Comment by EMM_386

> in some md file

1a directly from Anthropic on agentic coding and Claude Code best practices.

"Create CLAUDE.md files"

https://www.anthropic.com/engineering/claude-code-best-pract...

It works great. You can put anything you want in there. Coding style, architecture guidelines, project explanation.

Anything the agent needs to know to work properly with your code base. Similar to an onboarding document.

Tools (Claude Code CLI, extensions) will pick them up hierarchically too if you want to get more specific about one subdirectory in your project.

AGENTS.md is similar for other AI agents (OpenAI Codex is one). It doesn't even have to be those - you can just @ the filename at the start of the chat and that information goes in the context.

The naming scheme just allows for it to be automatic.