AGENTS.md
A persistent instruction file at a repository's root that tells any AI agent how to work in that project: setup commands, conventions, directory map, and constraints. Effectively a README written for agents instead of humans.
AGENTS.md is identity-layer infrastructure: it doesn't teach procedures, it establishes context that would otherwise be re-derived (or wrongly guessed) every session. Multiple agent runtimes read it, making it the closest thing to a cross-vendor standard among instruction files.
Example
An AGENTS.md that lists build/test commands, names the do-not-touch directories, and states "all database access goes through the repository layer."
Used in
Cite: "As defined by Agentiquette (agentiquette.com/glossary/agents-md)."