@haykal/notifications-backend

Multi-channel notification system for the Haykal platform.

Features

• Multi-channel delivery: Email, Push, SMS, and In-App notifications
• Template system: Handlebars-based notification templates with variable interpolation
• User preferences: Per-type, per-channel notification preferences
• Pluggable channels: Implement NotificationChannel interface to add custom channels
• Event-driven: Trigger notifications via domain events or direct service API
• Real-time: SSE support for in-app notification streaming

Usage

import { NotificationsModule } from '@haykal/notifications-backend';

@Module({
  imports: [
    NotificationsModule.forRoot({
      channels: {
        inApp: { enabled: true },
        email: { enabled: false },
        push: { enabled: false },
        sms: { enabled: false },
      },
      defaultChannels: ['in_app'],
      retentionDays: 90,
    }),
  ],
})
export class AppModule {}

Sending Notifications

@Injectable()
export class OrdersService {
  constructor(private readonly notifications: NotificationSenderService) {}

  async shipOrder(orderId: string) {
    await this.notifications.send({
      userId: order.userId,
      type: 'order.shipped',
      data: { orderId, trackingNumber },
    });
  }
}

Key Exports

| Export | Type | Description | | ------------------------------ | ------------- | ----------------------------------------------- | | NotificationsModule | NestJS Module | Main module with forRoot() / forRootAsync() | | NotificationSenderService | Service | Send notifications across channels | | NotificationEntity | Entity | Notification records | | NotificationPreferenceEntity | Entity | User notification preferences | | NotificationTemplateEntity | Entity | Notification templates | | NOTIFICATION_ENTITIES | Array | Entities for migration discovery | | EmailChannel | Channel | Email notification delivery | | InAppChannel | Channel | In-app notification (SSE) | | PushChannel | Channel | Push notification delivery | | SmsChannel | Channel | SMS notification delivery |

Related Packages

• @haykal/notifications-client — React Query hooks for notifications
• @haykal/email-backend — Email delivery provider
• @haykal/jobs-backend — Queue integration for async delivery
• @haykal/core-backend — Base infrastructure

Further Reading

• API Reference — Full endpoint listing
• Backend Style Guide — Coding conventions