The CLAUDE.md file

Purpose

• Provides Claude Code with persistent memory about your project
• Eliminates need to re-explore codebase at each session start
• Acts as an "onboarding script" for your codebase

How It Works

• Markdown file placed in project root
• Automatically read by Claude Code at session start
• Contents are appended to your prompt
• Can be auto-generated using /slash init command

What to Include

• Tech stack (frameworks, libraries, tools)
• Code style preferences (indentation, naming conventions, export types)
• Project structure (where files/routes go)
• Commands (dev server, tests, lint)
• Best practices (prefer server actions over API routes, etc. )

Memory Hierarchy

• **Project-level Claude. md** (root directory) - shared with team via version control
• **User-level Claude. md** (configuration folder) - personal preferences across all projects

Best Practices

• Start without Claude. md to identify where you need to course-correct
• Keep the file compact with only essential information
• Explicitly ask Claude to save corrections to memory for future sessions
• Reference project documentation using @ symbol with file paths
• Build incrementally as you discover what Claude needs to know

Key Benefit

• Transforms Claude Code from frustrating (constant corrections) to productive (proper context from start)

Takeaways

• **Claude. md provides persistent memory** for your project, automatically read at each session start to eliminate repetitive codebase re-exploration

• Include essential context: tech stack, code style preferences, project structure, commands, and best practices to guide Claude's work from the start

• Two-level memory system: project-level Claude. md (shared via version control) + user-level Claude. md (personal preferences across projects)

• Build incrementally and keep it compact—start without it, identify gaps, then add only critical information; explicitly ask Claude to save corrections for future sessions

• Transforms productivity: proper upfront context eliminates constant corrections and makes Claude Code genuinely useful rather than frustrating