# activeParticipants The set of participants currently engaged in the activity. ``` @Published> final var activeParticipants: Set { get } ``` ## Discussion This property reflects the set of people invited to a group session and currently engaged in the shared activity on their device. Members who join the conversation over FaceTime but don’t join the shared activity aren’t active participants. As people join or leave the activity, the session object updates the set of active participants. To detect changes to this property, configure a subscriber. Each [`Participant`](/documentation/GroupActivities/Participant) object corresponds to a joined session on a device. If a single person joins the activity from two devices simultaneously, the set contains a separate [`Participant`](/documentation/GroupActivities/Participant) object for each device. --- 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)