review-with-codex

name	review-with-codex
description	Spawn codex as an independent external reviewer in a new tmux window. Codex performs a general PR review and publishes findings back via hive messaging. Use standalone for an external second opinion, or alongside /review to run both concurrently.
allowed-tools	Bash(tmux:*),Bash(hive msg:*),Bash(hive session:*),Bash(git:*),Bash(mktemp:*),Bash(chmod:*),Bash(printf:*),Bash(rm:*)
disable-model-invocation	true
argument-hint	[base-branch]

Review with Codex

Spawn codex as an independent external reviewer in a new tmux window. Codex reviews the current branch and publishes its findings back to this session via hive messaging.

Default base branch: main. If an argument is provided, use it instead.

Step 0: Verify Tmux

Check that the session is running inside tmux. If not, fail immediately with a clear error.

if [ -z "$TMUX" ]; then
  echo "Error: review-with-codex requires a tmux session. Not currently in tmux."
  exit 1
fi

Step 1: Gather Context

git branch --show-current          # current branch name
git diff <base-branch>...HEAD --stat  # scope of changes
hive session info --json           # get session ID

Step 2: Generate Review Topic

REVIEW_TOPIC=$(hive msg topic --prefix "review")

Save this value. Codex will publish findings to <REVIEW_TOPIC>.codex. You will subscribe to that topic in Step 4.

Step 3: Spawn Codex in a New Tmux Window

Write a self-contained shell script to a tempfile and execute it in a new tmux window. Using a tempfile avoids quoting problems when embedding a multi-line prompt.

REVIEW_TOPIC=<from-step-2>
BASE_BRANCH=<base-branch>
REPO_PATH=$(pwd)
BRANCH=$(git branch --show-current)

SCRIPT=$(mktemp /tmp/codex-review-XXXXXX.sh)
chmod +x "$SCRIPT"

printf '#!/bin/bash\ncd %q && codex %q\n' "$REPO_PATH" "You are performing an independent code review of branch: $BRANCH

Your workflow:
1. Review all changes against $BASE_BRANCH:
   git diff $BASE_BRANCH...HEAD
   git diff

2. Analyse for issues including but not limited to: logic bugs, error handling, edge cases,
   race conditions, resource leaks, security vulnerabilities, naming problems, design issues,
   and test coverage gaps. You are a general reviewer — be thorough across all dimensions.

3. YOU MUST publish your findings before exiting. Run this exact command:
   hive msg pub --topic $REVIEW_TOPIC.codex \"your detailed findings\"

   This is not optional. The session that dispatched you is blocked waiting for this message.
   Do not summarise to stdout and stop. Do not skip this step." > "$SCRIPT"

tmux new-window -n "review-codex" "$SCRIPT"

This returns immediately. Codex runs asynchronously in the new window.

Step 4: Wait for Codex Findings

Block until codex publishes its findings (up to 1 hour):

hive msg sub --topic <REVIEW_TOPIC>.codex --wait --timeout 1h

The output is codex's full review. Capture it for synthesis.

Step 5: Synthesize and Present

Read the diff directly to verify and contextualise codex's findings:

git diff <base-branch>...HEAD
git diff

Then produce a review report:

• Challenge vague or unsupported findings — demand specific file/line evidence
• Note issues codex caught that you would have missed
• Note issues you can see that codex missed
• Follow the output format in the review skill (Step 5) for structure

---

Integration with /review

When using both skills together, run them so codex and Claude's internal sub-agents execute concurrently. The pattern:

1. Step 2 of review (before dispatching sub-agents): Run Steps 0–3 of this skill to spawn codex in tmux. This is non-blocking — codex starts immediately in the background.

2. Step 3 of review: Dispatch internal sub-agents in parallel as normal. They run concurrently with codex.

3. Step 4 of review: After internal sub-agents complete, run Step 4 of this skill (hive msg sub --wait) to collect codex's findings. By this point codex may already be done, so the wait is often short.

4. Synthesis: Merge all findings — internal sub-agents + codex — into a single report. Add a section identifying which issues were caught only by the external reviewer:

### External Review (Codex)

[Issues caught by codex that internal review missed, or where codex's independent
perspective adds confidence. Note any contradictions with internal findings.]

Include all findings in the unified Critical / Suggestions / Nits ranking.