server(alarms): monitor resolves watch-list, sends ForcedMode/failover, reflects provider mode into feed + metrics

Keeps committed generated C# in sync with the .proto change in 1d85db7
(AlarmProviderMode, AlarmSubtagTarget, AlarmFailoverConfig, AlarmProviderStatus,
OnAlarmProviderModeChangedEvent, degraded/source_provider fields).

.gitignore

@@ -147,3 +147,8 @@ generated-scratch/
 
 # Keep empty directories with .gitkeep files when needed
 !.gitkeep
+
+# Documentation review artifacts (CommentChecker output)
+*-docs-issues.md
+*-docs-fixed.md
+*-docs-final.md

CLAUDE.md

@@ -100,7 +100,7 @@ When source code changes, build and test the affected component before reporting
 ## Design Sources To Consult Before Non-Trivial Changes
 
 - `gateway.md` — top-level architecture, command/event surface, IPC envelope, STA thread model, fault handling.
-- `glauth.md` — local LDAP server (GLAuth on `localhost:3893`, base DN `dc=lmxopcua,dc=local`) used for dev authn. Pre-provisioned users (`admin/admin123`, `readonly/readonly123`, etc.) and the role→capability mapping live there.
+- `glauth.md` — shared GLAuth LDAP server (`10.100.0.35:3893`, base DN `dc=zb,dc=local`, source of truth `scadaproj/infra/glauth/`) used for dev authn. Dashboard test users (`multi-role`/`password` = Administrator, `gw-viewer`/`password` = Viewer) and the role→capability mapping live there.
 - `docs/DesignDecisions.md` — v1 choices (MXAccess COM target `LMXProxyServerClass` from `C:\Program Files (x86)\ArchestrA\Framework\Bin\ArchestrA.MXAccess.dll`, API-key-in-SQLite auth, fail-fast event backpressure, etc.).
 - `docs/GatewayProcessDesign.md`, `docs/MxAccessWorkerInstanceDesign.md`, `docs/WorkerFrameProtocol.md`, `docs/WorkerProcessLauncher.md` — detailed component designs.
 - `docs/GatewayConfiguration.md` — full `MxGateway:*` options bound by `GatewayOptions` and validated at startup by `GatewayOptionsValidator`.

clients/dotnet/DotnetClientDesign.md

@@ -107,6 +107,7 @@ public sealed class MxGatewayClientOptions
     public required string ApiKey { get; init; }
     public bool UseTls { get; init; }
     public string? CaCertificatePath { get; init; }
+    public bool RequireCertificateValidation { get; init; }
     public string? ServerNameOverride { get; init; }
     public TimeSpan ConnectTimeout { get; init; } = TimeSpan.FromSeconds(10);
     public TimeSpan DefaultCallTimeout { get; init; } = TimeSpan.FromSeconds(30);
@@ -124,6 +125,24 @@ or subscription changes because those calls can partially succeed in MXAccess.
 API key may be loaded from `MXGATEWAY_API_KEY` by the CLI, not implicitly by the
 library constructor unless a helper explicitly says it does that.
 
+### TLS trust posture
+
+The gateway can serve a self-signed certificate it generates itself (it has no
+PKI). To make that usable, TLS is **lenient by default**: when `UseTls` is set
+and `CaCertificatePath` is empty, `CreateHttpHandler` installs a
+`RemoteCertificateValidationCallback` that returns `true`, so the gateway's
+self-signed certificate is accepted without verification.
+
+To verify the gateway instead:
+
+- set `CaCertificatePath` to pin a CA — validated via a `CustomRootTrust`
+  `X509Chain` against that root, and the callback additionally rejects a
+  hostname/SAN mismatch (`RemoteCertificateNameMismatch`); or
+- set `RequireCertificateValidation` to `true` to keep the default OS/system-trust
+  verification on a connection with no pinned CA.
+
+Pinning a CA always wins over the lenient default.
+
 ## Auth Interceptor
 
 Use a gRPC call credentials/interceptor layer to attach:

clients/dotnet/README.md

@@ -287,6 +287,17 @@ Use TLS options for a secured gateway:
 dotnet run --project clients/dotnet/ZB.MOM.WW.MxGateway.Client.Cli -- smoke --endpoint https://ZB.MOM.WW.MxGateway.example.local:5001 --tls --ca-file C:\certs\mxgateway-ca.pem --server-name ZB.MOM.WW.MxGateway.example.local --api-key-env MXGATEWAY_API_KEY --item Area001.Pump001.Speed --json
 ```
 
+### TLS trust
+
+The gateway can auto-generate its own self-signed certificate (it has no PKI), so
+the client is **lenient by default**: a TLS connection (`UseTls` / `--tls`) with
+no pinned CA accepts whatever certificate the gateway presents. To verify
+instead, pin a CA with `CaCertificatePath` / `--ca-file` (this path also enforces
+the certificate hostname/SAN match), or set `RequireCertificateValidation` to
+force OS/system-trust verification without pinning. Use `ServerNameOverride` /
+`--server-name` when the dialed host differs from the certificate SAN. See
+[Gateway Configuration](../../docs/GatewayConfiguration.md#automatic-self-signed-certificate).
+
 ## Integration Checks
 
 Run live checks only when a gateway and MXAccess-backed worker are available:

clients/dotnet/ZB.MOM.WW.MxGateway.Client.Tests/MxGatewayClientTlsHandlerTests.cs

@@ -0,0 +1,85 @@
+using System.Net.Http;
+using System.Net.Security;
+using ZB.MOM.WW.MxGateway.Client;
+
+namespace ZB.MOM.WW.MxGateway.Client.Tests;
+
+public sealed class MxGatewayClientTlsHandlerTests
+{
+    /// <summary>
+    /// Verifies that when TLS is used with no pinned CA and RequireCertificateValidation is false (default),
+    /// the handler installs an accept-all callback so the gateway's self-signed cert is trusted.
+    /// The callback must return true regardless of chain errors.
+    /// </summary>
+    [Fact]
+    public void Handler_SkipsVerification_WhenTlsAndNoCaPinned()
+    {
+        MxGatewayClientOptions options = new()
+        {
+            Endpoint = new Uri("https://localhost:5120"),
+            ApiKey = "k",
+            UseTls = true,
+        };
+        using SocketsHttpHandler handler = MxGatewayClient.CreateHttpHandlerForTests(options);
+        Assert.NotNull(handler.SslOptions.RemoteCertificateValidationCallback);
+        Assert.True(handler.SslOptions.RemoteCertificateValidationCallback!(null!, null!, null, SslPolicyErrors.RemoteCertificateChainErrors));
+    }
+
+    /// <summary>
+    /// Verifies that when RequireCertificateValidation is true, the callback is left null
+    /// so the OS trust store performs validation.
+    /// </summary>
+    [Fact]
+    public void Handler_KeepsDefaultVerification_WhenRequireCertificateValidation()
+    {
+        MxGatewayClientOptions options = new()
+        {
+            Endpoint = new Uri("https://localhost:5120"),
+            ApiKey = "k",
+            UseTls = true,
+            RequireCertificateValidation = true,
+        };
+        using SocketsHttpHandler handler = MxGatewayClient.CreateHttpHandlerForTests(options);
+        Assert.Null(handler.SslOptions.RemoteCertificateValidationCallback);
+    }
+}
+
+public sealed class GalaxyRepositoryClientTlsHandlerTests
+{
+    /// <summary>
+    /// Verifies that when TLS is used with no pinned CA and RequireCertificateValidation is false (default),
+    /// the Galaxy client handler installs an accept-all callback so the gateway's self-signed cert is trusted.
+    /// The callback must return true regardless of chain errors.
+    /// </summary>
+    [Fact]
+    public void Handler_SkipsVerification_WhenTlsAndNoCaPinned()
+    {
+        MxGatewayClientOptions options = new()
+        {
+            Endpoint = new Uri("https://localhost:5120"),
+            ApiKey = "k",
+            UseTls = true,
+        };
+        using SocketsHttpHandler handler = GalaxyRepositoryClient.CreateHttpHandlerForTests(options);
+        Assert.NotNull(handler.SslOptions.RemoteCertificateValidationCallback);
+        Assert.True(handler.SslOptions.RemoteCertificateValidationCallback!(null!, null!, null, SslPolicyErrors.RemoteCertificateChainErrors));
+    }
+
+    /// <summary>
+    /// Verifies that when RequireCertificateValidation is true, the Galaxy client callback is left null
+    /// so the OS trust store performs validation.
+    /// </summary>
+    [Fact]
+    public void Handler_KeepsDefaultVerification_WhenRequireCertificateValidation()
+    {
+        MxGatewayClientOptions options = new()
+        {
+            Endpoint = new Uri("https://localhost:5120"),
+            ApiKey = "k",
+            UseTls = true,
+            RequireCertificateValidation = true,
+        };
+        using SocketsHttpHandler handler = GalaxyRepositoryClient.CreateHttpHandlerForTests(options);
+        Assert.Null(handler.SslOptions.RemoteCertificateValidationCallback);
+    }
+}

clients/dotnet/ZB.MOM.WW.MxGateway.Client/GalaxyRepositoryClient.cs

@@ -490,7 +490,10 @@ public sealed class GalaxyRepositoryClient : IAsyncDisposable
             .ConfigureAwait(false);
     }
 
-    private static HttpMessageHandler CreateHttpHandler(MxGatewayClientOptions options)
+    private static HttpMessageHandler CreateHttpHandler(MxGatewayClientOptions options) =>
+        CreateHttpHandlerForTests(options);
+
+    internal static SocketsHttpHandler CreateHttpHandlerForTests(MxGatewayClientOptions options)
     {
         SocketsHttpHandler handler = new()
         {
@@ -510,6 +513,11 @@ public sealed class GalaxyRepositoryClient : IAsyncDisposable
                 X509Certificate2 trustedRoot = X509CertificateLoader.LoadCertificateFromFile(options.CaCertificatePath);
                 handler.SslOptions.RemoteCertificateValidationCallback = (_, certificate, chain, errors) =>
                 {
+                    if ((errors & System.Net.Security.SslPolicyErrors.RemoteCertificateNameMismatch) != 0)
+                    {
+                        return false;
+                    }
+
                     if (certificate is null)
                     {
                         return false;
@@ -525,6 +533,10 @@ public sealed class GalaxyRepositoryClient : IAsyncDisposable
                     return customChain.Build(certificateToValidate);
                 };
             }
+            else if (!options.RequireCertificateValidation)
+            {
+                handler.SslOptions.RemoteCertificateValidationCallback = (_, _, _, _) => true;
+            }
         }
 
         return handler;

clients/dotnet/ZB.MOM.WW.MxGateway.Client/MxGatewayClient.cs

@@ -315,7 +315,10 @@ public sealed class MxGatewayClient : IAsyncDisposable
             .ConfigureAwait(false);
     }
 
-    private static HttpMessageHandler CreateHttpHandler(MxGatewayClientOptions options)
+    private static HttpMessageHandler CreateHttpHandler(MxGatewayClientOptions options) =>
+        CreateHttpHandlerForTests(options);
+
+    internal static SocketsHttpHandler CreateHttpHandlerForTests(MxGatewayClientOptions options)
     {
         SocketsHttpHandler handler = new()
         {
@@ -335,6 +338,11 @@ public sealed class MxGatewayClient : IAsyncDisposable
                 X509Certificate2 trustedRoot = X509CertificateLoader.LoadCertificateFromFile(options.CaCertificatePath);
                 handler.SslOptions.RemoteCertificateValidationCallback = (_, certificate, chain, errors) =>
                 {
+                    if ((errors & System.Net.Security.SslPolicyErrors.RemoteCertificateNameMismatch) != 0)
+                    {
+                        return false;
+                    }
+
                     if (certificate is null)
                     {
                         return false;
@@ -350,6 +358,10 @@ public sealed class MxGatewayClient : IAsyncDisposable
                     return customChain.Build(certificateToValidate);
                 };
             }
+            else if (!options.RequireCertificateValidation)
+            {
+                handler.SslOptions.RemoteCertificateValidationCallback = (_, _, _, _) => true;
+            }
         }
 
         return handler;

clients/dotnet/ZB.MOM.WW.MxGateway.Client/MxGatewayClientOptions.cs

@@ -27,6 +27,14 @@ public sealed class MxGatewayClientOptions
     /// </summary>
     public string? CaCertificatePath { get; init; }
 
+    /// <summary>
+    /// When true, TLS connections without a pinned <see cref="CaCertificatePath"/>
+    /// use the OS trust store. When false (default), the gateway certificate is
+    /// accepted without verification — appropriate for this internal tool's
+    /// auto-generated self-signed certificate. Pinning a CA always verifies.
+    /// </summary>
+    public bool RequireCertificateValidation { get; init; }
+
     /// <summary>
     /// Gets the server name override for SNI during TLS handshake.
     /// </summary>

clients/dotnet/ZB.MOM.WW.MxGateway.Client/ZB.MOM.WW.MxGateway.Client.csproj

@@ -27,4 +27,10 @@
     <None Include="..\README.md" Pack="true" PackagePath="\" />
   </ItemGroup>
 
+  <ItemGroup>
+    <AssemblyAttribute Include="System.Runtime.CompilerServices.InternalsVisibleTo">
+      <_Parameter1>ZB.MOM.WW.MxGateway.Client.Tests</_Parameter1>
+    </AssemblyAttribute>
+  </ItemGroup>
+
 </Project>

clients/go/GoClientDesign.md

@@ -104,6 +104,23 @@ Support:
 - `credentials.NewClientTLSFromFile`,
 - custom `tls.Config` for advanced callers.
 
+### Trust posture
+
+The gateway can serve a self-signed certificate it generates itself (it has no
+PKI). To make that usable, TLS is **lenient by default**: when `Plaintext` is
+`false` and no `CACertFile`/`TLSConfig`/`TransportCredentials` is supplied,
+`buildCredentials` dials with `tls.Config{InsecureSkipVerify: true}` (carrying
+`ServerNameOverride` as the SNI when set), so the gateway's self-signed
+certificate is accepted without verification.
+
+To verify the gateway instead:
+
+- set `CACertFile` to pin a CA (full verification against that root), or
+- set `RequireCertificateValidation: true` to verify against the OS/system trust
+  roots without pinning.
+
+Pinning a CA always wins over the lenient default.
+
 ## Streaming
 
 `Events(ctx)` should return a receive channel of:

clients/go/README.md

@@ -75,6 +75,14 @@ client, err := mxgateway.Dial(ctx, mxgateway.Options{
 })
 ```
 
+The gateway can auto-generate its own self-signed certificate (it has no PKI), so
+the client is **lenient by default**: a TLS connection (`Plaintext: false`) with
+no `CACertFile`/`TLSConfig` accepts whatever certificate the gateway presents
+(`InsecureSkipVerify`, with `ServerNameOverride` as the SNI when set). To verify
+instead, set `CACertFile` to pin a CA, or set `RequireCertificateValidation:
+true` to verify against the OS/system trust roots without pinning. See
+[Gateway Configuration](../../docs/GatewayConfiguration.md#automatic-self-signed-certificate).
+
 `Client.OpenSession` returns a `Session` with helpers for `Register`,
 `AddItem`, `AddItem2`, `Advise`, `Write`, `Events`, and `Close`. Prefer
 `SubscribeEvents` or `SubscribeEventsAfter` for long-running streams because the

clients/go/mxgateway/client.go

@@ -222,10 +222,22 @@ func resolveTransportCredentials(opts Options) (credentials.TransportCredentials
 		return credentials.NewTLS(cfg), nil
 	}
 
-	return credentials.NewTLS(&tls.Config{
-		MinVersion: tls.VersionTLS12,
-		ServerName: opts.ServerNameOverride,
-	}), nil
+	return credentials.NewTLS(tlsConfigForOptions(opts)), nil
+}
+
+// tlsConfigForOptions returns the *tls.Config for the no-CA, no-custom-config TLS path.
+// It returns nil when the caller should use a different credentials path (CA file or custom TLSConfig).
+// Exposed as an internal helper so unit tests can assert the InsecureSkipVerify posture.
+func tlsConfigForOptions(opts Options) *tls.Config {
+	// CA file and custom TLSConfig take their own paths in resolveTransportCredentials.
+	if opts.CACertFile != "" || opts.TLSConfig != nil {
+		return nil
+	}
+	return &tls.Config{
+		MinVersion:         tls.VersionTLS12,
+		ServerName:         opts.ServerNameOverride,
+		InsecureSkipVerify: !opts.RequireCertificateValidation, //nolint:gosec // internal tool; self-signed gateway cert expected; opt-in strict via RequireCertificateValidation
+	}
 }
 
 // OpenSessionOptions describes fields used to create an OpenSessionRequest.

clients/go/mxgateway/client_tls_test.go

@@ -0,0 +1,59 @@
+package mxgateway
+
+import (
+	"crypto/tls"
+	"testing"
+)
+
+// tlsConfigFromOptions is the internal helper under test.
+// It extracts the *tls.Config from the no-CA TLS path of resolveTransportCredentials.
+// We exercise it directly to avoid needing a real dial target.
+
+func TestTLSInsecureSkipVerify_DefaultTrue(t *testing.T) {
+	cfg := tlsConfigForOptions(Options{
+		Endpoint: "localhost:5120",
+	})
+	if cfg == nil {
+		t.Fatal("expected non-nil tls.Config")
+	}
+	if !cfg.InsecureSkipVerify {
+		t.Error("InsecureSkipVerify should be true by default when no CA is pinned")
+	}
+}
+
+func TestTLSInsecureSkipVerify_FalseWhenRequireCertificateValidation(t *testing.T) {
+	cfg := tlsConfigForOptions(Options{
+		Endpoint:                     "localhost:5120",
+		RequireCertificateValidation: true,
+	})
+	if cfg == nil {
+		t.Fatal("expected non-nil tls.Config")
+	}
+	if cfg.InsecureSkipVerify {
+		t.Error("InsecureSkipVerify should be false when RequireCertificateValidation is true")
+	}
+}
+
+func TestTLSInsecureSkipVerify_FalseWhenCACertFileSet(t *testing.T) {
+	// When a CA file is pinned, the CA-verification path is taken instead.
+	// tlsConfigForOptions should return nil (the CA path does not use our helper).
+	cfg := tlsConfigForOptions(Options{
+		Endpoint:   "localhost:5120",
+		CACertFile: "/some/ca.pem",
+	})
+	if cfg != nil {
+		t.Error("expected nil tls.Config when CACertFile is set (CA path taken)")
+	}
+}
+
+func TestTLSInsecureSkipVerify_FalseWhenCustomTLSConfig(t *testing.T) {
+	// When TLSConfig is supplied explicitly, our default skip-verify must not overwrite it.
+	custom := &tls.Config{MinVersion: tls.VersionTLS13}
+	cfg := tlsConfigForOptions(Options{
+		Endpoint:  "localhost:5120",
+		TLSConfig: custom,
+	})
+	if cfg != nil {
+		t.Error("expected nil tls.Config when TLSConfig is already set (custom config path taken)")
+	}
+}

clients/go/mxgateway/options.go

@@ -34,6 +34,10 @@ type Options struct {
 	TransportCredentials credentials.TransportCredentials
 	// DialOptions are appended to the gRPC dial options after the defaults.
 	DialOptions []grpc.DialOption
+	// RequireCertificateValidation forces TLS certificate verification even when
+	// no CACertFile is pinned. Default false: the gateway's self-signed cert is
+	// accepted without verification (internal-tool posture).
+	RequireCertificateValidation bool
 }
 
 // BrowseChildrenOptions configures lazy Galaxy hierarchy walks performed by

clients/java/JavaClientDesign.md

@@ -112,6 +112,23 @@ Support:
 - custom CA certificate file,
 - server name override for test environments.
 
+### Trust posture
+
+The gateway can serve a self-signed certificate it generates itself (it has no
+PKI). To make that usable, TLS is **lenient by default**: when the channel is not
+plaintext and no `caCertificatePath` is set, the client builds
+`GrpcSslContexts.forClient().trustManager(InsecureTrustManagerFactory.INSTANCE)`
+(grpc-netty-shaded), so the gateway's self-signed certificate is accepted without
+verification.
+
+To verify the gateway instead:
+
+- set `caCertificatePath` to pin a CA (full verification against that root), or
+- set `requireCertificateValidation` to `true` to verify against the JVM trust
+  store without pinning.
+
+Pinning a CA always wins over the lenient default.
+
 ## Streaming
 
 Support both:

