diff --git a/src/NATS.Server/Events/EventSubjects.cs b/src/NATS.Server/Events/EventSubjects.cs
index 4eed2bd..81401c6 100644
--- a/src/NATS.Server/Events/EventSubjects.cs
+++ b/src/NATS.Server/Events/EventSubjects.cs
@@ -22,6 +22,12 @@ public static class EventSubjects
     public const string AuthError = "$SYS.SERVER.{0}.CLIENT.AUTH.ERR";
     public const string AuthErrorAccount = "$SYS.ACCOUNT.CLIENT.AUTH.ERR";
 
+    // Remote server and leaf node events
+    public const string RemoteServerShutdown = "$SYS.SERVER.{0}.REMOTE.SHUTDOWN";
+    public const string RemoteServerUpdate = "$SYS.SERVER.{0}.REMOTE.UPDATE";
+    public const string LeafNodeConnected = "$SYS.SERVER.{0}.LEAFNODE.CONNECT";
+    public const string LeafNodeDisconnected = "$SYS.SERVER.{0}.LEAFNODE.DISCONNECT";
+
     // Request-reply subjects (server-specific)
     public const string ServerReq = "$SYS.REQ.SERVER.{0}.{1}";
 
diff --git a/tests/NATS.Server.Tests/Events/RemoteServerEventTests.cs b/tests/NATS.Server.Tests/Events/RemoteServerEventTests.cs
new file mode 100644
index 0000000..661b355
--- /dev/null
+++ b/tests/NATS.Server.Tests/Events/RemoteServerEventTests.cs
@@ -0,0 +1,200 @@
+using System.Text.Json;
+using NATS.Server.Events;
+
+namespace NATS.Server.Tests.Events;
+
+/// <summary>
+/// Tests for remote server and leaf node event DTOs and subject constants.
+/// Go reference: events.go — remote server lifecycle, leaf node advisory subjects.
+/// Gap 10.8: RemoteServerShutdown, RemoteServerUpdate, LeafNodeConnected events.
+/// </summary>
+public class RemoteServerEventTests
+{
+    // --- RemoteServerShutdownEvent ---
+
+    [Fact]
+    public void RemoteServerShutdownEvent_HasCorrectEventType()
+    {
+        RemoteServerShutdownEvent.EventType.ShouldBe("io.nats.server.advisory.v1.remote_shutdown");
+        var ev = new RemoteServerShutdownEvent();
+        ev.Type.ShouldBe(RemoteServerShutdownEvent.EventType);
+    }
+
+    [Fact]
+    public void RemoteServerShutdownEvent_GeneratesUniqueId()
+    {
+        var ev1 = new RemoteServerShutdownEvent();
+        var ev2 = new RemoteServerShutdownEvent();
+        ev1.Id.ShouldNotBeNullOrEmpty();
+        ev2.Id.ShouldNotBeNullOrEmpty();
+        ev1.Id.ShouldNotBe(ev2.Id);
+    }
+
+    // --- RemoteServerUpdateEvent ---
+
+    [Fact]
+    public void RemoteServerUpdateEvent_HasCorrectEventType()
+    {
+        RemoteServerUpdateEvent.EventType.ShouldBe("io.nats.server.advisory.v1.remote_update");
+        var ev = new RemoteServerUpdateEvent();
+        ev.Type.ShouldBe(RemoteServerUpdateEvent.EventType);
+    }
+
+    [Fact]
+    public void RemoteServerUpdateEvent_AllFieldsSettable()
+    {
+        var server = new EventServerInfo { Id = "srv1", Name = "my-server" };
+        var ev = new RemoteServerUpdateEvent
+        {
+            Server = server,
+            RemoteServerId = "remote-id-123",
+            RemoteServerName = "remote-server",
+            UpdateType = "routes_changed",
+        };
+
+        ev.Server.ShouldBeSameAs(server);
+        ev.RemoteServerId.ShouldBe("remote-id-123");
+        ev.RemoteServerName.ShouldBe("remote-server");
+        ev.UpdateType.ShouldBe("routes_changed");
+    }
+
+    // --- LeafNodeConnectEvent ---
+
+    [Fact]
+    public void LeafNodeConnectEvent_HasCorrectEventType()
+    {
+        LeafNodeConnectEvent.EventType.ShouldBe("io.nats.server.advisory.v1.leafnode_connect");
+        var ev = new LeafNodeConnectEvent();
+        ev.Type.ShouldBe(LeafNodeConnectEvent.EventType);
+    }
+
+    [Fact]
+    public void LeafNodeConnectEvent_AllFieldsSettable()
+    {
+        var server = new EventServerInfo { Id = "srv1", Name = "hub" };
+        var ev = new LeafNodeConnectEvent
+        {
+            Server = server,
+            LeafNodeId = "leaf-id-abc",
+            LeafNodeName = "leaf-node-1",
+            RemoteUrl = "nats://10.0.0.1:7422",
+            Account = "ACC",
+        };
+
+        ev.Server.ShouldBeSameAs(server);
+        ev.LeafNodeId.ShouldBe("leaf-id-abc");
+        ev.LeafNodeName.ShouldBe("leaf-node-1");
+        ev.RemoteUrl.ShouldBe("nats://10.0.0.1:7422");
+        ev.Account.ShouldBe("ACC");
+    }
+
+    // --- LeafNodeDisconnectEvent ---
+
+    [Fact]
+    public void LeafNodeDisconnectEvent_HasCorrectEventType()
+    {
+        LeafNodeDisconnectEvent.EventType.ShouldBe("io.nats.server.advisory.v1.leafnode_disconnect");
