diff --git a/src/Server/ZB.MOM.WW.OtOpcUa.Runtime/ScriptedAlarms/ScriptedAlarmHostActor.cs b/src/Server/ZB.MOM.WW.OtOpcUa.Runtime/ScriptedAlarms/ScriptedAlarmHostActor.cs
index 44091b70..6509e337 100644
--- a/src/Server/ZB.MOM.WW.OtOpcUa.Runtime/ScriptedAlarms/ScriptedAlarmHostActor.cs
+++ b/src/Server/ZB.MOM.WW.OtOpcUa.Runtime/ScriptedAlarms/ScriptedAlarmHostActor.cs
@@ -502,11 +502,14 @@ public sealed class ScriptedAlarmHostActor : ReceiveActor
 
     /// <summary>The acting user for an <see cref="AlarmTransitionEvent"/>. Engine-driven
     /// Activated / Cleared transitions are <c>"system"</c>; operator Acknowledged / Confirmed carry the
-    /// recorded user from the condition state, falling back to <c>"system"</c> when none was recorded.</summary>
+    /// recorded user from the condition state, falling back to <c>"system"</c> when none was recorded.
+    /// CommentAdded carries the commenter's identity from the last entry in
+    /// <see cref="AlarmConditionState.Comments"/>.</summary>
     private static string TransitionUser(ScriptedAlarmEvent e) => e.Emission switch
     {
         EmissionKind.Acknowledged => e.Condition.LastAckUser ?? "system",
         EmissionKind.Confirmed => e.Condition.LastConfirmUser ?? "system",
+        EmissionKind.CommentAdded => e.Condition.Comments.Count > 0 ? e.Condition.Comments[^1].User : "system",
         _ => "system",
     };
 
diff --git a/tests/Server/ZB.MOM.WW.OtOpcUa.Runtime.Tests/ScriptedAlarms/ScriptedAlarmHostActorTests.cs b/tests/Server/ZB.MOM.WW.OtOpcUa.Runtime.Tests/ScriptedAlarms/ScriptedAlarmHostActorTests.cs
index 34bee4ca..5dafa92b 100644
--- a/tests/Server/ZB.MOM.WW.OtOpcUa.Runtime.Tests/ScriptedAlarms/ScriptedAlarmHostActorTests.cs
+++ b/tests/Server/ZB.MOM.WW.OtOpcUa.Runtime.Tests/ScriptedAlarms/ScriptedAlarmHostActorTests.cs
@@ -389,6 +389,34 @@ public sealed class ScriptedAlarmHostActorTests : RuntimeActorTestBase
         evt.AlarmId.ShouldBe("alm-1");
     }
 
+    /// <summary>CommentAdded transition carries the commenter's identity: a non-empty AddComment drives
+    /// AddCommentAsync — the resulting AlarmTransitionEvent("CommentAdded") on the alerts topic must carry
+    /// <c>User == cmd.User</c> (the acting operator), NOT the generic <c>"system"</c> sentinel that
+    /// engine-driven transitions use. This verifies the <see cref="ScriptedAlarmHostActor"/>
+    /// TransitionUser arm for <see cref="EmissionKind.CommentAdded"/>.</summary>
+    [Fact]
+    public void CommentAdded_transition_carries_operator_user()
+    {
+        var publish = CreateTestProbe();
+        var mux = CreateTestProbe();
+        var alerts = CreateTestProbe();
+        SubscribeToAlerts(alerts);
+
+        var (host, _) = Spawn(publish, mux);
+        host.Tell(new ScriptedAlarmHostActor.ApplyScriptedAlarms(new[] { Plan(id: "alm-1", depRef: "M.T") }));
+        mux.ExpectMsg<DependencyMuxActor.RegisterInterest>(Timeout); // load completed
+
+        // Send AddComment — the alarm does NOT need to be active; AddCommentAsync is unconditional.
+        host.Tell(new AlarmCommand(
+            AlarmId: "alm-1", Operation: "AddComment", User: "carol", Comment: "operator note", UnshelveAtUtc: null));
+
+        // The CommentAdded AlarmTransitionEvent must carry the operator's identity, not "system".
+        var evt = alerts.FishForMessage<AlarmTransitionEvent>(e => e.TransitionKind == "CommentAdded", Timeout);
+        evt.AlarmId.ShouldBe("alm-1");
+        evt.User.ShouldBe("carol");           // operator — NOT "system"
+        evt.Comment.ShouldBe("operator note");
+    }
+
     /// <summary>Validation: a TimedShelve command missing UnshelveAtUtc is rejected (logged), NOT thrown —
     /// the actor stays alive and still processes a subsequent valid command, proving it didn't fault.</summary>
     [Fact]