Codex Plan Critique
A coding agent skill that invokes Codex CLI as a peer reviewer during planning phases. Get architectural critique on your implementation plans before committing to them.
Works with Claude Code and Codex (or any coding agent that supports skills).
What It Does
When you're planning an implementation, this skill runs Codex in your project directory to review the plan with full visibility into your codebase. Codex acts as a senior architect and evaluates:
- Architecture - Patterns, structure, separation of concerns
- Edge Cases - Security, error handling, missed scenarios
- Simplicity - Is anything overengineered? Are there simpler alternatives?
- File Locations - Do referenced files exist? Are there better locations?
It returns a structured critique with a verdict (APPROVE or CONCERNS), strengths, and actionable suggestions.
Install
As a plugin (recommended)
In Claude Code:
claude plugin marketplace add adrianleb/codex-plan-critique-skill
claude plugin install codex-plan-critique
Manual install
git clone https://github.com/adrianleb/codex-plan-critique-skill.git
# Copy into your global skills (available in all projects)
cp -r codex-plan-critique-skill/skills/codex-plan-critique ~/.claude/skills/
# Or copy into a specific project (available only in that project)
cp -r codex-plan-critique-skill/skills/codex-plan-critique your-project/.claude/skills/
Usage
The skill triggers automatically during planning phases. You can also invoke it explicitly:
> /codex-plan-critique
> critique this plan
> get a peer review
How It Works
- Your agent writes the current plan to a temp file
- The critique script runs Codex in your project directory
- Codex reviews the plan with access to your actual codebase
- The critique is displayed and incorporated into the final plan
Output Format
★ Codex Peer Review ─────────────────────────
## Verdict: APPROVE
## Strengths
- Clean separation between API and data layers
- Good use of existing middleware patterns
## Concerns
- Missing error handling for the webhook endpoint
- Consider using the existing EventBus instead of a new pub/sub
──────────────────────────────────────────────
If Codex is unavailable, the skill gracefully skips the review and continues without blocking.
Project Structure
.claude-plugin/
plugin.json # Plugin manifest
skills/
codex-plan-critique/
SKILL.md # Skill definition
scripts/
codex-critique.sh # Codex invocation script
Requirements
- Codex CLI installed and authenticated
OPENAI_API_KEY environment variable or codex login
Contributing
Ideas for improvement:
- Support for other review agents beyond Codex
- Configurable review criteria and depth
- Caching to avoid re-reviewing unchanged plans
- Integration with CI for automated plan review
PRs and ideas welcome. Open an issue to discuss before large changes.
License
MIT
adrianleb