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 --versionworks) - Valid OpenAI authentication (
codex logincompleted) - 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 $BASE_BRANCH HEAD 2>/dev/null
Auto-detect research topics from changed files if --research not provided:
- Check
package.jsonfor dependencies - Look at import statements in changed files
- Identify frameworks (Next.js, React, etc.)
Step 3: Generate Review Prompt
See PROMPT_TEMPLATE.md for the full prompt structure.
Key sections:
- Pre-Review Research — Technologies Codex should research
- Review Context — Branch, commits, changed files
- Upstream Context (if
--upstreamprovided) — Requirements to preserve - Review Instructions — What to check, output format
Step 4: Invoke Codex
See CODEX_INVOCATION.md for detailed command building.
IMPORTANT — Execution Rules:
- Execute synchronously. NEVER use
run_in_backgroundfor Codex invocations. - If this command fails, report the exit code and return
status: error. Do NOT retry with different flags or subcommands. - Use the Bash tool's
timeoutparameter set toTIMEOUT_MINS * 60 * 1000(ms) instead of the shelltimeoutcommand orrun_in_background.
Safety Guard (prevent accidental commits)
Before invoking Codex, protect the working tree:
# Record current HEAD so we can detect if Codex makes commits
HEAD_BEFORE=$(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
REMINDER: NEVER use run_in_background for Codex invocations. NEVER use 2>&1 — it corrupts parseable output.