CallKit iOS 14.4 to 14.5 API Differences

CXError.h

Added CXErrorDomainNotificationServiceExtension

Added CXErrorCodeMissingVoIPBackgroundMode

Added CXErrorCodeNotificationServiceExtensionError

Added CXErrorCodeNotificationServiceExtensionErrorUnknown

Added CXErrorCodeNotificationServiceExtensionErrorInvalidClientProcess

Added CXErrorCodeNotificationServiceExtensionErrorMissingNotificationFilteringEntitlement

CXProvider.h

Added +[CXProvider reportNewIncomingVoIPPushPayload:completion:]