Codex Subagent
Launch OpenAI Codex CLI as a subagent (ChatGPT subscription auth, no API key).
Install
npx skills add davidondrej/skills --skill codex-subagent -g -a claude-code -y- Repository
- davidondrej/skills4.2k
- Category
- AI and agents
- Updated
- 3d ago
- License
- MIT
- Context cost
- Lightabout 962 tokens
- Runs scripts
- No, instructions only
What it does
Launch OpenAI Codex CLI as a subagent (ChatGPT subscription auth, no API key). Use when delegating a self-contained coding task to Codex from another agent, parallel implementation work, a second opinion, or an independent verification pass.
Codex CLI as a Subagent
Codex CLI is OpenAI's terminal coding agent. codex exec runs it non-interactively:
it works autonomously in a sandbox, streams progress to stderr, and prints only the
final message to stdout. Auth reuses the user's ChatGPT subscription, never an API key.
When to delegate
- Self-contained coding task with clear success criteria (fix, feature, refactor, review).
- Parallel work: several independent tasks at once (see Parallel runs).
- Second opinion / independent verification of your own changes.
Do NOT delegate tasks that need conversation context you can't fully write into the prompt.
Preflight
codex --version # missing? npm i -g @openai/codex (or: brew install --cask codex)
codex login status # exit 0 + "Logged in using ChatGPT" = ready
Not logged in → stop and tell the user to run codex login (one-time browser OAuth).
Never read, print, or copy credentials (~/.codex/auth.json).
Launch
OUT=$(mktemp /tmp/codex-out.XXXXXX)
codex exec \
--cd /path/to/repo \
--model gpt-5.6-sol \
--config model_reasoning_effort=high \
--sandbox workspace-write \
--output-last-message "$OUT" \
"Full task prompt: goal, constraints, files to touch, definition of done." \
</dev/null
