Azure Event Grid event schema

 Events consist of a set of five required string properties and a required data object. The properties are common to all events from any publisher. The data object has properties that are specific to each publisher. For system topics, these properties are specific to the resource provider, such as Azure Storage or Azure Event Hubs.

Event sources send events to Azure Event Grid in an array, which can have several event objects. When posting events to an event grid topic, the array can have a total size of up to 1 MB. Each event in the array is limited to 64 KB (General Availability) or 1 MB (preview). If an event or the array is greater than the size limits, you receive the response 413 Payload Too Large.

[

  {

    "topic": string,

    "subject": string,

    "id": string,

    "eventType": string,

    "eventTime": string,

    "data":{

      object-unique-to-each-publisher

    },

    "dataVersion": string,

    "metadataVersion": string

  }

]

Property	Type	Description
topic	string	Full resource path to the event source. This field isn't writeable. Event Grid provides this value.
subject	string	Publisher-defined path to the event subject.
eventType	string	One of the registered event types for this event source.
eventTime	string	The time the event is generated based on the provider's UTC time.
id	string	Unique identifier for the event.
data	object	Event data specific to the resource provider.
dataVersion	string	The schema version of the data object. The publisher defines the schema version.
metadataVersion	string	The schema version of the event metadata. Event Grid defines the schema of the top-level properties. Event Grid provides this value

source: https://docs.microsoft.com/en-us/azure/event-grid/event-schema