A full-stack application that provides automated, AI-driven code reviews using Google's Gemini AI. Submit your code and receive professional, detailed feedback in seconds!

Live website link: AI-Powered Code Reviewer

• 🖥️ Modern Code Editor: Syntax-highlighted code editor powered by CodeMirror
• 🤖 AI-Powered Analysis: Professional code reviews using Google's Gemini AI
• 📊 Comprehensive Feedback:
  • Code quality and best practices assessment
  • Potential bugs and security issues
  • Performance optimization suggestions
  • Alternative approaches and improvements
  • Positive reinforcement for well-written code
• ⚡ Real-time Results: Fast, markdown-formatted reviews
• 🎯 Multi-language Support: Adaptable for various programming languages
• 🚀 Modern Stack: Built with React + Vite frontend and Node.js + Express backend

AI-Powered-Code-Reviewer/ ├── frontend/ │ ├── src/ │ │ ├── App.jsx # Main application component │ │ ├── main.jsx # Entry point for React app │ │ ├── App.css # Main CSS styles │ │ └── components/ # Reusable React components │ ├── index.html # HTML template for the app │ ├── package.json # Frontend dependencies and scripts │ ├── vite.config.js # Vite build configuration │ └── README.md # Frontend-specific documentation ├── Backend/ │ ├── src/ │ │ ├── app.js # Express application setup │ │ ├── routes/ │ │ │ └── ai.routes.js # API route definitions │ │ ├── controllers/ │ │ │ └── ai.controller.js# Request handlers │ │ └── services/ │ │ └── ai.service.js # AI integration logic │ ├── server.js # Server entry point │ ├── package.json # Backend dependencies and scripts │ ├── INSTRUCTIONS.md # Backend setup instructions │ └── .env.example # Environment variables template └── README.md # Project overview (this file) 

• Node.js (v16 or higher)
• npm or yarn
• Google Gemini API key (Get one here)

1. Clone the repository

   git clone https://github.com/Villwin007/AI-Powered-Code-Reviewer.git cd AI-Powered-Code-Reviewer

2. Backend Setup

   cd Backend npm install

   Set up environment variables:

   cp .env.example .env

   Edit the .env file:

   GOOGLE_GEMINI_KEY=your_actual_gemini_api_key_here PORT=3000

3. Frontend Setup

   cd ../frontend npm install

1. Start the Backend Server (Terminal 1)

   cd Backend npx nodemon server.js

   ✅ Backend running on: http://localhost:3000

2. Start the Frontend Development Server (Terminal 2)

   cd frontend npm run dev

   ✅ Frontend running on: http://localhost:5173

3. Open your browser and navigate to http://localhost:5173

1. Write Code: Use the built-in code editor to write or paste your code
2. Submit for Review: Click the "Review Code" button
3. AI Analysis: Your code is sent to the Gemini AI for comprehensive analysis
4. Get Feedback: Receive detailed, markdown-formatted review with suggestions

Frontend (React) → HTTP POST → Backend (Express) → Gemini AI → Review → Frontend 

Submit code for AI-powered review

Request:

{ "code": "function example() {\n console.log('Hello World');\n}" }

Response:

{ "review": "## Code Review\\n\\n### ✅ Strengths\\n- Clean function structure...\\n\\n### 🐛 Issues\\n- Missing error handling...\\n\\n### 💡 Suggestions\\n- Consider using const instead of function...\\n\\n### 🔒 Security\\n- No security vulnerabilities detected" }

• React 18 - UI framework
• Vite - Build tool and dev server
• CodeMirror - Code editor with syntax highlighting
• Axios - HTTP client for API calls
• ReactMarkdown - Markdown rendering for reviews

• Node.js - Runtime environment
• Express.js - Web framework
• Google Generative AI SDK - Gemini AI integration
• CORS - Cross-origin resource sharing
• dotenv - Environment variable management

• Google Gemini AI (gemini-2.5-flash-lite) - Code analysis and review generation
• RESTful API - Communication between frontend and backend

Modify the AI review behavior by editing Backend/src/services/ai.service.js:

const systemInstruction = ` You are an expert senior software engineer conducting code reviews.  Provide comprehensive feedback covering:  🔍 CODE QUALITY - Readability and maintainability - Code organization and structure - Naming conventions - Code smells and anti-patterns  🐛 BUGS & ISSUES  - Logical errors - Edge cases - Potential runtime issues - Type safety concerns  ⚡ PERFORMANCE - Optimization opportunities - Memory usage - Algorithm efficiency  🔒 SECURITY - Vulnerability assessment - Input validation - Data protection  💡 BEST PRACTICES - Language-specific conventions - Modern development practices - Scalability considerations  Format your response in clear markdown with emojis for better readability. Be constructive but honest in your feedback. `;

The AI model supports multiple programming languages. To enhance frontend support:

// In frontend components, add language extensions: import { javascript } from '@codemirror/lang-javascript'; import { python } from '@codemirror/lang-python'; import { java } from '@codemirror/lang-java'; // Add more as needed

URL: POST http://localhost:3000/ai/get-review

Headers:

Content-Type: application/json

Request Body:

{ code: string; // The source code to review }

Response:

{ review: string; // Markdown-formatted review success: boolean; }

Error Responses:

{ error: string; success: false; }

1. Backend connection refused

   • Ensure backend is running on port 3000
   • Check if GOOGLE_GEMINI_KEY is set in .env

2. AI review fails

   • Verify your Gemini API key is valid and has sufficient quota
   • Check network connectivity to Google AI services

3. CORS errors

   • Backend CORS is configured for http://localhost:5173
   • Ensure frontend is running on the correct port

4. Module not found errors

   • Run npm install in both frontend and backend directories
   • Delete node_modules and package-lock.json, then reinstall

Enable detailed logging by setting environment variable:

DEBUG=true

We welcome contributions! Here's how you can help:

1. Fork the repository
2. Create a 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

• Follow existing code style and structure
• Add comments for complex logic
• Update documentation for new features
• Test both frontend and backend changes

• Review history and favorites
• GitHub integration
• Custom review templates
• Batch file analysis
• CI/CD pipeline integration

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

Dhanush Saravanan

• GitHub: @Villwin007
• Email: s.dhanush1106@gmail.com
• Portfolio: [Your Portfolio/LinkedIn]

• Google Gemini AI for providing powerful code analysis capabilities
• CodeMirror team for the excellent code editor component
• React and Node.js communities for amazing tools and libraries
• Vite team for the fast build tool and dev experience

• Google AI Studio - Get Gemini API key
• React Documentation
• Express.js Guide
• Gemini API Documentation

⭐ If you find this project helpful, please give it a star on GitHub!

For questions, support, or contributions, please open an issue or contact s.dhanush1106@gmail.com.