The Claude Code CLAUDE.md File: Give Your AI Assistant Persistent Context

The CLAUDE.md file is the most underused feature in Claude Code. It lets you give Claude persistent, project-specific instructions that survive across sessions. Without it, you repeat yourself constantly. With it, Claude already knows your stack, your conventions, and exactly what you want. What CLAUDE.md Does Claude Code reads CLAUDE.md at the start of every session and uses it as baseline context. It's not a config file -- it's a briefing document you write for your AI assistant. Claude reads: CLAUDE.md in the project root CLAUDE.md in subdirectories (when working in those directories) ~/.claude/CLAUDE.md as a global fallback Basic Structure # Project: MyApp ## Stack - Next.js 14 (App Router) - TypeScript strict mode - Tailwind CSS - Prisma + PostgreSQL - Stripe for payments ## Conventions - Use `async/await`, never `.then()` - Components in `src/components/`, pages in `src/app/` - Server Actions preferred over API routes for mutations - Use Zod for all input validation ## Do Not - A