diff --git a/src/Core/ZB.MOM.WW.OtOpcUa.Commons/Messages/Admin/StartDeployment.cs b/src/Core/ZB.MOM.WW.OtOpcUa.Commons/Messages/Admin/StartDeployment.cs
new file mode 100644
index 0000000..797097c
--- /dev/null
+++ b/src/Core/ZB.MOM.WW.OtOpcUa.Commons/Messages/Admin/StartDeployment.cs
@@ -0,0 +1,11 @@
+using ZB.MOM.WW.OtOpcUa.Commons.Types;
+
+namespace ZB.MOM.WW.OtOpcUa.Commons.Messages.Admin;
+
+/// <summary>
+/// Request from the admin UI to the <c>AdminOperationsActor</c> singleton asking it to snapshot
+/// the current live-edit state and start a deployment.
+/// </summary>
+public sealed record StartDeployment(
+    string CreatedBy,
+    CorrelationId CorrelationId);
diff --git a/src/Core/ZB.MOM.WW.OtOpcUa.Commons/Messages/Admin/StartDeploymentResult.cs b/src/Core/ZB.MOM.WW.OtOpcUa.Commons/Messages/Admin/StartDeploymentResult.cs
new file mode 100644
index 0000000..8e72a5d
--- /dev/null
+++ b/src/Core/ZB.MOM.WW.OtOpcUa.Commons/Messages/Admin/StartDeploymentResult.cs
@@ -0,0 +1,23 @@
+using ZB.MOM.WW.OtOpcUa.Commons.Types;
+
+namespace ZB.MOM.WW.OtOpcUa.Commons.Messages.Admin;
+
+public enum StartDeploymentOutcome
+{
+    Accepted,
+    NoChanges,
+    AnotherDeploymentInFlight,
+    Rejected,
+}
+
+/// <summary>
+/// Reply from the <c>AdminOperationsActor</c> singleton. <c>Accepted</c> means the snapshot
+/// was sealed and a <c>Deployment</c> row was created; the in-flight deployment can be
+/// tracked through fleet-status broadcasts.
+/// </summary>
+public sealed record StartDeploymentResult(
+    StartDeploymentOutcome Outcome,
+    DeploymentId? DeploymentId,
+    RevisionHash? RevisionHash,
+    string? Message,
+    CorrelationId CorrelationId);
diff --git a/src/Core/ZB.MOM.WW.OtOpcUa.Commons/Messages/Audit/AuditEvent.cs b/src/Core/ZB.MOM.WW.OtOpcUa.Commons/Messages/Audit/AuditEvent.cs
new file mode 100644
index 0000000..ed12a26
--- /dev/null
+++ b/src/Core/ZB.MOM.WW.OtOpcUa.Commons/Messages/Audit/AuditEvent.cs
@@ -0,0 +1,17 @@
+using ZB.MOM.WW.OtOpcUa.Commons.Types;
+
+namespace ZB.MOM.WW.OtOpcUa.Commons.Messages.Audit;
+
+/// <summary>
+/// Cluster-broadcast audit event consumed by the <c>AuditWriterActor</c> singleton, which
+/// batches and idempotently inserts into <c>ConfigAuditLog</c>.
+/// </summary>
+public sealed record AuditEvent(
+    Guid EventId,
+    string Category,
+    string Action,
+    string Actor,
+    DateTime OccurredAtUtc,
+    string? DetailsJson,
+    NodeId SourceNode,
+    CorrelationId CorrelationId);
diff --git a/src/Core/ZB.MOM.WW.OtOpcUa.Commons/Messages/Deploy/ApplyAck.cs b/src/Core/ZB.MOM.WW.OtOpcUa.Commons/Messages/Deploy/ApplyAck.cs
new file mode 100644
index 0000000..10ff6f7
--- /dev/null
+++ b/src/Core/ZB.MOM.WW.OtOpcUa.Commons/Messages/Deploy/ApplyAck.cs
@@ -0,0 +1,15 @@
+using ZB.MOM.WW.OtOpcUa.Commons.Types;
+
+namespace ZB.MOM.WW.OtOpcUa.Commons.Messages.Deploy;
+
+public enum ApplyAckOutcome { Applied, Failed }
+
+/// <summary>
+/// Per-node acknowledgment returned by <c>DriverHostActor</c> to the dispatching coordinator.
