Codex CLI

Codex CLI is OpenAI's terminal-based coding agent. It reads skills from the .agents/skills/ directory.

Skill Paths

Scope	Path
User-level	~/.agents/skills/<name>/SKILL.md
Project-level	.agents/skills/<name>/SKILL.md

The project-level path is shared with cursor, gemini-cli, and github-copilot. A skill installed there is visible to every agent that reads from .agents/skills/ — see Platform Adapters › Shared project directory.

TIP

The user-level path stays at ~/.agents/skills/ for compatibility with skern's original layout. Detection covers both ~/.codex/ and ~/.agents/.

Install a Skill

# User-level (default scope is user)
skern skill install code-review --platform codex-cli

# Project-level
skern skill install code-review --platform codex-cli --scope project

Uninstall a Skill

skern skill uninstall code-review --platform codex-cli

Detection

Skern detects Codex CLI by the presence of ~/.codex/ (preferred) or ~/.agents/.

How Skills Work in Codex CLI

Codex CLI reads SKILL.md files from its skills directories at startup. The skill's instructions are incorporated into the agent's context, making the capabilities available during the coding session.