Integration between Front Systems POS and ERP

Overview

A seamless integration between a POS system and an ERP system ensures real-time data synchronization, improving operational efficiency, customer experience, and accurate inventory management. This integration can be implemented using webhooks, allowing the ERP system to receive instant updates when relevant events occur in the POS system.

Integration Architecture

The integration follows a webhook-based architecture, where the POS system triggers events and the ERP system processes them in real time.

Key Components:

  1. Webhook Subscription: The ERP subscribes to relevant events from the POS.

  2. Event Processing: The ERP receives and processes webhook events.

  3. Data Synchronization: The ERP updates its records based on received events.

  4. Failure Handling: A mechanism to resend failed webhook events.

Webhook Subscription

To receive real-time notifications, the ERP system must subscribe to specific webhook events provided by the POS system.

Example Webhook Subscription Request:

{    "event": "SaleCreated",    
     "url": "https://yourerp.com/api/webhook-handler" 
}

Webhook events and usage

  • SaleCreated: Triggered when a sale is completed in the POS. The ERP system records the sales transaction.

  • StockMovementCreated: Triggered when stock levels change. The ERP system synchronizes stock levels.

  • POSSettlementCreated: Triggered at the end of the day when the POS settlement occurs. The ERP system updates financial records.

  • ProductTransferCreated: Triggered when products are transferred between locations. The ERP system tracks stock movements.

  • StockReservationCreated: Triggered when stock is reserved. The ERP system manages stock allocation.

  • DeliveryCompleted: Triggered when a delivery is completed and archived. The ERP system records the final stock movements.

  • DeliveryItemsReceived: Triggered when a delivery is partially or fully received. The ERP system updates stock levels accordingly.

Event processing workflow

  1. Receive Webhook: The ERP system exposes an endpoint to receive webhook notifications.

  2. Validate Data: Ensure the payload is correctly formatted and contains expected data.

  3. Process Event: Update the corresponding records in the ERP system.

  4. Acknowledge success: Respond with HTTP 2xx to confirm successful processing. NB: if you are not able to handle the event really fast, you have to respond with HTTP 202 immediately, store the content in a queue (EventHub/Servicebus or similar) and then process it.

  5. Handle failures: Log failed events and implement a retry mechanism.

Handling Missed Webhook Events

If a webhook event is lost due to system downtime, the ERP can periodically check for missing events using:

Example request to retrieve failed events:

GET /api/WebhooksEvents?from=2025-03-01&to=2025-03-10&success=false

Example Response:

[
  {       
     "webhookId": "edd10354-7625-4f29-bd9f-e43c61cf2ebe",       
     "webhookEventId": "b38832a2-b522-4b2d-ba10-5f217a9efbc1",       
     "status": "Not found",       
     "statusCode": 404,       
     "success": false    
  } 
]

Resending a failed webhook

And then use ResendWebhookEvent to resend the ones not retrieved. If your back-end is idempotent, then you can make a small service to resend all failed events on a regular basis (until GetWebHooksEvents success=false return an empty payload)

Best Practices

  • Use Idempotency: Ensure duplicate webhook events do not cause duplicate transactions.

  • Monitor event logs: Regularly check for failed events and implement a retry mechanism.

  • Ensure scalability: Design the integration to handle high volumes of transactions efficiently.