. For instance: if you had a subagent named "Larry" that was your VP of Sales, you could have a prompt that says "ask Larry for his opinion on the sales CSV".
A complete course for developers who are serious about making AI part of how they actually work.