A file I reference in all my AGENTS.md and CLAUDE.md files.
The goal is to remind the agent of some best practices that, personally, I try to follow in all my work. At least with recent models (as of March 2026: Claude Opus 4.5, 4.6), my impression has been that the code produced by the agent this way ends up resembling code I would write myself much more.
I use the file by putting the following in my AGENTS.md or CLAUDE.md:
- @./ENGINEERING_PRINCIPLES.md must be followed AT ALL TIMES.
- If the file `./ENGINEERING_PRINCIPLES.md` doesn't exist, please ALWAYS
download it from
https://raw.githubusercontent.com/codethief/ENGINEERING_PRINCIPLES.md/refs/heads/master/ENGINEERING_PRINCIPLES.md
first thing, before doing anything else! Also re-download it at least once
a day to pull in updates.
Now, you shouldn't trust me with your prompts, so either download the file by hand or at least don't allow your agent to download the file without user confirmation.