+        var ev = new LeafNodeDisconnectEvent();
+        ev.Type.ShouldBe(LeafNodeDisconnectEvent.EventType);
+    }
+
+    [Fact]
+    public void LeafNodeDisconnectEvent_AllFieldsSettable()
+    {
+        var server = new EventServerInfo { Id = "srv1", Name = "hub" };
+        var ev = new LeafNodeDisconnectEvent
+        {
+            Server = server,
+            LeafNodeId = "leaf-id-xyz",
+            Reason = "connection closed",
+        };
+
+        ev.Server.ShouldBeSameAs(server);
+        ev.LeafNodeId.ShouldBe("leaf-id-xyz");
+        ev.Reason.ShouldBe("connection closed");
+    }
+
+    // --- EventSubjects ---
+
+    [Fact]
+    public void EventSubjects_RemoteShutdown_HasPlaceholder()
+    {
+        EventSubjects.RemoteServerShutdown.ShouldContain("{0}");
+        EventSubjects.RemoteServerUpdate.ShouldContain("{0}");
+        EventSubjects.LeafNodeConnected.ShouldContain("{0}");
+        EventSubjects.LeafNodeDisconnected.ShouldContain("{0}");
+
+        // Verify format strings produce expected subjects when formatted
+        var serverId = "ABCDEF123456";
+        string.Format(EventSubjects.RemoteServerShutdown, serverId)
+            .ShouldBe($"$SYS.SERVER.{serverId}.REMOTE.SHUTDOWN");
+        string.Format(EventSubjects.LeafNodeConnected, serverId)
+            .ShouldBe($"$SYS.SERVER.{serverId}.LEAFNODE.CONNECT");
+    }
+
+    // --- JSON serialization ---
+
+    [Fact]
+    public void AllRemoteEvents_SerializeToJson()
+    {
+        var server = new EventServerInfo { Id = "srv-id", Name = "test-server" };
+
+        var shutdown = new RemoteServerShutdownEvent
+        {
+            Server = server,
+            RemoteServerId = "r1",
+            RemoteServerName = "remote",
+            Reason = "graceful",
+        };
+        var shutdownJson = JsonSerializer.Serialize(shutdown);
+        var shutdownDoc = JsonDocument.Parse(shutdownJson).RootElement;
+        shutdownDoc.GetProperty("type").GetString().ShouldBe(RemoteServerShutdownEvent.EventType);
+        shutdownDoc.GetProperty("id").GetString().ShouldNotBeNullOrEmpty();
+        shutdownDoc.GetProperty("remote_server_id").GetString().ShouldBe("r1");
+        shutdownDoc.GetProperty("reason").GetString().ShouldBe("graceful");
+
+        var update = new RemoteServerUpdateEvent
+        {
+            Server = server,
+            RemoteServerId = "r2",
+            RemoteServerName = "remote2",
+            UpdateType = "config_updated",
+        };
+        var updateJson = JsonSerializer.Serialize(update);
+        var updateDoc = JsonDocument.Parse(updateJson).RootElement;
+        updateDoc.GetProperty("type").GetString().ShouldBe(RemoteServerUpdateEvent.EventType);
+        updateDoc.GetProperty("update_type").GetString().ShouldBe("config_updated");
+
+        var connect = new LeafNodeConnectEvent
+        {
+            Server = server,
+            LeafNodeId = "leaf1",
+            LeafNodeName = "leaf-node",
+            RemoteUrl = "nats://10.0.0.1:7422",
+            Account = "ACC",
+        };
+        var connectJson = JsonSerializer.Serialize(connect);
+        var connectDoc = JsonDocument.Parse(connectJson).RootElement;
+        connectDoc.GetProperty("type").GetString().ShouldBe(LeafNodeConnectEvent.EventType);
+        connectDoc.GetProperty("leaf_node_id").GetString().ShouldBe("leaf1");
+        connectDoc.GetProperty("account").GetString().ShouldBe("ACC");
+
+        var disconnect = new LeafNodeDisconnectEvent
+        {
+            Server = server,
+            LeafNodeId = "leaf1",
+            Reason = "timeout",
+        };
+        var disconnectJson = JsonSerializer.Serialize(disconnect);
+        var disconnectDoc = JsonDocument.Parse(disconnectJson).RootElement;
+        disconnectDoc.GetProperty("type").GetString().ShouldBe(LeafNodeDisconnectEvent.EventType);
+        disconnectDoc.GetProperty("leaf_node_id").GetString().ShouldBe("leaf1");
+        disconnectDoc.GetProperty("reason").GetString().ShouldBe("timeout");
+
+        // Roundtrip: deserialize back and verify type field survives
+        var shutdownRt = JsonSerializer.Deserialize<RemoteServerShutdownEvent>(shutdownJson);
+        shutdownRt.ShouldNotBeNull();
+        shutdownRt!.Type.ShouldBe(RemoteServerShutdownEvent.EventType);
+        shutdownRt.RemoteServerId.ShouldBe("r1");
+    }
+}