Copilot coding agent now supports AGENTS.md custom instructions

With custom instructions, you can guide Copilot on how to understand your project as well as how to build, test, and validate its changes.

Copilot coding agent, our autonomous background agent, now supports AGENTS.md custom instructions.

You can create a single AGENTS.md file in the root of your repository. You can also create nested AGENTS.md files which apply to specific parts of your project.

Alongside AGENTS.md, the agent continues to support GitHub’s .github/copilot-instructions.md and .github/instructions/**.instructions.md formats, plus CLAUDE.md and GEMINI.md files.

To learn more about custom instructions and other best practices for Copilot coding agent, head to our documentation.