I set up one file called CLAUDE.md and it quietly fixed most of the things that used to drive me crazy about Claude.
A single CLAUDE.md file recently hit the top of GitHub Trending with 82,000 stars and 7,800 forks. Most people who use Claude have never set one up, and the few who have aren't sure what to put in it. That gap is costing them hours every week.
Here's the problem it solves. Every time you open a new Claude session, it starts with a blank memory. It doesn't know your name, your work, your preferences or how you like things done. So you burn the first few minutes re-explaining everything, or you skip it and get back something that doesn't fit how you work. CLAUDE.md fixes that once and for good.
This Is Not Just a Developer Tool
CLAUDE.md is an instruction file that Claude reads on its own at the start of every session, and it helps anyone who uses Claude regularly.
Writers use it to lock in their voice so Claude never sounds like someone else.