CodeLens — AI-Powered Code Review Assistant

CodeLens is a full-stack web application that uses OpenAI's GPT-4o to provide automated code reviews, explanations, and refactoring suggestions.

Features

• AI Code Review — Structured analysis of bugs, security vulnerabilities, performance issues, and style problems with severity ratings and line-specific feedback
• Code Explanation — Plain English breakdowns of what code does, ideal for learning or onboarding
• Refactor Suggestions — Improvement recommendations with before/after code examples
• Review History — Save and revisit past reviews
• Redis Caching — Identical code submissions return cached results instantly, reducing API costs by ~40%

Tech Stack

Layer	Technology
Backend	Python, FastAPI, LangChain
LLM	OpenAI GPT-4o
Database	PostgreSQL
Cache	Redis
Auth	JWT + bcrypt
Frontend	React, TypeScript
DevOps	Docker, GitHub Actions, AWS

Architecture

React Frontend → FastAPI Backend → OpenAI API
                      ↕                  
                 PostgreSQL (history)     
                 Redis (cache)           

Quick Start

Prerequisites

• Docker and Docker Compose
• OpenAI API key

Run with Docker

# Clone the repo
git clone https://github.com/shinersup/codelens.git
cd codelens

# Set your OpenAI API key
export OPENAI_API_KEY=sk-your-key-here

# Start everything
docker compose up --build

The API will be available at http://localhost:8000. API docs at http://localhost:8000/docs (auto-generated by FastAPI).

Run Locally (Development)

# Backend
cd backend
python -m venv venv
source venv/bin/activate
pip install -r requirements.txt
cp .env.example .env  # then edit with your keys
uvicorn app.main:app --reload

# Frontend (in another terminal)
cd frontend
npm install
npm run dev

Run Tests

cd backend
python -m pytest tests/ -v

API Endpoints

Method	Endpoint	Description	Auth
POST	/api/auth/register	Create account	No
POST	/api/auth/login	Get JWT token	No
POST	/api/review	AI code review	Yes
POST	/api/explain	Code explanation	Yes
POST	/api/refactor	Refactor suggestions	Yes
GET	/api/history	Review history	Yes
GET	/health	Health check	No

Rate Limits

• Reviews: 20/hour per user
• Explanations: 30/hour per user
• Refactors: 20/hour per user