# setNotifications(_:) Attaches notification callbacks — tip updates, header tips, progress reports, warnings, and fatal errors. ``` func setNotifications(_ notifications: NotificationCallbacks) ``` ## Parameters `notifications` Preconfigured [`NotificationCallbacks`](/documentation/BitcoinKernel/NotificationCallbacks) with the closures you want invoked populated. ## Discussion The kernel takes ownership of the callback state; you may release your Swift reference to `notifications` after this call returns. All callbacks are dispatched on kernel-internal threads — see [`NotificationCallbacks`](/documentation/BitcoinKernel/NotificationCallbacks) for the list and their semantics.