Faster PR Reviews with Claude Code: Automate the Mechanical Checks

The Problem

Engineers spend 1-2 hours/day on PR reviews. Much of that is mechanical.

Claude Code can handle:

• Style and naming checks
• Basic bug detection
• Security pattern matching

Leaving humans to focus on:

• Design decisions
• Business logic
• Architecture review

Core Review Command

.claude/commands/review-pr.md:

# PR Review

Review: git diff main...HEAD

## Code Quality
1. Naming convention consistency
2. Function length (>30 lines = split candidate)
3. Nesting depth (>3 levels = refactor)

## Bug Risk
1. Missing null checks / error handling
2. Missing await in async code
3. Type mismatches

## Security
1. Input validation present
2. Auth/authorization verified

## Tests
1. Coverage of changed code
2. Edge cases covered

Severity: [REQUIRED] / [RECOMMENDED] / [SUGGESTION]

Auto-Post Review to GitHub

import subprocess
import anthropic

def review_pr(pr_number: int):
    diff = subprocess.check_output(['git', 'diff', 'main...HEAD'], text=True)

    client = anthropic.Anthropic()
    response = client.messages.create(
        model="claude-sonnet-4-6",
        max_tokens=2048,
        messages=[{"role": "user", "content": f"Review this diff:\n\n{diff}"}]
    )

    subprocess.run([
        'gh', 'pr', 'comment', str(pr_number),
        '--body', f"## Claude Code Review\n\n{response.content[0].text}"
    ])

Review Large PRs Efficiently

claude "Get changed files with: git diff main...HEAD --name-only
Review order:
1. Understand overall scope
2. Read tests first (reveals intent)
3. Review implementation

Report issues from most critical first."

Team Review Checklist

## Required (Merge Blockers)
- [ ] All tests pass
- [ ] No security issues
- [ ] Breaking changes have migration

## Recommended
- [ ] Consistent code style
- [ ] Docs updated

What Claude Handles vs. Humans

Type	Claude	Human
Style/naming	Auto-check	Final verify
Bug risk	Detect + report	Decide
Design	Present options	Decide
Business logic	Context	Review

Review time cut in half by automating mechanical checks.

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This article is an excerpt from the Claude Code Complete Guide (7 chapters), available on note.com.
myouga (@myougatheaxo) - VTuber axolotl. Sharing practical AI development tips.