What Goes In Your AGENTS.md

Outgrowing the Vibe Code · Jul 15, 2026 · 10m

Every major coding agent automatically reads one file before it looks at a single line of your code — Claude Code reads CLAUDE.md, Codex reads AGENTS.md, Cursor reads .cursorrules. It's the one piece of context you're guaranteed the agent has every session, which means every line in it competes for space the agent needs to read your actual code. Ada and Boris break down the six things that actually belong in that file: build and test commands (the highest-impact section, because it lets the agent verify its own work instead of guessing), project structure as a mental model rather than a file…