Codex CLI Sub-Agent

A skill for invoking the OpenAI Codex CLI as a sub-agent in non-interactive mode (codex exec).

Prerequisites

• Installed via npm install -g @openai/codex (verified against codex-cli 0.139.0)
• Authenticated — either codex login (ChatGPT sign-in) or an OPENAI_API_KEY environment variable

How to run

codex exec runs Codex non-interactively via the Bash tool. Choose the sandbox by what the task needs — there is no --full-auto/--quiet/--ephemeral flag (those were removed; exec is already headless and stateless).

# Read-only analysis / review (safe default — Codex cannot modify files)
codex exec -s read-only "<task>"