---

name: codex-review description: Have OpenAI Codex review the current branch with documentation research. Use for second-opinion code reviews or when you want cross-AI verification. argument-hint: "[focus] [--upstream FILE] [--research TOPICS] [--base BRANCH] [--model MODEL]" allowed-tools: Bash, Read, Glob, Grep

Codex Review

Invoke OpenAI's Codex CLI to review the current branch, with instructions to research relevant documentation before reviewing.

When to Use

• You want a second opinion on your implementation
• You want cross-verification between different AI models
• The implementation uses tools/libraries where current docs would help
• You've completed a feature and want thorough review before merging
• Can be invoked by other workflow skills for automated cross-model review

Prerequisites

• Codex CLI installed (codex --version works)
• Valid OpenAI authentication (codex login completed)
• On a feature branch with commits to review

Arguments

Argument	Example	Description
focus	security	Focus review on specific area
--upstream FILE	--upstream PRODUCT_SPEC.md	Check that code preserves requirements from upstream doc
--research TOPICS	--research "Supabase, NextAuth"	Explicit technologies for Codex to research
--base BRANCH	--base develop	Compare against different base branch
--model MODEL	--model gpt-5.2-codex	Use specific Codex model

Workflow

Copy this checklist and track progress:

Codex Review Progress:
- [ ] Step 1: Verify Codex CLI available
- [ ] Step 2: Gather branch context
- [ ] Step 3: Generate review prompt
- [ ] Step 4: Invoke Codex
- [ ] Step 5: Present results

Step 1: Verify Codex CLI

Check if Running Inside Codex

# Codex sets CODEX_SANDBOX when running
if [ -n "$CODEX_SANDBOX" ]; then
  echo "RUNNING_IN_CODEX"
fi

If running inside Codex CLI:

CODEX REVIEW: SKIPPED
=====================
Reason: Already running inside Codex CLI.

Cross-model verification requires a different model.
Continuing without cross-model verification.

Return early. Do NOT block the parent workflow.

Check Codex CLI Installed

codex --version

If not installed:

Codex CLI is not installed or not in PATH.

Install: https://github.com/openai/codex
Then run: codex login

Check Authentication

codex login status

If not authenticated:

Codex authentication failed. Run:
  codex login

If ANY pre-flight check fails: Report the specific failure and STOP. Do NOT attempt alternative commands or workarounds. Return status: skipped.

Read Configuration

Read .claude/settings.local.json for settings:

# Read config
CODE_MODEL=$(jq -r '.codexReview.codeModel // "gpt-5.3-codex"' .claude/settings.local.json 2>/dev/null || echo "gpt-5.3-codex")
TIMEOUT_MINS=$(jq -r '.codexReview.reviewTimeoutMinutes // 20' .claude/settings.local.json 2>/dev/null || echo "20")

If codexReview.enabled is explicitly false, skip with message.

Select Model

Priority order: --model flag > config > default (gpt-5.3-codex)

# 1. Explicit --model flag always wins
if [ -n "$EXPLICIT_MODEL" ]; then
  CODEX_MODEL="$EXPLICIT_MODEL"
# 2. Use configured code model
else
  CODEX_MODEL="$CODE_MODEL"
fi

Note: For reviewing non-code documents (specs, plans), use /codex-consult instead.

Step 2: Gather Branch Context

Collect information about the current branch:

# Current branch name
git branch --show-current

# Commits on this branch (vs main or specified base)
BASE_BRANCH="${BASE:-main}"
git log --oneline $BASE_BRANCH..HEAD 2>/dev/null || git log --oneline -10

# Changed files summary
git diff $BASE_BRANCH...HEAD --stat 2>/dev/null || git diff HEAD~5 --stat

# Get the merge base
git merge-base $BASE_BRANCH HEAD 2>/dev/null

Auto-detect research topics from changed files if --research not provided:

• Check package.json for dependencies
• Look at import statements in changed files
• Identify frameworks (Next.js, React, etc.)

Step 3: Generate Review Prompt

See PROMPT_TEMPLATE.md for the full prompt structure.

