Project Rules: Briefing AI on Your Project
Project rules live in a file Claude Code reads at the start of every session. Write your conventions and decisions there, and you stop repeating them in each new conversation.
The problem: AI doesn't know your project
Every time you start a new Claude Code session, you're working with an AI that knows nothing about your project. Your file structure, your naming conventions, the libraries you chose, the architectural decisions you made three months ago: it has to guess or ask.
When you're the only developer on a project, you carry all of that in your head. You know why the pages are organized the way they are. You know every form checks its fields for errors the same way. Claude Code doesn't know any of it until you tell it.
That's what a file called CLAUDE.md is for.