# Participants The set of participants to include in messages. ``` enum Participants ``` ## Topics ### Getting the set of participants [`case all`](/documentation/GroupActivities/Participants/all) The set of all participants. [`case only(Set)`](/documentation/GroupActivities/Participants/only(_:)-swift.enum.case) A custom subset of participants. [`static func only(Participant) -> Participants`](/documentation/GroupActivities/Participants/only(_:)-swift.type.method) Returns a set containing the specified participant. ## Relationships ### Conforms To [`Sendable`](/documentation/Swift/Sendable) [`SendableMetatype`](/documentation/Swift/SendableMetatype) --- 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)