Introduction
Event Subscription Service enables the users of the platform to react to various events happening in the platform. Currently only http callback (webhook) endpoints are supported as event handlers/receivers, and it must be available when creating a subscription so that you can validate it. Validation is done by passing a string token to the endpoint with a validation event type and then expecting that same token to be returned as response to the callback. By using subscriptions you can subscribe to one or all events for a single given resource. You can find the list of all events using Get event types endpoint.
how does it work?
When you create or update a subscription of an event using the end point Create or Update Event Subscription, you will receive call back to your notification URL with details of validation URL as shown below

To prove ownership of the endpoint, send the post request to the validation URL with validation code received in your callback response as shown below.

Note:
The event subscription remains in a Pending state until it is validated.
After successfully validated your end point, you will receive the notifications when the particular event happens in the platform as shown below.