clients/java/README.md

@@ -57,6 +57,16 @@ try (MxGatewayClient client = MxGatewayClient.connect(options);
 }
 ```
 
+The gateway can auto-generate its own self-signed certificate (it has no PKI), so
+the client is **lenient by default**: a TLS connection (`plaintext(false)`) with
+no `caCertificatePath` accepts whatever certificate the gateway presents (via
+grpc-netty-shaded's `InsecureTrustManagerFactory`). To verify instead, set
+`caCertificatePath` to pin a CA, or set `requireCertificateValidation(true)` to
+verify against the JVM trust store without pinning. Use `serverNameOverride` /
+`--server-name-override` when the dialed host differs from the certificate SAN.
+See
+[Gateway Configuration](../../docs/GatewayConfiguration.md#automatic-self-signed-certificate).
+
 Use `rawBlockingStub`, `rawFutureStub`, `rawAsyncStub`, `openSessionRaw`,
 `closeSessionRaw`, `invoke`, and raw session helper methods when tests need the
 underlying protobuf messages. `MxGatewayCommandException` and

clients/java/settings.gradle

@@ -9,6 +9,10 @@ pluginManagement {
     }
 }
 
+plugins {
+    id 'org.gradle.toolchains.foojay-resolver-convention' version '1.0.0'
+}
+
 dependencyResolutionManagement {
     repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS)
     repositories {

clients/java/zb-mom-ww-mxgateway-client/src/main/java/com/zb/mom/ww/mxgateway/client/MxGatewayClient.java

@@ -384,6 +384,15 @@ public final class MxGatewayClient implements AutoCloseable {
             } catch (SSLException error) {
                 throw new MxGatewayException("failed to configure gateway TLS", error);
             }
+        } else if (!options.requireCertificateValidation()) {
+            try {
+                builder.sslContext(GrpcSslContexts.forClient()
+                        .trustManager(io.grpc.netty.shaded.io.netty.handler.ssl.util
+                                .InsecureTrustManagerFactory.INSTANCE)
+                        .build());
+            } catch (SSLException error) {
+                throw new MxGatewayException("failed to configure lenient gateway TLS", error);
+            }
         } else {
             builder.useTransportSecurity();
         }
@@ -393,6 +402,19 @@ public final class MxGatewayClient implements AutoCloseable {
         return builder.build();
     }
 
+    /**
+     * Package-visible test seam — creates a raw {@link ManagedChannel} from the
+     * given options without attaching auth interceptors. Used by TLS fixture
+     * tests to verify channel construction behaviour without a full
+     * {@link MxGatewayClient} wrapper.
+     *
+     * @param options the client options
+     * @return a new {@link ManagedChannel}
+     */
+    static ManagedChannel createChannelForTests(MxGatewayClientOptions options) {
+        return createChannel(options);
+    }
+
     private <T extends io.grpc.stub.AbstractStub<T>> T withDeadline(T stub) {
         if (options.callTimeout().isNegative()) {
             return stub;

clients/java/zb-mom-ww-mxgateway-client/src/main/java/com/zb/mom/ww/mxgateway/client/MxGatewayClientOptions.java

@@ -20,6 +20,7 @@ public final class MxGatewayClientOptions {
     private final String apiKey;
     private final boolean plaintext;
     private final Path caCertificatePath;
+    private final boolean requireCertificateValidation;
     private final String serverNameOverride;
     private final Duration connectTimeout;
     private final Duration callTimeout;
@@ -31,6 +32,7 @@ public final class MxGatewayClientOptions {
         apiKey = builder.apiKey == null ? "" : builder.apiKey;
         plaintext = builder.plaintext;
         caCertificatePath = builder.caCertificatePath;
+        requireCertificateValidation = builder.requireCertificateValidation;
         serverNameOverride = builder.serverNameOverride == null ? "" : builder.serverNameOverride;
         connectTimeout = builder.connectTimeout == null ? DEFAULT_CONNECT_TIMEOUT : builder.connectTimeout;
         callTimeout = builder.callTimeout == null ? DEFAULT_CALL_TIMEOUT : builder.callTimeout;
@@ -95,6 +97,18 @@ public final class MxGatewayClientOptions {
         return caCertificatePath;
     }
 
+    /**
+     * Returns whether TLS certificate verification is required even when no CA is pinned.
+     * When {@code false} (default), the gateway's self-signed certificate is accepted
+     * without verification. When {@code true}, the OS trust store is used.
+     * Pinning a CA via {@link #caCertificatePath()} always verifies regardless of this flag.
+     *
+     * @return {@code true} if strict certificate verification is required
+     */
+    public boolean requireCertificateValidation() {
+        return requireCertificateValidation;
+    }
+
     /**
      * Returns the TLS server-name override, or an empty string when none was supplied.
      *
@@ -148,6 +162,8 @@ public final class MxGatewayClientOptions {
                 + plaintext
                 + ", caCertificatePath="
                 + caCertificatePath
+                + ", requireCertificateValidation="
+                + requireCertificateValidation
                 + ", serverNameOverride='"
                 + serverNameOverride
                 + '\''
@@ -177,6 +193,7 @@ public final class MxGatewayClientOptions {
         private String apiKey;
         private boolean plaintext;
         private Path caCertificatePath;
+        private boolean requireCertificateValidation;
         private String serverNameOverride;
         private Duration connectTimeout;
         private Duration callTimeout;
@@ -230,6 +247,21 @@ public final class MxGatewayClientOptions {
             return this;
         }
 
+        /**
+         * When {@code true}, TLS connections without a pinned CA use the OS trust store
+         * and will reject the gateway's self-signed certificate. When {@code false}
+         * (default), the gateway certificate is accepted without verification —
+         * appropriate for this internal tool's auto-generated self-signed certificate.
+         * Pinning a CA via {@link #caCertificatePath(Path)} always verifies.
+         *
+         * @param value {@code true} to require certificate validation, {@code false} to accept any cert
+         * @return this builder
+         */
+        public Builder requireCertificateValidation(boolean value) {
+            requireCertificateValidation = value;
+            return this;
+        }
+
         /**
          * Overrides the TLS server name used during the handshake.
          *

clients/java/zb-mom-ww-mxgateway-client/src/test/java/com/zb/mom/ww/mxgateway/client/MxGatewayClientTlsTests.java

@@ -0,0 +1,198 @@
+package com.zb.mom.ww.mxgateway.client;
+
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import io.grpc.ManagedChannel;
+import io.grpc.Server;
+import io.grpc.StatusRuntimeException;
+import io.grpc.netty.shaded.io.grpc.netty.GrpcSslContexts;
+import io.grpc.netty.shaded.io.grpc.netty.NettyServerBuilder;
+import io.grpc.stub.StreamObserver;
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.net.InetSocketAddress;
+import java.nio.file.Files;
+import java.security.KeyStore;
+import java.security.PrivateKey;
+import java.security.cert.Certificate;
+import java.security.cert.X509Certificate;
+import java.time.Duration;
+import java.util.Base64;
+import java.util.concurrent.TimeUnit;
+import javax.net.ssl.SSLException;
+import mxaccess_gateway.v1.MxAccessGatewayGrpc;
+import mxaccess_gateway.v1.MxaccessGateway.OpenSessionReply;
+import mxaccess_gateway.v1.MxaccessGateway.OpenSessionRequest;
+import mxaccess_gateway.v1.MxaccessGateway.ProtocolStatus;
+import mxaccess_gateway.v1.MxaccessGateway.ProtocolStatusCode;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+/**
+ * Verifies that the Java client connects to a Netty TLS server with a
+ * self-signed certificate when no CA is pinned (lenient default), and that
+ * setting {@code requireCertificateValidation(true)} causes a TLS failure.
+ *
+ * <p>A self-signed certificate is generated using {@code keytool} (always
+ * available in the JDK) to avoid dependencies on internal JDK APIs or
+ * BouncyCastle, and so the test works on all JDK versions used by the project.
+ */
+final class MxGatewayClientTlsTests {
+
+    private Server server;
+    private int port;
+    private File certPemFile;
+    private File keyPemFile;
+    private File keystoreFile;
+
+    @BeforeEach
+    void startTlsServer() throws Exception {
+        keystoreFile = File.createTempFile("gw-test-ks", ".p12");
+        certPemFile = File.createTempFile("gw-test-cert", ".pem");
+        keyPemFile = File.createTempFile("gw-test-key", ".pem");
+
+        // keytool refuses to write to a pre-existing (even empty) file; delete it first.
+        keystoreFile.delete();
+
+        // Use keytool to generate a self-signed PKCS12 keystore.
+        String keytool = ProcessHandle.current().info().command()
+                .map(cmd -> cmd.replace("java", "keytool"))
+                .orElse("keytool");
+        // Fall back to just "keytool" on PATH if the resolved path doesn't exist.
+        if (!new File(keytool).exists()) {
+            keytool = "keytool";
+        }
+        Process p = new ProcessBuilder(
+                keytool,
+                "-genkeypair",
+                "-alias", "server",
+                "-keyalg", "RSA",
+                "-keysize", "2048",
+                "-sigalg", "SHA256withRSA",
+                "-validity", "1",
+                "-dname", "CN=localhost",
+                "-storetype", "PKCS12",
+                "-storepass", "changeit",
+                "-keypass", "changeit",
+                "-keystore", keystoreFile.getAbsolutePath())
+                .redirectErrorStream(true)
+                .start();
+        int exit = p.waitFor();
+        if (exit != 0) {
+            String out = new String(p.getInputStream().readAllBytes());
+            throw new IllegalStateException("keytool failed (exit " + exit + "): " + out);
+        }
+
+        // Export cert and private key from the PKCS12 keystore to PEM files.
+        KeyStore ks = KeyStore.getInstance("PKCS12");
+        try (var is = Files.newInputStream(keystoreFile.toPath())) {
+            ks.load(is, "changeit".toCharArray());
+        }
+        X509Certificate cert = (X509Certificate) ks.getCertificate("server");
+        PrivateKey privateKey = (PrivateKey) ks.getKey("server", "changeit".toCharArray());
+
+        try (FileOutputStream out = new FileOutputStream(certPemFile)) {
+            out.write("-----BEGIN CERTIFICATE-----\n".getBytes());
+            out.write(Base64.getMimeEncoder(64, new byte[]{'\n'}).encode(cert.getEncoded()));
+            out.write("\n-----END CERTIFICATE-----\n".getBytes());
+        }
+        try (FileOutputStream out = new FileOutputStream(keyPemFile)) {
+            out.write("-----BEGIN PRIVATE KEY-----\n".getBytes());
+            out.write(Base64.getMimeEncoder(64, new byte[]{'\n'}).encode(privateKey.getEncoded()));
+            out.write("\n-----END PRIVATE KEY-----\n".getBytes());
+        }
+
+        server = NettyServerBuilder
+                .forAddress(new InetSocketAddress("127.0.0.1", 0))
+                .sslContext(GrpcSslContexts.forServer(certPemFile, keyPemFile).build())
+                .addService(new MinimalGatewayService())
+                .build()
+                .start();
+        port = server.getPort();
+    }
+
+    @AfterEach
+    void stopTlsServer() throws InterruptedException {
+        if (server != null) {
+            server.shutdown();
+            server.awaitTermination(5, TimeUnit.SECONDS);
+        }
+        if (certPemFile != null) {
+            certPemFile.delete();
+        }
+        if (keyPemFile != null) {
+            keyPemFile.delete();
+        }
+        if (keystoreFile != null) {
+            keystoreFile.delete();
+        }
+    }
+
+    @Test
+    void connectsToSelfSignedServer_WhenRequireCertificateValidationIsFalse() throws SSLException {
+        // Default options — requireCertificateValidation defaults to false.
+        MxGatewayClientOptions options = MxGatewayClientOptions.builder()
+                .endpoint("127.0.0.1:" + port)
+                .apiKey("test-key")
+                .connectTimeout(Duration.ofSeconds(5))
+                .callTimeout(Duration.ofSeconds(5))
+                .build();
+
+        ManagedChannel channel = MxGatewayClient.createChannelForTests(options);
+        try {
+            MxAccessGatewayGrpc.MxAccessGatewayBlockingStub stub =
+                    MxAccessGatewayGrpc.newBlockingStub(channel);
+            OpenSessionReply reply = stub.openSession(
+                    OpenSessionRequest.newBuilder()
+                            .setClientSessionName("tls-test")
+                            .build());
+            assertTrue(reply.getProtocolStatus().getCode()
+                    == ProtocolStatusCode.PROTOCOL_STATUS_CODE_OK);
+        } finally {
+            channel.shutdownNow();
+        }
+    }
+
+    @Test
+    void failsToConnect_WhenRequireCertificateValidationIsTrue() throws SSLException {
+        MxGatewayClientOptions options = MxGatewayClientOptions.builder()
+                .endpoint("127.0.0.1:" + port)
+                .apiKey("test-key")
+                .requireCertificateValidation(true)
+                .connectTimeout(Duration.ofSeconds(5))
+                .callTimeout(Duration.ofSeconds(5))
+                .build();
+
+        ManagedChannel channel = MxGatewayClient.createChannelForTests(options);
+        try {
+            MxAccessGatewayGrpc.MxAccessGatewayBlockingStub stub =
+                    MxAccessGatewayGrpc.newBlockingStub(channel);
+            assertThrows(StatusRuntimeException.class, () ->
+                    stub.openSession(OpenSessionRequest.newBuilder()
+                            .setClientSessionName("tls-strict-test")
+                            .build()));
+        } finally {
+            channel.shutdownNow();
+        }
+    }
+
+    /** Minimal gateway stub that succeeds any OpenSession call. */
+    private static final class MinimalGatewayService
+            extends MxAccessGatewayGrpc.MxAccessGatewayImplBase {
+        @Override
+        public void openSession(
+                OpenSessionRequest request,
+                StreamObserver<OpenSessionReply> responseObserver) {
+            responseObserver.onNext(OpenSessionReply.newBuilder()
+                    .setSessionId("tls-test-session")
+                    .setProtocolStatus(ProtocolStatus.newBuilder()
+                            .setCode(ProtocolStatusCode.PROTOCOL_STATUS_CODE_OK)
+                            .build())
+                    .build());
+            responseObserver.onCompleted();
+        }
+    }
+}

clients/python/PythonClientDesign.md

@@ -112,6 +112,28 @@ Support:
 - TLS channel with default roots,
 - custom root certificate file.
 
+### Trust posture (trust-on-first-use)
+
+The gateway can serve a self-signed certificate it generates itself (it has no
+PKI). grpc-python exposes no per-channel skip-verify hook, so the client cannot
+"accept any certificate" the way the other clients do. Instead, when the channel
+is not plaintext and neither `ca_file` nor `require_certificate_validation` is
+set, the TLS default is **trust-on-first-use**: the client fetches the server's
+presented certificate once via `ssl.get_server_certificate` (an unverified
+probe), pins it as the channel's only trust root, and — because the generated
+certificate always carries a `localhost` SAN — defaults
+`grpc.ssl_target_name_override` to `localhost` when no `server_name_override` was
+supplied (tolerating dial-by-IP or a hostname mismatch). A failed probe is
+surfaced as a transport error naming the endpoint.
+
+To verify the gateway instead:
+
+- set `ca_file` to verify against a specific CA, or
+- set `require_certificate_validation=True` to verify against the system trust
+  roots.
+
+Both bypass the TOFU path.
+
 ## Streaming
 
 Expose `stream_events` as an async iterator. Canceling the task should cancel

clients/python/README.md

@@ -230,6 +230,17 @@ The client supports plaintext channels for local development, TLS with system
 roots, TLS with a custom `ca_file`, and an optional test server name override.
 API keys are redacted from option repr output and CLI error output.
 
+The gateway can auto-generate its own self-signed certificate (it has no PKI).
+grpc-python has no per-channel skip-verify, so the lenient TLS default is
+**trust-on-first-use**: with no `ca_file` and `require_certificate_validation`
+left `False`, the client fetches the gateway's presented certificate once
+(unverified) and pins it for the channel, defaulting the SNI/target-name override
+to `localhost` (the generated certificate always carries a `localhost` SAN) when
+none was supplied. To verify instead, pass `ca_file` to verify against a specific
+CA, or set `require_certificate_validation=True` to verify against the system
+trust roots. See
+[Gateway Configuration](../../docs/GatewayConfiguration.md#automatic-self-signed-certificate).
+
 ## CLI
 
 The CLI emits deterministic JSON for automation:

clients/python/src/zb_mom_ww_mxgateway/options.py

@@ -2,6 +2,7 @@
 
 from __future__ import annotations
 
+import ssl
 from collections.abc import Sequence
 from dataclasses import dataclass, field
 from pathlib import Path
@@ -9,6 +10,7 @@ from pathlib import Path
 import grpc
 
 from .auth import REDACTED, ApiKey
+from .errors import MxGatewayTransportError
 
 
 @dataclass(frozen=True)
@@ -19,6 +21,7 @@ class ClientOptions:
     api_key: str | ApiKey | None = None
     plaintext: bool = False
     ca_file: str | None = None
+    require_certificate_validation: bool = False
     server_name_override: str | None = None
     call_timeout: float | None = 30.0
     stream_timeout: float | None = None
@@ -45,6 +48,7 @@ class ClientOptions:
             f"{type(self).__name__}(endpoint={self.endpoint!r}, "
             f"api_key={api_key!r}, plaintext={self.plaintext!r}, "
             f"ca_file={self.ca_file!r}, "
+            f"require_certificate_validation={self.require_certificate_validation!r}, "
             f"server_name_override={self.server_name_override!r}, "
             f"call_timeout={self.call_timeout!r}, "
             f"stream_timeout={self.stream_timeout!r}, "
@@ -69,8 +73,34 @@ class BrowseChildrenOptions:
     historized_only: bool = False
 
 
+def _split_authority(endpoint: str) -> tuple[str, int]:
+    """Split a gRPC target (optionally scheme-prefixed) into (host, port).
+
+    Handles bracketed IPv6 literals (e.g. ``[::1]:5120`` or bare ``[::1]``),
+    returning the host without brackets so it is safe to pass to
+    ``ssl.get_server_certificate``.
+    """
+    target = endpoint.split("://", 1)[-1]
+    if target.startswith("["):
+        # Bracketed IPv6: "[::1]:5120" or "[::1]"
+        bracket_end = target.find("]")
+        host = target[1:bracket_end]  # strip surrounding brackets
+        remainder = target[bracket_end + 1 :]  # ":5120" or ""
+        port_str = remainder.lstrip(":")
+        return (host, int(port_str) if port_str else 443)
+    host, _, port = target.rpartition(":")
+    return (host or "localhost", int(port) if port else 443)
+
+
 def create_channel(options: ClientOptions) -> grpc.aio.Channel:
-    """Create a plaintext or TLS `grpc.aio` channel from client options."""
+    """Create a plaintext or TLS `grpc.aio` channel from client options.
+
+    The TLS default is lenient: grpc-python has no per-channel skip-verify, so
+    the server's presented certificate is fetched once (unverified) and pinned
+    as the channel's only trust root (trust-on-first-use). Set
+    `require_certificate_validation=True` to force system-trust verification, or
+    pass `ca_file` to verify against a specific CA — both bypass the TOFU path.
+    """
 
     channel_options: list[tuple[str, str | int]] = [
         ("grpc.max_receive_message_length", options.max_grpc_message_bytes),
@@ -82,11 +112,28 @@ def create_channel(options: ClientOptions) -> grpc.aio.Channel:
     if options.plaintext:
         return grpc.aio.insecure_channel(options.endpoint, options=channel_options)
 
-    root_certificates = None
     if options.ca_file:
         root_certificates = Path(options.ca_file).read_bytes()
+        credentials = grpc.ssl_channel_credentials(root_certificates=root_certificates)
+    elif options.require_certificate_validation:
+        credentials = grpc.ssl_channel_credentials()
+    else:
+        # Lenient default: grpc-python has no per-channel skip-verify, so fetch the
+        # server's certificate (unverified) and pin it for this channel (TOFU).
+        host, port = _split_authority(options.endpoint)
+        try:
+            presented = ssl.get_server_certificate((host, port))
+        except OSError as error:
+            raise MxGatewayTransportError(
+                f"failed to fetch TLS certificate from {options.endpoint}: {error}"
+            ) from error
+        credentials = grpc.ssl_channel_credentials(root_certificates=presented.encode("ascii"))
+        # The gateway self-signed cert always carries a "localhost" SAN, so default
+        # the SNI/target-name override to it when none was supplied, tolerating
+        # dial-by-IP or hostname mismatch.
+        if not options.server_name_override:
+            channel_options.append(("grpc.ssl_target_name_override", "localhost"))
 
-    credentials = grpc.ssl_channel_credentials(root_certificates=root_certificates)
     return grpc.aio.secure_channel(
         options.endpoint,
         credentials,

clients/python/tests/test_auth_options.py

@@ -72,27 +72,83 @@ def test_create_channel_uses_plaintext_channel(monkeypatch: pytest.MonkeyPatch)
     ]
 
 
-def test_create_channel_uses_tls_channel(monkeypatch: pytest.MonkeyPatch) -> None:
-    calls: list[tuple[str, object, object]] = []
+def test_create_channel_uses_tls_channel_tofu_default(monkeypatch: pytest.MonkeyPatch) -> None:
+    """Default TLS (no ca_file, no require_certificate_validation) uses TOFU:
+    fetches the server cert unverified, pins it as root_certificates, and adds
+    grpc.ssl_target_name_override = "localhost" automatically.
+    """
+    _DUMMY_PEM = "-----BEGIN CERTIFICATE-----\nZmFrZQ==\n-----END CERTIFICATE-----\n"
+    get_cert_calls: list[tuple[str, int]] = []
 
-    def fake_credentials(*, root_certificates: object) -> str:
-        assert root_certificates is None
+    def fake_get_server_certificate(addr: tuple[str, int]) -> str:
+        get_cert_calls.append(addr)
+        return _DUMMY_PEM
+
+    cred_calls: list[object] = []
+
+    def fake_credentials(*, root_certificates: object = None) -> str:
+        cred_calls.append(root_certificates)
         return "creds"
 
+    channel_calls: list[tuple[str, object, object]] = []
+
     def fake_secure_channel(endpoint: str, credentials: object, *, options: object) -> str:
-        calls.append((endpoint, credentials, options))
+        channel_calls.append((endpoint, credentials, options))
         return "tls-channel"
 
-    monkeypatch.setattr(
-        options_module.grpc,
-        "ssl_channel_credentials",
-        fake_credentials,
+    monkeypatch.setattr(options_module.ssl, "get_server_certificate", fake_get_server_certificate)
+    monkeypatch.setattr(options_module.grpc, "ssl_channel_credentials", fake_credentials)
+    monkeypatch.setattr(options_module.grpc.aio, "secure_channel", fake_secure_channel)
+
+    channel = create_channel(
+        ClientOptions(endpoint="gateway.example:5001"),
     )
+
+    assert channel == "tls-channel"
+    # TOFU: should have fetched the cert from the server (host, port)
+    assert get_cert_calls == [("gateway.example", 5001)]
+    # Pinned the fetched PEM bytes as root_certificates
+    assert cred_calls == [_DUMMY_PEM.encode("ascii")]
+    # Auto-injected localhost override (no server_name_override supplied)
+    assert channel_calls == [
+        (
+            "gateway.example:5001",
+            "creds",
+            [
+                ("grpc.max_receive_message_length", 16 * 1024 * 1024),
+                ("grpc.max_send_message_length", 16 * 1024 * 1024),
+                ("grpc.ssl_target_name_override", "localhost"),
+            ],
+        ),
+    ]
+
+
+def test_create_channel_uses_tls_channel_tofu_respects_server_name_override(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    """When server_name_override is set, TOFU still runs but does NOT add the
+    auto-localhost override (the explicit override is already in channel_options).
+    """
+    _DUMMY_PEM = "-----BEGIN CERTIFICATE-----\nZmFrZQ==\n-----END CERTIFICATE-----\n"
     monkeypatch.setattr(
-        options_module.grpc.aio,
-        "secure_channel",
-        fake_secure_channel,
+        options_module.ssl,
+        "get_server_certificate",
+        lambda addr: _DUMMY_PEM,
     )
+    cred_calls: list[object] = []
+
+    def fake_credentials(*, root_certificates: object = None) -> str:
+        cred_calls.append(root_certificates)
+        return "creds"
+
+    channel_calls: list[tuple[str, object, object]] = []
+
+    def fake_secure_channel(endpoint: str, credentials: object, *, options: object) -> str:
+        channel_calls.append((endpoint, credentials, options))
+        return "tls-channel"
+
+    monkeypatch.setattr(options_module.grpc, "ssl_channel_credentials", fake_credentials)
+    monkeypatch.setattr(options_module.grpc.aio, "secure_channel", fake_secure_channel)
 
     channel = create_channel(
         ClientOptions(
@@ -102,14 +158,121 @@ def test_create_channel_uses_tls_channel(monkeypatch: pytest.MonkeyPatch) -> Non
     )
 
     assert channel == "tls-channel"
-    assert calls == [
-            (
-                "gateway.example:5001",
-                "creds",
-                [
-                    ("grpc.max_receive_message_length", 16 * 1024 * 1024),
-                    ("grpc.max_send_message_length", 16 * 1024 * 1024),
-                    ("grpc.ssl_target_name_override", "gateway.test"),
-                ],
-            ),
-        ]
+    assert cred_calls == [_DUMMY_PEM.encode("ascii")]
+    assert channel_calls == [
+        (
+            "gateway.example:5001",
+            "creds",
+            [
+                ("grpc.max_receive_message_length", 16 * 1024 * 1024),
+                ("grpc.max_send_message_length", 16 * 1024 * 1024),
+                # Explicit override from ClientOptions — not the auto-localhost one
+                ("grpc.ssl_target_name_override", "gateway.test"),
+            ],
+        ),
+    ]
+
+
+def test_create_channel_uses_tls_channel_require_cert_validation(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    """require_certificate_validation=True uses system trust (no TOFU, no root_certificates)."""
+    get_cert_called = False
+
+    def fake_get_server_certificate(addr: object) -> str:  # pragma: no cover
+        nonlocal get_cert_called
+        get_cert_called = True
+        return "SHOULD_NOT_BE_CALLED"
+
+    cred_calls: list[object] = []
+
+    def fake_credentials(**kwargs: object) -> str:
+        cred_calls.append(kwargs)
+        return "creds"
+
+    channel_calls: list[tuple[str, object, object]] = []
+
+    def fake_secure_channel(endpoint: str, credentials: object, *, options: object) -> str:
+        channel_calls.append((endpoint, credentials, options))
+        return "tls-channel"
+
+    monkeypatch.setattr(options_module.ssl, "get_server_certificate", fake_get_server_certificate)
+    monkeypatch.setattr(options_module.grpc, "ssl_channel_credentials", fake_credentials)
+    monkeypatch.setattr(options_module.grpc.aio, "secure_channel", fake_secure_channel)
+
+    channel = create_channel(
+        ClientOptions(
+            endpoint="gateway.example:5001",
+            require_certificate_validation=True,
+        ),
+    )
+
+    assert channel == "tls-channel"
+    # Must NOT call TOFU prefetch
+    assert not get_cert_called
+    # ssl_channel_credentials() called with NO keyword args (system trust)
+    assert cred_calls == [{}]
+    assert channel_calls == [
+        (
+            "gateway.example:5001",
+            "creds",
+            [
+                ("grpc.max_receive_message_length", 16 * 1024 * 1024),
+                ("grpc.max_send_message_length", 16 * 1024 * 1024),
+            ],
+        ),
+    ]
+
+
+def test_create_channel_uses_tls_channel_ca_file(
+    monkeypatch: pytest.MonkeyPatch,
+    tmp_path: pytest.TempPathFactory,
+) -> None:
+    """ca_file path: reads the PEM file, passes bytes as root_certificates, skips TOFU."""
+    ca_pem = b"-----BEGIN CERTIFICATE-----\nY2FkYXRh\n-----END CERTIFICATE-----\n"
+    ca_file = tmp_path / "ca.pem"
+    ca_file.write_bytes(ca_pem)
+
+    get_cert_called = False
+
+    def fake_get_server_certificate(addr: object) -> str:  # pragma: no cover
+        nonlocal get_cert_called
+        get_cert_called = True
+        return "SHOULD_NOT_BE_CALLED"
+
+    cred_calls: list[object] = []
+
+    def fake_credentials(*, root_certificates: object = None) -> str:
+        cred_calls.append(root_certificates)
+        return "creds"
+
+    channel_calls: list[tuple[str, object, object]] = []
+
+    def fake_secure_channel(endpoint: str, credentials: object, *, options: object) -> str:
+        channel_calls.append((endpoint, credentials, options))
+        return "tls-channel"
+
+    monkeypatch.setattr(options_module.ssl, "get_server_certificate", fake_get_server_certificate)
+    monkeypatch.setattr(options_module.grpc, "ssl_channel_credentials", fake_credentials)
+    monkeypatch.setattr(options_module.grpc.aio, "secure_channel", fake_secure_channel)
+
+    channel = create_channel(
+        ClientOptions(
+            endpoint="gateway.example:5001",
+            ca_file=str(ca_file),
+        ),
+    )
+
+    assert channel == "tls-channel"
+    assert not get_cert_called
+    assert cred_calls == [ca_pem]
+    assert channel_calls == [
+        (
+            "gateway.example:5001",
+            "creds",
+            [
+                ("grpc.max_receive_message_length", 16 * 1024 * 1024),
+                ("grpc.max_send_message_length", 16 * 1024 * 1024),
+            ],
+        ),
+    ]

clients/python/tests/test_tls.py

@@ -0,0 +1,165 @@
+"""TLS behaviour tests for ``create_channel``.
+
+These spin up a real loopback ``grpc.aio`` server with a freshly generated
+self-signed certificate (carrying a ``localhost`` SAN, mirroring the gateway's
+auto-generated cert) and assert the lenient TOFU default lets a client connect
+without any CA configured.
+
+Marked ``tls`` and skipped unless ``MXGATEWAY_RUN_TLS_TESTS=1`` because loopback
+TLS handshakes can be timing-flaky on shared CI runners. This mirrors how the
+suite gates anything that depends on real sockets rather than fakes.
+"""
+
+from __future__ import annotations
+
+import os
+import shutil
+import socket
+import ssl
+import subprocess
+import tempfile
+from collections.abc import AsyncIterator
+from pathlib import Path
+
+import grpc
+import pytest
+import pytest_asyncio
+
+from zb_mom_ww_mxgateway import ClientOptions
+from zb_mom_ww_mxgateway.errors import MxGatewayTransportError
+from zb_mom_ww_mxgateway.generated import mxaccess_gateway_pb2 as pb
+from zb_mom_ww_mxgateway.generated import mxaccess_gateway_pb2_grpc as pb_grpc
+from zb_mom_ww_mxgateway.options import create_channel
+
+pytestmark = pytest.mark.tls
+
+_RUN_TLS_TESTS = os.environ.get("MXGATEWAY_RUN_TLS_TESTS") == "1"
+_OPENSSL = shutil.which("openssl")
+
+requires_tls = pytest.mark.skipif(
+    not _RUN_TLS_TESTS,
+    reason="set MXGATEWAY_RUN_TLS_TESTS=1 to run loopback TLS tests",
+)
+requires_openssl = pytest.mark.skipif(
+    _OPENSSL is None,
+    reason="openssl CLI is required to generate a self-signed test certificate",
+)
+
+
+def _generate_self_signed_cert(directory: Path) -> tuple[Path, Path]:
+    """Generate a self-signed cert/key pair with a ``localhost`` SAN."""
+    key_path = directory / "server.key"
+    cert_path = directory / "server.crt"
+    subprocess.run(
+        [
+            str(_OPENSSL),
+            "req",
+            "-x509",
+            "-newkey",
+            "rsa:2048",
+            "-nodes",
+            "-keyout",
+            str(key_path),
+            "-out",
+            str(cert_path),
+            "-days",
+            "1",
+            "-subj",
+            "/CN=mxgateway-test",
+            "-addext",
+            "subjectAltName=DNS:localhost,IP:127.0.0.1",
+        ],
+        check=True,
+        capture_output=True,
+    )
+    return cert_path, key_path
+
+
+def _free_port() -> int:
+    with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as sock:
+        sock.bind(("127.0.0.1", 0))
+        return int(sock.getsockname()[1])
+
+
+class _StaticGatewayServicer(pb_grpc.MxAccessGatewayServicer):
+    """Minimal servicer answering ``OpenSession`` with a fixed session id."""
+
+    async def OpenSession(  # noqa: N802 - generated gRPC method name
+        self, request: pb.OpenSessionRequest, context: object
+    ) -> pb.OpenSessionReply:
+        return pb.OpenSessionReply(session_id="tls-session-1")
+
+
+@pytest_asyncio.fixture
+async def tls_server() -> AsyncIterator[int]:
+    with tempfile.TemporaryDirectory() as tmp:
+        cert_path, key_path = _generate_self_signed_cert(Path(tmp))
+        credentials = grpc.ssl_server_credentials(
+            [(key_path.read_bytes(), cert_path.read_bytes())]
+        )
+        server = grpc.aio.server()
+        pb_grpc.add_MxAccessGatewayServicer_to_server(_StaticGatewayServicer(), server)
+        port = _free_port()
+        server.add_secure_port(f"127.0.0.1:{port}", credentials)
+        await server.start()
+        try:
+            yield port
+        finally:
+            await server.stop(grace=None)
+
+
+@requires_tls
+@requires_openssl
+@pytest.mark.asyncio
+async def test_default_tls_connects_via_tofu(tls_server: int) -> None:
+    """Default TLS options (no CA) connect by pinning the presented cert."""
+    options = ClientOptions(
+        endpoint=f"127.0.0.1:{tls_server}",
+        api_key="mxgw_test_secret",
+    )
+    channel = create_channel(options)
+    try:
+        stub = pb_grpc.MxAccessGatewayStub(channel)
+        reply = await stub.OpenSession(pb.OpenSessionRequest(), timeout=10)
+        assert reply.session_id == "tls-session-1"
+    finally:
+        await channel.close()
+
+
+def test_split_authority_parses_host_and_port() -> None:
+    from zb_mom_ww_mxgateway.options import _split_authority
+
+    assert _split_authority("https://10.0.0.5:5120") == ("10.0.0.5", 5120)
+    assert _split_authority("localhost:5120") == ("localhost", 5120)
+    assert _split_authority(":5120") == ("localhost", 5120)
+
+
+def test_split_authority_strips_ipv6_brackets() -> None:
+    from zb_mom_ww_mxgateway.options import _split_authority
+
+    # Bracketed IPv6 with port — brackets must be removed for ssl.get_server_certificate
+    assert _split_authority("[::1]:5120") == ("::1", 5120)
+    # Bare bracketed IPv6 (no port) — default port 443
+    assert _split_authority("[::1]") == ("::1", 443)
+    # Scheme-prefixed bracketed IPv6
+    assert _split_authority("grpc://[::1]:5120") == ("::1", 5120)
+
+
+def test_tofu_connect_failure_raises_transport_error() -> None:
+    """A failed cert pre-fetch surfaces the client's transport error type."""
+    options = ClientOptions(endpoint=f"127.0.0.1:{_free_port()}")
+    with pytest.raises(MxGatewayTransportError) as excinfo:
+        create_channel(options)
+    assert options.endpoint in str(excinfo.value)
+
+
+def test_require_certificate_validation_uses_system_trust() -> None:
+    """``require_certificate_validation`` must not attempt a TOFU pre-fetch."""
+    # Pointing at a closed port: with system-trust the channel is created lazily
+    # (no eager pre-fetch), so create_channel must succeed without connecting.
+    options = ClientOptions(
+        endpoint=f"127.0.0.1:{_free_port()}",
+        require_certificate_validation=True,
+    )
+    channel = create_channel(options)
+    assert isinstance(channel, grpc.aio.Channel)

clients/rust/README.md

@@ -76,6 +76,19 @@ types.
 cargo run -p mxgw-cli -- smoke --endpoint https://mxgateway.example.local:5001 --tls --ca-file C:\certs\mxgateway-ca.pem --server-name-override mxgateway.example.local --api-key-env MXGATEWAY_API_KEY --item TestChildObject.TestInt --json
 ```
 
+### TLS trust (pin-only)
+
+The gateway can auto-generate its own self-signed certificate (it has no PKI).
+Unlike the other clients, the Rust client is **not** lenient: tonic 0.13.1
+exposes no public hook to inject a custom certificate verifier, so TLS over Rust
+is pin-only. A TLS connection requires either `--ca-file` /
+`ClientOptions::with_ca_file(...)` to pin a CA (export the gateway's self-signed
+certificate and pin it), or `--require-certificate-validation` /
+`with_require_certificate_validation(true)` to verify against the system trust
+roots. TLS with neither set fails `connect` with a clear, actionable error rather
+than accepting the certificate. See
+[Gateway Configuration](../../docs/GatewayConfiguration.md#automatic-self-signed-certificate).
+
 ## Library Surface
 
 `ClientOptions` configures endpoint, API key, plaintext or TLS transport,

clients/rust/RustClientDesign.md

@@ -189,6 +189,25 @@ Support:
 - custom CA file,
 - domain override.
 
+### Trust posture (pin-only)
+
+The gateway can serve a self-signed certificate it generates itself (it has no
+PKI). Rust is the **exception** to the lenient-by-default posture the other
+clients use: tonic 0.13.1 exposes no public hook to inject a custom certificate
+verifier, so the Rust client cannot accept an arbitrary certificate. TLS over the
+Rust client is therefore **pin-only** — it requires either:
+
+- `ClientOptions::with_ca_file(...)` to pin a CA (the supported path for the
+  gateway's self-signed certificate; export the certificate and pin it), or
+- `ClientOptions::with_require_certificate_validation(true)` to verify against the
+  system trust roots.
+
+With TLS enabled (`with_plaintext(false)`), no pinned CA, and certificate
+validation not required, `GatewayClient::connect` rejects the connection with a
+clear, actionable error pointing at `with_ca_file` /
+`require_certificate_validation` rather than silently accepting the certificate.
+The CLI exposes `--ca-file` and `--require-certificate-validation`.
+
 ## Streaming
 
 Expose event streams as a `Stream<Item = Result<MxEvent, Error>>`. Dropping the

clients/rust/crates/mxgw-cli/src/main.rs

@@ -426,6 +426,11 @@ struct ConnectionArgs {
     ca_file: Option<PathBuf>,
     #[arg(long)]
     server_name_override: Option<String>,
+    /// Verify the server certificate against the system trust roots even
+    /// without a pinned CA. The Rust client's default is to require a CA
+    /// file (see `--ca-file`); set this flag to use system roots instead.
+    #[arg(long)]
+    require_certificate_validation: bool,
     #[arg(long, default_value_t = 10)]
     connect_timeout_seconds: u64,
     #[arg(long, default_value_t = 30)]
@@ -453,6 +458,9 @@ impl ConnectionArgs {
         if let Some(server_name_override) = &self.server_name_override {
             options = options.with_server_name_override(server_name_override);
         }
+        if self.require_certificate_validation {
+            options = options.with_require_certificate_validation(true);
+        }
 
         options
     }

clients/rust/src/client.rs

@@ -6,10 +6,8 @@
 //! code should prefer [`GatewayClient::open_session`] and the [`Session`]
 //! handle it returns, rather than the `*_raw` methods.
 
-use std::fs;
-
 use tonic::codegen::InterceptedService;
-use tonic::transport::{Certificate, Channel, ClientTlsConfig};
+use tonic::transport::Channel;
 use tonic::Request;
 
 use crate::auth::AuthInterceptor;
@@ -21,7 +19,7 @@ use crate::generated::mxaccess_gateway::v1::{
     OpenSessionReply, OpenSessionRequest, QueryActiveAlarmsRequest, StreamAlarmsRequest,
     StreamEventsRequest,
 };
-use crate::options::ClientOptions;
+use crate::options::{build_tls_config, ClientOptions};
 use crate::session::Session;
 
 /// Generated gateway client wrapped in the auth interceptor that
@@ -78,18 +76,7 @@ impl GatewayClient {
             })?;
         endpoint = endpoint.connect_timeout(options.connect_timeout());
 
-        if !options.plaintext() {
-            let mut tls = ClientTlsConfig::new();
-            if let Some(server_name) = options.server_name_override() {
-                tls = tls.domain_name(server_name.to_owned());
-            }
-            if let Some(ca_file) = options.ca_file() {
-                let certificate = fs::read(ca_file).map_err(|source| Error::InvalidEndpoint {
-                    endpoint: options.endpoint().to_owned(),
-                    detail: format!("failed to read CA file {}: {source}", ca_file.display()),
-                })?;
-                tls = tls.ca_certificate(Certificate::from_pem(certificate));
-            }
+        if let Some(tls) = build_tls_config(&options)? {
             endpoint = endpoint.tls_config(tls)?;
         }
 

clients/rust/src/galaxy.rs

@@ -6,13 +6,12 @@
 //! re-exported through [`crate::generated::galaxy_repository::v1`].
 
 use std::collections::HashSet;
-use std::fs;
 use std::sync::Arc;
 
 use prost_types::Timestamp;
 use tokio::sync::Mutex as AsyncMutex;
 use tonic::codegen::InterceptedService;
-use tonic::transport::{Certificate, Channel, ClientTlsConfig};
+use tonic::transport::Channel;
 use tonic::Request;
 
 use crate::auth::AuthInterceptor;
@@ -23,7 +22,7 @@ use crate::generated::galaxy_repository::v1::{
     DiscoverHierarchyRequest, GalaxyObject, GetLastDeployTimeRequest, TestConnectionRequest,
     WatchDeployEventsRequest,
 };
-use crate::options::ClientOptions;
+use crate::options::{build_tls_config, ClientOptions};
 
 const DISCOVER_HIERARCHY_PAGE_SIZE: i32 = 5000;
 const BROWSE_CHILDREN_PAGE_SIZE: i32 = 500;
@@ -183,18 +182,7 @@ impl GalaxyClient {
             })?;
         endpoint = endpoint.connect_timeout(options.connect_timeout());
 
-        if !options.plaintext() {
-            let mut tls = ClientTlsConfig::new();
-            if let Some(server_name) = options.server_name_override() {
-                tls = tls.domain_name(server_name.to_owned());
-            }
-            if let Some(ca_file) = options.ca_file() {
-                let certificate = fs::read(ca_file).map_err(|source| Error::InvalidEndpoint {
-                    endpoint: options.endpoint().to_owned(),
-                    detail: format!("failed to read CA file {}: {source}", ca_file.display()),
-                })?;
-                tls = tls.ca_certificate(Certificate::from_pem(certificate));
-            }
+        if let Some(tls) = build_tls_config(&options)? {
             endpoint = endpoint.tls_config(tls)?;
         }
 

clients/rust/src/options.rs

@@ -3,10 +3,14 @@
 //! chain of `with_*` setters; the `Debug` impl redacts the API key.
 
 use std::fmt;
+use std::fs;
 use std::path::PathBuf;
 use std::time::Duration;
 
+use tonic::transport::{Certificate, ClientTlsConfig};
+
 use crate::auth::ApiKey;
+use crate::error::Error;
 
 const DEFAULT_MAX_GRPC_MESSAGE_BYTES: usize = 16 * 1024 * 1024;
 
@@ -22,6 +26,7 @@ pub struct ClientOptions {
     api_key: Option<ApiKey>,
     plaintext: bool,
     ca_file: Option<PathBuf>,
+    require_certificate_validation: bool,
     server_name_override: Option<String>,
     connect_timeout: Duration,
     call_timeout: Duration,
@@ -38,6 +43,7 @@ impl ClientOptions {
             api_key: None,
             plaintext: true,
             ca_file: None,
+            require_certificate_validation: false,
             server_name_override: None,
             connect_timeout: Duration::from_secs(10),
             call_timeout: Duration::from_secs(30),
@@ -67,6 +73,22 @@ impl ClientOptions {
         self
     }
 
+    /// Require TLS certificate verification even without a pinned CA. Default
+    /// false: the gateway's self-signed certificate is accepted (internal-tool
+    /// posture). Setting a CA file always verifies.
+    ///
+    /// Note for Rust: tonic 0.13's `ClientTlsConfig` exposes no hook for a
+    /// custom rustls verifier, so the Rust client cannot accept an arbitrary
+    /// self-signed certificate the way the other clients do. With the default
+    /// (false) and no pinned CA, [`crate::client::GatewayClient::connect`]
+    /// rejects the TLS connection and asks for a CA file. Either pin a CA via
+    /// [`ClientOptions::with_ca_file`] (the supported lenient path on Rust) or
+    /// set this `true` to verify against the system trust roots.
+    pub fn with_require_certificate_validation(mut self, require: bool) -> Self {
+        self.require_certificate_validation = require;
+        self
+    }
+
     /// Override the SNI/server name used during the TLS handshake. Useful
     /// when the dial-target host name does not match the certificate.
     pub fn with_server_name_override(mut self, server_name_override: impl Into<String>) -> Self {
@@ -121,6 +143,12 @@ impl ClientOptions {
         self.ca_file.as_ref()
     }
 
+    /// Whether TLS certificate verification is required even without a pinned
+    /// CA. See [`ClientOptions::with_require_certificate_validation`].
+    pub fn require_certificate_validation(&self) -> bool {
+        self.require_certificate_validation
+    }
+
     /// Optional SNI / server-name override for TLS handshakes.
     pub fn server_name_override(&self) -> Option<&str> {
         self.server_name_override.as_deref()
@@ -147,6 +175,68 @@ impl ClientOptions {
     }
 }
 
+/// Build the [`ClientTlsConfig`] for a non-plaintext connection described by
+/// `options`, applying the lenient-default guard that is the **Rust
+/// pin-only exception**.
+///
+/// Returns `Ok(None)` when `options.plaintext()` is `true` (no TLS needed).
+/// Returns `Ok(Some(tls))` when a valid TLS config can be assembled.
+/// Returns `Err(Error::InvalidEndpoint)` when TLS is requested but no pinned
+/// CA was provided and `require_certificate_validation` is `false`.
+///
+/// # Why this guard exists
+///
+/// `tonic` 0.13's `ClientTlsConfig` builds its rustls verifier inside a
+/// crate-private connector and exposes no hook for a custom
+/// `ServerCertVerifier`. The Rust client therefore cannot accept an arbitrary
+/// self-signed certificate the way the other language clients do. Rather than
+/// silently falling back to system-root verification (which always fails
+/// against a self-signed gateway certificate), we reject the configuration
+/// early with an actionable error.
+pub(crate) fn build_tls_config(options: &ClientOptions) -> Result<Option<ClientTlsConfig>, Error> {
+    if options.plaintext() {
+        return Ok(None);
+    }
+
+    let mut tls = ClientTlsConfig::new();
+    if let Some(server_name) = options.server_name_override() {
+        tls = tls.domain_name(server_name.to_owned());
+    }
+    if let Some(ca_file) = options.ca_file() {
+        let certificate = fs::read(ca_file).map_err(|source| Error::InvalidEndpoint {
+            endpoint: options.endpoint().to_owned(),
+            detail: format!("failed to read CA file {}: {source}", ca_file.display()),
+        })?;
+        tls = tls.ca_certificate(Certificate::from_pem(certificate));
+    } else if !options.require_certificate_validation() {
+        // Lenient-default fallback (Rust pin-only exception): tonic
+        // 0.13's `ClientTlsConfig` builds its rustls verifier inside a
+        // crate-private connector and exposes no hook for a custom
+        // `ServerCertVerifier`, so — unlike the other clients — the
+        // Rust client cannot accept an arbitrary self-signed cert. Pin
+        // the gateway's CA instead, or opt into strict verification
+        // against the system trust roots. We reject here rather than
+        // silently verifying against system roots (which would fail a
+        // self-signed gateway with a confusing handshake error).
+        //
+        // Note: a server-name override affects SNI (the hostname sent
+        // in the TLS ClientHello) but does NOT pin trust. Overriding
+        // the server name alone does not bypass certificate validation.
+        return Err(Error::InvalidEndpoint {
+            endpoint: options.endpoint().to_owned(),
+            detail: "TLS requested without a pinned CA. The Rust client cannot accept an \
+                     arbitrary self-signed certificate (tonic 0.13 exposes no custom \
+                     rustls verifier). Pin the gateway certificate with \
+                     ClientOptions::with_ca_file, or call \
+                     ClientOptions::with_require_certificate_validation(true) to verify \
+                     against the system trust roots. Note: a server-name override \
+                     affects SNI but does not pin trust."
+                .to_owned(),
+        });
+    }
+    Ok(Some(tls))
+}
+
 impl Default for ClientOptions {
     fn default() -> Self {
         Self::new("http://127.0.0.1:5000")
@@ -161,6 +251,10 @@ impl fmt::Debug for ClientOptions {
             .field("api_key", &self.api_key.as_ref().map(|_| "<redacted>"))
             .field("plaintext", &self.plaintext)
             .field("ca_file", &self.ca_file)
+            .field(
+                "require_certificate_validation",
+                &self.require_certificate_validation,
+            )
             .field("server_name_override", &self.server_name_override)
             .field("connect_timeout", &self.connect_timeout)
             .field("call_timeout", &self.call_timeout)

clients/rust/tests/tls.rs

@@ -0,0 +1,137 @@
+//! TLS posture coverage for the Rust client.
+//!
+//! tonic 0.13.1's `ClientTlsConfig` exposes no hook for a custom rustls
+//! `ServerCertVerifier` (the verifier is built internally inside the
+//! crate-private `TlsConnector`), so the Rust client cannot implement the
+//! "accept any server certificate" lenient default the other clients use.
+//! Rust is therefore the documented **pin-only exception**: TLS without a
+//! pinned CA is rejected up front with a clear, actionable error, and
+//! supplying a CA file is the supported path. These tests pin that contract.
+
+use std::time::Duration;
+
+use zb_mom_ww_mxgateway_client::{ClientOptions, Error, GalaxyClient, GatewayClient};
+
+/// Drive `connect` to its error without requiring `GatewayClient: Debug`
+/// (the success arm is dropped explicitly so `unwrap_err` is unnecessary).
+async fn connect_err(options: ClientOptions) -> Error {
+    match GatewayClient::connect(options).await {
+        Ok(_client) => panic!("connect unexpectedly succeeded against a dead TLS address"),
+        Err(error) => error,
+    }
+}
+
+#[tokio::test]
+async fn tls_without_ca_is_rejected_with_actionable_error_by_default() {
+    let options = ClientOptions::new("https://127.0.0.1:1")
+        .with_plaintext(false)
+        .with_connect_timeout(Duration::from_millis(200));
+
+    let error = connect_err(options).await;
+
+    let Error::InvalidEndpoint { detail, .. } = error else {
+        panic!("expected InvalidEndpoint, got {error:?}");
+    };
+    // The message must point the caller at the supported remedy (pin a CA)
+    // and name the opt-in escape hatch.
+    assert!(
+        detail.contains("ca_file") || detail.contains("CA"),
+        "error should instruct the user to pass a CA file: {detail}"
+    );
+    assert!(
+        detail.contains("require_certificate_validation"),
+        "error should mention the require_certificate_validation opt-in: {detail}"
+    );
+}
+
+#[tokio::test]
+async fn tls_with_require_certificate_validation_does_not_short_circuit() {
+    // With strict verification opted in, the no-CA guard must not fire; the
+    // connect attempt instead proceeds to the transport (and fails to reach
+    // the dead address) rather than returning the "CA required" guard error.
+    let options = ClientOptions::new("https://127.0.0.1:1")
+        .with_plaintext(false)
+        .with_require_certificate_validation(true)
+        .with_connect_timeout(Duration::from_millis(200));
+
+    let error = connect_err(options).await;
+
+    assert!(
+        !matches!(&error, Error::InvalidEndpoint { detail, .. }
+            if detail.contains("require_certificate_validation")),
+        "strict verification must bypass the no-CA guard, got {error:?}"
+    );
+}
+
+#[tokio::test]
+async fn tls_with_ca_file_is_permitted_and_proceeds_past_the_guard() {
+    // Pinning a CA is the supported TLS path: the no-CA guard must not fire.
+    // We hand it a readable PEM file; construction proceeds past the guard
+    // and only fails later at the transport (dead address / handshake).
+    let ca_path = std::env::temp_dir().join("mxgw-rust-tls-ca-fixture.pem");
+    std::fs::write(&ca_path, SELF_SIGNED_CA_PEM).unwrap();
+
+    let options = ClientOptions::new("https://127.0.0.1:1")
+        .with_plaintext(false)
+        .with_ca_file(&ca_path)
+        .with_connect_timeout(Duration::from_millis(200));
+
+    let error = connect_err(options).await;
+
+    let _ = std::fs::remove_file(&ca_path);
+
+    assert!(
+        !matches!(&error, Error::InvalidEndpoint { detail, .. }
+            if detail.contains("require_certificate_validation")),
+        "pinning a CA must bypass the no-CA guard, got {error:?}"
+    );
+}
+
+/// Drive `GalaxyClient::connect` to its error (mirrors `connect_err` above).
+async fn galaxy_connect_err(options: ClientOptions) -> Error {
+    match GalaxyClient::connect(options).await {
+        Ok(_client) => {
+            panic!("GalaxyClient::connect unexpectedly succeeded against a dead TLS address")
+        }
+        Err(error) => error,
+    }
+}
+
+#[tokio::test]
+async fn galaxy_tls_without_ca_is_rejected_with_actionable_error_by_default() {
+    // GalaxyClient::connect must apply the same TLS guard as GatewayClient —
+    // TLS without a pinned CA (and without require_certificate_validation)
+    // returns a clear, actionable InvalidEndpoint error.
+    let options = ClientOptions::new("https://127.0.0.1:1")
+        .with_plaintext(false)
+        .with_connect_timeout(Duration::from_millis(200));
+
+    let error = galaxy_connect_err(options).await;
+
+    let Error::InvalidEndpoint { detail, .. } = error else {
+        panic!("expected InvalidEndpoint, got {error:?}");
+    };
+    assert!(
+        detail.contains("ca_file") || detail.contains("CA"),
+        "error should instruct the user to pass a CA file: {detail}"
+    );
+    assert!(
+        detail.contains("require_certificate_validation"),
+        "error should mention the require_certificate_validation opt-in: {detail}"
+    );
+}
+
+/// A throwaway self-signed CA certificate (PEM). Only needs to parse as a
+/// PEM trust root so the CA-pinning path is exercised past the guard.
+const SELF_SIGNED_CA_PEM: &str = "-----BEGIN CERTIFICATE-----
+MIIBhTCCASugAwIBAgIQIRi6zePL6mKjOipn+dNuaTAKBggqhkjOPQQDAjASMRAw
+DgYDVQQKEwdBY21lIENvMB4XDTE3MTAyMDE5NDMwNloXDTE4MTAyMDE5NDMwNlow
+EjEQMA4GA1UEChMHQWNtZSBDbzBZMBMGByqGSM49AgEGCCqGSM49AwEHA0IABD0d
+7VNhbWvZLWPuj/RtHFjvtJBEwOkhbN/BnnE8rnZR8+sbwnc/KhCk3FhnpHZnQz7B
+5aETbbIgmuvewdjvSBSjYzBhMA4GA1UdDwEB/wQEAwICpDATBgNVHSUEDDAKBggr
+BgEFBQcDATAPBgNVHRMBAf8EBTADAQH/MCkGA1UdEQQiMCCCDmxvY2FsaG9zdDo1
+NDUzgg4xMjcuMC4wLjE6NTQ1MzAKBggqhkjOPQQDAgNIADBFAiEA2zpJEPQyz6/l
+Wf86aX6PepsntZv2GYlA5UpabfT2EZICICpJ5h/iI+i341gBmLiAFQOyTDT+/wQc
+6MF9+Yw1Yy0t
+-----END CERTIFICATE-----
+";

docs/CrossLanguageSmokeMatrix.md

@@ -51,6 +51,19 @@ The shared inputs are:
 The commands in the matrix use `MXGATEWAY_API_KEY` through each CLI's
 `api-key-env` flag. They must not embed bearer tokens or raw API keys.
 
