diff --git a/tests/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer.IntegrationTests/DualEndpointTests.cs b/tests/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer.IntegrationTests/DualEndpointTests.cs
new file mode 100644
index 0000000..d1652dd
--- /dev/null
+++ b/tests/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer.IntegrationTests/DualEndpointTests.cs
@@ -0,0 +1,121 @@
+using System.Net;
+using System.Net.Sockets;
+using Microsoft.Extensions.Logging.Abstractions;
+using Opc.Ua;
+using Opc.Ua.Client;
+using Opc.Ua.Configuration;
+using Opc.Ua.Server;
+using Shouldly;
+using Xunit;
+using ZB.MOM.WW.OtOpcUa.OpcUaServer;
+using ClientSession = Opc.Ua.Client.Session;
+
+namespace ZB.MOM.WW.OtOpcUa.OpcUaServer.IntegrationTests;
+
+/// <summary>
+/// Source plan Task 60 — closes the audit gap. Boots two real <see cref="StandardServer"/>
+/// instances on loopback, each configured with the other's <c>ApplicationUri</c> in
+/// <see cref="OpcUaApplicationHostOptions.PeerApplicationUris"/>. A real OPC UA client connects
+/// to Node A, reads <c>Server.ServerArray</c>, and asserts both URIs are visible — the
+/// warm-redundancy discovery contract clients depend on.
+/// </summary>
+public sealed class DualEndpointTests
+{
+    private const string NodeAUri = "urn:OtOpcUa.DualEndpoint.NodeA";
+    private const string NodeBUri = "urn:OtOpcUa.DualEndpoint.NodeB";
+
+    [Fact]
+    public async Task Client_reads_both_ApplicationUris_from_NodeA_ServerArray()
+    {
+        var pkiRootA = Path.Combine(Path.GetTempPath(), $"otopcua-pki-a-{Guid.NewGuid():N}");
+        var pkiRootB = Path.Combine(Path.GetTempPath(), $"otopcua-pki-b-{Guid.NewGuid():N}");
+        var portA = AllocateFreePort();
+        var portB = AllocateFreePort();
+
+        try
+        {
+            await using var nodeA = await StartNodeAsync(NodeAUri, portA, pkiRootA, peers: new[] { NodeBUri });
+            await using var nodeB = await StartNodeAsync(NodeBUri, portB, pkiRootB, peers: new[] { NodeAUri });
+
+            var serverArray = await ReadServerArrayAsync($"opc.tcp://127.0.0.1:{portA}/OtOpcUa");
+            serverArray.ShouldContain(NodeAUri);
+            serverArray.ShouldContain(NodeBUri);
+        }
+        finally
+        {
+            if (Directory.Exists(pkiRootA)) Directory.Delete(pkiRootA, recursive: true);
+            if (Directory.Exists(pkiRootB)) Directory.Delete(pkiRootB, recursive: true);
+        }
+    }
+
+    private static async Task<OpcUaApplicationHost> StartNodeAsync(
+        string applicationUri, int port, string pkiRoot, string[] peers)
+    {
+        var options = new OpcUaApplicationHostOptions
+        {
+            ApplicationName = applicationUri,
+            ApplicationUri = applicationUri,
+            OpcUaPort = port,
+            PublicHostname = "127.0.0.1",
+            PkiStoreRoot = pkiRoot,
+            EnabledSecurityProfiles = new List<OpcUaSecurityProfile> { OpcUaSecurityProfile.None },
+            AutoAcceptUntrustedClientCertificates = true,
+            PeerApplicationUris = peers,
+        };
+        var server = new StandardServer();
+        var host = new OpcUaApplicationHost(options, NullLogger<OpcUaApplicationHost>.Instance);
+        await host.StartAsync(server, CancellationToken.None);
+        return host;
+    }
+
+    private static async Task<string[]> ReadServerArrayAsync(string endpointUrl)
+    {
+        var appConfig = new ApplicationConfiguration
+        {
+            ApplicationName = "OtOpcUa.DualEndpointClient",
+            ApplicationUri = $"urn:OtOpcUa.DualEndpointClient.{Guid.NewGuid():N}",
+            ApplicationType = ApplicationType.Client,
+            SecurityConfiguration = new SecurityConfiguration
+            {
+                ApplicationCertificate = new CertificateIdentifier(),
+                AutoAcceptUntrustedCertificates = true,
+            },
+            ClientConfiguration = new ClientConfiguration { DefaultSessionTimeout = 60_000 },
+        };
+        // SDK 1.5.378 deprecates the no-arg ctors of CertificateValidator / DefaultSessionFactory
+        // and the non-telemetry overloads of SelectEndpointAsync. Inject a no-op telemetry context
+        // so the integration test (with TreatWarningsAsErrors=true) doesn't trip the CS0618 wall.
+        var telemetry = DefaultTelemetry.Create(static _ => { });
+        await appConfig.ValidateAsync(ApplicationType.Client, CancellationToken.None);
+        appConfig.CertificateValidator.CertificateValidation += (_, e) => e.Accept = true;
+
+        var endpoint = await CoreClientUtils.SelectEndpointAsync(
+            appConfig, endpointUrl, useSecurity: false, discoverTimeout: 15_000, telemetry,
+            CancellationToken.None);
+        var endpointConfiguration = EndpointConfiguration.Create(appConfig);
+        var configuredEndpoint = new ConfiguredEndpoint(null, endpoint, endpointConfiguration);
+
+        var factory = new DefaultSessionFactory(telemetry);
+        using var session = (ClientSession)await factory.CreateAsync(
+            appConfig,
+            configuredEndpoint,
+            updateBeforeConnect: false,
+            sessionName: "DualEndpointTests",
+            sessionTimeout: 60_000,
+            identity: new UserIdentity(new AnonymousIdentityToken()),
+            preferredLocales: null,
+            CancellationToken.None);
+
+        var value = await session.ReadValueAsync(VariableIds.Server_ServerArray, CancellationToken.None);
+        return (string[])value.Value;
+    }
+
+    private static int AllocateFreePort()
+    {
+        var listener = new TcpListener(IPAddress.Loopback, 0);
+        listener.Start();
+        var port = ((IPEndPoint)listener.LocalEndpoint).Port;
+        listener.Stop();
+        return port;
+    }
+}