backend

🚀 IoT Sensor Backend API

A modern backend API built with Express.js and Sequelize, designed for collecting, analyzing, and retrieving sensor data from IoT devices like ESP32 units.

🚀 Live API: https://backend-belz.onrender.com
📘 Swagger Docs: https://backend-belz.onrender.com/api-docs 📄 Swagger JSON:
https://backend-belz.onrender.com/swagger.json

---

📁 Project Structure

                     [ Hardware Device(s) ]
                             |
                Sends JSON via HTTP / MQTT
                             |
                             v
                  [ Express.js API Server ]
                             |
               ┌─────────────┴──────────────┐
               |                            |
     [ Middleware Layer ]        [ Route Handlers ]
  (Auth, Validation, etc.)     (auth, data, stats)

                             |
                    ┌────────┴────────┐
                    |                 |
         [ Controllers            Services ]
                    |                 |
                    └───[ Sequelize ORM ]────┐
                                             |
                                       [ PostgreSQL  ]
                                             |
                          Sensor Data, Users, Stats Tables
                             |
                             |
                             v
                ┌──────────────────────────┐
                |           JWT            |
                └──────────────────────────┘
                             |
                    Serves to Frontends
         ┌────────Consumes API    ( Fetch  )────┐
         |                                      |
  [ Web Frontend ]                       [ Mobile App ]
     (React)                             (React Native)****

---

🛠️ Getting Started

Clone the repo and install dependencies:

git clone https://github.com/chas-challenge-code-6/backend
cd backend
npm install
npm run dev

▶️ Run locally:

cd backend
npm install
npm run dev

Backend will be available at: http://localhost:3000

---

🔐 Authentication Flow

Register

POST /auth/register

{
  "username": "testuser",
  "password": "test1234",
  "email": "test@example.com"
}

Login

POST /auth/login

Returns a JWT token.

Authenticated Actions (require Bearer token)

• GET /auth/me - View profile
• PATCH /auth/me - Update profile
• DELETE /auth/me - Delete account
• POST /auth/logout - Logout (handled client-side)

Password Recovery

• POST /auth/forgot-password – Send reset email
• POST /auth/reset-password – Reset using token

---

📡 Sensor Data Endpoints

All routes require a valid JWT token.

Submit Data

POST /api/data

{
  "device_id": "ESP32-001",
  "sensors": {
    "gas": { "ppm": 400 },
    "temperature": 22.5,
    "humidity": 45,
    "fall_detected": false,
    "heart_rate": 75,
    "noise_level": 80,
    "steps": 1000,
    "device_battery": 85,
    "strap_battery": 100
  }
}

Latest per device

GET /api/data/latest

Get history for device

GET /api/data/:device_id?from=...&to=...

Alerts

GET /api/alerts

Detects gas > 1000 ppm, fall detection, noise > 100 dB

---

📊 Stats & Summary

GET /stats/summary

Returns:

• Total entries
• Device count
• Averages for temperature, humidity, etc.

---

📝 Notes

⚠️ .env file is public in this repo intentionally for educational purposes.
⚠️ Production apps should never expose secrets or config like this. Uses Render PostgreSQL as the cloud database.

---

🧪 Test it

You can explore and test the API using the following tools:

• 🔗 Swagger UI – Interactive API documentation
• 📄 Swagger JSON – Raw OpenAPI spec
• 🧪 Use tools like Thunder Client or Postman to make authenticated requests
• 🧼 Automated tests are available via Jest

Run tests locally

npm test