# postEvent(_:) Posts an event to the system, which displays the information in the system UI. ``` final func postEvent(_ event: GroupSession.Event) ``` ## Parameters `event` The event to display in the system UI. ## Discussion Call this method to update the system’s UI with information about session-related events. For example, a music-listening app might post an event to notify the group that a participant added a song to a shared playlist. The system displays the event information only on the current device. It doesn’t forward events to other devices. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)