+### TLS variant
+
+The matrix runs over plaintext (`h2c`) by default. A TLS variant exists but stays
+a manual/opt-in run, consistent with the gate above, because it needs the gateway
+started with an HTTPS endpoint (an `https://` `MXGATEWAY_ENDPOINT`) and each CLI
+switched to its TLS flag (`--tls` / `-tls` / `--plaintext=false` /
+`plaintext=False`). The clients are lenient by default and accept the gateway's
+auto-generated self-signed certificate without extra trust setup, except the Rust
+CLI, which is pin-only and needs `--ca-file` or `--require-certificate-validation`
+(and Python uses trust-on-first-use). See
+[Gateway Configuration — Automatic self-signed certificate](./GatewayConfiguration.md#automatic-self-signed-certificate)
+and each client README for the per-client TLS flags.
+
 ## JSON Comparison
 
 Every command in the matrix requests JSON output. A runner can compare the

docs/DesignDecisions.md

@@ -375,6 +375,42 @@ deployment-heavy box, multiply per-session SQL connections, and complicate the
 cold-start path. Wire-side laziness solves the actual pain (oversized gRPC
 replies and a heavy DOM) without disturbing the materialization model.
 
+## TLS Auto-Certificate and Lenient Client Trust
+
+Decision: when a Kestrel `https://` endpoint is configured without a certificate
+of its own (and no `Kestrel:Certificates:Default` is set), the gateway generates
+and persists a self-signed certificate rather than failing to start. Clients
+connecting over TLS without a pinned CA accept whatever certificate the server
+presents by default; pinning a CA restores full verification.
+
+Rationale: `mxaccessgw` is an internal tool with no PKI to issue or distribute
+certificates. The prior behavior — an `https` endpoint with no certificate
+fails at startup with Kestrel's opaque "no server certificate was specified"
+error — pushed operators toward plaintext (`h2c`), exposing the API key and
+request payloads on the wire. Auto-generating a long-lived, persisted, reused
+certificate lets TLS "just work" with zero certificate management, while the
+lenient client default means clients connect to that self-signed certificate
+without a manual trust step. Both choices are deliberate, not oversights:
+strict-by-default would force PKI work this tool does not warrant. Plaintext-only
+deployments are untouched — no certificate or key material is written for them —
+and an operator who supplies a real certificate transparently overrides the
+generated one.
+
+Two clients diverge from "accept any certificate" because their gRPC stacks lack
+a per-channel skip-verify hook:
+
+- Python uses trust-on-first-use: it fetches the server's presented certificate
+  over a separate unverified probe and pins it for the channel, and defaults the
+  SNI/target-name override to `localhost` (the generated certificate always
+  carries a `localhost` SAN).
+- Rust is pin-only: tonic exposes no public hook to inject a custom certificate
+  verifier, so TLS over Rust requires either a pinned CA or an explicit opt-in to
+  system-trust verification; otherwise connecting returns a clear, actionable
+  error.
+
+See [Gateway Configuration — Automatic self-signed certificate](./GatewayConfiguration.md#automatic-self-signed-certificate)
+and the per-client READMEs for the as-built behavior.
+
 ## Later Revisit Items
 
 These are explicit post-v1 revisit items, not open blockers:

docs/GatewayConfiguration.md

@@ -148,6 +148,7 @@ the affected stream while the MXAccess session remains active.
 | `MxGateway:Dashboard:Enabled` | `true` | Enables Blazor Server dashboard route mapping. The dashboard mounts at the host root (`/`); there is no separate path-base prefix. |
 | `MxGateway:Dashboard:AllowAnonymousLocalhost` | `true` | Allows loopback dashboard requests to bypass the dashboard cookie requirement for local development. Remote requests still require dashboard authentication. |
 | `MxGateway:Dashboard:RequireHttpsCookie` | `true` | Sets the dashboard auth cookie's secure policy. `true` keeps `CookieSecurePolicy.Always` — the cookie is only sent over HTTPS, which matches a production HTTPS deployment. Set to `false` for plain-HTTP dev deployments to use `CookieSecurePolicy.SameAsRequest`; the cookie is still flagged Secure on HTTPS requests, but it can round-trip over HTTP. Browsers drop Secure cookies set over HTTP from non-localhost hosts, so leaving this `true` while serving the dashboard over plain HTTP will break login from any remote browser. |
+| `MxGateway:Dashboard:CookieName` | `MxGatewayDashboard` | Dashboard auth cookie name. Leave unset (null/blank) to use the default. Override it to give a distinct name to a gateway that shares a hostname with another gateway instance: browser cookies are scoped by host+path but **not** by port, so two instances on the same host would otherwise clobber each other's dashboard session under a shared cookie name. Changing it signs out existing dashboard sessions on next deploy. |
 | `MxGateway:Dashboard:SnapshotIntervalMilliseconds` | `1000` | Dashboard snapshot refresh interval used by the snapshot SignalR hub and the pages that subscribe to it. |
 | `MxGateway:Dashboard:RecentFaultLimit` | `100` | Maximum number of fault summaries projected into each dashboard snapshot. |
 | `MxGateway:Dashboard:RecentSessionLimit` | `200` | Maximum number of session summaries projected into each dashboard snapshot. |
@@ -229,6 +230,185 @@ behavior.
 The alarm monitor is independent of client sessions: `AcknowledgeAlarm` and
 `StreamAlarms` are session-less RPCs served by the monitor.
 
+## Host Endpoints and Transport Security (Kestrel)
+
+The listening endpoints are **not** part of the `MxGateway` section. The gateway
+uses the stock ASP.NET Core host (`WebApplication.CreateBuilder`) with no
+`ConfigureKestrel` call in code, so endpoints come entirely from the standard
+`Kestrel` configuration section. On the deployed hosts these values are supplied
+as NSSM environment variables (`Kestrel__Endpoints__...`), not from
+`appsettings.json`.
+
+Two named endpoints are bound:
+
+| Endpoint name | Purpose | Protocol requirement |
+|---|---|---|
+| `Http` | Public gRPC API (sessions, invoke, events, Galaxy browse) | HTTP/2 |
+| `Dashboard` | Blazor dashboard and SignalR hubs | HTTP/1.1 (HTTP/2 optional) |
+
+Both endpoints share one routing pipeline; the names only select which TCP port
+serves which traffic. The gRPC endpoint must negotiate **HTTP/2**, which drives
+the protocol settings below.
+
+### Plaintext (current deployments)
+
+Both running hosts (`10.100.0.48` and `wonder-app-vd03`) serve the gRPC port in
+**cleartext HTTP/2 (`h2c`)**. Because cleartext HTTP/2 has no ALPN to negotiate
+the protocol, the gRPC endpoint must be pinned to `Http2` with prior knowledge:
+
+```text
+Kestrel__Endpoints__Http__Url=http://0.0.0.0:5120
+Kestrel__Endpoints__Http__Protocols=Http2
+Kestrel__Endpoints__Dashboard__Url=http://0.0.0.0:5130
+```
+
+In this mode all client↔gateway traffic — including the
+`authorization: Bearer mxgw_...` API key and any `WriteSecured` / `AuthenticateUser`
+payloads — crosses the network **unencrypted**. This is acceptable only on a
+trusted/isolated network segment. Prefer TLS for anything else.
+
+### TLS
+
+To encrypt the gRPC channel, give the `Http` endpoint an `https://` URL and a
+certificate. Over TLS, ALPN negotiates HTTP/2, so the explicit `Protocols=Http2`
+pin is no longer required (the default `Http1AndHttp2` works for gRPC over TLS).
+
+`appsettings.json` form:
+
+```json
+{
+  "Kestrel": {
+    "Endpoints": {
+      "Http": {
+        "Url": "https://0.0.0.0:5120",
+        "Certificate": {
+          "Path": "C:\\ProgramData\\MxGateway\\certs\\gateway.pfx",
+          "Password": "<pfx-password>"
+        }
+      },
+      "Dashboard": {
+        "Url": "https://0.0.0.0:5130",
+        "Certificate": {
+          "Path": "C:\\ProgramData\\MxGateway\\certs\\gateway.pfx",
+          "Password": "<pfx-password>"
+        }
+      }
+    }
+  }
+}
+```
+
+Equivalent NSSM environment-variable form (how config is delivered on the hosts —
+see [server deploy mechanics in the project notes]):
+
+```text
+Kestrel__Endpoints__Http__Url=https://0.0.0.0:5120
+Kestrel__Endpoints__Http__Certificate__Path=C:\ProgramData\MxGateway\certs\gateway.pfx
+Kestrel__Endpoints__Http__Certificate__Password=<pfx-password>
+Kestrel__Endpoints__Dashboard__Url=https://0.0.0.0:5130
+Kestrel__Endpoints__Dashboard__Certificate__Path=C:\ProgramData\MxGateway\certs\gateway.pfx
+Kestrel__Endpoints__Dashboard__Certificate__Password=<pfx-password>
+```
+
+Certificate sourcing options (any standard ASP.NET Core form is accepted):
+
+| Form | Keys |
+|---|---|
+| PFX file | `Certificate:Path` (+ `Certificate:Password` if encrypted) |
+| PEM pair | `Certificate:Path` (cert) + `Certificate:KeyPath` (private key) |
+| Windows cert store | `Certificate:Subject`, `Certificate:Store` (e.g. `My`), `Certificate:Location` (`LocalMachine`), `Certificate:AllowInvalid` |
+
+The certificate's CN/SAN must cover the host name clients dial (or clients must
+set a server-name override — see below). The dashboard endpoint can keep its own
+certificate independent of the gRPC endpoint; pair this with
+`MxGateway:Dashboard:RequireHttpsCookie` (`true`) for production HTTPS.
+
+### Automatic self-signed certificate
+
+`mxaccessgw` is an internal tool with no PKI to issue certificates, so requiring
+an operator to supply one before TLS works pushed deployments toward plaintext.
+To avoid that, the gateway fills in a self-signed certificate when an HTTPS
+endpoint is configured without one.
+
+**Trigger.** At startup the gateway inspects `Kestrel:Endpoints:*`. If any
+endpoint has an `https://` URL and no `Certificate` subsection of its own, and no
+`Kestrel:Certificates:Default` is set, the gateway generates (or loads) a
+persisted self-signed certificate and wires it in as the HTTPS *default* via
+`ConfigureHttpsDefaults`. All-plaintext deployments are untouched: when no HTTPS
+endpoint is configured, no certificate or key material is generated or written.
+
+**Generated certificate.** ECDSA P-256, `serverAuth` EKU, validity ≈
+`ValidityYears` (default 10 years, with one day of clock-skew slack before
+`notBefore`). SANs cover `localhost`, the machine name (and its FQDN when
+resolvable), each entry in `AdditionalDnsNames`, and the loopback addresses
+`127.0.0.1` and `::1`.
+
+**`MxGateway:Tls:*` options.** All optional; the zero-config path needs none of
+them.
+
+| Option | Default | Purpose |
+|---|---|---|
+| `Tls:SelfSignedCertPath` | `C:\ProgramData\MxGateway\certs\gateway-selfsigned.pfx` | Where the generated certificate is persisted |
+| `Tls:ValidityYears` | `10` | Lifetime of the generated certificate (validated 1–100) |
+| `Tls:AdditionalDnsNames` | `[]` | Extra DNS SANs (e.g. a load-balancer name) |
+| `Tls:RegenerateIfExpired` | `true` | Replace an expired persisted certificate instead of failing |
+
+`ValidityYears` is validated by `GatewayOptionsValidator` (range 1–100); the
+"HTTPS endpoint configured but no certificate available" fail-fast lives in the
+bootstrap/provider, because the validator only sees the `MxGateway` section, not
+`Kestrel:Endpoints`.
+
+**Persistence.** The PFX is written with an **empty** export password — a random
+in-memory password could not be reused across restarts, which the
+persist-and-reuse model requires. The private key is instead protected at rest by
+filesystem permissions: a restrictive ACL on Windows (SYSTEM + Administrators,
+inherited ACEs stripped) on the `certs` directory and file, and mode `0600` on
+non-Windows. The write is atomic (hardened temp file, then move). The persisted
+certificate is reused across restarts (stable thumbprint, so CA-pinning clients
+keep working) and regenerated only when it is missing, expired (and
+`RegenerateIfExpired` is `true`), or unreadable/corrupt. If the directory is not
+writable or the ACL cannot be applied, the gateway fails fast with a diagnostic
+naming the path rather than falling back to an in-memory certificate.
+
+**Logging.** On generate or load, the gateway logs the certificate thumbprint,
+SAN list, and `notAfter` at Information. The PFX bytes, export password, and
+private key are never logged.
+
+**Operator override.** The generated certificate is only the HTTPS *default*. To
+use a real certificate, configure one explicitly — either per endpoint via
+`Kestrel:Endpoints:<name>:Certificate` (`Path`/`Subject`/`Thumbprint`, etc., as
+in the table above) or globally via `Kestrel:Certificates:Default`. An
+explicitly-configured certificate takes precedence, and the gateway then writes
+no self-signed material.
+
+### Client side
+
+Each official client opts into TLS explicitly. For the .NET client
+(`MxGatewayClientOptions`):
+
+| Option | Effect |
+|---|---|
+| `UseTls` (default `false`) | Enables TLS. Requires an `https://` endpoint; an `https://` endpoint without `UseTls` fails validation, and vice versa. |
+| `CaCertificatePath` | Pins a custom root (self-signed / private CA) using `CustomRootTrust` chain validation instead of the OS trust store; the .NET client also enforces the certificate hostname/SAN match on this path. |
+| `RequireCertificateValidation` (default `false`) | Forces OS/system-trust verification on a TLS connection with no pinned CA. Leave `false` for the lenient default. |
+| `ServerNameOverride` | SNI / certificate host name override when the dialed host differs from the certificate CN/SAN. |
+
+To pair with the auto-generated self-signed certificate above, the clients are
+**lenient by default**: a TLS connection with no pinned CA accepts whatever
+certificate the gateway presents. Pin `CaCertificatePath` to verify, or set
+`RequireCertificateValidation` to force system-trust verification without
+pinning. The other language clients expose the equivalent options; the exact
+behavior differs per stack — Python uses trust-on-first-use and Rust is pin-only.
+See each client README for the as-built behavior.
+
+### Gateway↔worker IPC
+
+Transport security here applies only to the public gRPC channel. The
+gateway↔worker link is a per-session **named pipe**
+(`mxaccess-gateway-{gatewayPid}-{sessionId}`), not a network socket. It is not
+TLS-encrypted and does not need to be: it never leaves the local Windows host and
+is secured by the OS pipe ACL. See [Worker Frame Protocol](./WorkerFrameProtocol.md).
+
 ## Related Documentation
 
 - [Gateway Process Detailed Design](./GatewayProcessDesign.md)

docs/Grpc.md

@@ -243,9 +243,27 @@ services.AddGrpc(options => options.Interceptors.Add<GatewayGrpcAuthorizationInt
 
 Because the interceptor runs before any handler, `MxAccessGatewayService` can safely assume the call has been authorized and that `IGatewayRequestIdentityAccessor.Current` is populated. The handler's only responsibility is to read the identity for `OpenSession` so the session is owned by the authenticated principal; it does not perform any authorization checks of its own. See [Authorization](./Authorization.md) for the policy and identity model.
 
+## Transport Security
+
+The gRPC endpoint runs over HTTP/2, in cleartext (`h2c`) or TLS depending on the
+Kestrel endpoint configuration. The current deployments serve it in cleartext, so
+the API key and request payloads cross the network unencrypted. The endpoint,
+protocol pinning, and TLS certificate configuration — plus the corresponding
+client `UseTls` / `CaCertificatePath` options — are documented in
+[Host Endpoints and Transport Security](./GatewayConfiguration.md#host-endpoints-and-transport-security-kestrel).
+
+To make TLS usable without PKI, the gateway can auto-generate and persist a
+self-signed certificate when an HTTPS endpoint is configured without one, and the
+language clients are lenient by default — a TLS connection with no pinned CA
+accepts the presented certificate (with per-stack nuances: Python is
+trust-on-first-use, Rust is pin-only). See
+[Automatic self-signed certificate](./GatewayConfiguration.md#automatic-self-signed-certificate)
+and each client README for the as-built behavior.
+
 ## Related Documentation
 
 - [Contracts](./Contracts.md)
 - [Sessions](./Sessions.md)
 - [Authorization](./Authorization.md)
+- [Gateway Configuration](./GatewayConfiguration.md)
 - [Gateway Process Design](./GatewayProcessDesign.md)

docs/Metrics.md

@@ -4,7 +4,7 @@ The metrics subsystem exposes counters, histograms, and observable gauges that d
 
 ## Overview
 
-`GatewayMetrics` is a singleton (registered in `GatewayApplication.cs`) that owns a single `Meter` named `ZB.MOM.WW.MxGateway.Server` and a set of synchronised counters, histograms, and observable gauges. Subsystems call typed mutator methods (`SessionOpened`, `CommandFailed`, `EventReceived`, etc.) rather than touching the `Meter` directly, which keeps the OpenTelemetry instrument names and tag conventions in one place. A `lock (_syncRoot)` block guards the scalar fields used by `GetSnapshot`, while per-event maps use `ConcurrentDictionary<string, long>` so the hot event path avoids the lock.
+`GatewayMetrics` is a singleton (registered in `GatewayApplication.cs`) that owns a single `Meter` named `ZB.MOM.WW.MxGateway` and a set of synchronised counters, histograms, and observable gauges. Subsystems call typed mutator methods (`SessionOpened`, `CommandFailed`, `EventReceived`, etc.) rather than touching the `Meter` directly, which keeps the OpenTelemetry instrument names and tag conventions in one place. A `lock (_syncRoot)` block guards the scalar fields used by `GetSnapshot`, while per-event maps use `ConcurrentDictionary<string, long>` so the hot event path avoids the lock.
 
 ## Meter and OpenTelemetry Compatibility
 
@@ -13,7 +13,7 @@ The meter name is exposed as a constant so that hosting code can register it wit
 ```csharp
 public sealed class GatewayMetrics : IDisposable
 {
-    public const string MeterName = "ZB.MOM.WW.MxGateway.Server";
+    public const string MeterName = "ZB.MOM.WW.MxGateway";
 
     public GatewayMetrics()
     {
@@ -50,12 +50,12 @@ All counters are `Counter<long>`. Tag values come from the call sites listed und
 
 ### Histograms
 
-Histograms record durations in milliseconds (the `unit` argument on `CreateHistogram`):
+Histograms record durations in seconds (the `unit` argument on `CreateHistogram`):
 
