A lightweight Spring Boot microservice designed to send user notifications across multiple channels:
- 📧 Email (Plain Text + HTML)
- 📱 SMS (Text Message)
Built for scalability and easy integration across microservices, this service enables real-time communication with end users using pluggable notification providers.
This service allows other microservices to send notifications by simply calling an API. It abstracts the channel-specific logic and handles all formatting, templating, and delivery behind the scenes.
Supports:
- Single or multi-channel delivery
- Dynamic notification types (account alerts, OTPs, marketing, etc.)
- HTML templating for rich email content
- Message queuing or async processing (optional)
✅ Send notifications via Email, SMS, WhatsApp
✅ Supports both plain text and rich HTML emails
✅ Unified notification request format
✅ Extensible channel-specific handlers
✅ Easy to integrate with other services via REST or message queue
✅ Logging and error handling for failed deliveries
- Java 17+
- Spring Boot 3+
- JavaMail / SMTP for Email
- Twilio (SMS), WhatsApp Business API (or other providers)
- Thymeleaf / FreeMarker for HTML email templates
- RabbitMQ / Kafka (optional async support)
- Maven or Gradle
git clone https://github.com/ravikant-pal/notification-service.git
cd notification-service
./mvnw spring-boot:runUpdate application.yml with SMTP credentials and provider API keys.
| Method | Endpoint | Description |
|---|---|---|
| POST | /api/v1/notifications/send |
Sends a notification to a user |
{
"to": "ravikant@example.com",
"channel": ["EMAIL", "SMS", "WHATSAPP"],
"subject": "Welcome to Our Platform",
"template": "welcome",
"params": {
"username": "Ravikant",
"supportEmail": "support@yourdomain.com"
},
"isHtml": true
}to: Receiver's identifier (email, phone, or WhatsApp number)channel: Channels to send through (EMAIL,SMS,WHATSAPP)subject: Subject for email (optional for SMS/WhatsApp)template: HTML template name (for email rendering)params: Dynamic values injected into the templateisHtml: Indicates if the email should be rendered as HTML
- Located in
/resources/templates/ - Uses Thymeleaf or FreeMarker for dynamic content rendering
<html>
<body>
<h1>Welcome, [[${username}]]!</h1>
<p>We’re glad to have you. If you need help, contact [[${supportEmail}]].</p>
</body>
</html>Each notification is routed through one or more of the following providers:
- EMAIL: SMTP or SendGrid with HTML support
- SMS: Twilio or any SMS gateway
- WHATSAPP: WhatsApp Business API, Cloud API or Twilio
curl -X POST http://localhost:8080/api/v1/notifications/send \
-H "Content-Type: application/json" \
-d '{
"to": "ravikant@example.com",
"channel": ["EMAIL"],
"subject": "Login Alert",
"template": "login-alert",
"params": {
"username": "Ravikant",
"time": "10:45 PM"
},
"isHtml": true
}'./mvnw testCovers:
- Template rendering
- Email/SMS/WhatsApp sending
- Channel dispatching logic
- Error handling
This project is licensed under the MIT License. See the LICENSE file.
Ravikant Pal
Backend Developer | Notifications & Messaging | Microservices
LinkedIn • GitHub
Feel free to open an issue or PR:
👉 https://github.com/ravikant-pal/notification-service