Is it possible to add the current value of an "Azure App Configuration Key Value" to the Event Grid Subscription Event?

Question

Is there a way to add extra data to the Event Grid Subscription Event?
The normal schema looks like this:

[{
  "id": "84e17ea4-66db-4b54-8050-df8f7763f87b",
  "topic": "/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/testrg/providers/microsoft.appconfiguration/configurationstores/contoso",
  "subject": "https://contoso.azconfig.io/kv/Foo?label=FizzBuzz",
  "data": {
    "key": "Foo",
    "label": "FizzBuzz",
    "etag": "FnUExLaj2moIi4tJX9AXn9sakm0"
    "value": "Foo Value" // This is what I would like to add to the event...
  },
  "eventType": "Microsoft.AppConfiguration.KeyValueModified",
  "eventTime": "2019-05-31T20:05:03Z",
  "dataVersion": "1",
  "metadataVersion": "1"
}]

Answer 1

@Ottens, Vincent Currently, you can set custom headers (Custom delivery properties) on the events that are delivered to Webhooks, Azure Service Bus topics and queues, Azure Event Hubs, and Relay Hybrid Connections as mentioned in this document using delivery properties option. But as your requirement is to add the current value of an "Azure App Configuration Key Value" to the Event Grid Subscription then it is not possible. As rkiss mentioned you need to use your custom logic to get those details either using Azure management REST API and adding it before sending them to your destination.