Key sections:

1. Pre-Review Research — Technologies Codex should research
2. Review Context — Branch, commits, changed files
3. Upstream Context (if --upstream provided) — Requirements to preserve
4. Review Instructions — What to check, output format

Step 4: Invoke Codex

See CODEX_INVOCATION.md for detailed command building.

IMPORTANT — Execution Rules:

• Execute synchronously. NEVER use run_in_background for Codex invocations.
• If this command fails, report the exit code and return status: error. Do NOT retry with different flags or subcommands.
• Use the Bash tool's timeout parameter set to TIMEOUT_MINS * 60 * 1000 (ms) instead of the shell timeout command or run_in_background.

Safety Guard (prevent accidental commits)

Before invoking Codex, protect the working tree:

# Record current HEAD so we can detect if Codex makes commits
HEAD_BEFORE=$(git rev-parse HEAD)

Note: Do NOT stash uncommitted changes — stash/pop triggers file-system events that confuse IDE watchers, hot-reload, and other processes. The HEAD check alone is sufficient.

Invoke Codex

See CODEX_INVOCATION.md for the full command, effort handling, and safety checks. The invocation file is the single source of truth — do not duplicate the command here.

Flags explained:

• --sandbox danger-full-access: Enables network access for documentation research
• -c 'approval_policy="never"': Non-interactive execution
• -c 'features.search=true': Enable web search for documentation research
• -o $OUTPUT_FILE: Write final response to file for reliable parsing
• -: Read prompt from stdin

Important: Do NOT use 2>&1 — Codex streams progress to stderr and final output to stdout. Merging them corrupts the parseable response.

Step 5: Present Results

Parse and present the Codex output. See EVALUATION_PRACTICES.md for severity classification.

Output Format (User-Facing)

CODEX REVIEW COMPLETE
=====================
Branch: feature/add-auth
Reviewed by: Codex ({model})
Status: PASS WITH NOTES

Critical Issues: None

Recommendations:
1. [src/auth/handler.ts:45] Consider adding rate limiting
   → Suggestion: Use express-rate-limit middleware

2. [src/auth/session.ts:12] Session expiry not explicitly configured
   → Suggestion: Add explicit maxAge to session config

Positive Findings:
- Good separation of concerns in auth module
- Proper error handling for OAuth failures

{If --upstream provided}
Context Preservation: ✓ All 5 items from PRODUCT_SPEC.md preserved
{/If}

Output Format (Programmatic — when invoked by another skill)

When invoked by another skill, return structured data:

{
  "status": "pass | pass_with_notes | needs_attention | error | skipped",
  "critical_issues": [],
  "recommendations": [],
  "positive_findings": [],
  "context_preservation": {
    "checked": true,
    "all_preserved": true,
    "missing_items": []
  }
}

Error Handling

Failure	Action
Codex CLI not found	Report and stop
Authentication failed	Suggest codex login
No commits on branch	Report nothing to review
Codex times out	Return partial output if available
Output is malformed	Attempt best-effort parsing: extract any text between known markers (e.g., "Critical Issues:", "Recommendations:"). If no structure found, return the raw output as a single recommendation with status pass_with_notes and note "Codex output could not be parsed — raw response included"

Configuration

Read from .claude/settings.local.json:

{
  "codexReview": {
    "enabled": true,
    "codeModel": "gpt-5.3-codex",
    "reviewTimeoutMinutes": 20
  }
}

Setting	Default	Description
enabled	true	Set to false to disable Codex review
codeModel	"gpt-5.3-codex"	Model for code review tasks
reviewTimeoutMinutes	20	Max time for review invocations

For document consultation (specs, plans), see /codex-consult which uses codexConsult config.

For CI/headless environments: Set CODEX_API_KEY environment variable for authentication without interactive login.

Examples

Basic review:

/codex-review

Focus on security:

/codex-review security

Verify against upstream spec:

/codex-review --upstream PRODUCT_SPEC.md

Explicit research topics:

/codex-review --research "Supabase Auth, Next.js App Router"

Different base branch and model:

/codex-review --base develop --model gpt-5.2-codex

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REMINDER: NEVER use run_in_background for Codex invocations. NEVER use 2>&1 — it corrupts parseable output.