PR Reviewer Skill for Claude Code

Comprehensive GitHub Pull Request code review skill that automates data collection, analyzes against industry-standard criteria, and generates structured review files with an approval workflow.

Overview

PR Reviewer is a Claude Code skill that transforms your code review process. It automatically fetches all PR data using GitHub CLI, applies systematic analysis against industry-standard review criteria, and generates professional review documents ready for posting. The two-stage approval workflow ensures nothing is posted until you explicitly approve.

Features

• Automated Data Collection - Fetches PR metadata, diffs, comments, commits, and related issues via GitHub CLI
• Systematic Analysis - Reviews against comprehensive criteria: security, testing, maintainability, performance
• Structured Review Files - Generates detailed internal review, clean public review, and inline comment templates
• Two-Stage Approval - Nothing posts to GitHub until you explicitly approve with /send or /send-decline
• Inline Comments - Adds specific feedback directly to code lines with posting commands
• Ticket Tracking - Extracts and links JIRA/GitHub issue references
• Professional Templates - Clean, respectful review format without emojis or excessive formatting

Installation

Installing with Skilz (Recommended)

The easiest way to install this skill is using the Skilz Universal Installer:

# Install Skilz (one-time setup)
curl -fsSL https://raw.githubusercontent.com/SpillwaveSolutions/skilz/main/install.sh | bash

# Install this skill
skilz install SpillwaveSolutions_pr-reviewer-skill/pr-reviewer

View on the Skilz Marketplace: pr-reviewer

Manual Installation

1. Install GitHub CLI (if not already installed):

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   # macOS
   brew install gh
   
   # Linux
   sudo apt install gh  # or yum, dnf, etc.
   
   # Windows
   winget install GitHub.cli
   

2. Authenticate with GitHub:

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   gh auth login
   

3. Clone this skill to your Claude Code skills directory:

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   cd ~/.claude/skills
   git clone https://github.com/SpillwaveSolutions/pr-reviewer-skill.git pr-reviewer
   

4. Install Python dependencies (if needed):

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   cd pr-reviewer
   pip install requests  # Only needed for add_inline_comment.py
   

Quick Start

Basic PR Review

1. Fetch PR data:

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   python scripts/fetch_pr_data.py https://github.com/owner/repo/pull/123
   

2. Analyze the PR by reading the generated files:

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   /tmp/PRs/<repo-name>/123/SUMMARY.txt
   /tmp/PRs/<repo-name>/123/diff.patch
   /tmp/PRs/<repo-name>/123/metadata.json
   

3. Generate review files with your findings:

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   python scripts/generate_review_files.py /tmp/PRs/<repo-name>/123 --findings findings.json
   

4. Review and edit the generated files:

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   /show  # Opens review directory in VS Code
   

5. Approve and post:

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   /send          # Approve PR and post review
   # or
   /send-decline  # Request changes and post review
   

Workflow

┌─────────────────────────────────────────────────────────────────┐
│ 1. Fetch PR Data                                                │
│    python scripts/fetch_pr_data.py <pr_url>                     │
│    → Collects metadata, diff, comments, commits, issues         │
└─────────────────────────────────────────────────────────────────┘
                              ↓
┌─────────────────────────────────────────────────────────────────┐
│ 2. Analyze PR                                                   │
│    → Read SUMMARY.txt, diff.patch, metadata.json               │
│    → Apply review criteria (security, testing, etc.)           │
│    → Create findings JSON with your analysis                   │
└─────────────────────────────────────────────────────────────────┘
                              ↓
┌─────────────────────────────────────────────────────────────────┐
│ 3. Generate Review Files                                        │
│    python scripts/generate_review_files.py <dir> --findings ... │
│    → Creates review.md, human.md, inline.md                    │
│    → Generates /send, /send-decline, /show commands            │
└─────────────────────────────────────────────────────────────────┘
                              ↓
┌─────────────────────────────────────────────────────────────────┐
│ 4. Review & Edit                                                │
│    /show → Opens in VS Code                                     │
│    → Edit pr/human.md if needed                                │
│    → Review pr/inline.md for proposed comments                 │
└─────────────────────────────────────────────────────────────────┘
                              ↓
┌─────────────────────────────────────────────────────────────────┐
│ 5. Approve & Post                                               │
│    /send (approve) or /send-decline (request changes)          │
│    → Posts pr/human.md as review comment                       │
│    → Optionally post inline comments from pr/inline.md         │
└─────────────────────────────────────────────────────────────────┘