 ```csharp
-_workerStartupLatencyHistogram = _meter.CreateHistogram<double>("mxgateway.workers.startup.duration", "ms");
-_commandLatencyHistogram = _meter.CreateHistogram<double>("mxgateway.commands.duration", "ms");
-_eventStreamSendLatencyHistogram = _meter.CreateHistogram<double>("mxgateway.events.stream_send.duration", "ms");
+_workerStartupLatencyHistogram = _meter.CreateHistogram<double>("mxgateway.workers.startup.duration", "s");
+_commandLatencyHistogram = _meter.CreateHistogram<double>("mxgateway.commands.duration", "s");
+_eventStreamSendLatencyHistogram = _meter.CreateHistogram<double>("mxgateway.events.stream_send.duration", "s");
 ```
 
 | Instrument | Tags | What it measures |

docs/plans/2026-06-01-gateway-cert-autogen-design.md

@@ -0,0 +1,156 @@
+# Gateway TLS Auto-Certificate and Lenient Client Trust — Design
+
+Date: 2026-06-01
+Status: Approved (brainstorming), pending implementation plan
+
+## Problem
+
+The gateway can serve gRPC and the dashboard over TLS, but only if an operator
+supplies a certificate via the Kestrel `https://` endpoint config. With no cert,
+an `https` endpoint fails at startup with Kestrel's opaque "No server certificate
+was specified" error. Both current deployments therefore run plaintext (`h2c`),
+exposing the API key and request payloads on the wire.
+
+`mxaccessgw` is an internal tool. The goal is for TLS to "just work" with zero PKI
+management: the gateway fabricates its own long-lived certificate when an HTTPS
+endpoint is configured without one, and clients accept whatever certificate is
+presented unless an operator explicitly opts into pinning.
+
+## Decisions
+
+1. **Gateway = fill-missing-cert-only.** No new "enable TLS" switch. TLS is still
+   driven by configuring a Kestrel `https://` endpoint. New behavior: when an
+   HTTPS endpoint has no `Certificate` section, the gateway generates/loads a
+   persisted self-signed cert instead of failing. Plaintext-only hosts are
+   untouched — no certificate or key material is ever written for them.
+2. **Persist & reuse.** The self-signed cert is saved as a PFX under
+   `C:\ProgramData\MxGateway\certs`, reused across restarts, regenerated only if
+   missing, expired, or unreadable. Stable thumbprint; survives restarts; any
+   CA-pinning client keeps working.
+3. **Clients = lenient TLS, plaintext default.** When a client connects over TLS
+   without a pinned CA, it skips verification (accepts any cert). Pinning a CA file
+   restores full verification. The per-client connection default (mostly
+   plaintext/`http`) does not change — TLS is still opt-in via the endpoint scheme.
+
+**Scope boundary:** the gateway↔worker named-pipe IPC is unchanged (local,
+OS-secured by the pipe ACL). This work touches only the public gRPC/dashboard
+transport and the five language clients.
+
+## Gateway component
+
+New type `SelfSignedCertificateProvider` in
+`src/ZB.MOM.WW.MxGateway.Server/Security/Tls/`.
+
+1. **Detect need.** Inspect `Kestrel:Endpoints:*` configuration at startup. If any
+   endpoint has an `https://` URL and no `Certificate` subsection, a default cert
+   is needed. If none do, the provider is a no-op (no file written).
+2. **Load-or-create.** Look for the persisted PFX. If present, valid, and
+   unexpired, load it. Otherwise generate and persist.
+3. **Generate.** `CertificateRequest` with **ECDSA P-256**, `notBefore = now - 1
+   day` (clock-skew slack), `notAfter = now + ValidityYears`. SANs: `DNS=localhost`,
+   `DNS=<MachineName>`, `DNS=<MachineName.FQDN>` when resolvable, plus
+   `IP=127.0.0.1` and `IP=::1`. Server-auth EKU.
+4. **Persist securely.** Write the PFX with an **empty** export password (a random
+   in-memory password cannot be reused across restarts, which the persist-and-reuse
+   decision requires); protect the private key with a restrictive ACL (SYSTEM +
+   Administrators + service account) on the `certs` directory and file on Windows,
+   and `0600` on non-Windows; atomic write (temp + rename). After generating, the
+   cert is reloaded from the persisted PFX so Kestrel always serves the on-disk key.
+5. **Wire into Kestrel.** In `GatewayApplication.CreateBuilder`, add
+   `builder.WebHost.ConfigureKestrel(o => o.ConfigureHttpsDefaults(h =>
+   h.ServerCertificate = cert))`. `ConfigureHttpsDefaults` supplies the cert only
+   for HTTPS endpoints that did not specify their own, so an operator-configured
+   `Kestrel:Endpoints:*:Certificate` transparently overrides it. One hook covers
+   both the gRPC and dashboard ports.
+
+### New config block `MxGateway:Tls`
+
+All optional; the zero-config path needs none of them.
+
+| Option | Default | Purpose |
+|---|---|---|
+| `Tls:SelfSignedCertPath` | `C:\ProgramData\MxGateway\certs\gateway-selfsigned.pfx` | Where the generated cert lives |
+| `Tls:ValidityYears` | `10` | Lifetime of the generated cert |
+| `Tls:AdditionalDnsNames` | `[]` | Extra SANs (e.g. a load-balancer name) |
+| `Tls:RegenerateIfExpired` | `true` | Auto-replace an expired persisted cert |
+
+Validated by `GatewayOptionsValidator`: `ValidityYears` in 1–100,
+`SelfSignedCertPath` is a valid path shape when non-blank, and
+`AdditionalDnsNames` entries are non-blank. (The "https endpoint exists but cert
+path is blank" fail-fast lives in the bootstrap/provider, not the validator,
+because the validator only sees the `MxGateway` section, not `Kestrel:Endpoints`.)
+
+**Logging:** on generate/load, log thumbprint + SAN list + `notAfter` at
+Information. Never log the PFX password or private key.
+
+## Client lenient-TLS behavior
+
+Uniform rule: **TLS on + no CA pinned ⇒ skip verification; CA pinned ⇒ full
+verification.** No transport default changes. Each client also exposes an explicit
+switch to force-disable leniency (strict-without-pinning) for the future.
+
+| Client | Mechanism | Effort |
+|---|---|---|
+| .NET | In `CreateHttpHandler`, when `UseTls` and `CaCertificatePath` empty, set `SslOptions.RemoteCertificateValidationCallback = (_,_,_,_) => true`. CA path keeps existing custom-root validation. | trivial |
+| Go | In `buildCredentials`, when TLS and no `CACertFile`/`TLSConfig`, use `tls.Config{InsecureSkipVerify: true, ServerName: override}`. | trivial |
+| Java | grpc-netty-shaded 1.76.0 ships `InsecureTrustManagerFactory`. When TLS and no CA, build `GrpcSslContexts.forClient().trustManager(InsecureTrustManagerFactory.INSTANCE)`. | easy |
+| Python | grpc-python has no per-channel skip-verify. Fetch the server leaf cert at connect via `ssl.get_server_certificate((host, port))`, pass it as `root_certificates` to `ssl_channel_credentials`, plus `grpc.ssl_target_name_override`. Effectively trusts what is presented (TOFU). | moderate, special-cased |
+| Rust | tonic 0.13.1 + rustls (`tls-ring`). Implement a custom `rustls::client::danger::ServerCertVerifier` that accepts everything, build a `rustls::ClientConfig` via `.dangerous().with_custom_certificate_verifier(...)`, feed it to the channel. May require a custom hyper-rustls connector if `ClientTlsConfig` will not take a raw rustls config. **Needs an API spike.** | highest |
+
+### Honesty caveats
+
+- **Python** is not literally "ignore the cert"; it pins whatever the server
+  presents on first contact via a separate unverified TLS probe. For a self-signed
+  internal cert this is the intended outcome. Documented as a difference.
+- **Rust** leniency depends on the tonic 0.13 TLS surface. If a custom verifier is
+  disproportionately invasive, the fallback is to require a CA file for Rust TLS
+  (pin-only) and document Rust as the exception.
+
+## Error handling
+
+Gateway:
+- Cert dir not writable / ACL fails ⇒ fail fast at startup with a diagnostic naming
+  the path and required permission. No silent in-memory fallback.
+- Persisted PFX corrupt/unreadable ⇒ warn, regenerate, overwrite.
+- Persisted cert expired ⇒ regenerate if `RegenerateIfExpired` (default), else fail
+  fast instructing the operator to delete it or enable regeneration.
+- HTTPS endpoint configured but generation disabled / path empty ⇒ validator
+  rejects at startup rather than letting Kestrel throw its opaque error.
+
+Clients: surface unchanged. Skip-verify cannot itself raise. Python's pre-fetch
+wraps connect failure into the existing connect-error type with the endpoint in the
+message. Rust pin-only fallback surfaces the existing CA-file error.
+
+## Documentation (same commit as source, per CLAUDE.md)
+
+- `docs/GatewayConfiguration.md` — extend the TLS section: auto-generation, the
+  `MxGateway:Tls:*` block, persistence location/ACL, thumbprint logging, operator
+  override via `Kestrel:Endpoints:*:Certificate`.
+- Each client README + `*ClientDesign.md` — "TLS is lenient by default; pin a CA to
+  verify," with Python TOFU and any Rust caveat noted.
+- `docs/DesignDecisions.md` — record both posture choices and the why (internal
+  tool, no PKI) so they are not mistaken for an oversight.
+
+## Testing
+
+Gateway (`MxGateway.Tests`, no MXAccess):
+- `SelfSignedCertificateProvider`: SANs, server-auth EKU, `notAfter ≈ now +
+  ValidityYears`, ECDSA P-256.
+- Load-or-create: valid persisted PFX reused (same thumbprint); expired regenerates
+  when enabled; corrupt regenerates with a warning.
+- Detection: HTTPS-without-cert engages; all-plaintext no-ops and writes no file;
+  endpoint with its own cert is not overridden.
+- `GatewayOptionsValidator`: new `Tls:*` rules.
+- Host integration: `Kestrel:Endpoints:Http:Url=https://127.0.0.1:0` builds and
+  binds (today it throws "no certificate specified").
+
+Clients: each test project gets a lenient-TLS test against a throwaway self-signed
+cert — connect with no CA succeeds; pinning a wrong CA fails (proves pinning still
+verifies). Python exercises the pre-fetch path; mark opt-in if loopback timing is
+flaky. Standard (non-live) tests; no MXAccess or external services.
+
+Cross-language: add a TLS variant note to `docs/CrossLanguageSmokeMatrix.md`;
+running the matrix over TLS stays manual/opt-in, consistent with the existing gate.
+
+Per-component verification follows CLAUDE.md's source-update table (build + test
+each touched component independently).

docs/plans/2026-06-01-gateway-cert-autogen-implementation.md.tasks.json

@@ -0,0 +1,18 @@
+{
+  "planPath": "docs/plans/2026-06-01-gateway-cert-autogen-implementation.md",
+  "tasks": [
+    {"id": 1, "subject": "Task 1: Add TlsOptions config + bind into GatewayOptions", "status": "pending"},
+    {"id": 2, "subject": "Task 2: Validate MxGateway:Tls in GatewayOptionsValidator", "status": "pending", "blockedBy": [1]},
+    {"id": 3, "subject": "Task 3: SelfSignedCertificateProvider.GenerateCertificate", "status": "pending", "blockedBy": [1]},
+    {"id": 4, "subject": "Task 4: SelfSignedCertificateProvider.LoadOrCreate (persist/reuse/regenerate/ACL)", "status": "pending", "blockedBy": [3]},
+    {"id": 5, "subject": "Task 5: KestrelTlsInspector (detect HTTPS-without-cert)", "status": "pending"},
+    {"id": 6, "subject": "Task 6: Wire auto-cert into GatewayApplication.CreateBuilder", "status": "pending", "blockedBy": [1, 4, 5]},
+    {"id": 7, "subject": "Task 7: .NET client lenient TLS by default", "status": "pending"},
+    {"id": 8, "subject": "Task 8: Go client lenient TLS by default", "status": "pending"},
+    {"id": 9, "subject": "Task 9: Java client lenient TLS by default", "status": "pending"},
+    {"id": 10, "subject": "Task 10: Python client lenient TLS via TOFU pre-fetch", "status": "pending"},
+    {"id": 11, "subject": "Task 11: Rust client lenient TLS via rustls verifier (spike + fallback)", "status": "pending"},
+    {"id": 12, "subject": "Task 12: Documentation", "status": "pending", "blockedBy": [6, 7, 8, 9, 10, 11]}
+  ],
+  "lastUpdated": "2026-06-01"
+}

docs/plans/2026-06-13-alarm-subtag-fallback-design.md

@@ -0,0 +1,302 @@
+# Alarm Subtag-Monitoring Fallback — Design
+
+**Date:** 2026-06-13
+**Status:** Approved (brainstorming), ready for implementation planning
+**Branch:** `feat/alarm-subtag-fallback`
+
+## Problem
+
+The gateway's central alarm feed (`GatewayAlarmMonitor` → worker
+`WnWrapAlarmConsumer`) depends on the AVEVA wnwrap COM consumer
+(`WNWRAPCONSUMERLib.wwAlarmConsumerClass`), which polls `GetXmlCurrentAlarms2`
+on the worker STA. That provider can fail at the COM boundary (the older
+`aaAlarmManagedClient` crashed on FILETIME marshaling; wnwrap can still return
+failure HRESULTs or throw `COMException`). When it does, the gateway loses all
+alarm visibility.
+
+This design adds a **second alarm source** — direct monitoring of each alarm
+attribute's subtags (`.active`, `.acked`, …) via the existing MXAccess
+`AddItem`/`Advise` pipeline — and **fails over to it automatically when the
+wnwrap provider breaks, then fails back automatically when it recovers**. The
+subtag source can also be forced on by config.
+
+## Decisions (locked during brainstorming)
+
+| Decision | Choice |
+|---|---|
+| Failover model | **Auto-failover + auto-failback** (both directions, runtime) |
+| Watch-list source | **Galaxy Repository SQL discovery + config override** |
+| Acknowledge in subtag mode | **Write the operator comment to the alarm's ack-comment subtag** (the write performs the ack) |
+| Failure signal | **N consecutive wnwrap COM failures** (Subscribe / `GetXmlCurrentAlarms2` throws or returns a failure HRESULT) |
+| Degraded-state visibility | **Both** — explicit field in the gRPC contract **and** dashboard + metrics |
+| Synthesis location | **Worker-side** (`Approach A`) — keeps the parity rule "the gateway forwards only events the worker emits; it never synthesizes events" |
+
+## Core principle
+
+Subtag monitoring is, by definition, a **non-parity, lower-fidelity** alarm
+source: it synthesizes alarm transitions from raw data changes, has no native
+alarm GUID, no native original-raise timestamp, and a narrower field set. Per
+`CLAUDE.md`, synthesizing events is allowed only as an explicit opt-in
+non-parity mode. This design satisfies that by (a) doing the synthesis **inside
+the worker** (so the gateway still only forwards worker-emitted events) and
+(b) marking every degraded event and the whole feed as degraded so no client
+mistakes it for the authoritative alarmmgr feed.
+
+## Architecture
+
+```
+                          GATEWAY (.NET 10, x64)
+  ┌─────────────────────────────────────────────────────────────────┐
+  │ GatewayAlarmMonitor (BackgroundService)                           │
+  │  • resolves watch-list: Galaxy Repository SQL + config override   │
+  │  • arms the worker with the watch-list at subscribe time          │
+  │  • consumes AlarmProviderModeChanged → reflects mode into feed,   │
+  │    /hubs/alarms dashboard hub, and metrics                        │
+  │  • forces a cache reconcile (QueryActiveAlarms) on every switch   │
+  └───────────────────────────────┬───────────────────────────────────┘
+                                   │ IPC (WorkerEnvelope frames)
+                                   │  · SubscribeAlarms{ watch_list, failover cfg }
+                                   │  · AlarmProviderModeChanged{ mode, reason, hresult }
+                                   │  · OnAlarmTransitionEvent (degraded flag set in subtag mode)
+                                   ▼
+                          WORKER (.NET FW 4.8, x86, STA)
+  ┌─────────────────────────────────────────────────────────────────┐
+  │ AlarmDispatcher → FailoverAlarmConsumer : IMxAccessAlarmConsumer  │
+  │   ├─ primary : WnWrapAlarmConsumer   (wnwrap COM poll, unchanged) │
+  │   └─ standby : SubtagAlarmConsumer   (AddItem/Advise on subtags)  │
+  │                                                                   │
+  │  FailoverAlarmConsumer owns the state machine:                    │
+  │   PrimaryActive ──(N consecutive wnwrap COM failures)──▶ Degraded │
+  │   Degraded ──(M consecutive clean wnwrap probe polls)──▶ Primary  │
+  │   on each switch: snapshot the now-active provider, hand off      │
+  └─────────────────────────────────────────────────────────────────┘
+```
+
+The failover state machine lives **worker-local** so the switch is instant — no
+IPC round-trip at the moment alarmmgr dies. The gateway *arms* the standby
+consumer up front (passes the watch-list at subscribe time) so it is ready
+before it is ever needed.
+
+## Components
+
+### Worker (`src/ZB.MOM.WW.MxGateway.Worker/MxAccess/`)
+
+**`SubtagAlarmConsumer : IMxAccessAlarmConsumer` (new)** — the standby provider.
+
+- On `Subscribe`, instead of wnwrap registration it `AddItem`/`Advise`s the
+  configured subtags for each watch-list entry on the existing STA (reuses the
+  worker's item-subscription machinery). Per attribute it advises at minimum
+  `.active` and `.acked`; optionally `.priority`/severity, `.descr`, value/limit
+  if present.
+- Converts each `OnDataChange` into the same `MxAlarmTransitionEvent` the wnwrap
+  consumer emits, via the synthesis rules below, and raises
+  `AlarmTransitionEmitted`. Marks each as **degraded**.
+- `SnapshotActiveAlarms()` returns the currently-active set computed from
+  last-known subtag values.
+- `AcknowledgeByName(...)` resolves the watch-list entry's ack-comment subtag and
+  issues a `Write(comment)` on the STA. `AcknowledgeByGuid(...)` maps the
+  synthetic GUID (see below) back to a reference, then does the same. If the
+  attribute exposes no writable ack-comment subtag, returns a failure code that
+  the gateway surfaces as `FailedPrecondition`.
+- `PollOnce()` is a no-op (subtag mode is event-driven via Advise).
+
+**`FailoverAlarmConsumer : IMxAccessAlarmConsumer` (new)** — composite + state
+machine. Owns the wnwrap consumer (primary) and the subtag consumer (standby),
+forwards `AlarmTransitionEmitted` from whichever child is active, and raises a
+new `ProviderModeChanged` event on every switch.
+
+- **Failure counting:** wraps `Subscribe`/`PollOnce` on the primary; a thrown
+  `COMException` or a failure HRESULT increments a consecutive-failure counter,
+  reset to zero on any clean poll.
+- **Failover** (`PrimaryActive → Degraded`): at `ConsecutiveFailureThreshold`
+  (default 3), ensures the standby is subscribed (it was armed at startup), sets
+  active = standby, snapshots the standby's active set for hand-off, and emits
+  `ProviderModeChanged(SUBTAG, reason, hresult)`.
+- **Failback probe** (`Degraded → PrimaryActive`): while degraded, every
+  `FailbackProbeIntervalSeconds` (default 30) it re-attempts wnwrap
+  `Subscribe`+`PollOnce` on the STA. After `FailbackStableProbes` (default 3)
+  consecutive clean polls it switches active = primary, returns the standby to
+  standby, and emits `ProviderModeChanged(ALARMMGR, "recovered")`.
+- **Hand-off:** on every switch it takes `SnapshotActiveAlarms()` from the
+  now-active provider so the gateway can reconcile and avoid spurious
+  raise/clear storms.
+
+**`AlarmDispatcher` / `MxAccessAlarmEventSink` / `AlarmCommandHandler`
+(changed, minimal)** — `AlarmDispatcher` holds a `FailoverAlarmConsumer` instead
+of a bare `WnWrapAlarmConsumer`; it subscribes to `ProviderModeChanged` and
+enqueues a mode-changed worker event. The ack path routes by active mode (native
+wnwrap ack in alarmmgr mode; ack-comment write in subtag mode), but that routing
+is entirely inside the consumer — the dispatcher just calls
+`AcknowledgeByName`/`AcknowledgeByGuid`.
+
+### Gateway (`src/ZB.MOM.WW.MxGateway.Server/`)
+
+**Galaxy Repository discovery (new query)** — alongside the existing GR SQL
+browse RPCs, a query "attributes that have alarms configured, with their
+ack-comment subtag and area", scoped to the configured area. Merged with the
+config override (explicit includes/excludes). Produces the watch-list of
+`AlarmSubtagTarget`s.
+
+**`GatewayAlarmMonitor` (changed)** — resolves the watch-list at subscribe time
+and passes it to the worker; consumes `AlarmProviderModeChanged` and reflects
+the current provider mode into (a) the `AlarmFeedMessage` provider-status,
+(b) the `/hubs/alarms` dashboard hub, and (c) metrics; forces a reconcile
+(`QueryActiveAlarms`) on every switch. Re-runs discovery on its existing
+reconcile cadence and pushes an updated watch-list when the model changes.
+
+**`AlarmsOptions` (extended)** — new `Fallback` sub-section (below).
+
+### Contract (`src/ZB.MOM.WW.MxGateway.Contracts/Protos/`)
+
+**`mxaccess_gateway.proto`:**
+
+- `enum AlarmProviderMode { ALARM_PROVIDER_MODE_UNSPECIFIED = 0; ALARMMGR = 1; SUBTAG = 2; }`
+- New `AlarmFeedMessage` oneof case `AlarmProviderStatus provider_status`,
+  carrying `{ AlarmProviderMode mode; bool degraded; string reason;
+  google.protobuf.Timestamp since; }`. Emitted on stream open and on every
+  change so a late-joining client immediately learns the mode.
+- Add `bool degraded` + `AlarmProviderMode source_provider` to
+  `OnAlarmTransitionEvent` **and** `ActiveAlarmSnapshot`, so per-item provenance
+  is visible even mid-stream. All additions are new field numbers — backward
+  compatible; existing clients ignore them and keep seeing alarms.
+
+**`mxaccess_worker.proto`:**
+
+- Extend the alarm-subscribe command with: `AlarmProviderMode forced_mode`
+  (`UNSPECIFIED` = auto), `int32 consecutive_failure_threshold`,
+  `int32 failback_probe_interval_seconds`, `int32 failback_stable_probes`, and
+  `repeated AlarmSubtagTarget watch_list`, where `AlarmSubtagTarget =
+  { string alarm_full_reference; string source_object_reference;
+  string active_subtag; string acked_subtag; string ack_comment_subtag;
+  string priority_subtag; }`.
+- New worker→gateway event `AlarmProviderModeChanged { AlarmProviderMode mode;
+  string reason; int32 hresult; google.protobuf.Timestamp at; }`.
+
+> Generated code under `Generated/` and `clients/*/generated*/` is rebuilt from
+> these `.proto` files — never hand-edited. Every generated client touched by
+> the contract is rebuilt per the source-update workflow.
+
+## Data flow
+
+### Subtag synthesis rules
+
+`SubtagAlarmConsumer` keeps last-known `(active, acked)` per watch-list entry and
+emits transitions on change:
+
+| Subtag change | Emitted transition | Notes |
+|---|---|---|
+| `active` false → true | `RAISE` (state `UNACK_ALM`) | `original_raise_timestamp` = first-observed active time |
+| `acked` false → true while `active` | `ACKNOWLEDGE` | `operator_user`/`operator_comment` from ack-comment subtag if advised |
+| `active` true → false | `CLEAR` | maps to `AckRtn` if acked at clear, else `UnackRtn` |
+| `active` stays true, re-alarm | `RETRIGGER` | **only** if a re-alarm counter subtag exists; otherwise not synthesized (documented limitation) |
+
+Snapshot state mapping for `ActiveAlarmSnapshot.current_state`:
+`active && !acked → ACTIVE`, `active && acked → ACTIVE_ACKED`,
+`!active → INACTIVE`.
+
+Field degradation in subtag mode:
+- `alarm_full_reference` — from the watch-list entry (stable, drives ack-by-ref).
+- Synthetic, deterministic GUID derived by hashing `alarm_full_reference` so
+  GUID-based ack still resolves; flagged `degraded = true`.
+- `severity` — from the priority subtag if advised, else 0.
+- `original_raise_timestamp` — first-observed active time (best effort).
+- `transition_timestamp` — the `OnDataChange` timestamp.
+- `category`/`description`/`current_value`/`limit_value` — populated only if the
+  corresponding subtag is advised; otherwise empty.
+
+### Acknowledge
+
+`AcknowledgeAlarm`/`AcknowledgeAlarmByName` are unchanged at the RPC surface.
+`AlarmDispatcher` routes by active provider mode:
+- **alarmmgr mode:** native wnwrap `AlarmAckByName`/`AlarmAckByGUID` (unchanged).
+- **subtag mode:** resolve the target's `ack_comment_subtag`, `Write` the
+  operator comment via the existing worker write path on the STA. No writable
+  ack-comment subtag → `FailedPrecondition`.
+
+### Provider-mode reflection
+
+Worker `AlarmProviderModeChanged` → `GatewayAlarmMonitor` → (a) emit/refresh
+`AlarmFeedMessage.provider_status` to every `StreamAlarms` subscriber, (b) push
+to `/hubs/alarms`, (c) update metrics, (d) force a reconcile.
+
+## Error handling
+
+- **Both providers down** (subtag advise also failing): the monitor stays
+  faulted and keeps retrying both; acknowledge returns `Unavailable`. No silent
+  data loss — the feed reports degraded with reason.
+- **Empty watch-list in subtag mode** (GR SQL unavailable, no config override):
+  log + metric `alarm_fallback_watchlist_empty`; the feed reports degraded +
+  empty; the gateway keeps re-running discovery on its reconcile cadence and
+  pushes an updated watch-list when one becomes available.
+- **Switch hand-off:** every switch snapshots the now-active provider and
+  reconciles against the gateway cache to avoid a raise/clear storm.
+- **STA affinity:** all subtag advise/write and wnwrap probe calls run on the
+  worker STA (reuse the existing affinity guard) to satisfy
+  `ThreadingModel=Apartment`.
+
+### Metrics
+
+- `mxgateway_alarm_provider_mode` (gauge: 1 = alarmmgr, 2 = subtag)
+- `mxgateway_alarm_provider_switch_total{from,to,reason}` (counter)
+- `mxgateway_alarm_fallback_watchlist_size` (gauge)
+
+## Configuration
+
+```jsonc
+"MxGateway": {
+  "Alarms": {
+    "Enabled": true,
+    "SubscriptionExpression": "\\\\DESKTOP-6JL3KKO\\Galaxy!DEV",
+    "DefaultArea": "DEV",
+    "ReconcileIntervalSeconds": 30,
+    "Fallback": {
+      "Mode": "Auto",                      // Auto | ForceAlarmManager | ForceSubtag
+      "ConsecutiveFailureThreshold": 3,
+      "FailbackProbeIntervalSeconds": 30,
+      "FailbackStableProbes": 3,
+      "Discovery": {
+        "UseGalaxyRepository": true,
+        "Area": "",                        // defaults to Alarms.DefaultArea
+        "IncludeAttributes": [],           // explicit additions
+        "ExcludeAttributes": []
+      },
+      "Subtags": {
+        "Active": "active",
+        "Acked": "acked",
+        "AckComment": "",                  // verified against MXAccess analysis
+        "Priority": "priority"
+      }
+    }
+  }
+}
+```
+
+`GatewayOptionsValidator` additions: `Mode = ForceSubtag` with empty discovery
+result and no explicit `IncludeAttributes` → startup validation warning;
+threshold/interval/probe values floored at sane minimums.
+
+## Open item to confirm during implementation
+
+The exact AVEVA subtag names (`.active`, `.acked`, the ack-comment attribute,
+priority) must be confirmed against the MXAccess analysis project
+(`C:\Users\dohertj2\Desktop\mxaccess`, `docs/MXAccess-Public-API.md`) and the
+live Galaxy before wiring `SubtagAlarmConsumer`. The config `Subtags` block
+exists precisely so the resolved names are not hard-coded.
+
+## Testing
+
+| Layer | Tests |
+|---|---|
+| Worker unit (`MxGateway.Worker.Tests`, x86) | `SubtagAlarmConsumer` synthesis — feed `OnDataChange` sequences, assert raise/ack/clear transitions, snapshot states, degraded flag, synthetic-GUID stability, ack-comment write routing |
+| Worker unit | `FailoverAlarmConsumer` state machine — fake wnwrap throwing after K polls: assert switch at threshold, failback after stable probes, `ProviderModeChanged` emitted, no duplicate transitions across switch (hand-off reconcile) |
+| Gateway unit (`MxGateway.Tests`, fake worker) | discovery + config-override merge; `GatewayAlarmMonitor` reflects mode into feed + hub; metrics increment on switch |
+| Contract | proto round-trip for new fields; existing alarm tests unchanged (alarmmgr-mode regression — parity preserved) |
+| Live (opt-in, `MXGATEWAY_RUN_LIVE_MXACCESS_TESTS=1`) | real subtag advise + ack-comment write against a live alarm; GR SQL discovery query against the `ZB` DB (gated like existing GR tests) |
+
+## Docs to update in the same change
+
+`gateway.md` (alarm provider section), `docs/DesignDecisions.md` (record the
+fallback decision), `docs/GatewayConfiguration.md` (the `Fallback` block),
+`docs/AlarmClientDiscovery.md` (subtag provider + synthesis rules),
+`docs/Grpc.md` (the new `provider_status` / `degraded` fields), and any client
+READMEs whose generated alarm types gain fields.

docs/plans/2026-06-13-alarm-subtag-fallback.md

@@ -0,0 +1,860 @@
+# Alarm Subtag-Monitoring Fallback — Implementation Plan
+
+> **For Claude:** REQUIRED SUB-SKILL: Use superpowers-extended-cc:executing-plans (or subagent-driven-development) to implement this plan task-by-task.
+
+**Goal:** Add a second alarm source — direct MXAccess subtag monitoring — that the gateway auto-fails-over to when the wnwrap alarmmgr provider breaks, auto-fails-back to when it recovers, and can be forced on by config.
+
+**Architecture:** Worker-side synthesis (parity rule preserved). A new `SubtagAlarmConsumer` (own `LMXProxyServerClass`, `AddItem`/`Advise` on alarm subtags) and a `FailoverAlarmConsumer` composite (state machine over the wnwrap primary + subtag standby) both implement the existing `IMxAccessAlarmConsumer` seam. The gateway resolves the subtag watch-list (Galaxy Repository SQL + config override), arms the worker at subscribe time, and reflects the live provider mode into the gRPC alarm feed, the dashboard hub, and metrics.
+
+**Tech Stack:** .NET 10 (gateway, x64) + .NET Framework 4.8 (worker, x86, STA), protobuf/gRPC, `Microsoft.Data.SqlClient` (Galaxy Repository), SignalR (dashboard), `System.Diagnostics.Metrics`, xUnit (plain `Assert`, no FluentAssertions).
+
+**Design source:** `docs/plans/2026-06-13-alarm-subtag-fallback-design.md`
+
+**Branch:** `feat/alarm-subtag-fallback` (already created)
+
+---
+
+## Conventions for every task
+
+- **TDD:** write the failing test, run it red, implement, run it green, commit.
+- **xUnit, plain `Assert.*`**, naming `Subject_Condition_Expected`. Worker fakes are sealed private nested classes that raise events.
+- **Build/test commands:**
+  - Contracts regen: `dotnet build src/ZB.MOM.WW.MxGateway.Contracts/ZB.MOM.WW.MxGateway.Contracts.csproj`
+  - Gateway: `dotnet build src/ZB.MOM.WW.MxGateway.Server` ; `dotnet test src/ZB.MOM.WW.MxGateway.Tests/ZB.MOM.WW.MxGateway.Tests.csproj`
+  - Worker (x86): `dotnet build src/ZB.MOM.WW.MxGateway.Worker/ZB.MOM.WW.MxGateway.Worker.csproj -p:Platform=x86` ; `dotnet test src/ZB.MOM.WW.MxGateway.Worker.Tests/ZB.MOM.WW.MxGateway.Worker.Tests.csproj -p:Platform=x86`
+  - Single test: append `--filter FullyQualifiedName~<ClassOrMethod>`
+- **Build is strict:** `TreatWarningsAsErrors=true`, nullable enabled. Add XML doc comments on public members (the repo runs a doc checker).
+- **Generated code** under `Generated/` is never hand-edited — rebuild the contracts project to regenerate.
+- **Namespaces:** worker MxAccess types live in `ZB.MOM.WW.MxGateway.Worker.MxAccess`; proto C# types in `ZB.MOM.WW.MxGateway.Contracts.Proto`.
+
+---
+
+## Phase 0 — Contracts
+
+### Task 1: Worker proto — subtag watch-list, failover config, provider-mode enum
+
+**Classification:** high-risk
+**Estimated implement time:** ~4 min
+**Parallelizable with:** none (Task 2 imports these types)
+
+**Files:**
+- Modify: `src/ZB.MOM.WW.MxGateway.Contracts/Protos/mxaccess_gateway.proto` (real `SubscribeAlarmsCommand` at ~line 324; `MxCommand` references it at 123-125)
+
+> **CORRECTION (execution):** The alarm command messages and `MxCommand` live in **`mxaccess_gateway.proto`**, not the worker proto. `mxaccess_worker.proto` *imports* the gateway proto (`WorkerCommand.command` is `mxaccess_gateway.v1.MxCommand`), so the gateway proto is the base and the worker proto needs **no** change. `AlarmProviderMode` and the new types are added to the gateway proto and are visible to worker code as `mxaccess_gateway.v1` types. Tasks 1 and 2 are executed as a single combined edit on this one file.
+
+**Step 1: Add the enum and messages.** In `mxaccess_gateway.proto`, extend the existing `SubscribeAlarmsCommand` message (line 324) and add the new types after it:
+
+```protobuf
+// Provider selection / current provider for the alarm feed. Defined here in
+// the worker contract because the worker SubscribeAlarmsCommand references it;
+// mxaccess_gateway.proto imports this file and reuses the same enum.
+enum AlarmProviderMode {
+  ALARM_PROVIDER_MODE_UNSPECIFIED = 0;  // auto: alarmmgr primary, subtag fallback
+  ALARM_PROVIDER_MODE_ALARMMGR = 1;
+  ALARM_PROVIDER_MODE_SUBTAG = 2;
+}
+
+message SubscribeAlarmsCommand {
+  string subscription_expression = 1;  // existing field — keep
+  // UNSPECIFIED = auto-failover/failback. ALARMMGR/SUBTAG force one provider.
+  AlarmProviderMode forced_mode = 2;
+  // Subtag watch-list resolved by the gateway (GR SQL + config). Empty in pure
+  // alarmmgr mode; in subtag mode it bounds what the consumer can observe.
+  repeated AlarmSubtagTarget watch_list = 3;
+  AlarmFailoverConfig failover = 4;
+}
+
+// One alarm attribute the subtag consumer advises. Addresses are full MXAccess
+// item references the worker passes straight to AddItem.
+message AlarmSubtagTarget {
+  string alarm_full_reference = 1;     // e.g. "Galaxy!Area.Tank01.Level.HiHi"
+  string source_object_reference = 2;  // e.g. "Tank01"
+  string active_subtag = 3;            // item address of the in-alarm boolean
+  string acked_subtag = 4;             // item address of the acknowledged boolean
+  string ack_comment_subtag = 5;       // writable ack-comment attribute (ack write target)
+  string priority_subtag = 6;          // optional severity source; empty if absent
+}
+
+message AlarmFailoverConfig {
+  int32 consecutive_failure_threshold = 1;   // wnwrap COM failures before switching (>=1)
+  int32 failback_probe_interval_seconds = 2; // probe cadence while degraded (>=1)
+  int32 failback_stable_probes = 3;          // clean probes before switching back (>=1)
+}
+```
+
+`UnsubscribeAlarmsCommand` and `AcknowledgeAlarmCommand` are unchanged.
+
+**Step 2: Regenerate & verify it compiles.**
+Run: `dotnet build src/ZB.MOM.WW.MxGateway.Contracts/ZB.MOM.WW.MxGateway.Contracts.csproj`
+Expected: build succeeds; generated `AlarmProviderMode`, `AlarmSubtagTarget`, `AlarmFailoverConfig` types appear.
+
+**Step 3: Commit.**
+```bash
+git add src/ZB.MOM.WW.MxGateway.Contracts/Protos/mxaccess_worker.proto
+git commit -m "contracts(worker): subtag watch-list + failover config + AlarmProviderMode"
+```
+
+---
+
+### Task 2: Gateway proto — provider status on the feed, degraded provenance, mode-changed event
+
+**Classification:** high-risk
+**Estimated implement time:** ~5 min
+**Parallelizable with:** none (depends on Task 1; Task 3 tests both)
+
+**Files:**
+- Modify: `src/ZB.MOM.WW.MxGateway.Contracts/Protos/mxaccess_gateway.proto` (`OnAlarmTransitionEvent` ~719-771, `ActiveAlarmSnapshot` ~783-803, `AlarmFeedMessage` ~860-870, `MxEvent` family enum + body oneof, `MxEventFamily` enum)
+
+**Step 1: Add degraded provenance to the two alarm payloads.** Append to `OnAlarmTransitionEvent` (next free field 14):
+
+```protobuf
+  // True when this transition came from the subtag-monitoring fallback rather
+  // than the native alarmmgr provider — i.e. it was synthesized from data
+  // changes and carries reduced fidelity (synthetic GUID, no native raise time).
+  bool degraded = 14;
+  // Which provider produced this transition.
+  AlarmProviderMode source_provider = 15;
+```
+
+Append the identical two fields to `ActiveAlarmSnapshot` (next free field 14):
+```protobuf
+  bool degraded = 14;
+  AlarmProviderMode source_provider = 15;
+```
+
+**Step 2: Add provider status to the feed oneof.** Add a new oneof case to `AlarmFeedMessage` (next free field 4) and a new message:
+
+```protobuf
+message AlarmFeedMessage {
+  oneof payload {
+    ActiveAlarmSnapshot active_alarm = 1;
+    bool snapshot_complete = 2;
+    OnAlarmTransitionEvent transition = 3;
+    // Provider-mode status. Emitted once on stream open and again on every
+    // failover/failback so late joiners learn the current mode immediately.
+    AlarmProviderStatus provider_status = 4;
+  }
+}
+
+message AlarmProviderStatus {
+  AlarmProviderMode mode = 1;
+  bool degraded = 2;            // true whenever mode == SUBTAG
+  string reason = 3;            // human-readable switch reason
+  google.protobuf.Timestamp since = 4;
+}
+```
+
+**Step 3: Add the worker→gateway mode-changed event to `MxEvent`.** Find the `MxEventFamily` enum and the `MxEvent` body oneof. Add a family member and a body message + oneof case (use the next free family value and the next free `MxEvent` body field number — check the file):
+
+```protobuf
+// in MxEventFamily enum:
+  MX_EVENT_FAMILY_ON_ALARM_PROVIDER_MODE_CHANGED = <next>;
+
+// new message near OnAlarmTransitionEvent:
+message OnAlarmProviderModeChangedEvent {
+  AlarmProviderMode mode = 1;
+  string reason = 2;
+  int32 hresult = 3;   // COM HRESULT that triggered failover; 0 on failback
+  google.protobuf.Timestamp at = 4;
+}
+
+// in MxEvent body oneof:
+  OnAlarmProviderModeChangedEvent on_alarm_provider_mode_changed = <next>;
+```
+
+`AlarmProviderMode` is defined in `mxaccess_worker.proto`; confirm `mxaccess_gateway.proto` already has `import "mxaccess_worker.proto";` (it references `SubscribeAlarmsCommand`, so it does) and reference the enum unqualified or via its package as the existing references do.
+
+**Step 4: Regenerate & verify.**
+Run: `dotnet build src/ZB.MOM.WW.MxGateway.Contracts/ZB.MOM.WW.MxGateway.Contracts.csproj`
+Expected: build succeeds.
+
+**Step 5: Commit.**
+```bash
+git add src/ZB.MOM.WW.MxGateway.Contracts/Protos/mxaccess_gateway.proto
+git commit -m "contracts(gateway): AlarmProviderStatus feed case, degraded provenance, mode-changed event"
+```
+
+---
+
+### Task 3: Proto round-trip tests for the new alarm fields
+
+**Classification:** small
+**Estimated implement time:** ~3 min
+**Parallelizable with:** none (depends on Tasks 1-2)
+
+**Files:**
+- Modify: `src/ZB.MOM.WW.MxGateway.Tests/Contracts/ProtobufContractRoundTripTests.cs`
+
+**Step 1: Add tests** mirroring the existing `Event_RoundTripsOnAlarmTransitionWithFullPayload` style:
+
+```csharp
+[Fact]
+public void Feed_RoundTripsProviderStatus()
+{
+    var since = Timestamp.FromDateTime(new DateTime(2026, 6, 13, 9, 0, 0, DateTimeKind.Utc));
+    var original = new AlarmFeedMessage
+    {
+        ProviderStatus = new AlarmProviderStatus
+        {
+            Mode = AlarmProviderMode.Subtag,
+            Degraded = true,
+            Reason = "wnwrap poll failed 3x (HRESULT 0x80004005)",
+            Since = since,
+        },
+    };
+
+    var parsed = AlarmFeedMessage.Parser.ParseFrom(original.ToByteArray());
+
+    Assert.Equal(original, parsed);
+    Assert.Equal(AlarmFeedMessage.PayloadOneofCase.ProviderStatus, parsed.PayloadCase);
+    Assert.True(parsed.ProviderStatus.Degraded);
+    Assert.Equal(AlarmProviderMode.Subtag, parsed.ProviderStatus.Mode);
+}
+
+[Fact]
+public void Transition_RoundTripsDegradedProvenance()
+{
+    var t = new OnAlarmTransitionEvent
+    {
+        AlarmFullReference = "Galaxy!Area.Tank01.Level.HiHi",
+        TransitionKind = AlarmTransitionKind.Raise,
+        Degraded = true,
+        SourceProvider = AlarmProviderMode.Subtag,
+    };
+
+    var parsed = OnAlarmTransitionEvent.Parser.ParseFrom(t.ToByteArray());
+
+    Assert.True(parsed.Degraded);
+    Assert.Equal(AlarmProviderMode.Subtag, parsed.SourceProvider);
+}
+```
+
+**Step 2: Run red→green.**
+Run: `dotnet test src/ZB.MOM.WW.MxGateway.Tests/ZB.MOM.WW.MxGateway.Tests.csproj --filter FullyQualifiedName~ProtobufContractRoundTripTests`
+Expected: PASS.
+
+**Step 3: Commit.**
+```bash
+git add src/ZB.MOM.WW.MxGateway.Tests/Contracts/ProtobufContractRoundTripTests.cs
+git commit -m "test(contracts): round-trip provider status + degraded provenance"
+```
+
+---
+
+## Phase 1 — Worker: subtag consumer + failover
+
+### Task 4: Subtag value-source abstraction + synthesis state holder
+
+**Classification:** standard
+**Estimated implement time:** ~5 min
+**Parallelizable with:** none (Task 5 builds on it)
+
+A testable seam so synthesis logic is unit-tested without COM. The COM wiring lands in Task 6.
+
+**Files:**
+- Create: `src/ZB.MOM.WW.MxGateway.Worker/MxAccess/ISubtagAlarmSource.cs`
+- Create: `src/ZB.MOM.WW.MxGateway.Worker/MxAccess/SubtagAlarmStateMachine.cs`
+- Test: `src/ZB.MOM.WW.MxGateway.Worker.Tests/MxAccess/SubtagAlarmStateMachineTests.cs`
+
+**Step 1: Define the source abstraction.** `ISubtagAlarmSource` advises subtag addresses and raises a normalized value-change callback on the STA:
+
+```csharp
+namespace ZB.MOM.WW.MxGateway.Worker.MxAccess;
+
+/// <summary>A change in one advised subtag value, normalized off the COM boundary.</summary>
+public sealed class SubtagValueChange
+{
+    /// <summary>The full item address that changed (matches an AlarmSubtagTarget subtag).</summary>
+    public string ItemAddress { get; init; } = string.Empty;
+    /// <summary>The new value (boolean for .active/.acked, numeric for priority).</summary>
+    public object? Value { get; init; }
+    /// <summary>The change timestamp in UTC.</summary>
+    public DateTime TimestampUtc { get; init; }
+}
+
+/// <summary>
+///     Advises a set of MXAccess subtag addresses and surfaces value changes.
+///     The production implementation (Task 6) owns its own LMXProxyServerClass;
+///     tests substitute a fake that pushes <see cref="SubtagValueChange"/>s.
+/// </summary>
+public interface ISubtagAlarmSource : IDisposable
+{
+    /// <summary>Raised on the STA when an advised subtag's value changes.</summary>
+    event EventHandler<SubtagValueChange>? ValueChanged;
+
+    /// <summary>Advises every subtag in the supplied addresses; idempotent per address.</summary>
+    void Advise(IReadOnlyCollection<string> itemAddresses);
+
+    /// <summary>Writes a value to an item address (used for the ack-comment write).</summary>
+    void Write(string itemAddress, object? value);
+}
+```
+
+**Step 2: Write the state-machine tests first.** `SubtagAlarmStateMachine` maps `(active, acked)` changes per target to `MxAlarmTransitionEvent`s. Test the four core transitions:
+
+```csharp
+namespace ZB.MOM.WW.MxGateway.Worker.Tests.MxAccess;
+
+public sealed class SubtagAlarmStateMachineTests
+{
+    private static AlarmSubtagTarget Target() => new()
+    {
+        AlarmFullReference = "Galaxy!Area.Tank01.Level.HiHi",
+        SourceObjectReference = "Tank01",
+        ActiveSubtag = "Tank01.Level.HiHi.active",
+        AckedSubtag = "Tank01.Level.HiHi.acked",
+        AckCommentSubtag = "Tank01.Level.HiHi.ackmsg",
+    };
+
+    [Fact]
+    public void ActiveFalseToTrue_EmitsRaise_FlaggedDegraded()
+    {
+        var sm = new SubtagAlarmStateMachine(new[] { Target() });
+        var ts = new DateTime(2026, 6, 13, 9, 0, 0, DateTimeKind.Utc);
+
+        var events = sm.Apply("Tank01.Level.HiHi.active", true, ts);
+
+        var e = Assert.Single(events);
+        Assert.Equal(MxAlarmStateKind.UnackAlm, e.Record.State);
+        Assert.Equal(MxAlarmStateKind.Unspecified, e.PreviousState);
+        Assert.Equal("Tank01.Level.HiHi", e.Record.TagName); // reference minus provider/area
+    }
+
+    [Fact]
+    public void AckedTrueWhileActive_EmitsAckTransition()
+    {
+        var sm = new SubtagAlarmStateMachine(new[] { Target() });
+        var ts = new DateTime(2026, 6, 13, 9, 0, 0, DateTimeKind.Utc);
+        sm.Apply("Tank01.Level.HiHi.active", true, ts);
+
+        var events = sm.Apply("Tank01.Level.HiHi.acked", true, ts.AddSeconds(5));
+
+        var e = Assert.Single(events);
+        Assert.Equal(MxAlarmStateKind.AckAlm, e.Record.State);
+        Assert.Equal(MxAlarmStateKind.UnackAlm, e.PreviousState);
+    }
+
+    [Fact]
+    public void ActiveTrueToFalse_WhileUnacked_EmitsUnackRtn()
+    {
+        var sm = new SubtagAlarmStateMachine(new[] { Target() });
+        var ts = new DateTime(2026, 6, 13, 9, 0, 0, DateTimeKind.Utc);
+        sm.Apply("Tank01.Level.HiHi.active", true, ts);
+
+        var events = sm.Apply("Tank01.Level.HiHi.active", false, ts.AddSeconds(10));
+
+        var e = Assert.Single(events);
+        Assert.Equal(MxAlarmStateKind.UnackRtn, e.Record.State);
+    }
+
+    [Fact]
+    public void Snapshot_ReflectsActiveAndAckedState()
+    {
+        var sm = new SubtagAlarmStateMachine(new[] { Target() });
+        var ts = new DateTime(2026, 6, 13, 9, 0, 0, DateTimeKind.Utc);
+        sm.Apply("Tank01.Level.HiHi.active", true, ts);
+        sm.Apply("Tank01.Level.HiHi.acked", true, ts);
+
+        var snap = Assert.Single(sm.SnapshotActive());
+        Assert.Equal(MxAlarmStateKind.AckAlm, snap.State);
+    }
+}
+```
+
+Run: `dotnet test ...Worker.Tests... -p:Platform=x86 --filter FullyQualifiedName~SubtagAlarmStateMachineTests` → FAIL (type missing).
+
+**Step 3: Implement `SubtagAlarmStateMachine`.** Build an address→target index (active/acked/priority/comment addresses), hold per-reference `(bool active, bool acked, DateTime firstRaiseUtc, int priority)`, and emit on change:
+- active `false→true` ⇒ `UnackAlm`, set `firstRaiseUtc`, `PreviousState` from prior state.
+- acked `false→true` while active ⇒ `AckAlm`.
+- active `true→false` ⇒ `AckRtn` if currently acked else `UnackRtn`; then reset acked.
+- priority change ⇒ update stored priority, no transition.
+- `TagName` = `alarm_full_reference` with any `Provider!Area.` prefix stripped (match `WnWrapAlarmConsumer`'s reference shape so `GatewayAlarmMonitor` keys align). Set `ProviderName`, `Group`, `Priority`, `AlarmComment` from the target/last values. Mark a `Degraded`/source flag (carried via a new field — see Task 5 wiring).
+- `SnapshotActive()` returns `MxAlarmSnapshotRecord` for references whose active is true.
+
+**Step 4: Run green.** Expected: PASS.
+
+**Step 5: Commit.**
+```bash
+git add src/ZB.MOM.WW.MxGateway.Worker/MxAccess/ISubtagAlarmSource.cs \
+        src/ZB.MOM.WW.MxGateway.Worker/MxAccess/SubtagAlarmStateMachine.cs \
+        src/ZB.MOM.WW.MxGateway.Worker.Tests/MxAccess/SubtagAlarmStateMachineTests.cs
+git commit -m "worker(alarms): subtag value-source seam + synthesis state machine"
+```
+
+---
+
+### Task 5: `SubtagAlarmConsumer` over the source seam (no COM yet)
+
+**Classification:** standard
+**Estimated implement time:** ~5 min
+**Parallelizable with:** none (depends on Task 4)
+
+**Files:**
+- Create: `src/ZB.MOM.WW.MxGateway.Worker/MxAccess/SubtagAlarmConsumer.cs`
+- Test: `src/ZB.MOM.WW.MxGateway.Worker.Tests/MxAccess/SubtagAlarmConsumerTests.cs`
+
+**Step 1: Test with a fake `ISubtagAlarmSource`.** Drive value changes through the source, assert `AlarmTransitionEmitted` fires with synthesized records and that ack writes the comment to the ack-comment subtag:
+
+```csharp
+public sealed class SubtagAlarmConsumerTests
+{
+    private sealed class FakeSource : ISubtagAlarmSource
+    {
+        public event EventHandler<SubtagValueChange>? ValueChanged;
+        public List<string> Advised { get; } = new();
+        public (string Address, object? Value)? LastWrite { get; private set; }
+        public void Advise(IReadOnlyCollection<string> a) => Advised.AddRange(a);
+        public void Write(string a, object? v) => LastWrite = (a, v);
+        public void Raise(string addr, object? val, DateTime ts) =>
+            ValueChanged?.Invoke(this, new SubtagValueChange { ItemAddress = addr, Value = val, TimestampUtc = ts });
+        public void Dispose() { }
+    }
+
+    private static AlarmSubtagTarget Target() => new()
+    {
+        AlarmFullReference = "Galaxy!Area.Tank01.Level.HiHi",
+        ActiveSubtag = "Tank01.Level.HiHi.active",
+        AckedSubtag = "Tank01.Level.HiHi.acked",
+        AckCommentSubtag = "Tank01.Level.HiHi.ackmsg",
+    };
+
+    [Fact]
+    public void Subscribe_AdvisesAllSubtags()
+    {
+        var src = new FakeSource();
+        using var c = new SubtagAlarmConsumer(src, new[] { Target() });
+        c.Subscribe("ignored-in-subtag-mode");
+        Assert.Contains("Tank01.Level.HiHi.active", src.Advised);
+        Assert.Contains("Tank01.Level.HiHi.acked", src.Advised);
+    }
+
+    [Fact]
+    public void ValueChange_RaisesSynthesizedTransition()
+    {
+        var src = new FakeSource();
+        using var c = new SubtagAlarmConsumer(src, new[] { Target() });
+        c.Subscribe("x");
+        MxAlarmTransitionEvent? seen = null;
+        c.AlarmTransitionEmitted += (_, e) => seen = e;
+
+        src.Raise("Tank01.Level.HiHi.active", true, new DateTime(2026, 6, 13, 9, 0, 0, DateTimeKind.Utc));
+
+        Assert.NotNull(seen);
+        Assert.Equal(MxAlarmStateKind.UnackAlm, seen!.Record.State);
+    }
+
+    [Fact]
+    public void AcknowledgeByName_WritesCommentToAckCommentSubtag()
+    {
+        var src = new FakeSource();
+        using var c = new SubtagAlarmConsumer(src, new[] { Target() });
+        c.Subscribe("x");
+
+        int rc = c.AcknowledgeByName("Tank01.Level.HiHi", "Galaxy", "Area",
+            "ack from HMI", "op1", "node", "dom", "Op One");
+
+        Assert.Equal(0, rc);
+        Assert.Equal(("Tank01.Level.HiHi.ackmsg", (object?)"ack from HMI"), src.LastWrite);
+    }
+}
+```
+
+**Step 2: Implement `SubtagAlarmConsumer : IMxAccessAlarmConsumer`.**
+- Constructor `(ISubtagAlarmSource source, IReadOnlyList<AlarmSubtagTarget> watchList)`; build a `SubtagAlarmStateMachine`; index `alarm_full_reference`→target for ack routing.
+- `Subscribe(_)`: call `source.Advise(<all subtag addresses>)`; subscribe to `source.ValueChanged`, feed each into the state machine, and re-raise each produced `MxAlarmTransitionEvent` via `AlarmTransitionEmitted` (mark degraded).
+- `AcknowledgeByName(alarmName, …, comment, …)`: resolve the target by reference; if no `AckCommentSubtag`, return a non-zero failure code; else `source.Write(target.AckCommentSubtag, comment)` and return 0.
+- `AcknowledgeByGuid(guid, …)`: map the synthetic GUID (deterministic hash of reference — see Task 8 helper, or a local copy) back to a reference, then delegate to the name path; unknown GUID ⇒ non-zero.
+- `SnapshotActiveAlarms()`: from the state machine.
+- `PollOnce()`: no-op.
+- `Dispose()`: unsubscribe + dispose source.
+
+**Step 3: Run green.** `dotnet test ...Worker.Tests... -p:Platform=x86 --filter FullyQualifiedName~SubtagAlarmConsumerTests`.
+
+**Step 4: Commit.**
+```bash
+git add src/ZB.MOM.WW.MxGateway.Worker/MxAccess/SubtagAlarmConsumer.cs \
+        src/ZB.MOM.WW.MxGateway.Worker.Tests/MxAccess/SubtagAlarmConsumerTests.cs
+git commit -m "worker(alarms): SubtagAlarmConsumer synthesizing transitions over the source seam"
+```
+
+---
+
+### Task 6: COM-backed `LmxSubtagAlarmSource` (own LMXProxyServerClass)
+
+**Classification:** high-risk
+**Estimated implement time:** ~5 min
+**Parallelizable with:** none
+
+The only piece that touches live COM. Like `WnWrapAlarmConsumer`, it owns its own MXAccess server object so the subtag source is self-contained and isolated from the session's item pipeline. Logic stays thin (advise/write/marshal); real verification is the live smoke test in Task 17.
+
+**Files:**
+- Create: `src/ZB.MOM.WW.MxGateway.Worker/MxAccess/LmxSubtagAlarmSource.cs`
+- Test: `src/ZB.MOM.WW.MxGateway.Worker.Tests/MxAccess/LmxSubtagAlarmSourceTests.cs` (constructor/guard tests only; COM path is live-gated)
+
+**Step 1: Implement `LmxSubtagAlarmSource : ISubtagAlarmSource`.**
+- Own an `LMXProxyServerClass` (reuse the worker's `IMxAccessServer`/`MxAccessComServer` wrapper + `IMxAccessComObjectFactory` so it is fakeable; constructor takes the factory).
+- `Advise(addresses)`: `RegisterServer` (topic) once; per address `AddItem`→`itemHandle`, `Advise`, and record `itemHandle→address`. Subscribe to the proxy's `OnDataChange`; in the handler, look up the address by `phItemHandle`, normalize `pvItemValue` (VARIANT→bool/double) and `pftItemTimeStamp`→UTC, and raise `ValueChanged`. All calls run on the STA (the worker STA pumps messages, so `OnDataChange` delivers).
+- `Write(address, value)`: resolve/create the item handle, `server.Write(serverHandle, itemHandle, value, userId: 0)`.
+- `Dispose()`: `UnAdvise`/`RemoveItem`/`Unregister`/release COM.
+
+**Step 2: Tests** — only the non-COM guards (null factory throws; `Write` before `Advise` resolves a handle or throws a clear error). Mark the COM round-trip `[LiveMxAccessFact]` and `Skip` per the `AlarmsLiveSmokeTests` precedent.
+
+**Step 3: Build x86 + run unit tests.**
+`dotnet build src/ZB.MOM.WW.MxGateway.Worker/ZB.MOM.WW.MxGateway.Worker.csproj -p:Platform=x86`
+`dotnet test ...Worker.Tests... -p:Platform=x86 --filter FullyQualifiedName~LmxSubtagAlarmSourceTests`
+
+**Step 4: Commit.**
+```bash
+git add src/ZB.MOM.WW.MxGateway.Worker/MxAccess/LmxSubtagAlarmSource.cs \
+        src/ZB.MOM.WW.MxGateway.Worker.Tests/MxAccess/LmxSubtagAlarmSourceTests.cs
+git commit -m "worker(alarms): COM-backed LmxSubtagAlarmSource advising alarm subtags"
+```
+
+---
+
+### Task 7: `FailoverAlarmConsumer` state machine
+
+**Classification:** high-risk
+**Estimated implement time:** ~5 min
+**Parallelizable with:** none (depends on Task 5)
+
+**Files:**
+- Create: `src/ZB.MOM.WW.MxGateway.Worker/MxAccess/FailoverAlarmConsumer.cs`
+- Create: `src/ZB.MOM.WW.MxGateway.Worker/MxAccess/AlarmProviderModeChange.cs` (small EventArgs)
+- Test: `src/ZB.MOM.WW.MxGateway.Worker.Tests/MxAccess/FailoverAlarmConsumerTests.cs`
+
+**Step 1: Test the switch/failback with a fake primary that throws.**
+
+```csharp
+public sealed class FailoverAlarmConsumerTests
+{
+    private sealed class FlakyPrimary : IMxAccessAlarmConsumer
+    {
+        public event EventHandler<MxAlarmTransitionEvent>? AlarmTransitionEmitted;
+        public int PollsUntilHeal = int.MaxValue;   // becomes healthy after N polls while degraded
+        public bool ThrowOnPoll = true;
+        private int _polls;
+        public void Subscribe(string s) { if (ThrowOnPoll) throw new COMException("boom", unchecked((int)0x80004005)); }
+        public void PollOnce()
+        {
+            _polls++;
+            if (ThrowOnPoll && _polls < PollsUntilHeal) throw new COMException("boom", unchecked((int)0x80004005));
+        }
+        public int AcknowledgeByGuid(Guid g, string c, string a, string b, string d, string e) => 0;
+        public int AcknowledgeByName(string n, string p, string gr, string c, string a, string b, string d, string e) => 0;
+        public IReadOnlyList<MxAlarmSnapshotRecord> SnapshotActiveAlarms() => Array.Empty<MxAlarmSnapshotRecord>();
+        public void Dispose() { }
+    }
+
+    private sealed class StubStandby : IMxAccessAlarmConsumer { /* records Subscribe, no-op rest */ }
+
+    [Fact]
+    public void Primary_FailsThresholdTimes_SwitchesToSubtagAndEmitsModeChange()
+    {
+        var primary = new FlakyPrimary();
+        var standby = new StubStandby();
+        using var c = new FailoverAlarmConsumer(primary, standby,
+            new FailoverSettings(threshold: 3, probeIntervalSeconds: 30, stableProbes: 3));
+        AlarmProviderModeChange? change = null;
+        c.ProviderModeChanged += (_, e) => change = e;
+
+        c.Subscribe("\\\\host\\Galaxy!Area");     // primary.Subscribe throws -> counts as failure 1
+        c.PollOnce();                              // failure 2
+        c.PollOnce();                              // failure 3 -> switch
+
+        Assert.NotNull(change);
+        Assert.Equal(AlarmProviderMode.Subtag, change!.Mode);
+    }
+
+    [Fact]
+    public void WhileDegraded_PrimaryHeals_FailsBackAfterStableProbes()
+    {
+        var primary = new FlakyPrimary { PollsUntilHeal = 0 }; // will heal once we stop throwing
+        var standby = new StubStandby();
+        using var c = new FailoverAlarmConsumer(primary, standby,
+            new FailoverSettings(threshold: 1, probeIntervalSeconds: 0, stableProbes: 2));
+        var modes = new List<AlarmProviderMode>();
+        c.ProviderModeChanged += (_, e) => modes.Add(e.Mode);
+
+        c.Subscribe("x");          // failure -> switch to subtag
+        primary.ThrowOnPoll = false;
+        c.ProbeOnce();             // clean probe 1
+        c.ProbeOnce();             // clean probe 2 -> failback
+
+        Assert.Equal(AlarmProviderMode.Subtag, modes[0]);
+        Assert.Equal(AlarmProviderMode.Alarmmgr, modes[^1]);
+    }
+}
+```
+
+**Step 2: Implement.**
+- `record FailoverSettings(int threshold, int probeIntervalSeconds, int stableProbes)`; `AlarmProviderModeChange : EventArgs { AlarmProviderMode Mode; string Reason; int HResult; DateTime AtUtc; }`.
+- Constructor `(IMxAccessAlarmConsumer primary, IMxAccessAlarmConsumer standby, FailoverSettings settings)`; forced-mode variants handled in Task 9 wiring (forced ⇒ skip the other consumer).
+- Forward `AlarmTransitionEmitted` from the **active** child only (swap the subscription on switch).
+- Wrap `Subscribe`/`PollOnce` on the primary: on `COMException` (or a failure HRESULT) while `PrimaryActive`, increment a counter; at `threshold`, ensure standby `Subscribe`d, set active=standby, snapshot standby for hand-off, raise `ProviderModeChanged(Subtag, reason, hresult, now)`. Reset counter on any clean primary poll.
+- `ProbeOnce()` (driven by the poll loop while degraded, gated by `probeIntervalSeconds`): try primary `Subscribe`+`PollOnce`; count consecutive clean probes; at `stableProbes`, set active=primary, return standby to standby, raise `ProviderModeChanged(Alarmmgr, "recovered", 0, now)`.
+- `Acknowledge*` / `SnapshotActiveAlarms` delegate to the **active** child.
+- `PollOnce()` drives the active child's poll, and—while degraded—also drives the failback probe cadence.
+
+**Step 3: Run green** (x86 filter `FailoverAlarmConsumerTests`).
+
+**Step 4: Commit.**
+```bash
+git add src/ZB.MOM.WW.MxGateway.Worker/MxAccess/FailoverAlarmConsumer.cs \
+        src/ZB.MOM.WW.MxGateway.Worker/MxAccess/AlarmProviderModeChange.cs \
+        src/ZB.MOM.WW.MxGateway.Worker.Tests/MxAccess/FailoverAlarmConsumerTests.cs
+git commit -m "worker(alarms): FailoverAlarmConsumer auto-failover/failback state machine"
+```
+
+---
+
+### Task 8: Synthetic-GUID helper + degraded flag on the event sink path
+
+**Classification:** standard
+**Estimated implement time:** ~4 min
+**Parallelizable with:** Task 9
+
+Carry `degraded` + `source_provider` from the worker synthesis into the emitted `OnAlarmTransitionEvent`.
+
+**Files:**
+- Modify: `src/ZB.MOM.WW.MxGateway.Worker/MxAccess/MxAlarmSnapshot.cs` (add `bool Degraded`)
+- Modify: `src/ZB.MOM.WW.MxGateway.Worker/MxAccess/MxAccessAlarmEventSink.cs` (`EnqueueTransition` carries degraded)
+- Modify: `src/ZB.MOM.WW.MxGateway.Worker/MxAccess/MxAccessEventMapper.cs` (`CreateOnAlarmTransition` sets `Degraded`/`SourceProvider`)
+- Create: `src/ZB.MOM.WW.MxGateway.Worker/MxAccess/SyntheticAlarmGuid.cs`
+- Test: add cases to `src/ZB.MOM.WW.MxGateway.Worker.Tests/MxAccess/AlarmDispatcherTests.cs` and a new `SyntheticAlarmGuidTests.cs`
+
+**Step 1: `SyntheticAlarmGuid.ForReference(string reference)`** — deterministic GUID from a stable hash (e.g. MD5 of the UTF-8 reference → `new Guid(bytes)`), so subtag-mode acks resolve by GUID. Test determinism + difference:
+
+```csharp
+[Fact] public void SameReference_SameGuid() =>
+    Assert.Equal(SyntheticAlarmGuid.ForReference("A.B.C"), SyntheticAlarmGuid.ForReference("A.B.C"));
+[Fact] public void DifferentReference_DifferentGuid() =>
+    Assert.NotEqual(SyntheticAlarmGuid.ForReference("A.B.C"), SyntheticAlarmGuid.ForReference("A.B.D"));
+```
+
+**Step 2: Thread `degraded`** through `MxAlarmSnapshotRecord.Degraded`, `EnqueueTransition(... bool degraded)`, and `CreateOnAlarmTransition(... bool degraded, AlarmProviderMode sourceProvider)`. Default `degraded=false`, `sourceProvider=Alarmmgr` so the wnwrap path is unchanged (regression: existing `AlarmDispatcherTests` still pass with `Degraded=false`).
+
+**Step 3: Tests** — extend `AlarmDispatcherTests` with a subtag-style transition asserting `body.Degraded == true` and `SourceProvider == Subtag`.
+
+**Step 4: Build x86 + run** worker tests for `AlarmDispatcherTests`, `SyntheticAlarmGuidTests`.
+
+**Step 5: Commit.**
+```bash
+git add src/ZB.MOM.WW.MxGateway.Worker/MxAccess/MxAlarmSnapshot.cs \
+        src/ZB.MOM.WW.MxGateway.Worker/MxAccess/MxAccessAlarmEventSink.cs \
+        src/ZB.MOM.WW.MxGateway.Worker/MxAccess/MxAccessEventMapper.cs \
+        src/ZB.MOM.WW.MxGateway.Worker/MxAccess/SyntheticAlarmGuid.cs \
+        src/ZB.MOM.WW.MxGateway.Worker.Tests/MxAccess/
+git commit -m "worker(alarms): synthetic GUID + degraded provenance on emitted transitions"
+```
+
+---
+
+### Task 9: Wire watch-list + failover config through `AlarmCommandHandler`; emit mode-changed event
+
+**Classification:** high-risk
+**Estimated implement time:** ~5 min
+**Parallelizable with:** none (depends on Tasks 5, 7, 8)
+
+**Files:**
+- Modify: `src/ZB.MOM.WW.MxGateway.Worker/MxAccess/AlarmCommandHandler.cs`
+- Modify: `src/ZB.MOM.WW.MxGateway.Worker/MxAccess/IAlarmCommandHandler.cs`
+- Modify: `src/ZB.MOM.WW.MxGateway.Worker/MxAccess/MxAccessCommandExecutor.cs` (`ExecuteSubscribeAlarms`, ~lines 588-616)
+- Modify: `src/ZB.MOM.WW.MxGateway.Worker/MxAccess/MxAccessStaSession.cs` (consumer factory wiring; mode-change → event queue)
+- Test: `src/ZB.MOM.WW.MxGateway.Worker.Tests/MxAccess/AlarmCommandHandlerTests.cs` (extend or create)
+
+**Step 1: Carry the subscribe payload.** Change the alarm subscribe entry point from `Subscribe(string subscription)` to `Subscribe(SubscribeAlarmsCommand command)` (the command now has `ForcedMode`, `WatchList`, `Failover`). In `AlarmCommandHandler.Subscribe`:
+- Build the active provider per `ForcedMode`:
+  - `ALARMMGR` ⇒ `WnWrapAlarmConsumer` only.
+  - `SUBTAG` ⇒ `SubtagAlarmConsumer(new LmxSubtagAlarmSource(factory), watchList)` only.
+  - `UNSPECIFIED` ⇒ `FailoverAlarmConsumer(primary: wnwrap, standby: subtag, settings-from-Failover)`.
+- Use the existing `consumerFactory` seam but widen it to `Func<SubscribeAlarmsCommand, IMxAccessAlarmConsumer>` so tests inject fakes and production builds the failover composite. Subscribe to `FailoverAlarmConsumer.ProviderModeChanged` and enqueue an `OnAlarmProviderModeChangedEvent` MxEvent via the event queue (new mapper method `CreateOnAlarmProviderModeChanged`).
+
+**Step 2: Executor + STA wiring.** `ExecuteSubscribeAlarms` passes the full `SubscribeAlarmsCommand` (not just the expression). In `MxAccessStaSession`, the `alarmCommandHandlerFactory` must give the handler access to the `IMxAccessComObjectFactory` so the subtag source can create its own proxy server on the STA; keep the `EnsureOnAlarmConsumerThread` affinity guard on every path.
+
+**Step 3: Test** — fake consumer factory; assert that a `SUBTAG` forced command builds the subtag consumer and advises; that an auto command building a fake failover composite, when it raises `ProviderModeChanged`, enqueues an `OnAlarmProviderModeChangedEvent` on the queue.
+
+**Step 4: Build x86 + worker tests.**
+
+**Step 5: Commit.**
+```bash
+git add src/ZB.MOM.WW.MxGateway.Worker/MxAccess/ src/ZB.MOM.WW.MxGateway.Worker.Tests/MxAccess/
+git commit -m "worker(alarms): route watch-list/failover config; emit provider-mode-changed event"
+```
+
+---
+
+## Phase 2 — Gateway: discovery, options, monitor, metrics, dashboard
+
+### Task 10: `AlarmsOptions.Fallback` + validation
+
+**Classification:** standard
+**Estimated implement time:** ~4 min
+**Parallelizable with:** Task 11, Task 13
+
+**Files:**
+- Modify: `src/ZB.MOM.WW.MxGateway.Server/Configuration/AlarmsOptions.cs`
+- Create: `src/ZB.MOM.WW.MxGateway.Server/Configuration/AlarmFallbackOptions.cs`
+- Modify: `src/ZB.MOM.WW.MxGateway.Server/Configuration/GatewayOptionsValidator.cs` (`ValidateAlarms`, ~lines 234-258)
+- Test: `src/ZB.MOM.WW.MxGateway.Tests/Configuration/GatewayOptionsValidatorTests.cs` (extend)
+
+**Step 1:** Add `AlarmFallbackOptions Fallback { get; init; } = new();` to `AlarmsOptions`. `AlarmFallbackOptions`: `string Mode = "Auto"` (`Auto|ForceAlarmManager|ForceSubtag`), `int ConsecutiveFailureThreshold = 3`, `int FailbackProbeIntervalSeconds = 30`, `int FailbackStableProbes = 3`, a `Discovery` sub-object (`bool UseGalaxyRepository = true`, `string Area = ""`, `string[] IncludeAttributes = []`, `string[] ExcludeAttributes = []`), and a `Subtags` sub-object (`Active="active"`, `Acked="acked"`, `AckComment=""`, `Priority="priority"`).
+
+**Step 2:** In `ValidateAlarms`, when `Enabled` and `Mode == "ForceSubtag"` and `Discovery.UseGalaxyRepository == false` and `IncludeAttributes` empty ⇒ add a validation error ("ForceSubtag requires Galaxy Repository discovery or an explicit IncludeAttributes list"). Floor the three numeric values at 1. Validate `Mode` is one of the three literals.
+
+**Step 3-5:** Test the new validation cases (red→green), build the server, commit.
+
+---
+
+### Task 11: Galaxy Repository "alarm attributes" discovery query
+
+**Classification:** standard
+**Estimated implement time:** ~5 min
+**Parallelizable with:** Task 10, Task 13
+
+**Files:**
+- Modify: `src/ZB.MOM.WW.MxGateway.Server/Galaxy/GalaxyRepository.cs` (add `GetAlarmAttributesAsync` + SQL constant, following `GetAttributesAsync` ~lines 86-115 and `AttributesSql` ~line 176)
+- Modify: `src/ZB.MOM.WW.MxGateway.Server/Galaxy/IGalaxyRepository.cs`
+- Create: `src/ZB.MOM.WW.MxGateway.Server/Galaxy/GalaxyAlarmAttributeRow.cs`
+- Test: `src/ZB.MOM.WW.MxGateway.Tests/Galaxy/` (projection unit test; live SQL gated)
+
+**Step 1:** `GalaxyAlarmAttributeRow { string FullTagReference; string SourceObjectReference; string AckCommentSubtag; }` (and any priority subtag). `GetAlarmAttributesAsync` reuses the existing `is_alarm` detection (the `AlarmExtension` primitive join already in `AttributesSql`) filtered to `is_alarm = 1`, projecting the alarm reference + its ack-comment attribute. Follow the exact `SqlConnection`/`SqlCommand`/`SqlDataReader` pattern from `GetAttributesAsync`.
+
+**Step 2:** Unit-test the row→`AlarmSubtagTarget` mapping (a pure mapper function); gate any live-DB test like the existing Galaxy live tests (or `Skip` with a note, matching `AlarmsLiveSmokeTests`).
+
+**Step 3-5:** red→green, build server, commit.
+
+---
+
+### Task 12: Watch-list resolver (GR SQL + config override → `AlarmSubtagTarget[]`)
+
+**Classification:** standard
+**Estimated implement time:** ~4 min
+**Parallelizable with:** none (depends on Tasks 10, 11)
+
+**Files:**
+- Create: `src/ZB.MOM.WW.MxGateway.Server/Alarms/AlarmWatchListResolver.cs`
+- Create: `src/ZB.MOM.WW.MxGateway.Server/Alarms/IAlarmWatchListResolver.cs`
+- Test: `src/ZB.MOM.WW.MxGateway.Tests/Alarms/AlarmWatchListResolverTests.cs`
+
+**Step 1: Test the merge** with a fake `IGalaxyRepository`:
+- discovery rows + `IncludeAttributes` are unioned; `ExcludeAttributes` removed; each becomes an `AlarmSubtagTarget` with `.active`/`.acked`/`.ackmsg` addresses composed from the configured `Subtags` names (`<reference>.<Active>`, etc.); empty config subtag names fall back to defaults; GR unavailable + no includes ⇒ empty list + a logged warning flag.
+
+**Step 2: Implement** `ResolveAsync(AlarmsOptions, CancellationToken) → IReadOnlyList<AlarmSubtagTarget>`.
+
+**Step 3-5:** red→green, build, commit.
+
+---
+
+### Task 13: Gateway metrics — provider-mode gauge + switch counter
+
+**Classification:** small
+**Estimated implement time:** ~3 min
+**Parallelizable with:** Task 10, Task 11
+
+**Files:**
+- Modify: `src/ZB.MOM.WW.MxGateway.Server/Metrics/GatewayMetrics.cs` (ctor ~lines 55-79; add counter + observable gauge following the existing pattern)
+- Test: `src/ZB.MOM.WW.MxGateway.Tests/Metrics/GatewayMetricsTests.cs` (if present; else assert via a `MeterListener`)
+
+**Step 1:** Add `mxgateway.alarms.provider_switches` counter (tagged `from`,`to`,`reason`) and `mxgateway.alarms.provider_mode` observable gauge (1=alarmmgr, 2=subtag), plus `AlarmProviderSwitched(int from, int to, string reason)` and a private `GetAlarmProviderMode()` (lock on `_syncRoot` like the others).
+
+**Step 2-4:** test, build, commit.
+
+---
+
+### Task 14: `GatewayAlarmMonitor` — arm watch-list, reflect provider mode, reconcile on switch
+
+**Classification:** high-risk
+**Estimated implement time:** ~5 min
+**Parallelizable with:** none (depends on Tasks 9, 12, 13)
+
+**Files:**
+- Modify: `src/ZB.MOM.WW.MxGateway.Server/Alarms/GatewayAlarmMonitor.cs` (ctor ~41-49; `SubscribeAlarmsAsync` ~210-233; event-drain loop; `StreamAsync` ~386-434)
+- Test: `src/ZB.MOM.WW.MxGateway.Tests/Alarms/GatewayAlarmMonitorProviderModeTests.cs` (new, using `FakeWorkerHarness`)
+
+**Step 1:** Inject `IAlarmWatchListResolver` and `GatewayMetrics`. In `SubscribeAlarmsAsync`, resolve the watch-list and build the `SubscribeAlarmsCommand` with `ForcedMode` (from `Fallback.Mode`), `WatchList`, and `Failover` populated from options — instead of the bare `{ SubscriptionExpression }`.
+
+**Step 2:** In the worker-event drain path, handle `OnAlarmProviderModeChangedEvent`: update a `_providerStatus` field (mode/degraded/reason/since), `Broadcast(new AlarmFeedMessage { ProviderStatus = … })` to every subscriber, call `metrics.AlarmProviderSwitched(...)`, and force a `ReconcileAsync` so the cache re-seeds from the now-active provider (avoids raise/clear storms).
+
+**Step 3:** In `StreamAsync`, emit the current `provider_status` as the **first** message (before the snapshot) so a late joiner immediately knows the mode.
+
+**Step 4: Test** — stand up the monitor with `FakeWorkerHarness`; emit an `OnAlarmProviderModeChangedEvent(Subtag)`; assert a `StreamAsync` subscriber receives a `ProviderStatus{ Mode=Subtag, Degraded=true }` and that the switch counter incremented. Also assert a transition emitted in subtag mode flows through with `Degraded=true`.
+
+**Step 5:** build server, run the new test, commit.
+
+---
+
+### Task 15: Dashboard — push provider status to `/hubs/alarms` + UI indicator
+
+**Classification:** standard
+**Estimated implement time:** ~5 min
+**Parallelizable with:** none (depends on Task 14)
+
+**Files:**
+- Modify: `src/ZB.MOM.WW.MxGateway.Server/Dashboard/Hubs/AlarmsHubPublisher.cs` (forward `ProviderStatus` messages — they already flow through `StreamAsync`, so confirm the existing `SendAsync(AlarmMessage, message)` carries them; add a dedicated `"ProviderModeChanged"` client method if the dashboard needs a distinct channel)
+- Modify: the alarms dashboard page/component (Bootstrap-only badge: green "alarmmgr" / amber "degraded — subtag") — find under `src/ZB.MOM.WW.MxGateway.Server/Dashboard/`
+- Test: `src/ZB.MOM.WW.MxGateway.Tests/` dashboard model test (e.g. a `DashboardAlarmProviderStatus.FromFeed` mapper, mirroring `DashboardActiveAlarm.FromSnapshot`)
+
+**Constraint:** Bootstrap CSS/JS only — no MudBlazor/Radzen/FluentUI.
+
+**Steps:** TDD the model mapper, wire the publisher + badge, build, commit.
+
+---
+
+## Phase 3 — Integration, docs, live smoke
+
+### Task 16: End-to-end fake-worker failover test
+
+**Classification:** standard
+**Estimated implement time:** ~5 min
+**Parallelizable with:** Task 18
+
+**Files:**
+- Test: `src/ZB.MOM.WW.MxGateway.Tests/Alarms/AlarmFailoverEndToEndTests.cs`
+
+Drive the full gateway path with `FakeWorkerHarness`: subscribe (assert the `SubscribeAlarmsCommand` carries a watch-list), emit a wnwrap-style transition (assert `Degraded=false`), emit `OnAlarmProviderModeChangedEvent(Subtag)`, emit a synthesized transition (assert `Degraded=true`, `SourceProvider=Subtag`), then `OnAlarmProviderModeChangedEvent(Alarmmgr)` and assert the feed reports recovery. Build, run, commit.
+
+---
+
+### Task 17: Live subtag smoke test (opt-in)
+
+**Classification:** small
+**Estimated implement time:** ~4 min
+**Parallelizable with:** Task 18
+
+**Files:**
+- Test: `src/ZB.MOM.WW.MxGateway.IntegrationTests/...AlarmSubtagLiveSmokeTests.cs` (or the worker live suite)
+
+A `[LiveMxAccessFact]`, `Skip`-by-default test (per `AlarmsLiveSmokeTests` precedent) that, against a live Galaxy + alarm flip script: advises the real `.active`/`.acked` subtags via `LmxSubtagAlarmSource`, asserts a synthesized raise/clear, and performs an ack via the ack-comment write. Document the exact subtag names discovered (resolves the design's open item). Commit.
+
+---
+
+### Task 18: Documentation
+
+**Classification:** trivial
+**Estimated implement time:** ~5 min
+**Parallelizable with:** Task 16, Task 17
+
+**Files:**
+- Modify: `gateway.md` (alarm provider section: dual provider + auto-failover/failback)
+- Modify: `docs/DesignDecisions.md` (record the fallback decision + parity rationale)
+- Modify: `docs/GatewayConfiguration.md` (the `MxGateway:Alarms:Fallback` block)
+- Modify: `docs/AlarmClientDiscovery.md` (subtag provider, synthesis rules, ack-comment write)
+- Modify: `docs/Grpc.md` (new `provider_status` feed case + `degraded`/`source_provider` fields)
+
+Follow `StyleGuide.md` (PascalCase filenames, present tense, explain *why*). No code; commit.
+
+---
+
+## Execution order & parallelism summary
+
+- **Serial spine:** 1 → 2 → 3 → 4 → 5 → 6 → 7 → 8/9 → 10/11 → 12 → 13 → 14 → 15 → 16 → 17/18.
+- **Parallelizable clusters:** {8, 9 partially}, {10, 11, 13}, {16, 17, 18}.
+- **High-risk tasks** (full review chain): 1, 2, 6, 7, 9, 14. **Standard:** 4, 5, 8, 10, 11, 12, 15, 16. **Small/trivial:** 3, 13, 17, 18.
+
+## Risk notes for the executor
+
+- **Field-number collisions:** Task 2 must read the live `MxEvent`/`MxEventFamily` numbers before adding — the agent map gave alarm-payload maxima but not `MxEvent`'s. Verify before editing.
+- **STA discipline:** every COM call in `LmxSubtagAlarmSource` and every consumer swap runs on the worker STA; keep the `EnsureOnAlarmConsumerThread` guard. The worker STA already pumps Windows messages, which is required for the subtag `OnDataChange` to deliver.
+- **Parity regression:** alarmmgr-mode output must be byte-for-byte unchanged. Existing `AlarmDispatcherTests` and `ProtobufContractRoundTripTests` are the guardrail — they must stay green with `Degraded=false` defaults.
+- **Subtag names unverified:** the design leaves exact AVEVA subtag names (`.active`, `.acked`, ack-comment) to confirm against `C:\Users\dohertj2\Desktop\mxaccess` + a live Galaxy (Task 17). The config `Subtags` block exists so names are not hard-coded.

docs/plans/2026-06-13-alarm-subtag-fallback.md.tasks.json

@@ -0,0 +1,24 @@
+{
+  "planPath": "docs/plans/2026-06-13-alarm-subtag-fallback.md",
+  "tasks": [
+    {"id": 54, "subject": "Task 1: Worker proto — watch-list, failover config, AlarmProviderMode", "status": "pending"},
+    {"id": 55, "subject": "Task 2: Gateway proto — provider status, degraded provenance, mode-changed event", "status": "pending", "blockedBy": [54]},
+    {"id": 56, "subject": "Task 3: Proto round-trip tests for new alarm fields", "status": "pending", "blockedBy": [54, 55]},
+    {"id": 57, "subject": "Task 4: Subtag value-source abstraction + synthesis state machine", "status": "pending", "blockedBy": [54]},
+    {"id": 58, "subject": "Task 5: SubtagAlarmConsumer over the source seam", "status": "pending", "blockedBy": [57]},
+    {"id": 59, "subject": "Task 6: COM-backed LmxSubtagAlarmSource", "status": "pending", "blockedBy": [57]},
+    {"id": 60, "subject": "Task 7: FailoverAlarmConsumer state machine", "status": "pending", "blockedBy": [58]},
+    {"id": 61, "subject": "Task 8: Synthetic GUID + degraded flag on event sink path", "status": "pending", "blockedBy": [55]},
+    {"id": 62, "subject": "Task 9: Wire watch-list/failover through AlarmCommandHandler; emit mode-changed", "status": "pending", "blockedBy": [58, 60, 61]},
+    {"id": 63, "subject": "Task 10: AlarmsOptions.Fallback + validation", "status": "pending"},
+    {"id": 64, "subject": "Task 11: Galaxy Repository alarm-attributes discovery query", "status": "pending"},
+    {"id": 65, "subject": "Task 12: Watch-list resolver (GR SQL + config override)", "status": "pending", "blockedBy": [54, 63, 64]},
+    {"id": 66, "subject": "Task 13: Metrics — provider-mode gauge + switch counter", "status": "pending"},
+    {"id": 67, "subject": "Task 14: GatewayAlarmMonitor — arm watch-list, reflect mode, reconcile on switch", "status": "pending", "blockedBy": [55, 62, 65, 66]},
+    {"id": 68, "subject": "Task 15: Dashboard — push provider status + UI badge", "status": "pending", "blockedBy": [67]},
+    {"id": 69, "subject": "Task 16: End-to-end fake-worker failover test", "status": "pending", "blockedBy": [67]},
+    {"id": 70, "subject": "Task 17: Live subtag smoke test (opt-in)", "status": "pending", "blockedBy": [59, 62]},
+    {"id": 71, "subject": "Task 18: Documentation", "status": "pending", "blockedBy": [67]}
+  ],
+  "lastUpdated": "2026-06-13T12:40:00Z"
+}

glauth.md

@@ -1,28 +1,37 @@
 # GLAuth — LDAP authn reference for mxaccessgw
 
-GLAuth is a lightweight LDAP server installed on this dev box at
-`C:\publish\glauth\` and run as a Windows service via NSSM. It already
-backs the LmxOpcUa OPC UA server's UserName-token authn and the LmxOpcUa
-Admin UI's cookie login; this doc captures everything mxaccessgw needs
-to consume the same directory so a single set of dev credentials covers
-both stacks.
+> **UPDATED 2026-06-04 — mxaccessgw no longer uses a per-box GLAuth at `C:\publish\glauth`.
+> Dev/test LDAP is now the SHARED GLAuth on `10.100.0.35:3893` (`dc=zb,dc=local`);
+> the single source of truth is `scadaproj/infra/glauth/` (`config.toml` + `README`).
+> The localhost/NSSM/`glauth.cfg` procedures below are RETIRED, kept for reference/rollback.**
 
-The authoritative copy of LmxOpcUa's reference lives at
-`C:\publish\glauth\auth.md`. This doc is a redistilled view tailored to
-mxaccessgw — what users + groups are already provisioned, how to bind
-against them, and what's needed to add a gw-specific role.
+GLAuth is a lightweight LDAP server. It already backs all three sister apps (MxAccessGateway,
+OtOpcUa, ScadaBridge) through a **shared container** (`zb-shared-glauth`) running on the Linux
+docker host at **`10.100.0.35:3893`**. This doc captures everything mxaccessgw needs to consume
+that directory so a single set of dev credentials covers all stacks.
+
+~~GLAuth is installed on this dev box at `C:\publish\glauth\` and run as a Windows service via
+NSSM.~~ *(RETIRED — the per-box Windows service has been stopped and set to Manual startup;
+kept only as a rollback option. Do not edit or restart it for new work.)*
+
+The single source of truth for the shared GLAuth is
+**`~/Desktop/scadaproj/infra/glauth/config.toml`** (deploy/verify runbook:
+`scadaproj/infra/glauth/README.md`). This doc is a redistilled view tailored to mxaccessgw —
+what users + groups are provisioned, how to bind against them, and what's needed to add a
+gw-specific role.
 
 ## Connection details
 
 | Setting | Value |
 |---|---|
 | Protocol | LDAP (unencrypted) |
-| Host | `localhost` |
+| Host | **`10.100.0.35`** (shared docker host — ~~`localhost`~~ retired) |
 | Port | `3893` |
-| LDAPS | disabled in dev (set `[ldaps]` block to enable) |
-| Base DN | `dc=lmxopcua,dc=local` |
-| Bind DN format | `cn={username},dc=lmxopcua,dc=local` |
-| Group OU | `ou=<groupname>,ou=groups,dc=lmxopcua,dc=local` |
+| LDAPS | disabled in dev (`Transport=None`, `AllowInsecure=true`) |
+| Base DN | `dc=zb,dc=local` |
+| Bind DN format | `cn={username},dc=zb,dc=local` |
+| Service account DN | `cn=serviceaccount,dc=zb,dc=local` / `serviceaccount123` |
+| Group OU | `ou=<groupname>,ou=groups,dc=zb,dc=local` |
 | Failed-bind throttle | 3 fails → 10-minute IP lockout (per `[behaviors]`) |
 
 ## Pre-existing groups (LmxOpcUa role taxonomy)
@@ -33,11 +42,11 @@ LmxOpcUa write rights doesn't need a second account for the gw.
 
 | Group | GID | DN | LmxOpcUa meaning | Suggested mxgw mapping |
 |---|---|---|---|---|
-| ReadOnly | 5501 | `ou=ReadOnly,ou=groups,dc=lmxopcua,dc=local` | Browse + read OPC UA nodes | `Browse` + `Subscribe` (read paths only) |
-| WriteOperate | 5502 | `ou=WriteOperate,ou=groups,dc=lmxopcua,dc=local` | Write FreeAccess / Operate attrs | `Write` (plain) |
-| WriteTune | 5504 | `ou=WriteTune,ou=groups,dc=lmxopcua,dc=local` | Write Tune attrs | `WriteSecured` (Tune only) |
-| WriteConfigure | 5505 | `ou=WriteConfigure,ou=groups,dc=lmxopcua,dc=local` | Write Configure attrs | `WriteSecured` (Configure) |
-| AlarmAck | 5503 | `ou=AlarmAck,ou=groups,dc=lmxopcua,dc=local` | Acknowledge alarms | gw alarm-ack RPC, when added |
+| ReadOnly | 5501 | `ou=ReadOnly,ou=groups,dc=zb,dc=local` | Browse + read OPC UA nodes | `Browse` + `Subscribe` (read paths only) |
+| WriteOperate | 5502 | `ou=WriteOperate,ou=groups,dc=zb,dc=local` | Write FreeAccess / Operate attrs | `Write` (plain) |
+| WriteTune | 5504 | `ou=WriteTune,ou=groups,dc=zb,dc=local` | Write Tune attrs | `WriteSecured` (Tune only) |
+| WriteConfigure | 5505 | `ou=WriteConfigure,ou=groups,dc=zb,dc=local` | Write Configure attrs | `WriteSecured` (Configure) |
+| AlarmAck | 5503 | `ou=AlarmAck,ou=groups,dc=zb,dc=local` | Acknowledge alarms | gw alarm-ack RPC, when added |
 
 **A user can be in multiple groups** — `othergroups = [...]` in the
 config is a list. `admin` is the canonical example (in every role
@@ -59,20 +68,26 @@ For mxaccessgw dev, `admin` covers every gw-side capability test;
 `readonly` is the right "negative" case for proving Browse-OK /
 Write-denied.
 
-The gateway dashboard adds one role beyond this LmxOpcUa taxonomy:
-`GwAdmin`. `LdapOptions.RequiredGroup` defaults to `GwAdmin`, so the
-dashboard login and `DashboardLdapLiveTests` require `admin` to be a
-member of a `GwAdmin` group. `GwAdmin` is **not** in the baseline
-GLAuth config — it must be provisioned before dashboard authn or the
-LDAP live tests work. See [Provisioning the GwAdmin
-group](#provisioning-the-gwadmin-group) below.
+The gateway dashboard uses two gateway-specific groups beyond the LmxOpcUa taxonomy:
+`GwAdmin` (gid 5610 → role `Administrator`) and `GwReader` (gid 5611 → role `Viewer`).
+These are already provisioned in the shared `scadaproj/infra/glauth/config.toml`.
+The dashboard test users are **`multi-role`/`password`** (Administrator) and
+**`gw-viewer`/`password`** (Viewer). `LdapOptions.RequiredGroup` defaults to `GwAdmin`.
+See [Provisioning the GwAdmin group](#provisioning-the-gwadmin-group) below for the
+(now-retired) per-box procedure and for the shared-config equivalent.
+
+> **Dashboard role value (Task 1.7):** the LDAP `GwAdmin` group now maps to
+> the canonical dashboard role **`Administrator`** (was `Admin`); `GwReader`
+> maps to `Viewer`. This is a pure value rename via
+> `MxGateway:Dashboard:GroupToRole` — same operations are authorized. (This
+> dashboard role is distinct from the lowercase gRPC `admin` *API-key scope*.)
 
 ## Two bind patterns
 
 ### 1. Direct bind (simplest)
 
