code-review

name	code-review
description	Perform a fast, light, conservative code review for GitHub pull requests or local branch changes. Use for /code-review, quick PR reviews, current-branch reviews, and default review requests when the user has not asked for a deep, exhaustive, CodeRabbit-style, nitpick-level, or find-everything review. Aim for the top 1-3 material issues; use deep-review for exhaustive coverage.

Code Review

Run a fast, light review like a pragmatic senior engineer: understand the intent, inspect the diff in enough context to catch real risks, and report only the highest-signal findings.

This is the default review skill for /code-review. It optimizes for precision and speed, usually producing 0-3 issues. For exhaustive, CodeRabbit-style coverage with per-file sub-agents, full scanner batteries, inline comments, and nitpicks, use deep-review instead.

Use Cases

/code-review https://github.com/OWNER/REPO/pull/123
/skill:code-review https://github.com/OWNER/REPO/pull/123
Review PR #123 quickly
Review the current branch against main
Do a security-focused light review of this PR
Review these local changes but do not post to GitHub

Principles

• Prioritize bugs, security issues, data loss, regressions, broken edge cases, API compatibility issues, and missing tests with clear risk.
• Aim for the top 1-3 material findings. Cap the report at 3 findings unless additional clear Critical or High issues are present.
• Prefer false negatives over noisy findings. Do not report speculative issues without concrete evidence from the diff or surrounding code.
• Do not nitpick. Skip naming, formatting, import order, wording, docs, and micro-refactors unless an explicit project rule makes them merge-blocking.
• Do not fan out sub-agents or run the deep-review workflow from this skill.
• Be specific and actionable. Every finding should include the exact file/location, impact, and a concrete fix.
• Review only by default. Do not edit code unless the user explicitly asks you to fix the issues.
• Treat a direct GitHub PR URL as permission to post the completed review back to that PR, unless the user says not to post.
• Keep local branch reviews, file-only reviews, and non-URL PR references terminal-only unless the user explicitly asks to post.
• User wording such as "do not post", "review only", "don't comment", or "terminal only" overrides any posting permission.

Workflow

Follow this process for every review.

Phase 1: Establish the Review Target

Determine both the review target and the output destination. Review targets can be:

1. A GitHub PR, e.g. PR #123
2. The current branch against a base branch, usually main or master
3. Uncommitted local changes
4. A specific set of files

Output destination rules:

1. Direct GitHub PR URL, e.g. https://github.com/OWNER/REPO/pull/123 — post one PR comment by default.
2. GitHub PR number or shorthand, e.g. PR #123 — print to terminal unless the user explicitly asks to post.
3. Local branch, uncommitted, or file-only review — print to terminal unless the user explicitly asks to post and provides a PR target.
4. Any explicit "do not post" wording — print to terminal only.

For direct GitHub PR URLs with posting enabled, run gh auth status before resolving PR metadata. If gh is unavailable or auth fails, mark posting unavailable, continue terminal-only when the PR diff can still be gathered, and include the failure reason with the terminal review.

For GitHub PRs, gather PR metadata and diff with gh when available. Use the PR URL when one was provided:

gh auth status
gh pr view <url-or-number> --json title,body,author,baseRefName,headRefName,files,commits,url
gh pr diff <url-or-number>

For local branch reviews, inspect the merge base and diff:

git status --short
git branch --show-current
git merge-base HEAD origin/main 2>/dev/null || git merge-base HEAD main
git diff <merge-base>...HEAD

Adjust the base branch if the repository uses a different default branch.

Phase 2: Gather Focused Project Context

Read the changed files and only enough surrounding code to validate likely impact. Check project standards in this priority order:

1. REVIEW.md in the target repository root, if present
2. CLAUDE.md, .claude.md, or equivalent agent instructions
3. CONTRIBUTING.md, coding standards, architecture docs, ADRs
4. Package/tooling files such as package.json, pyproject.toml, go.mod, Cargo.toml, etc.
5. Existing nearby tests and similar implementations

Treat the target repo's REVIEW.md as the highest-priority review rules.

If this skill's bundled reference files are available, use them as support material:

• REFERENCE.md — examples, output templates, severity guidance
• PROJECT_REVIEW_TEMPLATE.md — starter REVIEW.md users can copy into a project

Phase 3: Run Available Checks

Run only cheap, already-configured checks that are likely to finish quickly and directly cover the changed area:

• Type checks
• Unit tests for changed areas
• Linters/format checks

Do not install tools, invoke one-shot package downloads, run broad scanner batteries, or run expensive full-suite checks by default. If the right check is too expensive or unavailable, note that it was not run and continue with manual review.

