AI-Powered PR Reviewer

A GitHub App that uses a multi-agent architecture to review Pull Requests with cross-file reasoning and codebase memory.

Unlike other AI reviewers that only see the diff, this bot understands your entire codebase:

• Indexes your repo on installation
• Finds related code across files you didn't change
• Learns patterns from your codebase
• Self-hosted = your code never leaves your infrastructure

• 🚫 Block Bad PRs: High-risk PRs get a failing status check (can't merge!)
• 🔧 Auto-Fix Suggestions: AI generates code fixes for issues found
• 🌐 Multi-Language: Python, JavaScript/TypeScript, Java, C/C++, Go, Rust
• 🧠 RAG Context: Indexes your codebase for smarter reviews
• 📊 Map-Reduce: Handles large PRs by summarizing files individually
• 🌳 Tree-sitter: Parses code structure (functions, classes, imports)
• 🔗 Cross-File Impact: Identifies files affected by your changes
• 🔑 Multi-Key Manager: Rotates Gemini API keys with rate-limit handling
• ⚠️ Risk Scoring: Assigns risk based on size, tests, and impact

1. Install Dependencies:

   pip install -r requirements.txt

2. Configure Environment: Copy .env.example to .env and fill in:

   • APP_ID: Your GitHub App ID
   • PRIVATE_KEY_PATH: Path to your GitHub App private key
   • WEBHOOK_SECRET: Your webhook secret
   • GEMINI_API_KEYS: Comma-separated list of Gemini API keys

3. Run the Server:

   uvicorn app.main:app --reload

1. Receives installation webhook
2. Indexes entire repository in background
3. Stores embeddings in local vector store

1. Status: Pending → Shows "AI review in progress"
2. Diff Analysis → Fetch changed files
3. Tree-sitter → Parse code structure (7 languages)
4. Map → Summarize each file
5. RAG → Find related code in codebase
6. Risk → Calculate risk score (0-100)
7. Reduce → Generate final review
8. Auto-Fix → Generate code suggestions if issues found
9. Status: Pass/Fail → Block merge if risk ≥ 70

app/
├── main.py # FastAPI + webhooks
├── core/
│ ├── config.py # Settings
│ ├── security.py # GitHub App JWT auth
│ ├── llm.py # Gemini client
│ ├── key_manager.py # Multi-key rotation
│ ├── embeddings.py # Gemini embeddings
│ ├── vector_store.py # ChromaDB wrapper
│ ├── indexer.py # Codebase indexer
│ └── code_parser.py # Tree-sitter parser
└── agents/
 ├── master.py # Orchestrator
 ├── diff.py # PR diff analysis
 ├── dependency.py # Cross-file dependencies
 ├── file_summary.py # File summarizer (MAP)
 ├── context.py # RAG context retrieval
 ├── test.py # Test impact
 ├── risk.py # Risk scoring
 └── writer.py # Review composer (REDUCE)

MIT