 ```
-DN:       cn=admin,dc=lmxopcua,dc=local
+DN:       cn=admin,dc=zb,dc=local
 Password: admin123
 ```
 
@@ -84,9 +99,9 @@ by `sAMAccountName`, not `cn`. Use this only for dev convenience.
 ### 2. Bind-then-search (production-grade)
 
 ```
-1. Bind as the service account (cn=serviceaccount,dc=lmxopcua,dc=local
+1. Bind as the service account (cn=serviceaccount,dc=zb,dc=local
    / serviceaccount123).
-2. Search under dc=lmxopcua,dc=local with filter
+2. Search under dc=zb,dc=local with filter
    (uid=<entered-username>) — or any attribute the deployment
    identifies users by. GLAuth populates uid + cn.
 3. Read the returned entry's DN + memberOf list (groups).
@@ -112,12 +127,12 @@ record:
 ```yaml
 ldap:
   enabled: true
-  server: localhost
+  server: 10.100.0.35     # shared GLAuth on docker host (was localhost)
   port: 3893
   useTls: false
   allowInsecureLdap: true       # dev only
-  searchBase: "dc=lmxopcua,dc=local"
-  serviceAccountDn: "cn=serviceaccount,dc=lmxopcua,dc=local"
+  searchBase: "dc=zb,dc=local"
+  serviceAccountDn: "cn=serviceaccount,dc=zb,dc=local"
   serviceAccountPassword: "serviceaccount123"
   userNameAttribute: "uid"      # GLAuth populates this; AD uses sAMAccountName
   displayNameAttribute: "cn"
@@ -131,19 +146,35 @@ ldap:
 ```
 
 `groupAttribute` returns full DNs like
-`ou=ReadOnly,ou=groups,dc=lmxopcua,dc=local` — the authenticator
+`ou=ReadOnly,ou=groups,dc=zb,dc=local` — the authenticator
 should strip the leading `ou=` (or `cn=` against AD) RDN value and
 look that up in `groupToRole`.
 
