Contents of an Event Message

Learn about the contents of an event message.

Every event message includes two main parts: 

  • Envelope: a container for all event messages

  • Payload: the data from the resource emitting the event message

Event Envelope

These attributes for an event envelope are the same for all events. The structure of the envelope follows the CloudEvents industry standard format hosted by the Cloud Native Computing Foundation ( CNCF).

Property Description

The version of the CloudEvents specification.

Note: Events uses version 0.1 specification of the CloudEvents event envelope.

contentType Set to application/json. The content type of the data contained in the data attribute.
data The payload of the event. All of the information within data comes from the resource emitting the event. See the following table for more detail on the structure of the payload.

The UUID of the event. This identifier is not an OCID, but just a unique ID for the event.

eventTime The time of the event, expressed in RFC 3339 timestamp format.

The type of event that happened. For a list of all services that produce events and the even types that those services track, see Services that Produce Events.

Note: The service that produces the event can also add, remove, or change the meaning of a field by publishing a new version of an eventType and revising the eventTypeVersion field.


The version of the event type.

extensions The OCID of the compartment from which the event originates. If the event originates from the root compartment of the tenancy, then this attribute specifies a tenancy OCID. This attribute is mandatory in the Oracle Cloud Infrastructure implementation of the CloudEvents specification.
source The resource that produced the event. For example, an Autonomous Database or an Object Storage bucket.


The data in these fields depends on which service produced the event and the event type it defines.

Property Description

The OCID of the compartment of the resource emitting the event.

compartmentName The name of the compartment of the resource emitting the event.
resourceName The name of the resource emitting the event.

An OCID or an ID for the resource emitting the event.

availabilityDomain The availability domain of the resource emitting the event.

Free-form tags added to the resource emitting the event.

definedTags Defined tags added to the resource emitting the event.

A container for attributes unique to the resource emitting the event. In the example bucket event that follows, the payload includes three Object Storage attributes: 

  • namespace
  • publicAccessType
  • eTag

To determine what attributes are included for other resources, retrieve an event or consult the reference samples listed on Services that Produce Events.

Resource Identifiers

Most types of Oracle Cloud Infrastructure resources have a unique, Oracle-assigned identifier called an Oracle Cloud ID (OCID). For information about the OCID format and other ways to identify your resources, see Resource Identifiers.

An Example Event

The following is an example bucket event emitted by Object Storage.

	"cloudEventsVersion": "0.1",
	"eventID": "<unique_ID>",
	"eventType": "com.oraclecloud.objectstorage.deletebucket",
	"source": "objectstorage",
	"eventTypeVersion": "1.0",
	"eventTime": "2019-01-10T21:19:24Z",
	"contentType": "application/json",
	"extensions": {
		"compartmentId": "ocid1.compartment.oc1..<unique_ID>"
	"data": {
		"compartmentId": "ocid1.compartment.oc1..<unique_ID>",
		"compartmentName": "example_name",
		"resourceName": "my_bucket",
		"resourceId": "ocid1.compartment.oc1..<unique_ID>",
		"availabilityDomain": "NfHZ:PHX-AD-2",
		"freeFormTags": {
			"Department": "Finance"
		"definedTags": {
			"Operations": {
				"CostCenter": "42"
		"additionalDetails": {
			"namespace": "example_namespace",
			"publicAccessType": "NoPublicAccess",
			"eTag": "f8ffb6e9-f602-460f-a6c0-00b5abfa24c7"