+/// </summary>
+public sealed record ApplyAck(
+    DeploymentId DeploymentId,
+    NodeId NodeId,
+    ApplyAckOutcome Outcome,
+    string? FailureReason,
+    CorrelationId CorrelationId);
diff --git a/src/Core/ZB.MOM.WW.OtOpcUa.Commons/Messages/Deploy/DeploymentFailed.cs b/src/Core/ZB.MOM.WW.OtOpcUa.Commons/Messages/Deploy/DeploymentFailed.cs
new file mode 100644
index 0000000..93878f9
--- /dev/null
+++ b/src/Core/ZB.MOM.WW.OtOpcUa.Commons/Messages/Deploy/DeploymentFailed.cs
@@ -0,0 +1,14 @@
+using ZB.MOM.WW.OtOpcUa.Commons.Types;
+
+namespace ZB.MOM.WW.OtOpcUa.Commons.Messages.Deploy;
+
+/// <summary>
+/// Coordinator-published event indicating that the deployment failed and was rolled back.
+/// Includes the set of nodes that NACKed or timed out so the admin UI can surface which
+/// node(s) are sticky on the prior good revision.
+/// </summary>
+public sealed record DeploymentFailed(
+    DeploymentId DeploymentId,
+    string FailureReason,
+    IReadOnlyList<NodeId> FailedNodes,
+    CorrelationId CorrelationId);
diff --git a/src/Core/ZB.MOM.WW.OtOpcUa.Commons/Messages/Deploy/DeploymentSealed.cs b/src/Core/ZB.MOM.WW.OtOpcUa.Commons/Messages/Deploy/DeploymentSealed.cs
new file mode 100644
index 0000000..7f98333
--- /dev/null
+++ b/src/Core/ZB.MOM.WW.OtOpcUa.Commons/Messages/Deploy/DeploymentSealed.cs
@@ -0,0 +1,13 @@
+using ZB.MOM.WW.OtOpcUa.Commons.Types;
+
+namespace ZB.MOM.WW.OtOpcUa.Commons.Messages.Deploy;
+
+/// <summary>
+/// Coordinator-published event indicating that every active driver node successfully applied
+/// the deployment and the row in <c>Deployment</c> has been transitioned to <c>Sealed</c>.
+/// </summary>
+public sealed record DeploymentSealed(
+    DeploymentId DeploymentId,
+    RevisionHash RevisionHash,
+    DateTime SealedAtUtc,
+    CorrelationId CorrelationId);
diff --git a/src/Core/ZB.MOM.WW.OtOpcUa.Commons/Messages/Deploy/DispatchDeployment.cs b/src/Core/ZB.MOM.WW.OtOpcUa.Commons/Messages/Deploy/DispatchDeployment.cs
new file mode 100644
index 0000000..616398f
--- /dev/null
+++ b/src/Core/ZB.MOM.WW.OtOpcUa.Commons/Messages/Deploy/DispatchDeployment.cs
@@ -0,0 +1,13 @@
+using ZB.MOM.WW.OtOpcUa.Commons.Types;
+
+namespace ZB.MOM.WW.OtOpcUa.Commons.Messages.Deploy;
+
+/// <summary>
+/// Sent from the admin-role <c>ConfigPublishCoordinator</c> singleton to each driver node's
+/// <c>DriverHostActor</c>. Tells the node to fetch the deployment artifact identified by
+/// <paramref name="DeploymentId"/> + <paramref name="RevisionHash"/> and apply it.