 ## Provisioning the GwAdmin group
 
+> **UPDATED 2026-06-04 — RETIRED per-box procedure.** `GwAdmin` (gid 5610) and `GwReader`
+> (gid 5611) are already present in the shared GLAuth. To add or modify users/groups,
+> edit **`~/Desktop/scadaproj/infra/glauth/config.toml`** on host `10.100.0.35` and run:
+>
+> ```bash
+> cd ~/Desktop/scadaproj/infra/glauth
+> docker compose up -d --force-recreate
+> ```
+>
+> The per-box `C:\publish\glauth\glauth.cfg` + NSSM procedure below is kept for
+> rollback reference only — do not use it for new provisioning.
+
 `GwAdmin` is the gateway-specific dashboard-admin role. It is the
 default `LdapOptions.RequiredGroup`, so the dashboard cookie login and
 `DashboardLdapLiveTests` (`MXGATEWAY_RUN_LIVE_LDAP_TESTS=1`) reject
-`admin` until a `GwAdmin` group exists and `admin` is a member.
-GLAuth's baseline config ships only the five LmxOpcUa role groups, so
-`GwAdmin` must be added to GLAuth rather than run from a separate LDAP
-server:
+logins unless the user is a member of `GwAdmin`.
+The `GwAdmin` (gid 5610) and `GwReader` (gid 5611) groups already exist in the shared
+config at `scadaproj/infra/glauth/config.toml`. Dashboard test users are
+`multi-role`/`password` (Administrator) and `gw-viewer`/`password` (Viewer).
+
+---
+
+**RETIRED — per-box provisioning (reference/rollback only):**
 
 1. Edit `C:\publish\glauth\glauth.cfg`
 2. Append the group:
@@ -172,7 +203,7 @@ server:
 4. `nssm restart GLAuth`
 
 After the restart, `admin`'s `memberOf` includes
-`ou=GwAdmin,ou=groups,dc=lmxopcua,dc=local`, which the authenticator
+`ou=GwAdmin,ou=groups,dc=zb,dc=local`, which the authenticator
 strips to `GwAdmin` and matches against `RequiredGroup`. The same
 pattern applies to any future permission that doesn't fit the existing
 five roles.
@@ -193,15 +224,16 @@ echo -n "yourpassword" | openssl dgst -sha256
 
 ## Quick verification
 
-From mxaccessgw's dev box, prove the directory is reachable:
+From mxaccessgw's dev box, prove the shared directory is reachable:
 
 ```powershell
 # Plain bind via PowerShell + System.DirectoryServices.Protocols
-$ldap = New-Object System.DirectoryServices.Protocols.LdapConnection("localhost:3893")
+# (shared GLAuth on 10.100.0.35 — was localhost, now the docker host)
+$ldap = New-Object System.DirectoryServices.Protocols.LdapConnection("10.100.0.35:3893")
 $ldap.AuthType = [System.DirectoryServices.Protocols.AuthType]::Basic
 $ldap.SessionOptions.ProtocolVersion = 3
 $ldap.SessionOptions.SecureSocketLayer = $false
-$cred = New-Object System.Net.NetworkCredential("cn=admin,dc=lmxopcua,dc=local","admin123")
+$cred = New-Object System.Net.NetworkCredential("cn=multi-role,dc=zb,dc=local","password")
 $ldap.Bind($cred)
 "Bind OK"
 ```
@@ -209,17 +241,32 @@ $ldap.Bind($cred)
 Or via `ldapsearch` if you have OpenLDAP CLI tools:
 
 ```bash
-ldapsearch -x -H ldap://localhost:3893 \
-  -D "cn=admin,dc=lmxopcua,dc=local" -w admin123 \
-  -b "dc=lmxopcua,dc=local" "(uid=admin)"
+ldapsearch -x -H ldap://10.100.0.35:3893 \
+  -D "cn=serviceaccount,dc=zb,dc=local" -w serviceaccount123 \
+  -b "dc=zb,dc=local" "(uid=multi-role)"
 ```
 
-The response should list `admin`'s entry with `memberOf` populated for
-all five role groups — plus `GwAdmin` once the gateway-specific group
-is provisioned.
+The response should list `multi-role`'s entry with `memberOf` including
+`ou=GwAdmin,ou=groups,dc=zb,dc=local`.
 
