diff --git a/NucleicRemote/NucleicRemote/Models/RemoteStore.swift b/NucleicRemote/NucleicRemote/Models/RemoteStore.swift
index b4d4f09..72acc23 100644
--- a/NucleicRemote/NucleicRemote/Models/RemoteStore.swift
+++ b/NucleicRemote/NucleicRemote/Models/RemoteStore.swift
@@ -60,6 +60,10 @@ final class RemoteStore: ObservableObject {
 
     // Open session projection.
     @Published private(set) var openSessionID: SessionID?
+    /// The paired Mac that owns the open session (mesh P3). The open transcript's intents route to
+    /// it, and the host-specific projected values (capabilities/scope/catalog/connectivity) follow
+    /// it while a session is open. `nil` when nothing is open.
+    private var openSessionHostID: String?
     @Published private(set) var openEvents: [AgentEvent] = []
     @Published private(set) var openApprovals: [ApprovalRequest] = []
     /// The open session's full diff (the Mac Diff tab's patch), fetched on demand when the