# Second Opinion

> Use when you want an independent, fresh-perspective review from a different model (OpenAI Codex) — either on a code change (diff/branch/commit) or on a plan/spec/design doc before it's built. A read-only advisory second opinion that never edits. Triggered by /second-opinion, or when the user asks for "a second opinion", "fresh eyes", "a Codex review", or "review this plan".

- Skill: `aetheris-solutions-llc/second-opinion` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add aetheris-solutions-llc/second-opinion`
- Raw SKILL.md: https://api.skillmd.com/api/skills/aetheris-solutions-llc/second-opinion/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: AI & ML
- Author: Aetheris-Solutions-LLC (https://skillmd.com/u/aetheris-solutions-llc)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/aetheris-solutions-llc/second-opinion

---


# Second Opinion

Spawn an independent **Codex CLI** review of the current change for a fresh
perspective from a *different model*. Codex advises only — it runs in a
read-only sandbox and **cannot edit code**. Complements your own review or
`/aetheris-review`; it does not replace them.

## When to use

- You want a fresh pair of eyes on a diff before merging — from a model
  other than the one that wrote the code.
- The user asks for "a second opinion", "fresh eyes", or "what would Codex
  say" about a change.
- Before a risky merge, when independent confirmation is worth a pass.

**Not for:** applying fixes (advisory only — acting on a finding is a
separate, explicit step the user must request), or posting PR comments (use
`/aetheris-review`).

## How to run

Run the bundled `review.sh` from this skill's own directory. It selects
scope, invokes Codex read-only, and saves the report **outside** the repo
(`~/.codex-reviews/<repo>/`) so the working tree stays pristine:

```bash
bash <this-skill-dir>/review.sh [scope-flag]
```

Two modes — **code review** (a diff) and **plan review** (a doc):

| Flag | Reviews |
|---|---|
| _(none)_ | code: smart default (feature branch → vs default branch; else working tree) |
| `--uncommitted` | code: staged + unstaged + untracked |
| `--base <branch>` | code: diff vs a base branch (PR-equivalent) |
| `--commit <sha>` | code: a single commit's changes |
| `--plan <file>` | **a plan / spec / design doc**, before it's built — Codex critiques soundness, dependency ordering, risk/cost/reversibility, and gaps, grounding against the code the doc references |

The helper streams Codex's review to stdout and ends with a `REPORT_PATH:`
line. Code mode uses `codex exec review` on the chosen scope, running Codex's
built-in review harness; plan mode uses `codex exec` with a baked-in
plan-critique prompt. Both run from the repo so Codex can cross-reference code.

**The report is the verdict, not the transcript.** Both modes capture Codex's
final message via `--output-last-message` and write it to the report; the
streamed run lands beside it in `<same-name>.transcript.log`. Read the report;
open the transcript only when the report says Codex never reached a verdict.

`codex exec review` does accept custom review instructions, but **not alongside
a scope flag** — `--uncommitted` / `--base` / `--commit` and a custom prompt are
mutually exclusive, so scope-selected reviews use the built-in harness.

## Presenting the result — faithful passthrough

Codex is the advisor. **Do not re-rank, soften, re-judge, or restate its
findings as your own analysis.**

1. Surface Codex's verdict under a clear frame, e.g. *"Codex's independent
   review (read-only):"* and quote its findings as written.
2. Give the saved report path.
3. Close with one line: *"Want me to act on any of these?"*

Acting on a finding (editing code) is a separate step — only after the user
asks. This skill itself never edits code.

## Guarantees

- **No changes:** `--sandbox read-only` makes writes impossible. Confirm with
  `git status` that the repo is untouched after a run.
- **Out-of-repo report:** written to `~/.codex-reviews/<repo>/`, never inside
  the repo, alongside a `.transcript.log` of the full run.
- **Focused & lean:** runs Codex with `--disable hooks` so the host machine's
  skill/plugin `session_start` hooks aren't injected into the review (without
  it, Codex rabbit-holes reading skill files — ~100x more output). Per-run
  only; your global Codex config is untouched.

## Troubleshooting

- *codex CLI not found* → install (`npm i -g @openai/codex`) or run the
  marketplace's `install-codex.sh`.
- *codex may not be logged in* → `codex login`.
- *no changes to review* → no diff for the chosen scope; pick a different
  scope flag.