# Ask Codex

> Gets a Codex second opinion or delegates bulky work to a Codex subagent. Use before a significant approach is settled, or instead of reading pages and long output here.

- Skill: `ryoppippi/ask-codex` (Agent Skill)
- Install (CLI): `npx skillmds@latest add ryoppippi/ask-codex`
- Raw SKILL.md: https://api.skillmd.com/api/skills/ryoppippi/ask-codex/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: ryoppippi (https://skillmd.com/u/ryoppippi)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/ryoppippi/ask-codex

---


<!--
Example prompts:
  /ask-codex Review my implementation plan
  /ask-codex Is this the right approach for error handling?
-->

# Ask Codex

This skill is shared by Codex Desktop, Codex CLI, and other agents. Choose the
execution path that matches the current agent:

- **Inside Codex (Desktop or CLI):** delegate to a native subagent. Never run
  `codex exec` from here; that starts a nested Codex process.
- **Outside Codex:** use the Codex CLI path below for an independent agent.

Both paths take a self-contained prompt: the subagent sees none of this
conversation, so whatever it cannot infer has to be in the prompt.

## Native subagent path

Use one native subagent for either job. Ask it to return the requested facts with
citations (`URL` or `file:line`), and ask for verbatim quotes where exact spelling
matters.

For a second opinion, ask for an independent assessment, then compare it with
your own reading and preserve disagreements in the response. For delegated grunt
work, ask for the small conclusion rather than forwarding the whole transcript.

The repository's Codex configuration sets native subagents to `gpt-5.6-luna`
with `max` reasoning and the `fast` service tier. Keep those defaults unless the
user requests another model or effort.

## Codex CLI path

Use this path only outside Codex:

```sh
codex exec "<question>"
```

Leave the model alone — the reasoning effort in Codex's own config is what makes
the answer worth having. Treat the reply as one data point: compare it against your
own reading of the codebase, report both views to the user with the disagreements
intact, and prefer established project patterns where they conflict.

## Delegated grunt work

```sh
codex exec --skip-git-repo-check --ephemeral -m gpt-5.6-luna "<task>"
```

For work whose output is bulky but whose conclusion is small: web search, page
reading, codebase investigation, summarising long output, drafting a commit message
from a diff. A cheap model is the point — the subscription pays for it and only the
answer costs tokens here. `codex exec --help` carries the rest; reach for `-o` to
capture the final message alone, and `--sandbox`/`--add-dir` to widen what it may
touch.

Measured, and not visible in the help output:

- Keep `model_reasoning_effort` at `medium` or above. At `low` it answered a
  "latest release version" search from stale knowledge.
- Never `--disable multi_agent`. Native web search runs through it, so disabling it
  makes a search task hang indefinitely with no tool call.
- Shell commands only reach the network under `--sandbox workspace-write` with
  `-c sandbox_workspace_write.network_access=true`. The native web search needs
  neither.
- `exa` cannot run there at all: no sandbox mode reaches its 1Password key, so run
  exa in this session. `ax` and `tgrab` live in `~/.agents/skills/web-fetch/` —
  prepend that to PATH when the task needs them.

Briefing it:

- Say which facts to return, and demand a citation for each — a URL, or a
  `file:line`.
- Ask for verbatim quotes wherever exact spelling matters: API options, flags,
  version numbers. A digest paraphrases them away.
- The `web-fetch` skill holds the search tool selection; name the choice rather
  than leaving it open.