Phase 4: Analyze in Order

Analyze the change in this order, stopping once the highest-signal issues are identified:

1. Intent — What is the PR/change trying to accomplish?
2. Correctness — logic errors, invalid assumptions, broken edge cases, race conditions, bad state transitions
3. Security — auth/authz, injection, unsafe input handling, secrets, SSRF, XSS, unsafe deserialization, sensitive logging
4. Reliability — error handling, retries, idempotency, null/undefined handling, resource cleanup
5. Data & API compatibility — migrations, schema changes, response shapes, backwards compatibility
6. Testing — missing coverage for new logic, regression tests, edge cases, integration boundaries
7. Performance — N+1 queries, hot path regressions, unnecessary expensive work
8. Maintainability — only concrete complexity or inconsistency likely to cause bugs

For large PRs, inspect the highest-risk files first and sample enough of the rest to catch obvious blockers. If the change is too large for a meaningful light review, say so briefly and recommend /deep-review for exhaustive coverage.

Suppression rules:

• Omit Low/Nit findings by default.
• Report missing tests only when a specific new behavior or regression risk clearly needs coverage.
• Do not report issues that require assumptions about undocumented product requirements.
• Do not summarize long lists of minor issues; leave them for deep-review.

Severity Scale

• Critical — security vulnerability, data loss, production crash, auth bypass, major regression
• High — logic bug, missing critical error handling, broken feature, serious performance issue
• Medium — missing test with concrete regression risk, maintainability risk likely to cause future bugs, minor behavior issue
• Low/Nit — normally out of scope for code-review; use only for explicit project-rule violations that should block merge

Rule of thumb: if you would not block a real merge for it, do not mark it Medium or higher.

Output Format

Start with a short overall assessment. Then list findings from highest to lowest severity. Keep the report concise: 0-3 findings is the expected result for most reviews.

For every issue, use this format:

## [Severity] Issue: [Short descriptive title]

**File:** `path/to/file.ext:line-range`
**Category:** Bug | Security | Logic | Reliability | Maintainability | Testing | Performance | Style

**Problem:**
[Clear 1-2 sentence explanation of what is wrong and why it matters.]

**Impact:**
[Specific consequence if this is not fixed.]

**Suggested Fix:**
```diff
[Exact unified diff, or a precise before/after code block if a diff is not practical.]
```

**Handoff Prompt:**
```
In the file `path/to/file.ext`, around lines X-Y:

[Detailed, self-contained instruction explaining the exact change needed, why it is required, edge cases to consider, and how to verify it. Reference relevant project patterns if applicable.]

Only modify the necessary lines. Keep unrelated code unchanged.
```

After all issues, include:

### PR Summary
[2-4 sentence overview of the change and overall assessment.]

### Recommendations
- [ ] Highest-priority fixes before merge
- [ ] Tests to add or run
- [ ] Optional improvements

### Statistics
- Files changed: X
- Issues found: Y (Critical: A, High: B, Medium: C, Low: D)
- Checks run: [commands or "not run"]

If no issues are found, say so clearly and include a brief positive summary of what looked good.

GitHub PR Posting

When posting is permitted, use one normal PR comment by default. Do not create inline comments unless the user explicitly asks for them.

Posting workflow:

1. Run gh auth status.
2. If auth fails or gh is unavailable, print the full review to the terminal and include the failure reason.
3. Resolve PR metadata with gh pr view <url-or-number> --json title,body,author,baseRefName,headRefName,files,commits,url.
4. Generate the same findings and overall assessment you would produce for a terminal review.
5. Write the GitHub comment body to a temporary Markdown file.
6. Post with gh pr comment <url-or-number> --body-file <tmp-review.md>.
7. If posting fails, print the full review to the terminal and include the posting error.

The posted comment must include the summary and statistics at the top, followed by one collapsible <details> section per finding. Each <summary> line must use:

[Severity] File:line - issue title

Each details section must include the problem, impact, suggested fix, and handoff prompt. See REFERENCE.md for the exact GitHub comment template and fallback commands.

For terminal-only reviews, use the standard output format above.