Review Criteria

This skill reviews PRs against comprehensive industry-standard criteria:

1. Functionality & Correctness

• Does code solve the intended problem?
• Are there bugs or logical errors?
• Edge cases and error handling covered?

2. Security & Best Practices

• Common vulnerabilities (SQL injection, XSS, CSRF)?
• Secrets not hardcoded?
• Dependencies justified and secure?

3. Testing & Quality Assurance

• Tests exist for new code?
• Tests cover happy paths, errors, edge cases?
• CI/CD checks pass?

4. Readability & Maintainability

• Code clarity and meaningful names?
• Functions follow Single Responsibility?
• Code duplication avoided (DRY)?

5. Performance & Efficiency

• Algorithm efficiency (avoid O(n²) where possible)?
• Scalability under load?

6. Style & Conventions

• Follows project linter rules?
• Consistent with existing codebase?

7. Overall PR Quality

• PR scope focused (single feature/fix)?
• Clean commit history?
• Clear PR description?

See references/review_criteria.md for complete checklist.

Scripts

fetch_pr_data.py

Automated PR data collection and organization.

python scripts/fetch_pr_data.py <pr_url> [options]

Options:
  --output-dir DIR    Base output directory (default: /tmp)
  --no-clone         Skip cloning repository (faster)

Output structure:

/tmp/PRs/<repo-name>/<PR-NUMBER>/
├── metadata.json           # PR metadata (title, author, branches, etc.)
├── diff.patch             # PR diff from gh CLI
├── git_diff.patch         # Git diff (if cloned)
├── comments.json          # Review comments on code
├── commits.json           # Commit history
├── related_issues.json    # Linked GitHub issues
├── ticket_numbers.json    # Extracted ticket references
├── SUMMARY.txt            # Human-readable summary
└── source/                # Cloned repository (if not --no-clone)

generate_review_files.py

Generates structured review documents from analysis findings.

python scripts/generate_review_files.py <pr_review_dir> --findings <findings_json> [--metadata <metadata_json>]

Creates:

• pr/review.md - Detailed internal review with emojis and line numbers
• pr/human.md - Clean review for posting (no emojis, em-dashes, line numbers)
• pr/inline.md - Proposed inline comments with posting commands
• .claude/commands/send.md - Slash command to approve and post
• .claude/commands/send-decline.md - Slash command to request changes
• .claude/commands/show.md - Slash command to open in VS Code

Example findings JSON:

{
  "summary": "Overall assessment of the PR",
  "metadata": {
    "repository": "owner/repo",
    "number": 123,
    "title": "PR title",
    "author": "username"
  },
  "blockers": [
    {
      "category": "Security",
      "issue": "SQL injection vulnerability",
      "file": "src/db/queries.py",
      "line": 45,
      "details": "Using string concatenation for SQL query",
      "fix": "Use parameterized queries",
      "code_snippet": "result = db.execute('SELECT * FROM users WHERE id = ' + user_id)"
    }
  ],
  "important": [...],
  "nits": [...],
  "suggestions": ["Consider adding...", "Future enhancement..."],
  "questions": ["Is this intended to...", "Should we..."],
  "praise": ["Excellent test coverage", "Clear documentation"],
  "inline_comments": [
    {
      "file": "src/app.py",
      "line": 42,
      "comment": "Consider edge case handling for empty input",
      "code_snippet": "def process(data):\n    return data.strip()",
      "start_line": 41,
      "end_line": 43
    }
  ]
}

add_inline_comment.py

Posts inline comments to specific lines in a PR.

