APISentinel

Agentic API Contract Intelligence

Overview

APISentinel is a full-stack application that connects to GitHub, scans repositories, and uses an agentic LLM to map frontend API calls and backend routes, then surfaces inconsistencies and drift. It combines OAuth-powered repo access, automated endpoint discovery, and GPT-4.1-mini via GitHub Models to deliver fast contract insights.

Built using React.js with Vite for the frontend and Node.js (Express + TypeScript) for the backend, the system provides repository-level API intelligence with a modern UI.

Live Demo: https://api-sentinel-sigma.vercel.app

Key Features

OAuth and Identity

• GitHub OAuth for repository access
• Google sign-up and login
• Secure session handling

Repository Linkage

• Link and sync GitHub repositories
• Public repository linking by URL
• Rate-limit aware fetch and caching

Agentic LLM Scanning

• GPT-4.1-mini via GitHub Models
• Agentic code scanning that discovers endpoints
• Normalizes paths and methods across stacks
• Detects frontend frameworks (React, Next.js, Angular, Vue, Svelte, Django, HTML/CSS)

Contract Inconsistency Detection

• Detect missing, extra, and method mismatches
• Highlight request and response schema drift
• Frontend vs backend inconsistencies and drift
• Backend endpoint totals vs OpenAPI spec totals
• Backend vs OpenAPI contract mismatches
• Confidence annotations for resolved findings

Health Checks and Dashboard

• Queue health checks with retry logic
• Dashboard stats and request logs
• Endpoint usage summaries per repository

Tech Stack

Frontend

• React.js with TypeScript
• Vite for fast development and building
• Tailwind CSS for styling
• React Query for data fetching
• Radix UI components

Backend

• Node.js with TypeScript
• Express
• TypeORM with MongoDB
• GitHub OAuth and Google OAuth
• GitHub Models with GPT-4.1-mini

Project Structure

APISentinel/
├── frontend/           # React frontend application
│   ├── src/
│   │   ├── components/ # UI components
│   │   ├── hooks/      # API hooks
│   │   ├── lib/        # Utilities and API paths
│   │   ├── pages/      # Application pages
│   │   └── types/      # Shared types
│   └── ...
│
├── backend/            # Node.js backend application
│   ├── src/
│   │   ├── application/   # Use-case services
│   │   ├── domain/        # Domain entities and repositories
│   │   ├── infrastructure/# HTTP, persistence, analysis
│   │   ├── shared/        # Config and errors
│   │   ├── app.ts         # Express app setup
│   │   └── server.ts      # Composition root
│   └── ...
└── README.md

Getting Started

Prerequisites

• Node.js (v18 or higher)
• MongoDB instance (DATABASE_URI)
• GitHub OAuth App (for private repository access)

Installation

1. Clone the repository

   git clone https://github.com/irtaza-shahzad/APISentinel.git
   cd APISentinel

2. Setup Backend

   cd backend
   npm install
   npm run dev

3. Setup Frontend

   cd frontend
   npm install
   npm run dev

4. Access the Application

   • Frontend: http://localhost:8080
   • Backend API: http://localhost:3000

Build and Run (Deployment)

Backend

cd backend
npm run build
npm start

Frontend

cd frontend
npm run build
npm start

Environment Variables

Frontend (.env)

Create a .env file in the frontend/ directory:

VITE_API_BASE_URL=http://localhost:3000

Backend (.env)

Create a .env file in the backend/ directory:

PORT=3000
DATABASE_URI=your_mongodb_connection_string

# GitHub OAuth
GITHUB_CLIENT_ID=your_github_client_id
GITHUB_CLIENT_SECRET=your_github_client_secret
GITHUB_CALLBACK_URL=http://localhost:3000/auth/github/callback

# Google OAuth
GOOGLE_CLIENT_ID=your_google_client_id
GOOGLE_CLIENT_SECRET=your_google_client_secret
GOOGLE_CALLBACK_URL=http://localhost:3000/auth/google/callback

# Frontend URL for CORS and redirects
FRONTEND_BASE_URL=http://localhost:8080

# Session signing secret
SESSION_SECRET=replace_with_a_long_random_secret

# LLM features
LLM_ENABLED=true
GITHUB_MODELS_TOKEN=your_github_models_token

Tip: you can copy backend/.env.example to backend/.env and fill in real values.

Core Modules

Module	Description
Authentication	GitHub and Google OAuth with secure sessions
Repositories	Link and list GitHub repositories
Agentic Analysis	LLM-powered endpoint discovery and scanning
Inconsistency Engine	Detect missing, extra, method, and schema drift
Health Checks	Queue and track repository health scans
Dashboard	Summary stats and request logs

Security Features

• HTTP-only session cookies
• OAuth-based authentication
• Server-side validation and error handling
• Config-based CORS

Contributing

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

License

This project is developed for educational purposes.