Data Breach Checker

A modern, fast, secure, and deployment-ready web application to detect whether an email address has been compromised in public data breach incidents. The application is tailored for Indonesian users, featuring a 100 percent Indonesian user interface.

The application utilizes a clean architecture combining high-performance technologies:

• Frontend: Astro, TypeScript, Tailwind CSS (utilizing Static Site Generation for instant load times and a Largest Contentful Paint under 2 seconds).
• Backend: Python 3.13, FastAPI, Uvicorn, HTTPX, and Async (utilizing custom risk scoring and a rule-based mitigation recommendation engine).
• Deployment: Vercel Serverless (Astro static edge hosting and FastAPI Serverless Functions).

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Key Features

1. Fast and Lightweight Examination: Direct integration with a public data breach API database with optimal client-side rendering.
2. Custom Risk Evaluation: An algorithm calculating risk scores from 0 to 100 and risk categories (Safe, Low, Moderate, High, Critical).
3. Intelligent Recommendation Engine: Specific security mitigation actions provided in Indonesian, tailored to the type of compromise (such as password, telephone number, username, new credentials, or old credentials).
4. Protection and Security:
   • A thread-safe in-memory cache with a 10-minute Time-To-Live (TTL) to reduce redundant external API requests.
   • IP-based rate limiting (maximum of 10 requests per minute per IP address) to prevent API exploitation.
   • Comprehensive security headers including Content Security Policy (CSP), Strict Transport Security (HSTS), X-Frame-Options, and X-Content-Type-Options.
   • Safe error handling that prevents internal system stack traces from being exposed to the client.
5. Accessibility (A11y): Built with full keyboard navigation support, semantic HTML elements, high-contrast focus rings, and Accessible Rich Internet Applications (ARIA) attributes.
6. SEO Optimization: Fully integrated JSON-LD structured schema metadata (WebSite and FAQPage), robots.txt, sitemap.xml, comprehensive Open Graph and Twitter Card tags, and Cumulative Layout Shift (CLS) values near zero.

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System Requirements

• Python: Version 3.13 or newer.
• Node.js: Version 18.x, 20.x, or newer.
• Vercel CLI (optional, for local deployment simulation).

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Local Execution Instructions

1. Repository Setup

Verify that you are in the workspace root directory. Copy the environment configuration file:

cp .env.example .env

2. Run the FastAPI Backend

1. Create a virtual environment (recommended):

   python -m venv venv
   # On Windows:
   .\venv\Scripts\activate
   # On macOS or Linux:
   source venv/bin/activate

2. Install Python dependencies:

   pip install -r requirements.txt

3. Start the FastAPI server using Uvicorn:

   uvicorn api.index:app --reload --port 8000

   Note: The backend will be accessible at http://localhost:8000.

3. Run the Astro Frontend

1. Open a new terminal session and install Node.js dependencies:

   npm install

2. Start the Astro development server:

   npm run dev

   Note: The frontend will be accessible at http://localhost:4321.

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Local Deployment Simulation Using Vercel CLI

To replicate the Vercel production environment locally, which automatically routes static frontend pages and serverless backend functions, use the Vercel CLI:

1. Install the Vercel CLI globally:

   npm install -g vercel

2. Start the local simulation:

   vercel dev

   Note: The Vercel CLI will build the frontend assets and run the FastAPI serverless functions under a single unified local address (typically http://localhost:3000).

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Deploying to Vercel

The application is structured for zero-configuration deployment:

1. Connect this repository to your Vercel account.
2. Vercel will automatically identify the Astro framework.
3. Click the Deploy button. The serverless functions inside the api/ directory will be built automatically using the Python runtime.

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License

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