🛰️ Lost & Found Platform (Real-Time, Family-Based, AI-Powered)

A real-time Lost & Found tracking platform that uses AI-powered face matching, geo-fencing, and live location updates to help families track missing members efficiently. The platform features family-specific visibility, Socket.io live streaming, and MapLibre for open-source maps.

---

🚀 Features

🔍 AI-Powered Face Matching

• Upload an image to search for potential matches across the user base.
• Uses a lightweight ML model to compute face embeddings and match similarity.

👨‍👩‍👧 Family-Based Visibility

• Each user belongs to a family group.

• Users can see only:

  • Their own family members
  • The family head

• Ensures privacy and secure access control.

📡 Real-Time Location Tracking

• Live location updates every 20 seconds via Socket.io.
• Automatic re-subscription on reconnect.
• Shows the last known location if the user disconnects.

🗺️ Dynamic Map Visualization

• Uses MapLibre GL (fully open-source alternative to Google Maps).
• Real-time markers for all active family members.
• Smooth transitions based on live data stream.

🛡️ Geo-Fencing Alerts

• Define a safe region.
• Trigger warnings when a member moves outside the boundary.

🔐 Secure Backend

• Built using Express.js, MongoDB, and JWT authentication.
• Role-based access (Family Head, Member).
• Robust validation and error handling.

---

🏗️ Tech Stack

Frontend

• React.js
• JavaScript (ES6)
• MapLibre GL
• Socket.io Client

Backend

• Node.js
• Express.js
• MongoDB (Mongoose)
• Socket.io Server
• JWT Authentication

AI / ML

• Face embedding generation
• Image similarity scoring
• Lightweight model for fast inference

---

📁 Folder Structure

/client
  /src
    /components
    /pages
    /hooks
    /utils

/server
  /controllers
  /models
  /routes
  /middlewares
  /services

/ml-service (optional)
  /face-matching

---

🔧 Environment Variables

Create a .env file in /server:

PORT=5000
MONGO_URI=your_mongo_connection_string
JWT_SECRET=your-secret-key

If using an external ML service:

ML_SERVICE_URL=http://localhost:8000/match

---

🛠️ Installation & Setup

1️⃣ Clone the Repository

git clone https://github.com/your-username/lost-and-found.git
cd lost-and-found

2️⃣ Install Dependencies

Frontend:

cd client
npm install

Backend:

cd server
npm install

3️⃣ Start the App

Backend:

npm run dev

Frontend:

npm start

---

⚡ Real-Time Flow Overview

1. User logs in → receives JWT token.
2. User shares live location → Socket.io sends updates every 20 seconds.
3. Backend stores last known location and broadcasts to relevant family members.
4. Map updates markers in real time.
5. Geo-fence rules checked for every update → send alert if breached.
6. For missing person reports → Face matching generates top similarity matches.

---

🧪 API Endpoints (Short Version)

Auth

Method	Endpoint	Description
POST	/auth/register	Create account
POST	/auth/login	Login & get token

Family & Users

Method	Endpoint	Description
GET	/family/members	List family members
POST	/family/add	Add a new user

Location

| POST | /location/update | Update user location | | GET | /location/last | Get last known location |

AI

| POST | /ai/match | Upload image & find similar faces |

---

🧩 Architecture Diagram (Text Version)

[React Frontend] 
    ↕ Socket.io
    ↕ REST APIs
[Express Backend] 
    ↕
[MongoDB]

[Optional ML Face-Matching Service]

---

📜 License

MIT License.

---