Over time, AGENTS.md has become the common open standard for project-wide and system-wide instructions, basically anything that provides non-specific information. There's other competing standards, like CLAUDE.md and GEMINI.md.
AGENTS.md is made to be machine-readable, keeping README.md as human-readable. It exists at the root of the repository and should cover things like the project overview, code style guidelines, build/test commands, etc.
As always, consider [[20260318091849-ai-context-tokens]]. This file is loaded on every request, so keep it lightweight. As a rule of thumb, it should only contain guidance that is relevant to every single task in the repository. For additional information, link to it from AGENTS.md, using the file as a table of contents.
Be careful when referencing files. Stale documentation is actively harmful for context. Instead of referencing an exact file path which may change, describe capabilities and provide hints on where things might be.
https://agents.md/ https://www.aihero.dev/a-complete-guide-to-agents-md
[[20260306121823-ai-instructions]]