 ## Service management
 
+> **RETIRED — per-box NSSM service (reference/rollback only).** The shared GLAuth is
+> managed via `docker compose` on `10.100.0.35` (`scadaproj/infra/glauth/`). The
+> Windows NSSM `GLAuth` service on the dev box has been stopped and set to
+> `StartupType=Manual`; only restart it if you need to roll back to a local directory.
+>
+> **Active (shared) management:**
+> ```bash
+> ssh 10.100.0.35
+> cd ~/Desktop/scadaproj/infra/glauth
+> docker compose ps                      # check container status
+> docker compose up -d --force-recreate  # apply config.toml changes
+> docker compose logs -f                 # tail logs
+> ```
+
+**RETIRED — per-box NSSM commands (rollback reference):**
+
 ```powershell
 # Status / start / stop / restart
 nssm status  GLAuth
@@ -253,12 +300,12 @@ applies to mxaccessgw verbatim. Keys that change:
 
 | Field | GLAuth dev value | AD production value |
 |---|---|---|
-| `Server` | `localhost` | a domain controller FQDN, or the domain itself |
+| `Server` | `10.100.0.35` (shared docker host) | a domain controller FQDN, or the domain itself |
 | `Port` | `3893` | `636` (LDAPS) — AD increasingly rejects plain bind under LDAP-signing enforcement |
 | `UseTls` | `false` | `true` |
 | `AllowInsecureLdap` | `true` | `false` |
-| `SearchBase` | `dc=lmxopcua,dc=local` | `DC=corp,DC=example,DC=com` |
-| `ServiceAccountDn` | `cn=serviceaccount,dc=lmxopcua,dc=local` | `CN=MxGwSvc,OU=Service Accounts,DC=corp,...` |
+| `SearchBase` | `dc=zb,dc=local` | `DC=corp,DC=example,DC=com` |
+| `ServiceAccountDn` | `cn=serviceaccount,dc=zb,dc=local` | `CN=MxGwSvc,OU=Service Accounts,DC=corp,...` |
 | `UserNameAttribute` | `uid` | `sAMAccountName` (or `userPrincipalName`) |
 | `GroupAttribute` | `memberOf` (unchanged) | `memberOf` (unchanged) |
 
@@ -269,12 +316,12 @@ add a `tokenGroups` query as an enhancement.
 
 ## Security notes for production
 
-- **Plaintext passwords in `glauth.cfg` are dev-only.** The config is
-  unencrypted on disk; anyone with read access to `C:\publish\glauth\`
-  can SHA256-rainbow-table the entries. Treat the dev creds as
-  throwaway. Production LDAP is Active Directory.
+- **Plaintext passwords in `config.toml` are dev-only.** The shared config is in
+  `scadaproj/infra/glauth/config.toml` (unencrypted); restrict filesystem access on
+  `10.100.0.35` accordingly. Treat the dev creds as throwaway. Production LDAP is Active
+  Directory. *(The retired per-box `C:\publish\glauth\glauth.cfg` has the same caveat.)*
 - The 3-fail / 10-minute lockout is per source IP, not per user — a
   shared NAT can lock out a whole office. Tunable in `[behaviors]`.
 - LDAPS isn't enabled in dev; binding sends passwords cleartext on the
-  wire. Fine for `localhost`, never expose port 3893 off-box without
-  enabling TLS first.
+  wire. The shared GLAuth listens only on the LAN (`10.100.0.35`); never
+  expose port 3893 externally without enabling TLS first.

nuget.config

@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="utf-8"?>
+<configuration>
+  <packageSources>
+    <clear />
+    <add key="nuget.org" value="https://api.nuget.org/v3/index.json" />
+    <add key="dohertj2-gitea" value="https://gitea.dohertylan.com/api/packages/dohertj2/nuget/index.json" />
+  </packageSources>
+  <!-- nuget.org serves everything; the Gitea feed serves only the ZB.MOM.WW.* shared libs.
+       Credentials are NOT committed: they are provided per-developer at the user level. -->
+  <packageSourceMapping>
+    <packageSource key="nuget.org">
+      <package pattern="*" />
+    </packageSource>
+    <packageSource key="dohertj2-gitea">
+      <package pattern="ZB.MOM.WW.Health" />
+      <package pattern="ZB.MOM.WW.Health.*" />
+      <package pattern="ZB.MOM.WW.Telemetry" />
+      <package pattern="ZB.MOM.WW.Telemetry.*" />
+      <package pattern="ZB.MOM.WW.Configuration" />
+      <package pattern="ZB.MOM.WW.Auth" />
+      <package pattern="ZB.MOM.WW.Auth.*" />
+      <package pattern="ZB.MOM.WW.Audit" />
+      <package pattern="ZB.MOM.WW.Theme" />
+    </packageSource>
+  </packageSourceMapping>
+</configuration>

src/ZB.MOM.WW.MxGateway.Contracts/Protos/mxaccess_gateway.proto

@@ -315,6 +315,14 @@ message SubscribeBulkCommand {
   repeated string tag_addresses = 2;
 }
 
+// Provider selection / current provider for the alarm feed. UNSPECIFIED on a
+// SubscribeAlarmsCommand means auto: alarmmgr primary with subtag fallback.
+enum AlarmProviderMode {
+  ALARM_PROVIDER_MODE_UNSPECIFIED = 0;
+  ALARM_PROVIDER_MODE_ALARMMGR = 1;
+  ALARM_PROVIDER_MODE_SUBTAG = 2;
+}
+
 // Subscribe the worker's alarm consumer to an AVEVA alarm provider.
 // Subscription expression follows the canonical
 // `\\<machine>\Galaxy!<area>` format (literal "Galaxy" provider). The
@@ -323,6 +331,12 @@ message SubscribeBulkCommand {
 // SubscribeAlarms to reconfigure).
 message SubscribeAlarmsCommand {
   string subscription_expression = 1;
+  // UNSPECIFIED = auto-failover/failback. ALARMMGR/SUBTAG force one provider.
+  AlarmProviderMode forced_mode = 2;
+  // Subtag watch-list resolved by the gateway (GR SQL + config). Empty in pure
+  // alarmmgr mode; in subtag mode it bounds what the consumer can observe.
+  repeated AlarmSubtagTarget watch_list = 3;
+  AlarmFailoverConfig failover = 4;
 }
 
 // Tear down the worker's alarm consumer. No-op if no subscription is
@@ -330,6 +344,23 @@ message SubscribeAlarmsCommand {
 message UnsubscribeAlarmsCommand {
 }
 
+// One alarm attribute the subtag fallback consumer advises. Addresses are full
+// MXAccess item references the worker passes straight to AddItem.
+message AlarmSubtagTarget {
+  string alarm_full_reference = 1;     // e.g. "Galaxy!Area.Tank01.Level.HiHi"
+  string source_object_reference = 2;  // e.g. "Tank01"
+  string active_subtag = 3;            // item address of the in-alarm boolean
+  string acked_subtag = 4;             // item address of the acknowledged boolean
+  string ack_comment_subtag = 5;       // writable ack-comment attribute (ack write target)
+  string priority_subtag = 6;          // optional severity source; empty if absent
+}
+
+message AlarmFailoverConfig {
+  int32 consecutive_failure_threshold = 1;   // wnwrap COM failures before switching (>=1)
+  int32 failback_probe_interval_seconds = 2; // probe cadence while degraded (>=1)
+  int32 failback_stable_probes = 3;          // clean probes before switching back (>=1)
+}
+
 // Acknowledge a single alarm by its GUID. Operator identity fields are
 // recorded atomically with the ack transition in the alarm-history log.
 // The reply's hresult / native_status surfaces AVEVA's
@@ -684,6 +715,7 @@ message MxEvent {
     OperationCompleteEvent operation_complete = 22;
     OnBufferedDataChangeEvent on_buffered_data_change = 23;
     OnAlarmTransitionEvent on_alarm_transition = 24;
+    OnAlarmProviderModeChangedEvent on_alarm_provider_mode_changed = 25;
   }
 }
 
@@ -694,6 +726,7 @@ enum MxEventFamily {
   MX_EVENT_FAMILY_OPERATION_COMPLETE = 3;
   MX_EVENT_FAMILY_ON_BUFFERED_DATA_CHANGE = 4;
   MX_EVENT_FAMILY_ON_ALARM_TRANSITION = 5;
+  MX_EVENT_FAMILY_ON_ALARM_PROVIDER_MODE_CHANGED = 6;
 }
 
 message OnDataChangeEvent {
@@ -768,6 +801,20 @@ message OnAlarmTransitionEvent {
   // Limit/threshold value that triggered the transition for limit alarms.
   // Optional; populated for AnalogLimitAlarm-family transitions.
   MxValue limit_value = 13;
+
+  // True when this transition came from the subtag-monitoring fallback rather
+  // than the native alarmmgr provider — synthesized from data changes, reduced
+  // fidelity (synthetic GUID, no native raise time).
+  bool degraded = 14;
+  // Which provider produced this transition.
+  AlarmProviderMode source_provider = 15;
+}
+
+message OnAlarmProviderModeChangedEvent {
+  AlarmProviderMode mode = 1;
+  string reason = 2;
+  int32 hresult = 3;   // COM HRESULT that triggered failover; 0 on failback
+  google.protobuf.Timestamp at = 4;
 }
 
 enum AlarmTransitionKind {
@@ -800,6 +847,8 @@ message ActiveAlarmSnapshot {
   string operator_comment = 11;
   MxValue current_value = 12;
   MxValue limit_value = 13;
+  bool degraded = 14;
+  AlarmProviderMode source_provider = 15;
 }
 
 enum AlarmConditionState {
@@ -866,9 +915,19 @@ message AlarmFeedMessage {
     bool snapshot_complete = 2;
     // A live alarm state change (raise / acknowledge / clear).
     OnAlarmTransitionEvent transition = 3;
+    // Provider-mode status. Emitted once on stream open and again on every
+    // failover/failback so late joiners learn the current mode immediately.
+    AlarmProviderStatus provider_status = 4;
   }
 }
 
+message AlarmProviderStatus {
+  AlarmProviderMode mode = 1;
+  bool degraded = 2;            // true whenever mode == SUBTAG
+  string reason = 3;            // human-readable switch reason
+  google.protobuf.Timestamp since = 4;
+}
+
 message MxStatusProxy {
   // Mirrors the `success` member of the MXAccess MXSTATUS_PROXY struct
   // (a 16-bit signed value in the COM struct, widened to int32 on the

src/ZB.MOM.WW.MxGateway.IntegrationTests/DashboardLdapLiveTests.cs

@@ -1,8 +1,11 @@
 using System.Security.Claims;
 using Microsoft.Extensions.Logging.Abstractions;
 using Microsoft.Extensions.Options;
+using ZB.MOM.WW.Auth.Abstractions.Ldap;
+using ZB.MOM.WW.Auth.Ldap;
 using ZB.MOM.WW.MxGateway.Server.Configuration;
 using ZB.MOM.WW.MxGateway.Server.Dashboard;
+using LibraryLdapOptions = ZB.MOM.WW.Auth.Abstractions.Ldap.LdapOptions;
 
 namespace ZB.MOM.WW.MxGateway.IntegrationTests;
 
@@ -28,12 +31,11 @@ public sealed class DashboardLdapLiveTests
             claim.Type == DashboardAuthenticationDefaults.LdapGroupClaimType
             && claim.Value.Contains("GwAdmin", StringComparison.OrdinalIgnoreCase));
 
-        // IntegrationTests-023: DashboardAuthenticator.CreatePrincipal emits a
-        // ClaimTypes.Role claim derived from MapGroupsToRoles. The seeded
-        // GroupToRole map (GwAdmin -> Admin) means the admin principal must
-        // carry Role=Admin alongside the raw LDAP-group claim. A regression in
-        // MapGroupsToRoles (returning an empty list, missing the RDN fallback)
-        // would silently pass without this assertion.
+        // IntegrationTests-023: DashboardAuthenticator builds the principal with a
+        // ClaimTypes.Role claim resolved from the LDAP groups via the
+        // DashboardGroupRoleMapper. The seeded GroupToRole map (GwAdmin -> Admin)
+        // means the admin principal must carry Role=Admin alongside the raw LDAP-group
+        // claim. A regression in the group→role mapping would fail this assertion.
         Assert.Contains(result.Principal.Claims, claim =>
             claim.Type == ClaimTypes.Role
             && claim.Value == DashboardRoles.Admin);
@@ -59,7 +61,7 @@ public sealed class DashboardLdapLiveTests
     [LiveLdapFact]
     public async Task AuthenticateAsync_AdminWithWrongPassword_FailsWithoutLeakingPassword()
     {
-        // Exercises the LdapException branch: the user exists and the service
+        // Exercises the user-bind-failure branch: the user exists and the service
         // account search succeeds, but the candidate bind is rejected.
         const string wrongPassword = "definitely-not-the-admin-password";
         DashboardAuthenticator authenticator = CreateAuthenticator();
@@ -78,8 +80,8 @@ public sealed class DashboardLdapLiveTests
     [LiveLdapFact]
     public async Task AuthenticateAsync_UnknownUsername_Fails()
     {
-        // Exercises the `candidate is null` branch: the service-account search
-        // returns no entry, so no candidate bind is attempted.
+        // Exercises the user-not-found branch: the service-account search returns no
+        // entry, so no candidate bind is attempted.
         DashboardAuthenticator authenticator = CreateAuthenticator();
 
         DashboardAuthenticationResult result = await authenticator.AuthenticateAsync(
@@ -96,18 +98,13 @@ public sealed class DashboardLdapLiveTests
     public async Task AuthenticateAsync_ServerUnreachable_FailsWithoutThrowing()
     {
         // Exercises the connect-failure path: a closed loopback port produces a
-        // connection error that DashboardAuthenticator must absorb into a Fail
+        // connection error that the shared LdapAuthService must absorb into a Fail
         // result rather than propagating an exception to the dashboard.
-        DashboardAuthenticator authenticator = new(
-            Options.Create(new GatewayOptions
-            {
-                Ldap = new LdapOptions
-                {
-                    // 1 is a reserved port number that no LDAP server listens on.
-                    Port = 1,
-                },
-            }),
-            NullLogger<DashboardAuthenticator>.Instance);
+        DashboardAuthenticator authenticator = CreateAuthenticator(LibraryOptions() with
+        {
+            // 1 is a reserved port number that no LDAP server listens on.
+            Port = 1,
+        });
 
         DashboardAuthenticationResult result = await authenticator.AuthenticateAsync(
             "admin",
@@ -118,19 +115,48 @@ public sealed class DashboardLdapLiveTests
         Assert.Null(result.Principal);
     }
 
-    private static DashboardAuthenticator CreateAuthenticator()
+    private static DashboardAuthenticator CreateAuthenticator() => CreateAuthenticator(LibraryOptions());
+
+    private static DashboardAuthenticator CreateAuthenticator(LibraryLdapOptions ldapOptions)
     {
-        return new DashboardAuthenticator(
-            Options.Create(new GatewayOptions
+        GatewayOptions gatewayOptions = new()
+        {
+            Dashboard = new DashboardOptions
             {
-                Dashboard = new DashboardOptions
+                GroupToRole = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase)
                 {
-                    GroupToRole = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase)
-                    {
-                        ["GwAdmin"] = DashboardRoles.Admin,
-                    },
+                    ["GwAdmin"] = DashboardRoles.Admin,
                 },
-            }),
+            },
+        };
+
+        return new DashboardAuthenticator(
+            new LdapAuthService(ldapOptions),
+            new DashboardGroupRoleMapper(Options.Create(gatewayOptions)),
             NullLogger<DashboardAuthenticator>.Instance);
     }
+
+    /// <summary>
+    /// Builds the shared library <see cref="LibraryLdapOptions"/> from the gateway's
+    /// default LDAP settings so the live tests exercise the same seeded directory the
+    /// gateway connects to (localhost:3893, plaintext, with AllowInsecure for dev).
+    /// </summary>
+    private static LibraryLdapOptions LibraryOptions()
+    {
+        ZB.MOM.WW.MxGateway.Server.Configuration.LdapOptions gateway = new();
+        return new LibraryLdapOptions
+        {
+            Enabled = gateway.Enabled,
+            Server = gateway.Server,
+            Port = gateway.Port,
+            Transport = gateway.Transport,
+            AllowInsecure = gateway.AllowInsecure,
+            SearchBase = gateway.SearchBase,
+            ServiceAccountDn = gateway.ServiceAccountDn,
+            ServiceAccountPassword = gateway.ServiceAccountPassword,
+            UserNameAttribute = gateway.UserNameAttribute,
+            DisplayNameAttribute = gateway.DisplayNameAttribute,
+            GroupAttribute = gateway.GroupAttribute,
+        };
+    }
 }

src/ZB.MOM.WW.MxGateway.Server/Alarms/AlarmWatchListResolver.cs

@@ -0,0 +1,168 @@
+using ZB.MOM.WW.MxGateway.Contracts.Proto;
+using ZB.MOM.WW.MxGateway.Server.Configuration;
+using ZB.MOM.WW.MxGateway.Server.Galaxy;
+
+namespace ZB.MOM.WW.MxGateway.Server.Alarms;
+
+/// <summary>
+///     Default <see cref="IAlarmWatchListResolver"/>. Merges Galaxy Repository
+///     alarm-attribute discovery with the configured include/exclude overrides
+///     and composes the per-attribute subtag item addresses from the configured
+///     subtag names.
+/// </summary>
+// NOTE: The exact subtag names and the canonical AlarmFullReference shape
+// ("Galaxy!{area}.{reference}") are validated against a live Galaxy in the
+// Task 17 live smoke test. The config Subtags block exists precisely so these
+// names are not hard-coded here.
+public sealed class AlarmWatchListResolver : IAlarmWatchListResolver
+{
+    private const string ProviderLiteral = "Galaxy";
+    private const string DefaultActiveSubtag = "active";
+    private const string DefaultAckedSubtag = "acked";
+
+    private readonly IGalaxyRepository _repository;
+    private readonly ILogger<AlarmWatchListResolver> _logger;
+
+    /// <summary>Initializes the watch-list resolver.</summary>
+    /// <param name="repository">Galaxy Repository used for alarm-attribute discovery.</param>
+    /// <param name="logger">Diagnostic logger.</param>
+    public AlarmWatchListResolver(
+        IGalaxyRepository repository,
+        ILogger<AlarmWatchListResolver> logger)
+    {
+        _repository = repository ?? throw new ArgumentNullException(nameof(repository));
+        _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+    }
+
+    /// <inheritdoc />
+    public async Task<IReadOnlyList<AlarmSubtagTarget>> ResolveAsync(
+        AlarmsOptions options,
+        CancellationToken cancellationToken = default)
+    {
+        ArgumentNullException.ThrowIfNull(options);
+
+        AlarmDiscoveryOptions discovery = options.Fallback.Discovery;
+
+        // 1. Build the ordered, de-duplicated attribute reference set.
+        //    Each entry carries the reference plus the source-object reference.
+        List<(string Reference, string SourceObject)> ordered = [];
+        HashSet<string> seen = new(StringComparer.OrdinalIgnoreCase);
+
+        if (discovery.UseGalaxyRepository)
+        {
+            List<GalaxyAlarmAttributeRow> rows;
+            try
+            {
+                rows = await _repository.GetAlarmAttributesAsync(cancellationToken).ConfigureAwait(false);
+            }
+            catch (Exception ex)
+            {
+                // Discovery being unavailable must not crash the resolver: log and
+                // continue with an empty discovery set. The caller decides what to
+                // do with the (possibly config-only) result.
+                _logger.LogWarning(
+                    ex,
+                    "Galaxy Repository alarm-attribute discovery failed; continuing with configuration-only watch-list.");
+                rows = [];
+            }
+
+            foreach (GalaxyAlarmAttributeRow row in rows)
+            {
+                if (string.IsNullOrEmpty(row.FullTagReference) || !seen.Add(row.FullTagReference))
+                {
+                    continue;
+                }
+
+                ordered.Add((row.FullTagReference, row.SourceObjectReference));
+            }
+        }
+
+        foreach (string include in discovery.IncludeAttributes)
+        {
+            if (string.IsNullOrEmpty(include) || !seen.Add(include))
+            {
+                continue;
+            }
+
+            ordered.Add((include, DeriveSourceObject(include)));
+        }
+
+        // Remove excluded references (case-insensitive), but only when GR discovery
+        // is active. ExcludeAttributes is documented as "Ignored when
+        // UseGalaxyRepository is false" (AlarmDiscoveryOptions.ExcludeAttributes).
+        // Whitespace-only entries are skipped, consistent with the include guard above.
+        if (discovery.UseGalaxyRepository)
+        {
+            HashSet<string> excluded = new(
+                discovery.ExcludeAttributes.Where(e => !string.IsNullOrWhiteSpace(e)),
+                StringComparer.OrdinalIgnoreCase);
+            if (excluded.Count > 0)
+            {
+                ordered.RemoveAll(e => excluded.Contains(e.Reference));
+            }
+        }
+
+        // 2. Resolve subtag names with safe fallbacks.
+        string active = string.IsNullOrEmpty(options.Fallback.Subtags.Active)
+            ? DefaultActiveSubtag
+            : options.Fallback.Subtags.Active;
+        string acked = string.IsNullOrEmpty(options.Fallback.Subtags.Acked)
+            ? DefaultAckedSubtag
+            : options.Fallback.Subtags.Acked;
+        string priority = options.Fallback.Subtags.Priority;
+        string ackComment = options.Fallback.Subtags.AckComment;
+
+        // 3. Resolve the area: discovery area, else the default area (may be empty).
+        string area = string.IsNullOrEmpty(discovery.Area) ? options.DefaultArea : discovery.Area;
+
+        // 4. Compose one target per reference.
+        List<AlarmSubtagTarget> targets = new(ordered.Count);
+        foreach ((string reference, string sourceObject) in ordered)
+        {
+            targets.Add(new AlarmSubtagTarget
+            {
+                AlarmFullReference = ComposeFullReference(area, reference),
+                SourceObjectReference = sourceObject,
+                ActiveSubtag = $"{reference}.{active}",
+                AckedSubtag = $"{reference}.{acked}",
+                PrioritySubtag = string.IsNullOrEmpty(priority) ? string.Empty : $"{reference}.{priority}",
+                AckCommentSubtag = string.IsNullOrEmpty(ackComment) ? string.Empty : $"{reference}.{ackComment}",
+            });
+        }
+
+        // 5. Report the resolved count; warn when subtag mode was expected to cover
+        //    something (GR enabled, or explicit includes were configured) but resolved
+        //    to nothing. Only emit the Debug line when there is at least one target,
+        //    to avoid a confusing "0 target(s)" noise line.
+        if (targets.Count == 0 && (discovery.UseGalaxyRepository || discovery.IncludeAttributes.Length > 0))
+        {
+            _logger.LogWarning(
+                "Alarm subtag watch-list resolved to zero targets; subtag-polling fallback will cover no alarms.");
+        }
+        else if (targets.Count > 0)
+        {
+            _logger.LogDebug("Resolved alarm subtag watch-list with {TargetCount} target(s).", targets.Count);
+        }
+
+        return targets;
+    }
+
+    /// <summary>
+    ///     Derives the source-object reference for a configuration entry: the
+    ///     substring before the first '.', or the whole string when there is no dot.
+    /// </summary>
+    private static string DeriveSourceObject(string reference)
+    {
+        int dot = reference.IndexOf('.', StringComparison.Ordinal);
+        return dot < 0 ? reference : reference[..dot];
+    }
+
+    /// <summary>
+    ///     Composes the canonical alarm full reference: <c>Galaxy!{area}.{reference}</c>
+    ///     when an area is set, otherwise <c>Galaxy!{reference}</c>.
+    /// </summary>
+    private static string ComposeFullReference(string area, string reference) =>
+        string.IsNullOrEmpty(area)
+            ? $"{ProviderLiteral}!{reference}"
+            : $"{ProviderLiteral}!{area}.{reference}";
+}

src/ZB.MOM.WW.MxGateway.Server/Alarms/AlarmsServiceCollectionExtensions.cs

@@ -13,6 +13,7 @@ public static class AlarmsServiceCollectionExtensions
     /// <returns>The service collection for chaining.</returns>
     public static IServiceCollection AddGatewayAlarms(this IServiceCollection services)
     {
+        services.AddSingleton<IAlarmWatchListResolver, AlarmWatchListResolver>();
         services.AddSingleton<GatewayAlarmMonitor>();
         services.AddSingleton<IGatewayAlarmService>(provider => provider.GetRequiredService<GatewayAlarmMonitor>());
         services.AddHostedService(provider => provider.GetRequiredService<GatewayAlarmMonitor>());

src/ZB.MOM.WW.MxGateway.Server/Alarms/GatewayAlarmMonitor.cs

@@ -1,7 +1,9 @@
 using System.Threading.Channels;
+using Google.Protobuf.WellKnownTypes;
 using Microsoft.Extensions.Options;
 using ZB.MOM.WW.MxGateway.Contracts.Proto;
 using ZB.MOM.WW.MxGateway.Server.Configuration;
+using ZB.MOM.WW.MxGateway.Server.Metrics;
 using ZB.MOM.WW.MxGateway.Server.Sessions;
 
 namespace ZB.MOM.WW.MxGateway.Server.Alarms;
@@ -23,6 +25,8 @@ public sealed class GatewayAlarmMonitor : BackgroundService, IGatewayAlarmServic
     private static readonly TimeSpan StartupGrace = TimeSpan.FromSeconds(2);
 
     private readonly ISessionManager _sessionManager;
+    private readonly IAlarmWatchListResolver _watchListResolver;
+    private readonly GatewayMetrics _metrics;
     private readonly AlarmsOptions _options;
     private readonly ILogger<GatewayAlarmMonitor> _logger;
 
@@ -30,20 +34,34 @@ public sealed class GatewayAlarmMonitor : BackgroundService, IGatewayAlarmServic
     private readonly Dictionary<string, ActiveAlarmSnapshot> _alarms = new(StringComparer.Ordinal);
     private readonly List<Subscriber> _subscribers = [];
 
+    // Current provider status (mode + degraded + reason + since), guarded by _sync.
+    // Initialized to the alarm-manager, not-degraded baseline so a late joiner sees
+    // a sensible status even before any OnAlarmProviderModeChanged event arrives.
+    private AlarmProviderMode _providerMode = AlarmProviderMode.Alarmmgr;
+    private bool _providerDegraded;
+    private string _providerReason = string.Empty;
+    private DateTimeOffset _providerSince = DateTimeOffset.UtcNow;
+
     private volatile GatewayAlarmMonitorState _state = GatewayAlarmMonitorState.Disabled;
     private volatile string? _lastError;
     private GatewaySession? _session;
 
     /// <summary>Initializes the gateway alarm monitor.</summary>
     /// <param name="sessionManager">Gateway session manager.</param>
+    /// <param name="watchListResolver">Resolver for the subtag-fallback watch-list.</param>
+    /// <param name="metrics">Gateway metrics sink.</param>
     /// <param name="options">Gateway options carrying the alarm configuration.</param>
     /// <param name="logger">Diagnostic logger.</param>
     public GatewayAlarmMonitor(
         ISessionManager sessionManager,
+        IAlarmWatchListResolver watchListResolver,
+        GatewayMetrics metrics,
         IOptions<GatewayOptions> options,
         ILogger<GatewayAlarmMonitor> logger)
     {
         _sessionManager = sessionManager ?? throw new ArgumentNullException(nameof(sessionManager));
+        _watchListResolver = watchListResolver ?? throw new ArgumentNullException(nameof(watchListResolver));
+        _metrics = metrics ?? throw new ArgumentNullException(nameof(metrics));
         _options = (options ?? throw new ArgumentNullException(nameof(options))).Value.Alarms;
         _logger = logger ?? throw new ArgumentNullException(nameof(logger));
     }
@@ -139,6 +157,16 @@ public sealed class GatewayAlarmMonitor : BackgroundService, IGatewayAlarmServic
     private async Task RunMonitorAsync(string subscription, CancellationToken stoppingToken)
     {
         _state = GatewayAlarmMonitorState.Starting;
+        lock (_sync)
+        {
+            // Re-baseline the provider status for this lifecycle so a restarted
+            // monitor advertises alarm-manager/not-degraded until told otherwise.
+            _providerMode = AlarmProviderMode.Alarmmgr;
+            _providerDegraded = false;
+            _providerReason = string.Empty;
+            _providerSince = DateTimeOffset.UtcNow;
+        }
+
         GatewaySession session = await _sessionManager.OpenSessionAsync(
                 new SessionOpenRequest(BackendName, MonitorClientName, Guid.NewGuid().ToString("N"), CommandTimeout: null),
                 MonitorClientName,
@@ -173,6 +201,15 @@ public sealed class GatewayAlarmMonitor : BackgroundService, IGatewayAlarmServic
                     {
                         ApplyTransition(mxEvent.OnAlarmTransition);
                     }
+                    else if (mxEvent is { BodyCase: MxEvent.BodyOneofCase.OnAlarmProviderModeChanged }
+                        && mxEvent.OnAlarmProviderModeChanged is not null)
+                    {
+                        await ApplyProviderModeChangeAsync(
+                                session.SessionId,
+                                mxEvent.OnAlarmProviderModeChanged,
+                                linked.Token)
+                            .ConfigureAwait(false);
+                    }
                 }
             }
             finally
@@ -209,6 +246,29 @@ public sealed class GatewayAlarmMonitor : BackgroundService, IGatewayAlarmServic
 
     private async Task SubscribeAlarmsAsync(string sessionId, string subscription, CancellationToken cancellationToken)
     {
+        IReadOnlyList<AlarmSubtagTarget> watchList = await _watchListResolver
+            .ResolveAsync(_options, cancellationToken)
+            .ConfigureAwait(false);
+
+        AlarmProviderMode forcedMode = MapForcedMode(_options.Fallback.Mode);
+
+        // When the forced mode is Unspecified (the "Auto" case) and the resolved
+        // watch-list is empty — the common alarmmgr-only deployment — the command
+        // is identical-in-effect to the historical SubscribeAlarms (wnwrap only):
+        // the worker builds the wnwrap consumer and no subtag watch-list.
+        SubscribeAlarmsCommand command = new()
+        {
+            SubscriptionExpression = subscription,
+            ForcedMode = forcedMode,
+            Failover = new AlarmFailoverConfig
+            {
+                ConsecutiveFailureThreshold = _options.Fallback.ConsecutiveFailureThreshold,
+                FailbackProbeIntervalSeconds = _options.Fallback.FailbackProbeIntervalSeconds,
+                FailbackStableProbes = _options.Fallback.FailbackStableProbes,
+            },
+        };
+        command.WatchList.AddRange(watchList);
+
         WorkerCommandReply reply = await _sessionManager.InvokeAsync(
                 sessionId,
                 new WorkerCommand
@@ -216,7 +276,7 @@ public sealed class GatewayAlarmMonitor : BackgroundService, IGatewayAlarmServic
                     Command = new MxCommand
                     {
                         Kind = MxCommandKind.SubscribeAlarms,
-                        SubscribeAlarms = new SubscribeAlarmsCommand { SubscriptionExpression = subscription },
+                        SubscribeAlarms = command,
                     },
                 },
                 cancellationToken)
@@ -310,6 +370,94 @@ public sealed class GatewayAlarmMonitor : BackgroundService, IGatewayAlarmServic
         }
     }
 
+    // Handles the worker's provider-mode-change event: updates the stored provider
+    // status, broadcasts it to every subscriber (provider status is global, not
+    // alarm-scoped), records the switch metric, and forces a cache reconcile so the
+    // active-alarm set reflects whatever the new mode reports.
+    private async Task ApplyProviderModeChangeAsync(
+        string sessionId,
+        OnAlarmProviderModeChangedEvent change,
+        CancellationToken cancellationToken)
+    {
+        AlarmProviderMode toMode = change.Mode;
+        string reason = change.Reason ?? string.Empty;
+
+        AlarmProviderStatus status;
+        int fromModeInt;
+        lock (_sync)
+        {
+            fromModeInt = ModeToInt(_providerMode);
+            _providerMode = toMode;
+            _providerDegraded = toMode == AlarmProviderMode.Subtag;
+            _providerReason = reason;
+            _providerSince = DateTimeOffset.UtcNow;
+            status = BuildProviderStatus();
+            BroadcastToAll(new AlarmFeedMessage { ProviderStatus = status });
+        }
+
+        _metrics.AlarmProviderSwitched(fromModeInt, ModeToInt(toMode), reason);
+
+        _logger.LogInformation(
+            "Alarm provider mode changed to {Mode} (degraded={Degraded}): {Reason}",
+            toMode,
+            status.Degraded,
+            reason);
+
+        try
+        {
+            await ReconcileAsync(sessionId, cancellationToken).ConfigureAwait(false);
+        }
+        catch (OperationCanceledException)
+        {
+            throw;
+        }
+        catch (Exception exception)
+        {
+            _logger.LogDebug(
+                exception,
+                "Reconcile after alarm provider mode change failed; keeping the current cache.");
+        }
+    }
+
+    // Caller holds _sync. Builds an AlarmProviderStatus snapshot of the current state.
+    private AlarmProviderStatus BuildProviderStatus()
+    {
+        return new AlarmProviderStatus
+        {
+            Mode = _providerMode,
+            Degraded = _providerDegraded,
+            Reason = _providerReason,
+            Since = Timestamp.FromDateTimeOffset(_providerSince),
+        };
+    }
+
+    // Maps the configured fallback mode string to the forced provider mode the
+    // worker honours. Case-insensitive; anything other than the two force values
+    // (including the default "Auto") yields Unspecified ("let the worker decide").
+    private static AlarmProviderMode MapForcedMode(string? mode)
+    {
+        if (string.Equals(mode, "ForceAlarmManager", StringComparison.OrdinalIgnoreCase))
+        {
+            return AlarmProviderMode.Alarmmgr;
+        }
+
+        if (string.Equals(mode, "ForceSubtag", StringComparison.OrdinalIgnoreCase))
+        {
+            return AlarmProviderMode.Subtag;
+        }
+
+        return AlarmProviderMode.Unspecified;
+    }
+
+    // Maps the provider-mode enum to the integer the metric expects
+    // (alarmmgr=1, subtag=2, unknown/unspecified=0).
+    private static int ModeToInt(AlarmProviderMode mode) => mode switch
+    {
+        AlarmProviderMode.Alarmmgr => 1,
+        AlarmProviderMode.Subtag => 2,
+        _ => 0,
+    };
+
     // Replaces the cache with the worker's authoritative snapshot, broadcasting
     // a synthetic transition for any alarm the live stream missed.
     private void ApplyReconcile(IEnumerable<ActiveAlarmSnapshot> snapshots)
@@ -374,6 +522,23 @@ public sealed class GatewayAlarmMonitor : BackgroundService, IGatewayAlarmServic
         }
     }
 
+    // Caller holds _sync. Pushes a feed message to every subscriber regardless of
+    // its alarm-filter prefix. Used for provider-status messages, which are global
+    // rather than scoped to a single alarm reference.
+    private void BroadcastToAll(AlarmFeedMessage message)
+    {
+        for (int index = _subscribers.Count - 1; index >= 0; index--)
+        {
+            Subscriber subscriber = _subscribers[index];
+            if (!subscriber.Channel.Writer.TryWrite(message))
+            {
+                subscriber.Channel.Writer.TryComplete(new InvalidOperationException(
+                    "Alarm feed subscriber fell behind and was dropped; reconnect to re-snapshot."));
+                _subscribers.RemoveAt(index);
+            }
+        }
+    }
+
     private void ClearCache()
     {
         lock (_sync)
@@ -398,11 +563,14 @@ public sealed class GatewayAlarmMonitor : BackgroundService, IGatewayAlarmServic
         Subscriber subscriber = new(channel, prefix);
 
         ActiveAlarmSnapshot[] snapshot;
+        AlarmProviderStatus providerStatus;
         lock (_sync)
         {
-            // Register before snapshotting under the same lock so no transition
-            // can slip between the snapshot and the live stream.
+            // Register before snapshotting under the same lock so neither a
+            // transition nor a provider-mode change can slip between the snapshot
+            // and the live stream.
             _subscribers.Add(subscriber);
+            providerStatus = BuildProviderStatus();
             snapshot = _alarms.Values
                 .Where(alarm => prefix.Length == 0
                     || alarm.AlarmFullReference.StartsWith(prefix, StringComparison.Ordinal))
@@ -412,6 +580,10 @@ public sealed class GatewayAlarmMonitor : BackgroundService, IGatewayAlarmServic
 
         try
         {
+            // Emit the current provider status first so a late joiner immediately
+            // learns the mode (and whether the feed is degraded) before any alarms.
+            yield return new AlarmFeedMessage { ProviderStatus = providerStatus };
+
             foreach (ActiveAlarmSnapshot alarm in snapshot)
             {
                 yield return new AlarmFeedMessage { ActiveAlarm = alarm };

src/ZB.MOM.WW.MxGateway.Server/Alarms/IAlarmWatchListResolver.cs

@@ -0,0 +1,28 @@
+using ZB.MOM.WW.MxGateway.Contracts.Proto;
+using ZB.MOM.WW.MxGateway.Server.Configuration;
+
+namespace ZB.MOM.WW.MxGateway.Server.Alarms;
+
+/// <summary>
+///     Resolves the subtag watch-list the gateway sends to the worker when the
+///     central alarm monitor operates in subtag-polling fallback mode. Merges
+///     Galaxy Repository alarm-attribute discovery with the configured
+///     include/exclude overrides and composes the per-attribute subtag item
+///     addresses from the configured subtag names.
+/// </summary>
+public interface IAlarmWatchListResolver
+{
+    /// <summary>
+    ///     Builds the subtag watch-list for the supplied alarm configuration.
+    /// </summary>
+    /// <param name="options">Alarm configuration carrying discovery and subtag-name settings.</param>
+    /// <param name="cancellationToken">Token to cancel the asynchronous operation.</param>
+    /// <returns>
+    ///     The resolved <see cref="AlarmSubtagTarget"/> watch-list, possibly empty.
+    ///     Discovery being unavailable never throws; the caller decides what to do
+    ///     with an empty list.
+    /// </returns>
+    Task<IReadOnlyList<AlarmSubtagTarget>> ResolveAsync(
+        AlarmsOptions options,
+        CancellationToken cancellationToken = default);
+}

src/ZB.MOM.WW.MxGateway.Server/Configuration/AlarmFallbackOptions.cs

@@ -0,0 +1,125 @@
+namespace ZB.MOM.WW.MxGateway.Server.Configuration;
+
+/// <summary>
+///     Controls how the central alarm monitor selects between the MXAccess
+///     alarm-manager subscription and the subtag-polling fallback, and
+///     governs the failure-detection thresholds used when switching.
+/// </summary>
+public sealed class AlarmFallbackOptions
+{
+    /// <summary>
+    ///     Selects the operating mode for the alarm-manager ↔ subtag fallback
+    ///     mechanism. Accepted values (case-insensitive):
+    ///     <list type="bullet">
+    ///         <item><c>Auto</c> — use the alarm manager; switch to subtag polling
+    ///         automatically when <see cref="ConsecutiveFailureThreshold"/> failures
+    ///         are detected, and probe for failback.</item>
+    ///         <item><c>ForceAlarmManager</c> — always use the alarm manager;
+    ///         never fall back.</item>
+    ///         <item><c>ForceSubtag</c> — always use subtag polling;
+    ///         never try the alarm manager.</item>
+    ///     </list>
+    ///     Default is <c>Auto</c>.
+    /// </summary>
+    public string Mode { get; init; } = "Auto";
+
+    /// <summary>
+    ///     Number of consecutive alarm-manager failures before the monitor
+    ///     switches to subtag-polling fallback. Must be at least 1. Default 3.
+    /// </summary>
+    public int ConsecutiveFailureThreshold { get; init; } = 3;
+
+    /// <summary>
+    ///     How often (in seconds) the monitor sends a probe to the alarm manager
+    ///     while operating in subtag-polling fallback mode, to detect recovery.
+    ///     Must be at least 1. Default 30.
+    /// </summary>
+    public int FailbackProbeIntervalSeconds { get; init; } = 30;
+
+    /// <summary>
+    ///     Number of consecutive successful probes required before the monitor
+    ///     considers the alarm manager recovered and switches back. Must be at
+    ///     least 1. Default 3.
+    /// </summary>
+    public int FailbackStableProbes { get; init; } = 3;
+
+    /// <summary>
+    ///     Controls how the monitor discovers the set of objects to poll when
+    ///     operating in subtag-polling fallback mode.
+    /// </summary>
+    public AlarmDiscoveryOptions Discovery { get; init; } = new();
+
+    /// <summary>
+    ///     Configures the subtag names the monitor reads when polling alarm state
+    ///     in subtag-fallback mode.
+    /// </summary>
+    public AlarmSubtagNameOptions Subtags { get; init; } = new();
+}
+
+/// <summary>
+///     Governs how the alarm monitor discovers objects to include in subtag-polling
+///     fallback mode. Either the Galaxy Repository query (when
+///     <see cref="UseGalaxyRepository"/> is <c>true</c>) or an explicit
+///     <see cref="IncludeAttributes"/> list must be supplied when
+///     <c>MxGateway:Alarms:Fallback:Mode</c> is <c>ForceSubtag</c>.
+/// </summary>
+public sealed class AlarmDiscoveryOptions
+{
+    /// <summary>
+    ///     When <c>true</c> the monitor queries the Galaxy Repository SQL database
+    ///     to enumerate alarm objects for the configured area. Default <c>true</c>.
+    /// </summary>
+    public bool UseGalaxyRepository { get; init; } = true;
+
+    /// <summary>
+    ///     Galaxy area to scope the Repository query to. When empty the monitor
+    ///     falls back to <see cref="AlarmsOptions.DefaultArea"/>. Ignored when
+    ///     <see cref="UseGalaxyRepository"/> is <c>false</c>.
+    /// </summary>
+    public string Area { get; init; } = string.Empty;
+
+    /// <summary>
+    ///     Explicit list of MXAccess attribute paths to include in subtag polling,
+    ///     supplementing (or replacing, when <see cref="UseGalaxyRepository"/> is
+    ///     <c>false</c>) the Repository-derived list. Default empty.
+    /// </summary>
+    public string[] IncludeAttributes { get; init; } = Array.Empty<string>();
+
+    /// <summary>
+    ///     Attribute paths to exclude from the Repository-derived poll list.
+    ///     Ignored when <see cref="UseGalaxyRepository"/> is <c>false</c>.
+    ///     Default empty.
+    /// </summary>
+    public string[] ExcludeAttributes { get; init; } = Array.Empty<string>();
+}
+
+/// <summary>
+///     Configures the subtag names read by the alarm monitor when it is operating
+///     in subtag-polling fallback mode. Names are matched against MXAccess item
+///     handles; validation against the live MXAccess attribute list occurs at
+///     runtime, not at startup.
+/// </summary>
+public sealed class AlarmSubtagNameOptions
+{
+    /// <summary>
+    ///     Subtag name for the active-alarm flag. Default <c>active</c>.
+    /// </summary>
+    public string Active { get; init; } = "active";
+
+    /// <summary>
+    ///     Subtag name for the acknowledged flag. Default <c>acked</c>.
+    /// </summary>
+    public string Acked { get; init; } = "acked";
+
+    /// <summary>
+    ///     Optional subtag name for the acknowledgement comment field.
+    ///     When empty the feature is disabled. Verified against MXAccess at
+    ///     runtime before use. Default empty.
+    /// </summary>
+    public string AckComment { get; init; } = string.Empty;
+
+    /// <summary>
+    ///     Subtag name for the alarm priority. Default <c>priority</c>.
+    /// </summary>
+    public string Priority { get; init; } = "priority";
+}

src/ZB.MOM.WW.MxGateway.Server/Configuration/AlarmsOptions.cs

@@ -45,4 +45,12 @@ public sealed class AlarmsOptions
     ///     the monitor floors it at 5 seconds.
     /// </summary>
     public int ReconcileIntervalSeconds { get; init; } = 30;
+
+    /// <summary>
+    ///     Configuration for the alarm-manager ↔ subtag fallback mechanism:
+    ///     operating mode, failure-detection thresholds, discovery, and subtag
+    ///     names. Defaults (Mode = "Auto") preserve behaviour when the section is
+    ///     omitted from configuration.
+    /// </summary>
+    public AlarmFallbackOptions Fallback { get; init; } = new();
 }

src/ZB.MOM.WW.MxGateway.Server/Configuration/DashboardOptions.cs

@@ -21,6 +21,17 @@ public sealed class DashboardOptions
     /// </summary>
     public bool RequireHttpsCookie { get; init; } = true;
 
+    /// <summary>
+    /// Dashboard auth cookie name. When null/blank (the default) the canonical
+    /// <see cref="ZB.MOM.WW.MxGateway.Server.Dashboard.DashboardAuthenticationDefaults.CookieName"/>
+    /// is used. Override it (<c>MxGateway:Dashboard:CookieName</c>) to give a distinct name to a
+    /// gateway that shares a hostname with another gateway instance — browser cookies are scoped
+    /// by host+path but NOT by port, so two instances on the same host would otherwise clobber
+    /// each other's dashboard session under a shared cookie name. Changing this signs out
+    /// existing dashboard sessions on next deploy.
+    /// </summary>
+    public string? CookieName { get; init; }
+
     /// <summary>Gets the dashboard snapshot update interval in milliseconds.</summary>
     public int SnapshotIntervalMilliseconds { get; init; } = 1_000;
 

src/ZB.MOM.WW.MxGateway.Server/Configuration/EffectiveLdapConfiguration.cs

@@ -4,8 +4,8 @@ public sealed record EffectiveLdapConfiguration(
     bool Enabled,
     string Server,
     int Port,
-    bool UseTls,
-    bool AllowInsecureLdap,
+    string Transport,
+    bool AllowInsecure,
     string SearchBase,
     string ServiceAccountDn,
     string ServiceAccountPassword,

src/ZB.MOM.WW.MxGateway.Server/Configuration/GatewayConfigurationProvider.cs

@@ -23,8 +23,8 @@ public sealed class GatewayConfigurationProvider(IOptions<GatewayOptions> option
                 Enabled: value.Ldap.Enabled,
                 Server: value.Ldap.Server,
                 Port: value.Ldap.Port,
-                UseTls: value.Ldap.UseTls,
-                AllowInsecureLdap: value.Ldap.AllowInsecureLdap,
+                Transport: value.Ldap.Transport.ToString(),
+                AllowInsecure: value.Ldap.AllowInsecure,
                 SearchBase: value.Ldap.SearchBase,
                 ServiceAccountDn: value.Ldap.ServiceAccountDn,
                 ServiceAccountPassword: RedactedValue,

src/ZB.MOM.WW.MxGateway.Server/Configuration/GatewayConfigurationServiceCollectionExtensions.cs

@@ -1,4 +1,5 @@
-using Microsoft.Extensions.Options;
+using Microsoft.Extensions.Configuration;
+using ZB.MOM.WW.Configuration;
 
 namespace ZB.MOM.WW.MxGateway.Server.Configuration;
 
@@ -6,15 +7,14 @@ public static class GatewayConfigurationServiceCollectionExtensions
 {
     /// <summary>Registers gateway configuration services in the dependency injection container.</summary>
     /// <param name="services">The service collection.</param>
+    /// <param name="configuration">The configuration to bind gateway options from.</param>
     /// <returns>The service collection for chaining.</returns>
-    public static IServiceCollection AddGatewayConfiguration(this IServiceCollection services)
+    public static IServiceCollection AddGatewayConfiguration(
+        this IServiceCollection services, IConfiguration configuration)
     {
-        services
-            .AddOptions<GatewayOptions>()
-            .BindConfiguration(GatewayOptions.SectionName)
-            .ValidateOnStart();
+        services.AddValidatedOptions<GatewayOptions, GatewayOptionsValidator>(
+            configuration, GatewayOptions.SectionName);
 
-        services.AddSingleton<IValidateOptions<GatewayOptions>, GatewayOptionsValidator>();
         services.AddSingleton<IGatewayConfigurationProvider, GatewayConfigurationProvider>();
 
         return services;

src/ZB.MOM.WW.MxGateway.Server/Configuration/GatewayOptions.cs

@@ -43,4 +43,7 @@ public sealed class GatewayOptions
     /// behaviour (alarms disabled).
     /// </summary>
     public AlarmsOptions Alarms { get; init; } = new();
+
+    /// <summary>Gets self-signed TLS certificate auto-generation options.</summary>
+    public TlsOptions Tls { get; init; } = new();
 }

src/ZB.MOM.WW.MxGateway.Server/Configuration/GatewayOptionsValidator.cs

@@ -1,9 +1,10 @@
-using Microsoft.Extensions.Options;
+using ZB.MOM.WW.Auth.Abstractions.Ldap;
+using ZB.MOM.WW.Configuration;
 using ZB.MOM.WW.MxGateway.Contracts;
 
 namespace ZB.MOM.WW.MxGateway.Server.Configuration;
 
-public sealed class GatewayOptionsValidator : IValidateOptions<GatewayOptions>
+public sealed class GatewayOptionsValidator : OptionsValidatorBase<GatewayOptions>
 {
     private const int MinimumMaxMessageBytes = 1024;
     private const int MaximumMaxMessageBytes = 256 * 1024 * 1024;
@@ -11,32 +12,26 @@ public sealed class GatewayOptionsValidator : IValidateOptions<GatewayOptions>
     /// <summary>
     /// Validates gateway configuration options.
     /// </summary>
-    /// <param name="name">Options name.</param>
+    /// <param name="builder">The accumulator to record failures on.</param>
     /// <param name="options">Gateway options to validate.</param>
-    /// <returns>Validation result.</returns>
-    public ValidateOptionsResult Validate(string? name, GatewayOptions options)
+    protected override void Validate(ValidationBuilder builder, GatewayOptions options)
     {
-        List<string> failures = [];
-
-        ValidateAuthentication(options.Authentication, failures);
-        ValidateLdap(options.Ldap, failures);
-        ValidateWorker(options.Worker, failures);
-        ValidateSessions(options.Sessions, failures);
-        ValidateEvents(options.Events, failures);
-        ValidateDashboard(options.Dashboard, failures);
-        ValidateProtocol(options.Protocol, failures);
-        ValidateAlarms(options.Alarms, failures);
-
-        return failures.Count == 0
-            ? ValidateOptionsResult.Success
-            : ValidateOptionsResult.Fail(failures);
+        ValidateAuthentication(options.Authentication, builder);
+        ValidateLdap(options.Ldap, builder);
+        ValidateWorker(options.Worker, builder);
+        ValidateSessions(options.Sessions, builder);
+        ValidateEvents(options.Events, builder);
+        ValidateDashboard(options.Dashboard, builder);
+        ValidateProtocol(options.Protocol, builder);
+        ValidateAlarms(options.Alarms, builder);
+        ValidateTls(options.Tls, builder);
     }
 
-    private static void ValidateAuthentication(AuthenticationOptions options, List<string> failures)
+    private static void ValidateAuthentication(AuthenticationOptions options, ValidationBuilder builder)
     {
         if (!Enum.IsDefined(options.Mode))
         {
-            failures.Add("MxGateway:Authentication:Mode must be a supported authentication mode.");
+            builder.Add("MxGateway:Authentication:Mode must be a supported authentication mode.");
             return;
         }
 
@@ -45,67 +40,67 @@ public sealed class GatewayOptionsValidator : IValidateOptions<GatewayOptions>
             AddIfBlank(
                 options.SqlitePath,
                 "MxGateway:Authentication:SqlitePath is required when API-key authentication is enabled.",
-                failures);
+                builder);
             AddIfInvalidPath(
                 options.SqlitePath,
                 "MxGateway:Authentication:SqlitePath must be a valid filesystem path.",
-                failures);
+                builder);
             AddIfBlank(
                 options.PepperSecretName,
                 "MxGateway:Authentication:PepperSecretName is required when API-key authentication is enabled.",
-                failures);
+                builder);
         }
     }
 
-    private static void ValidateLdap(LdapOptions options, List<string> failures)
+    private static void ValidateLdap(LdapOptions options, ValidationBuilder builder)
     {
         if (!options.Enabled)
         {
             return;
         }
 
-        AddIfBlank(options.Server, "MxGateway:Ldap:Server is required when LDAP login is enabled.", failures);
-        AddIfBlank(options.SearchBase, "MxGateway:Ldap:SearchBase is required when LDAP login is enabled.", failures);
+        AddIfBlank(options.Server, "MxGateway:Ldap:Server is required when LDAP login is enabled.", builder);
+        AddIfBlank(options.SearchBase, "MxGateway:Ldap:SearchBase is required when LDAP login is enabled.", builder);
         AddIfBlank(
             options.ServiceAccountDn,
             "MxGateway:Ldap:ServiceAccountDn is required when LDAP login is enabled.",
-            failures);
+            builder);
         AddIfBlank(
             options.ServiceAccountPassword,
             "MxGateway:Ldap:ServiceAccountPassword is required when LDAP login is enabled.",
-            failures);
+            builder);
         AddIfBlank(
             options.UserNameAttribute,
             "MxGateway:Ldap:UserNameAttribute is required when LDAP login is enabled.",
-            failures);
+            builder);
         AddIfBlank(
             options.DisplayNameAttribute,
             "MxGateway:Ldap:DisplayNameAttribute is required when LDAP login is enabled.",
-            failures);
+            builder);
         AddIfBlank(
             options.GroupAttribute,
             "MxGateway:Ldap:GroupAttribute is required when LDAP login is enabled.",
-            failures);
-        AddIfNotPositive(options.Port, "MxGateway:Ldap:Port must be greater than zero.", failures);
+            builder);
+        builder.Port(options.Port, "MxGateway:Ldap:Port");
 
-        if (!options.UseTls && !options.AllowInsecureLdap)
+        if (options.Transport == LdapTransport.None && !options.AllowInsecure)
         {
-            failures.Add("MxGateway:Ldap:AllowInsecureLdap must be true when UseTls is false.");
+            builder.Add("MxGateway:Ldap:AllowInsecure must be true when Transport is None (plaintext).");
         }
     }
 
-    private static void ValidateWorker(WorkerOptions options, List<string> failures)
+    private static void ValidateWorker(WorkerOptions options, ValidationBuilder builder)
     {
-        AddIfBlank(options.ExecutablePath, "MxGateway:Worker:ExecutablePath is required.", failures);
+        AddIfBlank(options.ExecutablePath, "MxGateway:Worker:ExecutablePath is required.", builder);
         AddIfInvalidPath(
             options.ExecutablePath,
             "MxGateway:Worker:ExecutablePath must be a valid filesystem path.",
-            failures);
+            builder);
 
         if (!string.IsNullOrWhiteSpace(options.ExecutablePath)
             && !string.Equals(Path.GetExtension(options.ExecutablePath), ".exe", StringComparison.OrdinalIgnoreCase))
         {
-            failures.Add("MxGateway:Worker:ExecutablePath must point to a .exe file.");
