A robust notification microservice built with Node.js, Express.js, MongoDB, and Redis that supports multiple notification channels like Email and SMS, along with a retry mechanism for failed messages.
- ✅ Send Email or SMS notifications
- 📦 Queue-based architecture using Redis
- 🔁 Retry mechanism for failed notifications
- 🛠️ Modular, production-ready structure with ES Modules
- 🧪 Easily extensible for in-app or push notifications
- 📊 MongoDB used to store notification history
| Technology | Usage |
|---|---|
| Node.js | Backend runtime |
| Express.js | REST API framework |
| MongoDB | Stores notification logs |
| Mongoose | ODM for MongoDB |
| Redis | Message queue for background jobs |
| Nodemailer | Sending emails |
| Twilio | Sending SMS messages |
| ES Modules | Clean and modern import/export support |
src/
├── config/ # MongoDB connection
├── controllers/ # Request handlers
├── models/ # Mongoose models
├── routes/ # API route definitions
├── services/ # Notification & SMS logic
├── utils/ # Redis and Email clients
├── worker/ # Background job processor
└── app.js # Entry point
Create a .env file in the root with the following:
PORT=3000
MONGO_URI=mongodb://localhost:27017/notifications
REDIS_URL=redis://localhost:6379
EMAIL_USER=your-email@gmail.com
EMAIL_PASS=your-email-password
TWILIO_SID=your-twilio-sid
TWILIO_AUTH_TOKEN=your-twilio-token
TWILIO_PHONE=your-twilio-phone-numberNote: Use application-specific passwords for Gmail or service credentials for production.
Send a notification (SMS or Email).
{
"userId": "12345",
"type": "sms",
"message": "Hello!",
"userPhone": "+1234567890"
}Fetch all notifications for a user.
A background job runs every second to:
- Pull jobs from Redis queue
- Attempt delivery (email/SMS)
- Retry up to 3 times before marking as failed
node ./src/worker/notificationWorker.js# Install dependencies
npm install
# Start server
npm run start
# In another terminal, start the worker
node ./src/worker/notificationWorker.jsSee the full documentation here 👉 API_DOCUMENTATION.md
Send a notification (SMS or Email).
Fetch all notifications for a specific user.
Retry logic is built-in: failed notifications will retry up to 3 times automatically using a background worker.
- Add unit tests with Jest
- Swagger/OpenAPI documentation
- In-app and push notifications
- Dashboard UI (frontend)
MIT © Aaditya514