CLAUDE.md

A plain-text file that gives Claude persistent instructions at the start of every session in Claude Code. You write it; Claude reads it automatically. CLAUDE.md files can exist at different levels: project-level (shared with your team via version control), personal (applies to all your projects), project-local (just you, not shared), and organization-managed (deployed by IT to all users). Think of it as the briefing document you'd write for a contractor who starts fresh every day. See also: Auto Memory, Skills.