This project documents the development of Radius, a hyper-local, decentralized disaster relief platform. It focuses on connecting people in immediate proximity during crises by enabling real-time resource sharing and SOS broadcasting without relying on complex external infrastructure.

The code is organized into core backend and frontend components, each handling a specific aspect of the application:

• FastAPI Server: Acts as the central traffic controller, handling API requests for creating posts and fetching nearby data.
• Geospatial Logic: Implements the Haversine Formula manually to calculate precise distances between users and resources on a spherical surface.
• Static File Serving: Automatically serves the frontend files, enabling a unified deployment structure.
• Database Management: Handles connections to the SQLite database to store and retrieve live alerts.

• Automatic Initialization: A standalone script that initializes the lifeline.db SQLite database.
• Schema Design: Creates the posts table with fields for geolocation (lat, lon), item type (REQUEST/OFFER), and descriptions.
• Seeding: Includes logic to insert dummy data for immediate testing upon setup.

• Command Center (index.html): A desktop-first dashboard for NGOs and responders. It integrates Leaflet.js to visualize all active requests on an interactive map.
• Field Unit (mobile.html): A lightweight, mobile-first interface designed for victims or volunteers to quickly broadcast their location and needs.
• Client Logic (app.js): Manages the browser's navigator.geolocation API to capture precise coordinates and performs asynchronous fetch calls to the backend.
• Responsive Styling (styles.css): Uses modern CSS to ensure the app works on both large dashboard screens and small mobile devices, with color-coded badges for "Requests" (Red) and "Offers" (Green).

To run this project, you need Python installed on your machine. The system relies on the following lightweight libraries:

• fastapi
• uvicorn
• pydantic

You can run the platform locally by following these steps:

1. Install Dependencies:

   pip install -r requirements.txt

2. Initialize the Database:

   python setup_db.py

3. Start the Server:

   uvicorn main:app --reload --host 0.0.0.0 --port 8000

4. Access the Platform:
   • Dashboard: Open http://localhost:8000 in your browser.
   • Mobile: Connect your phone to the same Wi-Fi and visit http://<YOUR_LAPTOP_IP>:8000/static/mobile.html.

• Python (FastAPI): High-performance backend logic.
• SQLite: Zero-configuration, serverless database engine.
• Leaflet.js: Interactive maps for the command center.
• HTML5/CSS3: Semantic markup and responsive design.
• JavaScript (ES6): Async/Await logic and DOM manipulation.

Radius • Created by Pushti Kadia