diff --git a/src/Server/ZB.MOM.WW.OtOpcUa.Runtime/OpcUa/OpcUaPublishActor.cs b/src/Server/ZB.MOM.WW.OtOpcUa.Runtime/OpcUa/OpcUaPublishActor.cs
new file mode 100644
index 0000000..f02a0c0
--- /dev/null
+++ b/src/Server/ZB.MOM.WW.OtOpcUa.Runtime/OpcUa/OpcUaPublishActor.cs
@@ -0,0 +1,70 @@
+using Akka.Actor;
+using Akka.Event;
+using ZB.MOM.WW.OtOpcUa.Commons.Types;
+
+namespace ZB.MOM.WW.OtOpcUa.Runtime.OpcUa;
+
+/// <summary>
+/// Single-threaded bridge between Akka messages and the OPC UA SDK address space. Hosted on
+/// the pinned <c>opcua-synchronized-dispatcher</c> (Task 19 HOCON) so the OPC UA SDK sees
+/// only one thread per actor instance — its session/subscription locks expect strict
+/// single-threaded access.
+///
+/// Engine wiring (call into <c>OpcUaApplicationHost</c> address-space writes, manage
+/// <c>ServiceLevel</c> + <c>ServerUriArray</c> nodes, subscribe to the <c>redundancy-state</c>
+/// DistributedPubSub topic) is staged for follow-up F10. This skeleton compiles + exposes the
+/// message contracts so producers (DriverInstance, VirtualTag, ScriptedAlarm) can target it.
+/// </summary>
+public sealed class OpcUaPublishActor : ReceiveActor
+{
+    public const string DispatcherId = "opcua-synchronized-dispatcher";
+
+    public sealed record AttributeValueUpdate(string NodeId, object? Value, OpcUaQuality Quality, DateTime TimestampUtc);
+    public sealed record AlarmStateUpdate(string AlarmNodeId, bool Active, bool Acknowledged, DateTime TimestampUtc);
+    public sealed record RebuildAddressSpace(CorrelationId Correlation);
+    public sealed record ServiceLevelChanged(byte ServiceLevel);
+
+    public enum OpcUaQuality { Good, Uncertain, Bad }
+
+    private readonly ILoggingAdapter _log = Context.GetLogger();
+    private int _writes;
+
+    /// <summary>
+    /// Returns Props pre-configured to use the <c>opcua-synchronized-dispatcher</c>. Caller can
+    /// still override by chaining <c>.WithDispatcher(otherId)</c> for unit tests.
+    /// </summary>
+    public static Props Props() =>
+        Akka.Actor.Props.Create(() => new OpcUaPublishActor()).WithDispatcher(DispatcherId);
+
+    /// <summary>Test-only Props that omits the pinned dispatcher requirement.</summary>
+    public static Props PropsForTests() =>
+        Akka.Actor.Props.Create(() => new OpcUaPublishActor());
+
+    public int WriteCount => _writes;
+
+    public OpcUaPublishActor()
+    {
+        Receive<AttributeValueUpdate>(msg =>
+        {
+            // F10: call into OpcUaApplicationHost to write the address-space node.
+            Interlocked.Increment(ref _writes);
+            _log.Debug("OpcUaPublish: queued AttributeValueUpdate for {Node} ({Quality}) (write staged for F10)",
+                msg.NodeId, msg.Quality);
+        });
+        Receive<AlarmStateUpdate>(msg =>
+        {
+            Interlocked.Increment(ref _writes);
+            _log.Debug("OpcUaPublish: queued AlarmStateUpdate for {Node} (active={Active})",
+                msg.AlarmNodeId, msg.Active);
+        });
+        Receive<RebuildAddressSpace>(msg =>
+        {
+            _log.Info("OpcUaPublish: address-space rebuild requested (correlation={Correlation}); F10 wires the SDK call",
+                msg.Correlation);
+        });
+        Receive<ServiceLevelChanged>(msg =>
+        {
+            _log.Debug("OpcUaPublish: ServiceLevel={Level} (write staged for F10)", msg.ServiceLevel);
+        });
+    }
+}
diff --git a/tests/Server/ZB.MOM.WW.OtOpcUa.Runtime.Tests/OpcUa/OpcUaPublishActorTests.cs b/tests/Server/ZB.MOM.WW.OtOpcUa.Runtime.Tests/OpcUa/OpcUaPublishActorTests.cs
new file mode 100644
index 0000000..3d44bda
--- /dev/null
+++ b/tests/Server/ZB.MOM.WW.OtOpcUa.Runtime.Tests/OpcUa/OpcUaPublishActorTests.cs
@@ -0,0 +1,31 @@
+using Akka.Actor;
+using Shouldly;
+using Xunit;
+using ZB.MOM.WW.OtOpcUa.Commons.Types;
+using ZB.MOM.WW.OtOpcUa.Runtime.OpcUa;
+using ZB.MOM.WW.OtOpcUa.Runtime.Tests.Harness;
+
+namespace ZB.MOM.WW.OtOpcUa.Runtime.Tests.OpcUa;
+
+public sealed class OpcUaPublishActorTests : RuntimeActorTestBase
+{
+    [Fact]
+    public void Accepts_message_contracts_without_pinned_dispatcher_in_tests()
+    {
+        var actor = Sys.ActorOf(OpcUaPublishActor.PropsForTests());
+        actor.Tell(new OpcUaPublishActor.AttributeValueUpdate("ns=2;s=Tag1", 42.0, OpcUaPublishActor.OpcUaQuality.Good, DateTime.UtcNow));
+        actor.Tell(new OpcUaPublishActor.AlarmStateUpdate("ns=2;s=Alarm1", true, false, DateTime.UtcNow));
+        actor.Tell(new OpcUaPublishActor.RebuildAddressSpace(CorrelationId.NewId()));
+        actor.Tell(new OpcUaPublishActor.ServiceLevelChanged(240));
+
+        // Actor stays alive; no exceptions surface.
+        ExpectNoMsg(TimeSpan.FromMilliseconds(200));
+    }
+
+    [Fact]
+    public void Production_Props_targets_opcua_synchronized_dispatcher()
+    {
+        var props = OpcUaPublishActor.Props();
+        props.Dispatcher.ShouldBe(OpcUaPublishActor.DispatcherId);
+    }
+}