+/// </summary>
+public sealed record DispatchDeployment(
+    DeploymentId DeploymentId,
+    RevisionHash RevisionHash,
+    CorrelationId CorrelationId);
diff --git a/src/Core/ZB.MOM.WW.OtOpcUa.Commons/Messages/Fleet/FleetStatusChanged.cs b/src/Core/ZB.MOM.WW.OtOpcUa.Commons/Messages/Fleet/FleetStatusChanged.cs
new file mode 100644
index 0000000..e5095e9
--- /dev/null
+++ b/src/Core/ZB.MOM.WW.OtOpcUa.Commons/Messages/Fleet/FleetStatusChanged.cs
@@ -0,0 +1,21 @@
+using ZB.MOM.WW.OtOpcUa.Commons.Types;
+
+namespace ZB.MOM.WW.OtOpcUa.Commons.Messages.Fleet;
+
+public enum FleetNodeHealth { Healthy, Degraded, Unreachable }
+
+public sealed record FleetNodeStatus(
+    NodeId NodeId,
+    FleetNodeHealth Health,
+    RevisionHash? CurrentRevision,
+    DateTime LastSeenUtc);
+
+/// <summary>
+/// Periodic fleet-wide status broadcast pushed by <c>FleetStatusBroadcaster</c> to admin UI
+/// subscribers via SignalR.
+/// </summary>
+public sealed record FleetStatusChanged(
+    IReadOnlyList<FleetNodeStatus> Nodes,
+    DeploymentId? CurrentDeployment,
+    DateTime AsOfUtc,
+    CorrelationId CorrelationId);
diff --git a/src/Core/ZB.MOM.WW.OtOpcUa.Commons/Messages/Redundancy/NodeRedundancyState.cs b/src/Core/ZB.MOM.WW.OtOpcUa.Commons/Messages/Redundancy/NodeRedundancyState.cs
new file mode 100644
index 0000000..c1e6cca
--- /dev/null
+++ b/src/Core/ZB.MOM.WW.OtOpcUa.Commons/Messages/Redundancy/NodeRedundancyState.cs
@@ -0,0 +1,16 @@
+using ZB.MOM.WW.OtOpcUa.Commons.Types;
+
+namespace ZB.MOM.WW.OtOpcUa.Commons.Messages.Redundancy;
+
+public enum RedundancyRole { Primary, Secondary, Detached }
+
+/// <summary>
+/// Snapshot of a single node's redundancy state. Aggregated by <c>RedundancyStateActor</c>
+/// to compute fleet-wide ServiceLevel.
+/// </summary>
+public sealed record NodeRedundancyState(
+    NodeId NodeId,
+    RedundancyRole Role,
+    bool IsClusterLeader,
+    bool IsRoleLeaderForDriver,
+    DateTime AsOfUtc);
diff --git a/src/Core/ZB.MOM.WW.OtOpcUa.Commons/Messages/Redundancy/RedundancyStateChanged.cs b/src/Core/ZB.MOM.WW.OtOpcUa.Commons/Messages/Redundancy/RedundancyStateChanged.cs
new file mode 100644
index 0000000..6b21638
--- /dev/null
+++ b/src/Core/ZB.MOM.WW.OtOpcUa.Commons/Messages/Redundancy/RedundancyStateChanged.cs
@@ -0,0 +1,11 @@
+using ZB.MOM.WW.OtOpcUa.Commons.Types;
+
+namespace ZB.MOM.WW.OtOpcUa.Commons.Messages.Redundancy;
+
+/// <summary>
+/// Broadcast whenever the cluster's redundancy topology changes (node up/down, role-leader
+/// change, partition heal). Subscribers compute their local OPC UA ServiceLevel from this.
+/// </summary>
+public sealed record RedundancyStateChanged(
+    IReadOnlyList<NodeRedundancyState> Nodes,
+    CorrelationId CorrelationId);