Glossary
What is a Codex skill?
A Codex skill is an Agent Skills folder with a SKILL.md file that OpenAI Codex loads from .agents/skills. The file teaches Codex one workflow: instructions, optional scripts, and references. Codex picks it when the task matches the description, or you invoke it with a dollar-name. OpenAI documents the load path and $skill-installer; Skillselion ranks the same SKILL.md files by real installs.