Party and Lobby Membership

A party is a UCIK lobby with your party attributes and policy. FUCIK_Lobby.Members contains FUCIK_LobbyMember rows with the player handle, display name, ownership/local flags, and member attributes.

Use these unified nodes:

• Query Lobby Members for the roster
• Kick Lobby Member and Promote Lobby Member for owner controls
• Send Lobby Message and OnLobbyMessage for party chat
• Join Lobby (By Handle) or Join Lobby (By Code) for direct joining
• Resolve Lobby Handle (From Invite Or Presence) for normalized join requests
• Send Crossplay Invite and Show Crossplay Invite UI for invites

Listen to typed member-joined, member-left, owner-changed, message, invite, and join-request events on the lobby subsystem. Steam uses native lobby chat. EOS uses the reserved UCIK_LobbyMessage member attribute and its member-update notification so the sender and payload remain typed.

Use a unified node first. Use a kit-specific lobby node only for that platform's exact option set.