What Is CLAUDE.md? A Practical Guide to Configuring Claude Code

If you use Claude Code, there is one file that quietly shapes every session: CLAUDE.md. Most developers either do not have one or have one that works against them. Here is what it actually is, in plain terms. The file Claude reads every session CLAUDE.md is a markdown file that Claude Code reads at the start of every conversation. Think of it as your project's constitution — the source of truth for how your specific repository works. Because Claude reads it every time, you stop re-ex...