ASP.NET ZERO has built-in webhook system designed with pub/sub pattern.
In Webhook Subscriptions page, you can see all of your webhook subscriptions:
You can click a row to see detail of a subscription.
In Webhook Subscription Detail page, you can edit, activate or deactivate a subscription. You can also see all webhook send attempts that your subscription received.
You can resend a webhook with same parameter or view webhook event.
In Webhook Event Detail page, you can see the detail of a created webhook. And you can see all send attempts for all of your subscriptions.
For more information. You can check ASP.NET Boilerplate webhook documentation.