CLAUDE.md: The Config File That Makes Claude Code Remember Your Rules

Every developer I've shown this to has the same reaction: "Why didn't I know about this sooner?" Claude Code s a project-level configuration file called CLAUDE.md. Drop it in your repo root and Claude reads it at the start of every session - before it writes a single line of code or answers a single question. It's the closest thing to onboarding a new developer to your project in under 30 seconds. Here's what that means in practice.