GitHub Copilot app for Beginners explains how to teach Copilot about your codebase

GitHub's latest GitHub Copilot app for Beginners guide describes four ways to tailor Copilot to a project: custom instructions, agent skills, custom agents, and MCP servers.

Repository-wide guidance goes in .github/copilot-instructions.md, while path-specific rules use files in .github/instructions with an applyTo field.

The guide says these customizations work together, so Copilot can follow project conventions, run repeatable procedures, and connect to external tools without users repeating the same setup each time.