python scripts/add_inline_comment.py <owner> <repo> <pr_number> <commit_id> <file_path> <line> "<comment>" [options]

Options:
  --side RIGHT|LEFT       Side of diff (default: RIGHT)
  --start-line N         Starting line for multi-line comment
  --start-side RIGHT|LEFT Starting side for multi-line comment

Example:

python scripts/add_inline_comment.py facebook react 28476 latest "packages/react/src/React.js" 42 "Consider edge case handling here"

Usage with Claude Code

When you install this skill, Claude Code can automatically use it when you:

1. Provide a GitHub PR URL and request a review
2. Say "review this PR" or "code review"
3. Ask to check PR quality before merging
4. Mention GitHub PR review in any context

Trigger phrases:

• "review pr"
• "code review"
• "review pull request"
• "check pr"
• "github.com//pull/" (any PR URL)

Examples

Example 1: Quick Review

User: Can you review this PR? https://github.com/facebook/react/pull/28476

Claude Code:
1. Runs fetch_pr_data.py to collect all PR data
2. Reads SUMMARY.txt and metadata.json for context
3. Scans diff.patch for critical issues
4. Applies security, functionality, and testing criteria
5. Creates findings JSON with analysis
6. Runs generate_review_files.py to create review files
7. Tells you to review pr/review.md and pr/human.md
8. Reminds you to use /show to edit, then /send or /send-decline

Example 2: Comprehensive Review with Inline Comments

User: Do a thorough review and add inline comments where needed

Claude Code:
1. Fetches complete PR data including cloned repository
2. Analyzes all files against full review_criteria.md checklist
3. Identifies blockers, important issues, and nits
4. Creates findings JSON with detailed inline_comments array
5. Generates all review files (review.md, human.md, inline.md)
6. Provides /show, /send, /send-decline commands
7. You review, edit, approve, and optionally post inline comments

Example 3: Security-Focused Review

User: Check this PR for security issues

Claude Code:
1. Fetches PR data
2. Focuses on security criteria (SQL injection, XSS, secrets, etc.)
3. Examines dependencies and authentication changes
4. Reports security findings with severity levels
5. Generates review with security-focused recommendations

Best Practices

Communication

• Be constructive - Frame as suggestions, not criticism
• Explain why - Don't just say what's wrong, explain why it matters
• Acknowledge good work - Call out excellent practices
• Prioritize - Focus on blockers first, style issues last

Review Efficiency

• Use scripts - Automate data fetching and comment posting
• Reference criteria - Use review_criteria.md as checklist
• Focus review - Critical issues > Important > Nice-to-have
• Be timely - Review promptly (within 24 hours if possible)

Inline Comments

• Be specific - Reference exact lines and files
• Provide examples - Show better alternatives
• Test first - Try inline comments on test PRs
• Use sparingly - Too many inline comments can overwhelm

Troubleshooting

"gh CLI not found"

Install GitHub CLI: https://cli.github.com/

"Permission denied" errors

Check authentication:

gh auth status
gh auth refresh -s repo

"Invalid PR URL"

Ensure URL format: https://github.com/owner/repo/pull/NUMBER

Rate limit errors

# Check rate limit
gh api /rate_limit

# Authenticated users get higher limits
gh auth login

Reference Documentation

• references/review_criteria.md - Complete checklist with examples
• references/gh_cli_guide.md - GitHub CLI commands and patterns
• SKILL.md - Detailed skill documentation for Claude Code

Resources

• GitHub PR Review Documentation
• Google Engineering Practices
• OWASP Top 10
• GitHub CLI Documentation

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

1. Fork the repository
2. Create your feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

License

This project is licensed under the MIT License - see the LICENSE file for details.

Acknowledgments

• Built for Claude Code
• Uses GitHub CLI for API interactions
• Inspired by industry-standard code review practices

Support

For issues, questions, or suggestions:

• Open an issue on GitHub
• Consult the documentation in SKILL.md and references/

Made with care for better code reviews