code-review

What this skill does

# Code Review Skill


**Purpose:** Enforce automated code reviews as a mandatory guardrail before every commit and deployment. Choose between Claude, OpenAI Codex, Google Gemini, or multiple engines for comprehensive analysis.

**Sub-skills:**
- [adr-gate.md](./adr-gate.md) — Pre-review ADR and spec enforcement

---

## Pre-Review: ADR Gate (Mandatory)

Before any review engine runs, the ADR gate executes automatically:

1. **Classify** — trivial changes (typos, deps, tests-only) skip the gate
2. **Discover** — scan `docs/adr/`, `_project_specs/`, iCPG ReasonNodes, git history for linked ADRs and specs
3. **Enforce** — if no ADRs found for non-trivial changes:
   - **Interactive** (default): draft ADR from git history, ask user to confirm
   - **Unattended** (CI): write as `Status: proposed`, proceed
   - **Strict**: block review until ADR exists
4. **Inject** — feed discovered ADRs + specs into the review prompt as architectural context

### ADR Compliance Review Dimension

Added to the standard 7 review categories:

| Category | What It Checks |
|----------|----------------|
| **ADR Compliance** | Change conforms to documented decisions, no undocumented architectural shifts |

| Finding | Severity |
|---------|----------|
| Change contradicts accepted ADR | Critical |
| Architectural decision not in any ADR | High |
| ADR exists but is outdated/stale | Medium |
| Minor drift from ADR intent | Low |

See [adr-gate.md](./adr-gate.md) for full protocol, reverse-engineering rules, and configuration.

---

## Review Engine Choice

When running `/code-review`, users can choose their preferred review engine:

```
┌─────────────────────────────────────────────────────────────────┐
│  CODE REVIEW - Choose Your Engine                               │
├─────────────────────────────────────────────────────────────────┤
│                                                                 │
│  ○ Claude (default)                                             │
│    Built-in, no extra setup, full conversation context          │
│                                                                 │
│  ○ OpenAI Codex CLI                                             │
│    GPT-5.2-Codex specialized for code review, 88% detection     │
│    Requires: npm install -g @openai/codex                       │
│                                                                 │
│  ○ Google Gemini CLI                                            │
│    Gemini 2.5 Pro with 1M token context, free tier available    │
│    Requires: npm install -g @google/gemini-cli                  │
│                                                                 │
│  ○ Dual Engine (any two)                                        │
│    Run two engines, compare findings, catch more issues         │
│                                                                 │
│  ○ All Three (maximum coverage)                                 │
│    Run Claude + Codex + Gemini for critical/security code       │
│                                                                 │
└─────────────────────────────────────────────────────────────────┘
```

### Engine Comparison

| Aspect | Claude | Codex | Gemini | Multi-Engine |
|--------|--------|-------|--------|--------------|
| **Setup** | None | npm + OpenAI API | npm + Google Account | All setups |
| **Speed** | Fast | Fast | Fast | 2-3x time |
| **Context** | Conversation | Fresh per review | 1M tokens | N/A |
| **Detection** | Good | 88% (best) | 63.8% SWE-Bench | Combined |
| **Free Tier** | N/A | Limited | 1,000/day | Varies |
| **Best for** | Quick reviews | High accuracy | Large codebases | Critical code |

### Set Default Engine

```toml
# ~/.claude/settings.toml or project CLAUDE.md
[code-review]
default_engine = "claude"  # Options: claude, codex, gemini, dual, all
```

### Usage Examples

```bash
# Use default engine
/code-review

# Explicitly choose engine
/code-review --engine claude
/code-review --engine codex
/code-review --engine gemini

# Dual engine (pick any two)
/code-review --engine claude,codex
/code-review --engine claude,gemini
/code-review --engine codex,gemini

# All three engines
/code-review --engine all

# Quick shortcuts
/code-review              # Uses default
/code-review --codex      # Use Codex
/code-review --gemini     # Use Gemini
/code-review --all        # All three engines
```

---

## Multi-Engine Output

When using multiple engines, findings are compared and deduplicated:

### Dual Engine Example

```
┌─────────────────────────────────────────────────────────────────┐
│  CODE REVIEW RESULTS - DUAL ENGINE (Claude + Codex)             │
├─────────────────────────────────────────────────────────────────┤
│                                                                 │
│  ✅ AGREED (Found by both):                                     │
│  🔴 SQL injection in auth.ts:45                                 │
│  🟡 Missing error handling in api.ts:112                        │
│                                                                 │
│  🔷 CLAUDE ONLY:                                                │
│  🟠 Potential race condition in worker.ts:89                    │
│  🟢 Consider extracting helper function                         │
│                                                                 │
│  🔶 CODEX ONLY:                                                 │
│  🟠 Memory leak - unclosed stream in upload.ts:34               │
│  🟡 N+1 query pattern in orders.ts:156                          │
│                                                                 │
├─────────────────────────────────────────────────────────────────┤
│  SUMMARY                                                        │
│  Agreed: 2 | Claude only: 2 | Codex only: 2                     │
│  Critical: 1 | High: 2 | Medium: 2 | Low: 1                     │
│  Status: ❌ BLOCKED - Fix critical/high issues                  │
└─────────────────────────────────────────────────────────────────┘
```

### Triple Engine Example (All Three)

```
┌─────────────────────────────────────────────────────────────────┐
│  CODE REVIEW RESULTS - TRIPLE ENGINE                            │
├─────────────────────────────────────────────────────────────────┤
│                                                                 │
│  ✅ UNANIMOUS (All 3 found):                                    │
│  🔴 SQL injection in auth.ts:45                                 │
│                                                                 │
│  ✅ MAJORITY (2 of 3 found):                                    │
│  🟠 Memory leak - unclosed stream in upload.ts:34 (Codex+Gemini)│
│  🟡 Missing error handling in api.ts:112 (Claude+Codex)         │
│                                                                 │
│  🔷 CLAUDE ONLY:                                                │
│  🟠 Potential race condition in worker.ts:89                    │
│                                                                 │
│  🔶 CODEX ONLY:                                                 │
│  🟡 N+1 query pattern in orders.ts:156                          │
│                                                                 │
│  🟢 GEMINI ONLY:                                                │
│  🟡 Consider using batch API for better performance             │
│  🟢 Type could be more specific in types.ts:23                  │
│                                                                 │
├─────────────────────────────────────────────────────────────────┤
│  SUMMARY                                                        │
│  Unanimous: 1 | Majority: 2 | Single: 5                         │
│  Critical: 1 | High: 2 | Medium: 3 | Low: 2                     │
│  Status: ❌ BLOCKED - Fix critical/high issues                  │
└─────────────────────────────────────────────────────────────────┘
```

### When to Use Each Mode

| Mode | Use When |
|------|----------|
| **Single (Claude)** | Quick in-flow reviews,