Critically review implementation plans before execution. Use when validating plans, checking standards compliance, or before running implement-plan.
Critically review implementation plans using Codex CLI with high-reasoning capabilities.
Validate implementation plans to ensure they:
implement-plancreate-planThis skill MUST delegate to Codex CLI. The review cannot be performed by the agent creating the plan - an independent third-party model must validate the work.
Why third-party review matters:
If Codex CLI is not available, inform the user and do not proceed with a self-review.
Use the dedicated codex review command for non-interactive review:
# Pass instructions directly as argument
codex review "Review the plan at docs/plans/0042_feature.md for feasibility and completeness"
# Or read instructions from stdin
cat <<'PROMPT' | codex review -
Review the implementation plan at docs/plans/0042_feature.md
Check for: logical coherence, completeness, standards compliance, feasibility.
Provide PASS/FAIL/NEEDS_REVISION verdict.
PROMPT
Key options:
[PROMPT] argument for simple instructions- to read longer instructions from stdin'PROMPT' (quoted) to prevent variable expansionNote: When reviewing plans (not code changes), use the [PROMPT] form since --base, --commit, and --uncommitted flags are for reviewing code diffs.
If plan path provided: Use the specified path directly.
If no path provided:
docs/plans/ for the most recently modified planBefore invoking Codex, gather relevant context:
CLAUDE.md or AGENTS.mdcontent/standards/ based on tech stackMANDATORY: You must invoke Codex CLI. Do not perform the review yourself.
First, verify Codex is available:
which codex || echo "Codex CLI not installed"
If not available, stop and inform the user they need to install Codex CLI.
Build the review prompt and invoke Codex using stdin:
cat <<'PROMPT' | codex review -
Review the implementation plan at {plan-path}
Check against these criteria:
1. Logical Coherence - Do phases flow logically? Dependencies correct?
2. Completeness - All steps included? Testing strategy adequate?
3. Standards Compliance - Follows project conventions?
4. Feasibility - File paths correct? Referenced files exist?
5. Risk Assessment - What could go wrong?
Provide:
1. PASS/FAIL/NEEDS_REVISION verdict
2. Summary of findings
3. Specific issues with severity (HIGH/MEDIUM/LOW)
4. Recommended changes
PROMPT
Important: Let Codex read the plan file itself - it has filesystem access. This allows it to:
Do NOT paste plan content into the prompt - this wastes tokens and prevents Codex from exploring the codebase.
After Codex returns, format the results:
## Plan Review: {plan-name}
**Verdict:** PASS | FAIL | NEEDS_REVISION
**Reviewed by:** Codex (gpt-5.1-codex-max)
**Date:** {timestamp}
### Summary
{Brief overview of findings}
### Issues Found
| Severity | Issue | Location | Recommendation |
|----------|-------|----------|----------------|
| HIGH | {issue} | {section} | {fix} |
| MEDIUM | {issue} | {section} | {fix} |
| LOW | {issue} | {section} | {fix} |
### Standards Compliance
- [x] Follows project conventions
- [ ] Testing strategy adequate
- [x] Architecture aligned
### Questions for Author
1. {clarifying question}
### Recommendation
{Next steps - proceed, revise, or reject}
See references/review-criteria.md for the complete checklist.
The review checks against:
Project Instructions
CLAUDE.md or AGENTS.md in project root.claude/ configurationContent Standards (based on tech stack)
content/standards/backend/java/ - Java backend standardscontent/standards/frontend/react/ - React frontend standardsPlan Format Requirements
{NNNN}_{name}.mdUser: Review the plan at docs/plans/0042_user-auth.md
Claude: I'll review this plan using Codex CLI for independent validation.
[Runs: which codex]
/opt/homebrew/bin/codex
[Runs: cat <<'PROMPT' | codex review -
Review the implementation plan at docs/plans/0042_user-auth.md
...
PROMPT]
Codex returned:
Verdict: NEEDS_REVISION
Summary: The plan is well-structured but missing integration tests
and has an incorrect dependency ordering in Phase 3.
Issues:
- HIGH — Missing integration tests (Testing Strategy section)
- MEDIUM — Task 3.2 depends on 3.4 but is ordered before it (Phase 3)
Recommended changes:
- Add API integration tests to Testing Strategy
- Reorder Phase 3 tasks so 3.4 comes before 3.2
---
Based on Codex's review, you should address the HIGH severity issue
before proceeding with implementation.
User: Review the plan
Claude: I need to invoke Codex CLI for third-party review.
[Runs: which codex]
codex not found
I cannot proceed with the review. This skill requires Codex CLI
for independent third-party validation. Please install it:
npm install -g @openai/codex
Then run /review-plan again.
The skill produces:
create-plan - Creates plans that this skill reviewsimplement-plan - Executes plans after review passesskill-validator - Similar validation pattern for skills