Andrej Karpathy, a co-founder of OpenAI, put the biggest problem with AI coding in one line: the models make wrong assumptions on your behalf and just run along with them without checking. Someone turned his notes into a single CLAUDE.md file for Claude Code, and it's past 221,000 stars.
Here's what the four rules do, how to add the file in two minutes, and when to tell Claude to skip them.
The four rules
- Think before coding: Claude states its assumptions, lays out the options and asks you when something is unclear.
- Simplicity first: the least code that solves the problem, nothing extra 'just in case'.
- Surgical changes: Claude only touches what you asked for and leaves working parts alone (it points out other problems instead of rewriting them).
- Goal-driven: your request becomes checks Claude can run, like tests, and it keeps going until they pass.
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Get the full setup steps + the copy-paste setup prompt
The rest of this guide (3 more sections, 1 copy-paste prompt) opens right here. The setup prompt, one paste into Claude that sets it all up, comes by email only. Use your real address.
Unlocks: Add it in two minutes · The catch · Sources
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