The CAPIF core function enables the subscribing entity (i.e. the API invoker, the API exposing function, the API publishing function, the API management function) to subscribe to and unsubscribe from the CAPIF events such as availability events of service APIs, change in service API information, monitoring service API invocations, API invoker onboarding events, etc. The subscription, unsubscription and notification for the CAPIF events are enabled on the following CAPIF reference points:
CAPIF-1 or CAPIF-1e: the API invoker can subscribe to and unsubscribe from CAPIF events and receive notifications from the CAPIF core function;
CAPIF-3 or CAPIF-3e: the AEF can subscribe to and unsubscribe from CAPIF events and receive notifications from the CAPIF core function;
CAPIF-4 or CAPIF-4e: the API publishing function can subscribe to and unsubscribe from CAPIF events and receive notifications from the CAPIF core function; and
CAPIF-5 or CAPIF-5e: the API management function can subscribe to and unsubscribe from CAPIF events and receive notifications from the CAPIF core function.
The information to determine the identity of the subscribing entity
Event criteria
M
The event criteria include event type information like failure API invocation event, new API available event, API version change event, API location change event, API invoker status etc and other query information like service API identifier, service API name, onboarding criteria etc.
Notification reception information
O
The information of the subscribing entity for receiving the notifications for the event.
Indicates the success or failure of the event subscription operation
Cause
O
The cause for the request failure.
Subscription identifier
O
(see NOTE)
The unique identifier for the event subscription.
NOTE:
Shall be present if the Result information element indicates that the event subscription operation is successful. Otherwise subscription identifier shall not be present.
Table 8.8.2.3-1 describes the information flow for event notification from the CAPIF core function to the subscribing entity. A notification about an event is sent to a subscribing entity if the event criteria in the related subscription match the corresponding attributes of the event content.
Upon receiving the event subscription request from the subscribing entity, the CAPIF core function checks for the relevant authorization for the event subscription.
The CAPIF core function sends event notifications to all the subscribing entity(s) that have subscribed for the event matching the criteria. If a notification reception information is available as part of the subscribing entity event subscription, then the notification reception information is used by the CAPIF core function to send event notifications to the subscribing entity.
Upon receiving the event unsubscription request from the subscribing entity, the CAPIF core function checks for the event subscription corresponding to the subscribing entity and further checks if the subscribing entity is authorized to unsubscribe from the CAPIF event.
If the event subscription information corresponding to the subscribing entity is available and the subscribing entity is authorized to unsubscribe for the CAPIF event, the CAPIF core function removes the subscription information.
The subscribing entity sends an event subscription update request to the CAPIF core function in order update a previous subscription to receive notification of events.
Upon receiving the event subscription update request from the subscribing entity, the CAPIF core function checks for the relevant authorization for the event subscription update.
Availability events of service APIs (e.g. active, inactive).
Service API updated
Events related to change in service API information.
Monitoring service API invocations
Events corresponding to service API invocations.
API invoker status
Events related to API invoker status in CAPIF (onboarded, offboarded, onboarding criteria not met status along with the criteria information that is not met).
API topology hiding status
Events related to API topology hiding status in CAPIF (created, revoked).
System related events
Alarm events providing fault information.
Performance related events
Events related to system load conditions.
CAPIF-1/1e interaction events
Events related to CAPIF-1/1e interactions for a service API (e.g. onboarded API invokers).