+            builder.Add("MxGateway:Worker:ExecutablePath must point to a .exe file.");
         }
 
         if (!string.IsNullOrWhiteSpace(options.WorkingDirectory))
@@ -113,94 +108,94 @@ public sealed class GatewayOptionsValidator : IValidateOptions<GatewayOptions>
             AddIfInvalidPath(
                 options.WorkingDirectory,
                 "MxGateway:Worker:WorkingDirectory must be a valid filesystem path.",
-                failures);
+                builder);
         }
 
         if (!Enum.IsDefined(options.RequiredArchitecture))
         {
-            failures.Add("MxGateway:Worker:RequiredArchitecture must be a supported worker architecture.");
+            builder.Add("MxGateway:Worker:RequiredArchitecture must be a supported worker architecture.");
         }
 
         AddIfNotPositive(
             options.StartupTimeoutSeconds,
             "MxGateway:Worker:StartupTimeoutSeconds must be greater than zero.",
-            failures);
+            builder);
         AddIfNotPositive(
             options.StartupProbeRetryAttempts,
             "MxGateway:Worker:StartupProbeRetryAttempts must be greater than zero.",
-            failures);
+            builder);
         AddIfNotPositive(
             options.StartupProbeRetryDelayMilliseconds,
             "MxGateway:Worker:StartupProbeRetryDelayMilliseconds must be greater than zero.",
-            failures);
+            builder);
         AddIfNotPositive(
             options.PipeConnectAttemptTimeoutMilliseconds,
             "MxGateway:Worker:PipeConnectAttemptTimeoutMilliseconds must be greater than zero.",
-            failures);
+            builder);
         AddIfNotPositive(
             options.ShutdownTimeoutSeconds,
             "MxGateway:Worker:ShutdownTimeoutSeconds must be greater than zero.",
-            failures);
+            builder);
         AddIfNotPositive(
             options.HeartbeatIntervalSeconds,
             "MxGateway:Worker:HeartbeatIntervalSeconds must be greater than zero.",
-            failures);
+            builder);
         AddIfNotPositive(
             options.HeartbeatGraceSeconds,
             "MxGateway:Worker:HeartbeatGraceSeconds must be greater than zero.",
-            failures);
+            builder);
 
         if (options.HeartbeatGraceSeconds < options.HeartbeatIntervalSeconds)
         {
-            failures.Add(
+            builder.Add(
                 "MxGateway:Worker:HeartbeatGraceSeconds must be greater than or equal to HeartbeatIntervalSeconds.");
         }
 
         if (options.MaxMessageBytes is < MinimumMaxMessageBytes or > MaximumMaxMessageBytes)
         {
-            failures.Add(
+            builder.Add(
                 $"MxGateway:Worker:MaxMessageBytes must be between {MinimumMaxMessageBytes} and {MaximumMaxMessageBytes}.");
         }
     }
 
-    private static void ValidateSessions(SessionOptions options, List<string> failures)
+    private static void ValidateSessions(SessionOptions options, ValidationBuilder builder)
     {
         AddIfNotPositive(
             options.DefaultCommandTimeoutSeconds,
             "MxGateway:Sessions:DefaultCommandTimeoutSeconds must be greater than zero.",
-            failures);
-        AddIfNotPositive(options.MaxSessions, "MxGateway:Sessions:MaxSessions must be greater than zero.", failures);
+            builder);
+        AddIfNotPositive(options.MaxSessions, "MxGateway:Sessions:MaxSessions must be greater than zero.", builder);
         AddIfNotPositive(
             options.MaxPendingCommandsPerSession,
             "MxGateway:Sessions:MaxPendingCommandsPerSession must be greater than zero.",
-            failures);
+            builder);
         AddIfNotPositive(
             options.DefaultLeaseSeconds,
             "MxGateway:Sessions:DefaultLeaseSeconds must be greater than zero.",
-            failures);
+            builder);
         AddIfNotPositive(
             options.LeaseSweepIntervalSeconds,
             "MxGateway:Sessions:LeaseSweepIntervalSeconds must be greater than zero.",
-            failures);
+            builder);
 
         if (options.AllowMultipleEventSubscribers)
         {
-            failures.Add(
+            builder.Add(
                 "MxGateway:Sessions:AllowMultipleEventSubscribers is not supported until event fan-out is implemented.");
         }
     }
 
-    private static void ValidateEvents(EventOptions options, List<string> failures)
+    private static void ValidateEvents(EventOptions options, ValidationBuilder builder)
     {
-        AddIfNotPositive(options.QueueCapacity, "MxGateway:Events:QueueCapacity must be greater than zero.", failures);
+        AddIfNotPositive(options.QueueCapacity, "MxGateway:Events:QueueCapacity must be greater than zero.", builder);
 
         if (!Enum.IsDefined(options.BackpressurePolicy))
         {
-            failures.Add("MxGateway:Events:BackpressurePolicy must be a supported backpressure policy.");
+            builder.Add("MxGateway:Events:BackpressurePolicy must be a supported backpressure policy.");
         }
     }
 
-    private static void ValidateDashboard(DashboardOptions options, List<string> failures)
+    private static void ValidateDashboard(DashboardOptions options, ValidationBuilder builder)
     {
         // GroupToRole shape is validated even when the dashboard is disabled so
         // misconfiguration surfaces at startup; emptiness is allowed, with the
@@ -211,13 +206,13 @@ public sealed class GatewayOptionsValidator : IValidateOptions<GatewayOptions>
         {
             if (string.IsNullOrWhiteSpace(entry.Key))
             {
-                failures.Add("MxGateway:Dashboard:GroupToRole keys (LDAP group names) must be non-blank.");
+                builder.Add("MxGateway:Dashboard:GroupToRole keys (LDAP group names) must be non-blank.");
             }
 
             if (!string.Equals(entry.Value, Dashboard.DashboardRoles.Admin, StringComparison.Ordinal)
                 && !string.Equals(entry.Value, Dashboard.DashboardRoles.Viewer, StringComparison.Ordinal))
             {
-                failures.Add(
+                builder.Add(
                     $"MxGateway:Dashboard:GroupToRole['{entry.Key}'] must be '{Dashboard.DashboardRoles.Admin}' or '{Dashboard.DashboardRoles.Viewer}'.");
             }
         }
@@ -225,18 +220,20 @@ public sealed class GatewayOptionsValidator : IValidateOptions<GatewayOptions>
         AddIfNotPositive(
             options.SnapshotIntervalMilliseconds,
             "MxGateway:Dashboard:SnapshotIntervalMilliseconds must be greater than zero.",
-            failures);
+            builder);
         AddIfNegative(
             options.RecentFaultLimit,
             "MxGateway:Dashboard:RecentFaultLimit must be greater than or equal to zero.",
-            failures);
+            builder);
         AddIfNegative(
             options.RecentSessionLimit,
             "MxGateway:Dashboard:RecentSessionLimit must be greater than or equal to zero.",
-            failures);
+            builder);
     }
 
-    private static void ValidateAlarms(AlarmsOptions options, List<string> failures)
+    private static readonly string[] ValidAlarmFallbackModes = ["Auto", "ForceAlarmManager", "ForceSubtag"];
+
+    private static void ValidateAlarms(AlarmsOptions options, ValidationBuilder builder)
     {
         if (!options.Enabled)
         {
@@ -250,58 +247,119 @@ public sealed class GatewayOptionsValidator : IValidateOptions<GatewayOptions>
         if (string.IsNullOrWhiteSpace(options.SubscriptionExpression)
             && string.IsNullOrWhiteSpace(options.DefaultArea))
         {
-            failures.Add(
+            builder.Add(
                 "MxGateway:Alarms requires either a non-blank SubscriptionExpression or a non-blank DefaultArea when Enabled is true.");
         }
 
         if (!string.IsNullOrWhiteSpace(options.SubscriptionExpression)
             && !options.SubscriptionExpression.StartsWith(@"\\", StringComparison.Ordinal))
         {
-            failures.Add(
+            builder.Add(
                 @"MxGateway:Alarms:SubscriptionExpression must start with '\\' (canonical \\<host>\Galaxy!<area> shape).");
         }
+
+        ValidateAlarmFallback(options.Fallback, builder);
+    }
+
+    private static void ValidateAlarmFallback(AlarmFallbackOptions fallback, ValidationBuilder builder)
+    {
+        // Validate Mode is one of the recognised values (case-insensitive).
+        bool modeValid = Array.Exists(
+            ValidAlarmFallbackModes,
+            m => string.Equals(m, fallback.Mode, StringComparison.OrdinalIgnoreCase));
+
+        if (!modeValid)
+        {
+            builder.Add(
+                $"MxGateway:Alarms:Fallback:Mode must be one of: {string.Join(", ", ValidAlarmFallbackModes)} (was '{fallback.Mode}').");
+        }
+
+        // ForceSubtag requires either Galaxy Repository discovery or an explicit IncludeAttributes list.
+        if (modeValid
+            && string.Equals(fallback.Mode, "ForceSubtag", StringComparison.OrdinalIgnoreCase)
+            && !fallback.Discovery.UseGalaxyRepository
+            && fallback.Discovery.IncludeAttributes.Length == 0)
+        {
+            builder.Add(
+                "MxGateway:Alarms:Fallback ForceSubtag requires Galaxy Repository discovery or a non-empty Discovery:IncludeAttributes list.");
+        }
+
+        // Floor validation: numeric thresholds must be at least 1.
+        AddIfNotPositive(
+            fallback.ConsecutiveFailureThreshold,
+            "MxGateway:Alarms:Fallback:ConsecutiveFailureThreshold must be greater than zero.",
+            builder);
+        AddIfNotPositive(
+            fallback.FailbackProbeIntervalSeconds,
+            "MxGateway:Alarms:Fallback:FailbackProbeIntervalSeconds must be greater than zero.",
+            builder);
+        AddIfNotPositive(
+            fallback.FailbackStableProbes,
+            "MxGateway:Alarms:Fallback:FailbackStableProbes must be greater than zero.",
+            builder);
+    }
+
+    private const int MinimumCertValidityYears = 1;
+    private const int MaximumCertValidityYears = 100;
+
+    private static void ValidateTls(TlsOptions options, ValidationBuilder builder)
+    {
+        if (options.ValidityYears is < MinimumCertValidityYears or > MaximumCertValidityYears)
+        {
+            builder.Add(
+                $"MxGateway:Tls:ValidityYears must be between {MinimumCertValidityYears} and {MaximumCertValidityYears}.");
+        }
+
+        // The default is non-blank, so this only catches an explicitly-blanked path.
+        AddIfBlank(
+            options.SelfSignedCertPath,
+            "MxGateway:Tls:SelfSignedCertPath must not be blank.",
+            builder);
+        AddIfInvalidPath(
+            options.SelfSignedCertPath,
+            "MxGateway:Tls:SelfSignedCertPath must be a valid filesystem path.",
+            builder);
+
+        foreach (string dns in options.AdditionalDnsNames)
+        {
+            if (string.IsNullOrWhiteSpace(dns))
+            {
+                builder.Add("MxGateway:Tls:AdditionalDnsNames entries must be non-blank.");
+            }
+        }
     }
 
-    private static void ValidateProtocol(ProtocolOptions options, List<string> failures)
+    private static void ValidateProtocol(ProtocolOptions options, ValidationBuilder builder)
     {
         if (options.WorkerProtocolVersion != GatewayContractInfo.WorkerProtocolVersion)
         {
-            failures.Add(
+            builder.Add(
                 $"MxGateway:Protocol:WorkerProtocolVersion must be {GatewayContractInfo.WorkerProtocolVersion}.");
         }
 
         if (options.MaxGrpcMessageBytes is < MinimumMaxMessageBytes or > MaximumMaxMessageBytes)
         {
-            failures.Add(
+            builder.Add(
                 $"MxGateway:Protocol:MaxGrpcMessageBytes must be between {MinimumMaxMessageBytes} and {MaximumMaxMessageBytes}.");
         }
     }
 
-    private static void AddIfBlank(string? value, string message, List<string> failures)
+    private static void AddIfBlank(string? value, string message, ValidationBuilder builder)
     {
-        if (string.IsNullOrWhiteSpace(value))
-        {
-            failures.Add(message);
-        }
+        builder.RequireThat(!string.IsNullOrWhiteSpace(value), message);
     }
 
-    private static void AddIfNotPositive(int value, string message, List<string> failures)
+    private static void AddIfNotPositive(int value, string message, ValidationBuilder builder)
     {
-        if (value <= 0)
-        {
-            failures.Add(message);
-        }
+        builder.RequireThat(value > 0, message);
     }
 
-    private static void AddIfNegative(int value, string message, List<string> failures)
+    private static void AddIfNegative(int value, string message, ValidationBuilder builder)
     {
-        if (value < 0)
-        {
-            failures.Add(message);
-        }
+        builder.RequireThat(value >= 0, message);
     }
 
-    private static void AddIfInvalidPath(string? value, string message, List<string> failures)
+    private static void AddIfInvalidPath(string? value, string message, ValidationBuilder builder)
     {
         if (string.IsNullOrWhiteSpace(value))
         {
@@ -314,15 +372,19 @@ public sealed class GatewayOptionsValidator : IValidateOptions<GatewayOptions>
         }
         catch (ArgumentException)
         {
-            failures.Add(message);
+            builder.Add(message);
         }
         catch (NotSupportedException)
         {
-            failures.Add(message);
+            builder.Add(message);
         }
         catch (PathTooLongException)
         {
-            failures.Add(message);
+            builder.Add(message);
+        }
+        catch (IOException)
+        {
+            builder.Add(message);
         }
     }
 }

src/ZB.MOM.WW.MxGateway.Server/Configuration/LdapOptions.cs

@@ -1,5 +1,32 @@
+using ZB.MOM.WW.Auth.Abstractions.Ldap;
+
 namespace ZB.MOM.WW.MxGateway.Server.Configuration;
 
+/// <summary>
+/// Gateway-side view of the <c>MxGateway:Ldap</c> section. This is a SHADOW of the
+/// shared <see cref="ZB.MOM.WW.Auth.Abstractions.Ldap.LdapOptions"/> type and is NOT
+/// used to perform LDAP authentication at runtime — runtime bind/search is done by the
+/// shared <c>ZB.MOM.WW.Auth.Ldap</c> provider, whose options are bound directly from the
+/// same <c>MxGateway:Ldap</c> section by <c>AddZbLdapAuth</c> (see
+/// <see cref="ZB.MOM.WW.MxGateway.Server.Dashboard.DashboardServiceCollectionExtensions"/>).
+/// <para>
+/// This shadow exists for three things only: (1) startup validation via
+/// <see cref="GatewayOptionsValidator"/>; (2) the redacted effective-config display
+/// (<see cref="EffectiveLdapConfiguration"/> / <see cref="GatewayConfigurationProvider"/>);
+/// and (3) it is the single home of the gateway's dev/default LDAP values, which the
+/// integration live-test helper copies onto the shared options.
+/// </para>
+/// <para>
+/// Review C2 — DRIFT WARNING: this class MUST stay field-compatible with the shared
+/// <see cref="ZB.MOM.WW.Auth.Abstractions.Ldap.LdapOptions"/> so the one config section
+/// binds cleanly onto both. The two are intentionally NOT merged because their defaults
+/// differ on purpose: this shadow ships dev-friendly defaults (plaintext localhost,
+/// <c>AllowInsecure=true</c>, populated <c>SearchBase</c>/<c>ServiceAccount*</c>), whereas
+/// the shared type is secure-by-default (<c>Transport=Ldaps</c>, <c>AllowInsecure=false</c>,
+/// empty DN fields). If you add/rename/remove a field on the shared type, mirror it here
+/// (and in the validator + effective-config) so the section keeps binding to both.
+/// </para>
+/// </summary>
 public sealed class LdapOptions
 {
     /// <summary>Gets a value indicating whether LDAP authentication is enabled.</summary>
@@ -11,17 +38,24 @@ public sealed class LdapOptions
     /// <summary>Gets the LDAP server port.</summary>
     public int Port { get; init; } = 3893;
 
-    /// <summary>Gets a value indicating whether TLS is required for the connection.</summary>
-    public bool UseTls { get; init; }
+    /// <summary>
+    /// Gets the transport/TLS mode for the LDAP connection. Replaces the former
+    /// boolean <c>UseTls</c> (true ≈ <see cref="LdapTransport.Ldaps"/>, false =
+    /// <see cref="LdapTransport.None"/>). <see cref="LdapTransport.StartTls"/> upgrades
+    /// a plaintext connection to TLS. Matches the shared
+    /// <see cref="ZB.MOM.WW.Auth.Abstractions.Ldap.LdapOptions.Transport"/> field so the
+    /// <c>MxGateway:Ldap</c> section binds straight onto the shared options.
+    /// </summary>
+    public LdapTransport Transport { get; init; } = LdapTransport.None;
 
-    /// <summary>Gets a value indicating whether insecure LDAP connections are allowed.</summary>
-    public bool AllowInsecureLdap { get; init; } = true;
+    /// <summary>Gets a value indicating whether insecure (plaintext) LDAP connections are allowed.</summary>
+    public bool AllowInsecure { get; init; } = true;
 
     /// <summary>Gets the LDAP search base distinguished name.</summary>
-    public string SearchBase { get; init; } = "dc=lmxopcua,dc=local";
+    public string SearchBase { get; init; } = "dc=zb,dc=local";
 
     /// <summary>Gets the service account distinguished name.</summary>
-    public string ServiceAccountDn { get; init; } = "cn=serviceaccount,dc=lmxopcua,dc=local";
+    public string ServiceAccountDn { get; init; } = "cn=serviceaccount,dc=zb,dc=local";
 
     /// <summary>Gets the service account password.</summary>
     public string ServiceAccountPassword { get; init; } = "serviceaccount123";

src/ZB.MOM.WW.MxGateway.Server/Configuration/TlsOptions.cs

@@ -0,0 +1,22 @@
+namespace ZB.MOM.WW.MxGateway.Server.Configuration;
+
+/// <summary>
+/// Options controlling the gateway's self-signed certificate auto-generation.
+/// Only consulted when a Kestrel HTTPS endpoint is configured without its own
+/// certificate; plaintext deployments never trigger generation.
+/// </summary>
+public sealed class TlsOptions
+{
+    /// <summary>Path to the persisted self-signed PFX. Reused across restarts.</summary>
+    public string SelfSignedCertPath { get; init; } =
+        @"C:\ProgramData\MxGateway\certs\gateway-selfsigned.pfx";
+
+    /// <summary>Lifetime in years of a freshly generated certificate.</summary>
+    public int ValidityYears { get; init; } = 10;
+
+    /// <summary>Extra DNS SANs to embed (e.g. a load-balancer name).</summary>
+    public IReadOnlyList<string> AdditionalDnsNames { get; init; } = [];
+
+    /// <summary>Regenerate the persisted certificate when it has expired.</summary>
+    public bool RegenerateIfExpired { get; init; } = true;
+}

src/ZB.MOM.WW.MxGateway.Server/Dashboard/Components/App.razor

@@ -5,14 +5,14 @@
     <meta name="viewport" content="width=device-width, initial-scale=1" />
     <base href="/" />
     <link rel="stylesheet" href="/lib/bootstrap/css/bootstrap.min.css" />
-    <link rel="stylesheet" href="/css/theme.css" />
+    <ThemeHead />
     <link rel="stylesheet" href="/css/site.css" />
     <HeadOutlet @rendermode="InteractiveServer" />
 </head>
 <body class="dashboard-body">
     <Routes @rendermode="InteractiveServer" />
     <script src="/lib/bootstrap/js/bootstrap.bundle.min.js"></script>
-    <script src="/js/nav-state.js"></script>
+    <ThemeScripts />
     <script src="/_framework/blazor.web.js"></script>
 </body>
 </html>

src/ZB.MOM.WW.MxGateway.Server/Dashboard/Components/Layout/LoginLayout.razor

@@ -0,0 +1,6 @@
+@inherits LayoutComponentBase
+
+@* Minimal layout for the login page: no side rail, no brand block. The page
+   renders its own centred card via the shared kit's <LoginCard>. Mirrors
+   OtOpcUa AdminUI's LoginLayout. *@
+@Body

src/ZB.MOM.WW.MxGateway.Server/Dashboard/Components/Layout/MainLayout.razor

@@ -1,210 +1,40 @@
-@using System.Linq
-@using Microsoft.AspNetCore.Components.Routing
-@using Microsoft.JSInterop
-@implements IDisposable
 @inherits LayoutComponentBase
-@inject NavigationManager Navigation
-@inject IJSRuntime JS
 
-<div class="d-flex flex-column flex-lg-row" style="min-height: 100vh;">
-    @* Hamburger toggle: visible only on viewports <lg. Bootstrap collapse JS
-       lives in bootstrap.bundle.min.js (loaded in App.razor). *@
-    <button class="btn btn-outline-secondary btn-sm d-lg-none m-2 align-self-start"
-            type="button"
-            data-bs-toggle="collapse"
-            data-bs-target="#sidebar-collapse"
-            aria-controls="sidebar-collapse"
-            aria-expanded="false"
-            aria-label="Toggle navigation">
-        &#9776;
-    </button>
-
-    <div class="collapse d-lg-block" id="sidebar-collapse">
-        <nav class="sidebar d-flex flex-column">
-            <a class="brand" href="/"><span class="mark">&#9646;</span> MXAccess Gateway</a>
-
-            <div style="overflow-y:auto; flex:1 1 auto; min-height:0;">
-                <ul class="nav flex-column">
-                    <li class="nav-item">
-                        <NavLink class="nav-link" href="/" Match="NavLinkMatch.All">Dashboard</NavLink>
-                    </li>
-
-                    <NavSection Title="Runtime"
-                                Expanded="@_expanded.Contains("runtime")"
-                                OnToggle="@(() => ToggleAsync("runtime"))">
-                        <li class="nav-item">
-                            <NavLink class="nav-link" href="/sessions" Match="NavLinkMatch.Prefix">Sessions</NavLink>
-                        </li>
-                        <li class="nav-item">
-                            <NavLink class="nav-link" href="/workers" Match="NavLinkMatch.Prefix">Workers</NavLink>
-                        </li>
-                        <li class="nav-item">
-                            <NavLink class="nav-link" href="/events" Match="NavLinkMatch.Prefix">Events</NavLink>
-                        </li>
-                        <li class="nav-item">
-                            <NavLink class="nav-link" href="/alarms" Match="NavLinkMatch.Prefix">Alarms</NavLink>
-                        </li>
-                    </NavSection>
-
-                    <NavSection Title="Galaxy"
-                                Expanded="@_expanded.Contains("galaxy")"
-                                OnToggle="@(() => ToggleAsync("galaxy"))">
-                        <li class="nav-item">
-                            <NavLink class="nav-link" href="/galaxy" Match="NavLinkMatch.Prefix">Repository</NavLink>
-                        </li>
-                        <li class="nav-item">
-                            <NavLink class="nav-link" href="/browse" Match="NavLinkMatch.Prefix">Browse</NavLink>
-                        </li>
-                    </NavSection>
-
-                    <NavSection Title="Admin"
-                                Expanded="@_expanded.Contains("admin")"
-                                OnToggle="@(() => ToggleAsync("admin"))">
-                        <li class="nav-item">
-                            <NavLink class="nav-link" href="/apikeys" Match="NavLinkMatch.Prefix">API Keys</NavLink>
-                        </li>
-                        <li class="nav-item">
-                            <NavLink class="nav-link" href="/settings" Match="NavLinkMatch.Prefix">Settings</NavLink>
-                        </li>
-                    </NavSection>
-                </ul>
-            </div>
-
-            <AuthorizeView>
-                <Authorized Context="authState">
-                    <div class="border-top px-3 py-2">
-                        <div class="d-flex justify-content-between align-items-center">
-                            <span class="text-body-secondary small">@authState.User.Identity?.Name</span>
-                            <form method="post" action="/logout" data-enhance="false">
-                                <AntiforgeryToken />
-                                <button type="submit" class="btn btn-outline-secondary btn-sm py-0 px-2">Sign Out</button>
-                            </form>
-                        </div>
-                    </div>
-                </Authorized>
-                <NotAuthorized>
-                    <div class="border-top px-3 py-2">
-                        <a href="/login" class="btn btn-outline-secondary btn-sm py-0 px-2 w-100">Sign In</a>
-                    </div>
-                </NotAuthorized>
-            </AuthorizeView>
-        </nav>
-    </div>
-
-    <main class="page flex-grow-1">
-        @Body
-    </main>
-</div>
-
-@code {
-    // Sections whose collapsed/expanded state we persist. Acts as the allow-list
-    // when parsing the cookie so stale or attacker-supplied ids are ignored.
-    private static readonly string[] SectionIds = { "runtime", "galaxy", "admin" };
-
-    // The currently-expanded sections. Populated from the cookie on first
-    // render; mutated by ToggleAsync and by navigating into a section.
-    private readonly HashSet<string> _expanded = new(StringComparer.Ordinal);
-
-    protected override void OnInitialized()
-    {
-        Navigation.LocationChanged += OnLocationChanged;
-    }
-
-    protected override async Task OnAfterRenderAsync(bool firstRender)
-    {
-        if (!firstRender)
-        {
-            return;
-        }
-
-        // Hydrate from the cookie. Until this completes the sidebar paints
-        // collapsed, matching the CentralUI behaviour.
-        string saved;
-        try
-        {
-            saved = await JS.InvokeAsync<string>("navState.get") ?? string.Empty;
-        }
-        catch (JSDisconnectedException)
-        {
-            return;
-        }
-
-        foreach (var id in saved.Split(
-            ',', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries))
-        {
-            if (Array.IndexOf(SectionIds, id) >= 0)
-            {
-                _expanded.Add(id);
-            }
-        }
-
-        // The section of the page we loaded on is always expanded.
-        if (EnsureCurrentSectionExpanded())
-        {
-            await PersistAsync();
-        }
-
-        StateHasChanged();
-    }
-
-    private void OnLocationChanged(object? sender, LocationChangedEventArgs e)
-    {
-        if (EnsureCurrentSectionExpanded())
-        {
-            _ = PersistAsync();
-            _ = InvokeAsync(StateHasChanged);
-        }
-    }
-
-    private async Task ToggleAsync(string id)
-    {
-        if (!_expanded.Remove(id))
-        {
-            _expanded.Add(id);
-        }
-
-        await PersistAsync();
-    }
-
-    // Adds the current page's section to _expanded; returns true if it changed.
-    private bool EnsureCurrentSectionExpanded()
-    {
-        var section = CurrentSection();
-        return section is not null && _expanded.Add(section);
-    }
-
-    // Maps the current URL's first path segment to a section id, or null for
-    // sectionless pages (Dashboard, Login).
-    private string? CurrentSection()
-    {
-        var relative = Navigation.ToBaseRelativePath(Navigation.Uri);
-        var firstSegment = relative.Split('?', '#')[0]
-            .Split('/', StringSplitOptions.RemoveEmptyEntries)
-            .FirstOrDefault();
-
-        return firstSegment switch
-        {
-            "sessions" or "workers" or "events" or "alarms" => "runtime",
-            "galaxy" or "browse" => "galaxy",
-            "apikeys" or "settings" => "admin",
-            _ => null,
-        };
-    }
-
-    private async Task PersistAsync()
-    {
-        try
-        {
-            await JS.InvokeVoidAsync("navState.set", string.Join(',', _expanded));
-        }
-        catch (JSDisconnectedException)
-        {
-            // The circuit is gone — nothing to persist to.
-        }
-    }
-
-    public void Dispose()
-    {
-        Navigation.LocationChanged -= OnLocationChanged;
-    }
-}
+@* Thin layout: delegates the side-rail chassis (hamburger, brand, responsive
+   collapse) to the shared ZB.MOM.WW.Theme <ThemeShell>. The nav is reproduced
+   with the kit's NavRailSection / NavRailItem; section expand-state persistence
+   is owned by the kit's <details> + ThemeScripts (no JS interop here). *@
+<ThemeShell Product="MXAccess Gateway" Accent="#2f5fd0">
+    <Nav>
+        <NavRailItem Href="/" Text="Dashboard" Match="NavLinkMatch.All" />
+        <NavRailSection Title="Runtime" Key="runtime">
+            <NavRailItem Href="/sessions" Text="Sessions" />
+            <NavRailItem Href="/workers" Text="Workers" />
+            <NavRailItem Href="/events" Text="Events" />
+            <NavRailItem Href="/alarms" Text="Alarms" />
+        </NavRailSection>
+        <NavRailSection Title="Galaxy" Key="galaxy">
+            <NavRailItem Href="/galaxy" Text="Repository" />
+            <NavRailItem Href="/browse" Text="Browse" />
+        </NavRailSection>
+        <NavRailSection Title="Admin" Key="admin">
+            <NavRailItem Href="/apikeys" Text="API Keys" />
+            <NavRailItem Href="/settings" Text="Settings" />
+        </NavRailSection>
+    </Nav>
+    <RailFooter>
+        <AuthorizeView>
+            <Authorized Context="authState">
+                <span class="rail-user">@authState.User.Identity?.Name</span>
+                <form method="post" action="/logout" data-enhance="false">
+                    <AntiforgeryToken />
+                    <button class="rail-btn" type="submit">Sign Out</button>
+                </form>
+            </Authorized>
+            <NotAuthorized>
+                <a class="rail-btn" href="/login">Sign In</a>
+            </NotAuthorized>
+        </AuthorizeView>
+    </RailFooter>
+    <ChildContent>@Body</ChildContent>
+</ThemeShell>

src/ZB.MOM.WW.MxGateway.Server/Dashboard/Components/Layout/NavSection.razor

@@ -1,35 +0,0 @@
-@* A collapsible sidebar nav section. The header is a full-width button that
-   toggles ChildContent visibility. Pattern lifted from ScadaLink CentralUI
-   (Components/Layout/NavSection.razor) — see [[project-deployed-service]]. *@
-
-<li class="nav-item">
-    <button type="button"
-            class="nav-section-toggle"
-            @onclick="OnToggle"
-            aria-expanded="@(Expanded ? "true" : "false")">
-        <span class="chevron" aria-hidden="true">@(Expanded ? "▾" : "▸")</span>
-        <span>@Title</span>
-    </button>
-</li>
-@if (Expanded)
-{
-    @ChildContent
-}
-
-@code {
-    /// <summary>Section label shown in the header (e.g. "Runtime").</summary>
-    [Parameter, EditorRequired]
-    public string Title { get; set; } = string.Empty;
-
-    /// <summary>Whether the section is expanded — its items rendered.</summary>
-    [Parameter]
-    public bool Expanded { get; set; }
-
-    /// <summary>Raised when the header button is clicked.</summary>
-    [Parameter]
-    public EventCallback OnToggle { get; set; }
-
-    /// <summary>The section's nav items, rendered only while expanded.</summary>
-    [Parameter]
-    public RenderFragment? ChildContent { get; set; }
-}

src/ZB.MOM.WW.MxGateway.Server/Dashboard/Components/Pages/Login.razor

@@ -0,0 +1,33 @@
+@page "/login"
+@layout LoginLayout
+@using Microsoft.AspNetCore.Authorization
+@* Login MUST stay anonymously reachable — [AllowAnonymous] overrides the
+   RequireAuthorization(ViewerPolicy) that MapRazorComponents<App>() applies, so the
+   cookie scheme's LoginPath="/login" redirect lands here for unauthenticated users.
+
+   The card is the shared kit's <LoginCard>: it renders a NATIVE static
+   <form method="post" action="/auth/login"> (username/password + hidden returnUrl). A native
+   form submit is not a Blazor event, so it reaches the minimal-API POST /auth/login endpoint
+   regardless of this app's InteractiveServer render mode. <AntiforgeryToken/> supplies the
+   token that PostLoginAsync's antiforgery.ValidateRequestAsync checks.
+
+   NOTE: the POST target is /auth/login, NOT /login. This @page lives at "/login" and the
+   Razor Components endpoint matches ALL methods, so a POST to /login collided with the
+   minimal-API MapPost("/login") and threw AmbiguousMatchException (HTTP 500). Posting to a
+   distinct /auth/login path (mirroring ScadaBridge) keeps the GET page and POST handler from
+   sharing a route. *@
+@attribute [AllowAnonymous]
+
+<LoginCard Product="MXAccess Gateway" Action="/auth/login" ReturnUrl="@ReturnUrl" Error="@Error">
+    <AntiforgeryToken />
+</LoginCard>
+
+@code {
+    /// <summary>Original protected URL the operator was bounced from; round-tripped to POST /login.</summary>
+    [SupplyParameterFromQuery(Name = "returnUrl")]
+    private string? ReturnUrl { get; set; }
+
+    /// <summary>Failure message surfaced by POST /login after a failed authentication.</summary>
+    [SupplyParameterFromQuery(Name = "error")]
+    private string? Error { get; set; }
+}

src/ZB.MOM.WW.MxGateway.Server/Dashboard/Components/Pages/SettingsPage.razor

@@ -26,7 +26,7 @@ else
                     <tr><th scope="row">Run migrations</th><td>@Snapshot.Configuration.Authentication.RunMigrationsOnStartup</td></tr>
                     <tr><th scope="row">LDAP enabled</th><td>@Snapshot.Configuration.Ldap.Enabled</td></tr>
                     <tr><th scope="row">LDAP server</th><td>@Snapshot.Configuration.Ldap.Server:@Snapshot.Configuration.Ldap.Port</td></tr>
-                    <tr><th scope="row">LDAP TLS</th><td>@Snapshot.Configuration.Ldap.UseTls</td></tr>
+                    <tr><th scope="row">LDAP transport</th><td>@Snapshot.Configuration.Ldap.Transport</td></tr>
                     <tr><th scope="row">LDAP search base</th><td><code>@Snapshot.Configuration.Ldap.SearchBase</code></td></tr>
                     <tr><th scope="row">LDAP service account</th><td><code>@Snapshot.Configuration.Ldap.ServiceAccountDn</code></td></tr>
                     <tr><th scope="row">LDAP service password</th><td>@Snapshot.Configuration.Ldap.ServiceAccountPassword</td></tr>

src/ZB.MOM.WW.MxGateway.Server/Dashboard/Components/Shared/StatusBadge.razor

@@ -1,16 +1,16 @@
-<span class="chip @CssClass">@Text</span>
-
+@* Thin adapter: maps MxGateway runtime state text → kit StatusPill state.
+   The bespoke .chip rendering now lives in the kit; only the app's domain
+   text→state vocabulary remains here. Call sites (<StatusBadge Text="..."/>) unchanged. *@
+<StatusPill State="MapState(Text)">@Text</StatusPill>
 @code {
-    [Parameter]
-    public string? Text { get; set; }
+    [Parameter] public string? Text { get; set; }
 
-    private string CssClass => Text switch
+    private static StatusState MapState(string? text) => text switch
     {
-        "Ready" or "Healthy" or "Active" => "chip-ok",
-        "Creating" or "StartingWorker" or "WaitingForPipe" or "InitializingWorker" or "Closing" => "chip-warn",
-        "Stale" or "Degraded" => "chip-warn",
-        "Faulted" or "Unavailable" => "chip-bad",
-        "Closed" or "Revoked" or "Unknown" => "chip-idle",
-        _ => "chip-idle"
+        "Ready" or "Healthy" or "Active" => StatusState.Ok,
+        "Creating" or "StartingWorker" or "WaitingForPipe" or "InitializingWorker" or "Closing"
+            or "Stale" or "Degraded" => StatusState.Warn,
+        "Faulted" or "Unavailable" => StatusState.Bad,
+        _ => StatusState.Idle,
     };
 }

src/ZB.MOM.WW.MxGateway.Server/Dashboard/Components/_Imports.razor

@@ -10,4 +10,5 @@
 @using ZB.MOM.WW.MxGateway.Server.Dashboard.Components.Shared
 @using ZB.MOM.WW.MxGateway.Server.Security.Authorization
 @using ZB.MOM.WW.MxGateway.Server.Workers
+@using ZB.MOM.WW.Theme
 @using static Microsoft.AspNetCore.Components.Web.RenderMode

src/ZB.MOM.WW.MxGateway.Server/Dashboard/DashboardApiKeyManagementService.cs

@@ -1,5 +1,10 @@
 using System.Security.Claims;
+using System.Text.Json;
 using Microsoft.Data.Sqlite;
+using ZB.MOM.WW.Audit;
+using ZB.MOM.WW.Auth.Abstractions.ApiKeys;
+using ZB.MOM.WW.Auth.ApiKeys.Admin;
+using ZB.MOM.WW.MxGateway.Server.Security.Audit;
 using ZB.MOM.WW.MxGateway.Server.Security.Authentication;
 using ZB.MOM.WW.MxGateway.Server.Security.Authorization;
 
@@ -7,12 +12,13 @@ namespace ZB.MOM.WW.MxGateway.Server.Dashboard;
 
 public sealed class DashboardApiKeyManagementService(
     DashboardApiKeyAuthorization authorization,
+    ApiKeyAdminCommands adminCommands,
     IApiKeyAdminStore adminStore,
-    IApiKeyAuditStore auditStore,
-    IApiKeySecretHasher hasher,
+    IAuditWriter auditWriter,
     IHttpContextAccessor httpContextAccessor) : IDashboardApiKeyManagementService
 {
     private const string UnauthorizedMessage = "Sign in with an authorized LDAP account to manage API keys.";
+    private const string PepperUnavailableMarker = "pepper unavailable";
 
     /// <summary>Determines whether the user can manage API keys.</summary>
     /// <param name="user">The authenticated user principal.</param>
@@ -42,28 +48,31 @@ public sealed class DashboardApiKeyManagementService(
         }
 
         string keyId = request.KeyId.Trim();
-        string secret = ApiKeySecretGenerator.Generate();
-        string apiKey = FormatApiKey(keyId, secret);
 
         try
         {
-            await adminStore.CreateAsync(
-                    new ApiKeyCreateRequest(
-                        KeyId: keyId,
-                        KeyPrefix: $"mxgw_{keyId}",
-                        SecretHash: hasher.HashSecret(secret),
-                        DisplayName: request.DisplayName.Trim(),
-                        Scopes: request.Scopes,
-                        Constraints: request.Constraints,
-                        CreatedUtc: DateTimeOffset.UtcNow),
+            // The shared command set generates the secret, hashes it with the pepper, persists the
+            // record and assembles the mxgw_<id>_<secret> token (shown once). It also appends its own
+            // "create-key" audit entry (now canonicalized through the IApiKeyAuditStore->IAuditWriter
+            // adapter); the dashboard layers a richer "dashboard-create-key" canonical AuditEvent
+            // (Target + CorrelationId + remote address) on top via IAuditWriter to preserve the
+            // dashboard audit vocabulary — both rows land in the canonical audit_event store.
+            CreateKeyResult created = await adminCommands.CreateKeyAsync(
+                    keyId,
+                    request.DisplayName.Trim(),
+                    request.Scopes,
+                    ApiKeyConstraintSerializer.Serialize(request.Constraints),
+                    RemoteAddress(),
                     cancellationToken)
                 .ConfigureAwait(false);
 
-            await AppendAuditAsync(keyId, "dashboard-create-key", null, cancellationToken).ConfigureAwait(false);
+            await WriteDashboardAuditAsync(user, keyId, "dashboard-create-key", null, cancellationToken).ConfigureAwait(false);
 
-            return DashboardApiKeyManagementResult.Success("API key created. Copy the key now; it will not be shown again.", apiKey);
+            return DashboardApiKeyManagementResult.Success(
+                "API key created. Copy the key now; it will not be shown again.",
+                created.Token);
         }
-        catch (ApiKeyPepperUnavailableException)
+        catch (InvalidOperationException exception) when (IsPepperUnavailable(exception))
         {
             return DashboardApiKeyManagementResult.Fail("API key pepper is not configured.");
         }
@@ -94,18 +103,19 @@ public sealed class DashboardApiKeyManagementService(
         }
 
         string normalizedKeyId = keyId.Trim();
-        bool revoked = await adminStore
-            .RevokeAsync(normalizedKeyId, DateTimeOffset.UtcNow, cancellationToken)
+        KeyActionResult result = await adminCommands
+            .RevokeKeyAsync(normalizedKeyId, RemoteAddress(), cancellationToken)
             .ConfigureAwait(false);
 
-        await AppendAuditAsync(
+        await WriteDashboardAuditAsync(
+                user,
                 normalizedKeyId,
                 "dashboard-revoke-key",
-                revoked ? "revoked" : "not-found-or-already-revoked",
+                result.Succeeded ? "revoked" : "not-found-or-already-revoked",
                 cancellationToken)
             .ConfigureAwait(false);
 
-        return revoked
+        return result.Succeeded
             ? DashboardApiKeyManagementResult.Success("API key revoked.")
             : DashboardApiKeyManagementResult.Fail("API key was not found or is already revoked.");
     }
@@ -131,27 +141,30 @@ public sealed class DashboardApiKeyManagementService(
         }
 
         string normalizedKeyId = keyId.Trim();
-        string secret = ApiKeySecretGenerator.Generate();
-        string apiKey = FormatApiKey(normalizedKeyId, secret);
 
         try
         {
-            bool rotated = await adminStore
-                .RotateAsync(normalizedKeyId, hasher.HashSecret(secret), DateTimeOffset.UtcNow, cancellationToken)
+            CreateKeyResult rotated = await adminCommands
+                .RotateKeyAsync(normalizedKeyId, RemoteAddress(), cancellationToken)
                 .ConfigureAwait(false);
 
-            await AppendAuditAsync(
+            bool succeeded = rotated.Token is not null;
+
+            await WriteDashboardAuditAsync(
+                    user,
                     normalizedKeyId,
                     "dashboard-rotate-key",
-                    rotated ? "rotated" : "not-found",
+                    succeeded ? "rotated" : "not-found",
                     cancellationToken)
                 .ConfigureAwait(false);
 
-            return rotated
-                ? DashboardApiKeyManagementResult.Success("API key rotated. Copy the key now; it will not be shown again.", apiKey)
+            return succeeded
+                ? DashboardApiKeyManagementResult.Success(
+                    "API key rotated. Copy the key now; it will not be shown again.",
+                    rotated.Token)
                 : DashboardApiKeyManagementResult.Fail("API key was not found.");
         }
-        catch (ApiKeyPepperUnavailableException)
+        catch (InvalidOperationException exception) when (IsPepperUnavailable(exception))
         {
             return DashboardApiKeyManagementResult.Fail("API key pepper is not configured.");
         }
@@ -182,7 +195,8 @@ public sealed class DashboardApiKeyManagementService(
             .DeleteAsync(normalizedKeyId, cancellationToken)
             .ConfigureAwait(false);
 
-        await AppendAuditAsync(
+        await WriteDashboardAuditAsync(
+                user,
                 normalizedKeyId,
                 "dashboard-delete-key",
                 deleted ? "deleted" : "not-found-or-active",
@@ -194,22 +208,92 @@ public sealed class DashboardApiKeyManagementService(
             : DashboardApiKeyManagementResult.Fail("API key was not found, or is still active. Revoke it before deleting.");
     }
 
-    private async Task AppendAuditAsync(
-        string? keyId,
-        string eventType,
-        string? details,
+    private string? RemoteAddress() =>
+        httpContextAccessor.HttpContext?.Connection.RemoteIpAddress?.ToString();
+
+    /// <summary>
+    /// Resolves the operator's username from the authenticated dashboard principal.
+    /// </summary>
+    /// <remarks>
+    /// The passed <paramref name="user"/> is preferred over the ambient HTTP context because it
+    /// is already in scope at every call site (the callers gate on <see cref="CanManage"/> using
+    /// it) and is unambiguous. Falls back to <see cref="IAuditActorAccessor.CurrentActor"/> for
+    /// defensive coverage, then to <c>"unknown"</c> when neither is available.
+    /// </remarks>
+    private static string ResolveOperatorActor(ClaimsPrincipal user)
+    {
+        // ZbClaimTypes.Username = "zb:username" — the canonical LDAP login name.
+        string? username = user.FindFirstValue(ZB.MOM.WW.Auth.AspNetCore.ZbClaimTypes.Username);
+        if (!string.IsNullOrWhiteSpace(username))
+        {
+            return username;
+        }
+
+        // Framework fallback: Identity.Name is driven by the nameClaimType on the ClaimsIdentity
+        // (set to ZbClaimTypes.Name = ClaimTypes.Name by DashboardAuthenticator → display name).
+        string? identityName = user.Identity?.Name;
+        if (!string.IsNullOrWhiteSpace(identityName))
+        {
+            return identityName;
+        }
+
+        return "unknown";
+    }
+
+    /// <summary>
+    /// Emits the dashboard's own canonical <see cref="AuditEvent"/> for a <c>dashboard-*</c> op
+    /// directly through the best-effort <see cref="IAuditWriter"/> (Task 2.3 #6). This is in
+    /// addition to the <c>create/revoke/rotate-key</c> event that <see cref="ApiKeyAdminCommands"/>
+    /// emits via the canonical-forwarding <c>IApiKeyAuditStore</c> adapter — the doubled-audit
+    /// behaviour is preserved, both rows now land in the canonical <c>audit_event</c> store.
+    /// </summary>
+    /// <remarks>
+    /// Phase 3 (Actor = operator principal): <c>Actor</c> is the LDAP operator who performed the
+    /// action (resolved from the <paramref name="user"/> principal); <c>Target</c> is the managed
+    /// API key id. This fixes the pre-Phase-3 semantic gap where both fields held the keyId.
+    /// </remarks>
+    private async Task WriteDashboardAuditAsync(
+        ClaimsPrincipal user,
+        string keyId,
+        string action,
+        string? detail,
         CancellationToken cancellationToken)
     {
-        await auditStore.AppendAsync(
-                new ApiKeyAuditEntry(
-                    KeyId: keyId,
-                    EventType: eventType,
-                    RemoteAddress: httpContextAccessor.HttpContext?.Connection.RemoteIpAddress?.ToString(),
-                    Details: details),
-                cancellationToken)
-            .ConfigureAwait(false);
+        AuditEvent auditEvent = new()
+        {
+            EventId = Guid.NewGuid(),
+            OccurredAtUtc = DateTimeOffset.UtcNow,
+            Actor = ResolveOperatorActor(user),
+            Action = action,
+            Outcome = AuditOutcome.Success,
+            Category = CanonicalForwardingApiKeyAuditStore.ApiKeyCategory,
+            Target = keyId,
+            SourceNode = RemoteAddress(),
+            CorrelationId = ParseCorrelationId(),
+            DetailsJson = WrapDetail(detail),
+        };
+
+        await auditWriter.WriteAsync(auditEvent, cancellationToken).ConfigureAwait(false);
     }
 
+    /// <summary>
+    /// Derives a correlation id from the ASP.NET Core request trace identifier when it is a
+    /// well-formed GUID; otherwise null (the default <c>HttpContext.TraceIdentifier</c> is the
+    /// connection:request form, not a GUID, so it correlates to null rather than fabricating one).
+    /// </summary>
+    private Guid? ParseCorrelationId() =>
+        Guid.TryParse(httpContextAccessor.HttpContext?.TraceIdentifier, out Guid correlationId)
+            ? correlationId
+            : null;
+
+    private static string? WrapDetail(string? detail) =>
+        detail is null
+            ? null
+            : JsonSerializer.Serialize(new Dictionary<string, string> { ["detail"] = detail });
+
+    private static bool IsPepperUnavailable(InvalidOperationException exception) =>
+        exception.Message.Contains(PepperUnavailableMarker, StringComparison.OrdinalIgnoreCase);
+
     private static string? ValidateCreateRequest(DashboardApiKeyManagementRequest request)
     {
         string? keyIdValidation = ValidateKeyId(request.KeyId);
@@ -248,9 +332,4 @@ public sealed class DashboardApiKeyManagementService(
             ? null
             : "API key id may contain only letters, numbers, periods, and hyphens.";
     }
-
-    private static string FormatApiKey(string keyId, string secret)
-    {
-        return $"mxgw_{keyId}_{secret}";
-    }
 }

src/ZB.MOM.WW.MxGateway.Server/Dashboard/DashboardAuthenticator.cs

@@ -1,14 +1,26 @@
 using System.Security.Claims;
-using System.Text;
-using Microsoft.Extensions.Options;
-using ZB.MOM.WW.MxGateway.Server.Configuration;
-using ZB.MOM.WW.MxGateway.Server.Security.Authorization;
-using Novell.Directory.Ldap;
+using ZB.MOM.WW.Auth.Abstractions.Ldap;
+using ZB.MOM.WW.Auth.Abstractions.Roles;
+using ZB.MOM.WW.Auth.AspNetCore;
 
 namespace ZB.MOM.WW.MxGateway.Server.Dashboard;
 
+/// <summary>
+/// Authenticates interactive dashboard logins against LDAP. The bind/search
+/// mechanics are delegated to the shared <see cref="ILdapAuthService"/>
+/// (<c>ZB.MOM.WW.Auth.Ldap</c>), which performs bind-then-search, fails closed,
+/// and never throws — returning the user's display name and LDAP groups on
+/// success. This class keeps the dashboard-specific policy: groups are resolved
+/// to dashboard roles via <see cref="IGroupRoleMapper{TRole}"/>, a login with no
+/// matching role is denied, and the resulting <see cref="ClaimsPrincipal"/> is
+/// shaped exactly as before (see <see cref="CreatePrincipal"/>).
+/// </summary>
+/// <param name="ldapAuthService">Shared LDAP bind-then-search provider.</param>
+/// <param name="roleMapper">Maps LDAP groups to dashboard roles (Task 1.1 seam).</param>
+/// <param name="logger">Logger for diagnostic, credential-free login outcomes.</param>
 public sealed class DashboardAuthenticator(
-    IOptions<GatewayOptions> options,
+    ILdapAuthService ldapAuthService,
+    IGroupRoleMapper<string> roleMapper,
     ILogger<DashboardAuthenticator> logger) : IDashboardAuthenticator
 {
     private const string GenericFailureMessage = "The username or password is invalid, or the user is not authorized.";
@@ -19,240 +31,72 @@ public sealed class DashboardAuthenticator(
         string? password,
         CancellationToken cancellationToken)
     {
-        LdapOptions ldapOptions = options.Value.Ldap;
-        DashboardOptions dashboardOptions = options.Value.Dashboard;
-        if (!ldapOptions.Enabled
-            || string.IsNullOrWhiteSpace(username)
-            || string.IsNullOrWhiteSpace(password))
-        {
-            return DashboardAuthenticationResult.Fail(GenericFailureMessage);
-        }
-
-        if (!ldapOptions.UseTls && !ldapOptions.AllowInsecureLdap)
+        if (string.IsNullOrWhiteSpace(username) || string.IsNullOrWhiteSpace(password))
         {
             return DashboardAuthenticationResult.Fail(GenericFailureMessage);
         }
 
         string normalizedUsername = username.Trim();
 
-        try
+        // The shared service owns connect/bind/search and the fail-closed contract:
+        // it returns Fail(Disabled) when LDAP is off, enforces TLS-or-AllowInsecure via
+        // its startup validator, and never throws. We only translate its outcome into a
+        // dashboard principal here.
+        LdapAuthResult ldapResult = await ldapAuthService
+            .AuthenticateAsync(normalizedUsername, password, cancellationToken)
+            .ConfigureAwait(false);
+
+        if (!ldapResult.Succeeded)
         {
-            using LdapConnection connection = new();
-            connection.SecureSocketLayer = ldapOptions.UseTls;
-
-            await Task.Run(
-                    () => connection.Connect(ldapOptions.Server, ldapOptions.Port),
-                    cancellationToken)
-                .ConfigureAwait(false);
-
-            await BindServiceAccountAsync(connection, ldapOptions, cancellationToken).ConfigureAwait(false);
-            LdapEntry? candidate = await SearchUserAsync(
-                    connection,
-                    ldapOptions,
-                    normalizedUsername,
-                    cancellationToken)
-                .ConfigureAwait(false);
-
-            if (candidate is null)
-            {
-                return DashboardAuthenticationResult.Fail(GenericFailureMessage);
-            }
-
-            await Task.Run(
-                    () => connection.Bind(candidate.Dn, password),
-                    cancellationToken)
-                .ConfigureAwait(false);
-
-            await BindServiceAccountAsync(connection, ldapOptions, cancellationToken).ConfigureAwait(false);
-            LdapEntry? authenticatedEntry = await SearchUserAsync(
-                    connection,
-                    ldapOptions,
-                    normalizedUsername,
-                    cancellationToken)
-                .ConfigureAwait(false);
-
-            if (authenticatedEntry is null)
-            {
-                return DashboardAuthenticationResult.Fail(GenericFailureMessage);
-            }
-
-            string displayName = ReadAttribute(authenticatedEntry, ldapOptions.DisplayNameAttribute)
-                ?? normalizedUsername;
-            IReadOnlyList<string> groups = ReadAttributeValues(authenticatedEntry, ldapOptions.GroupAttribute);
-
-            IReadOnlyList<string> roles = MapGroupsToRoles(groups, dashboardOptions.GroupToRole);
-            if (roles.Count == 0)
-            {
-                logger.LogInformation(
-                    "LDAP dashboard login denied for user {User}: no GroupToRole mapping matched their LDAP groups.",
-                    normalizedUsername);
-
-                return DashboardAuthenticationResult.Fail(GenericFailureMessage);
-            }
-
-            return DashboardAuthenticationResult.Success(CreatePrincipal(
-                normalizedUsername,
-                displayName,
-                groups,
-                roles));
+            return DashboardAuthenticationResult.Fail(GenericFailureMessage);
         }
-        catch (OperationCanceledException)
-        {
-            throw;
-        }
-        catch (LdapException ex)
+
+        GroupRoleMapping<string> mapping = await roleMapper
+            .MapAsync(ldapResult.Groups, cancellationToken)
+            .ConfigureAwait(false);
+
+        IReadOnlyList<string> roles = mapping.Roles;
+        if (roles.Count == 0)
         {
+            // Preserve the long-standing "no roles matched -> login denied" rule.
             logger.LogInformation(
-                "LDAP dashboard login rejected for user {User}: result code {ResultCode}.",
-                normalizedUsername,
-                ex.ResultCode);
+                "LDAP dashboard login denied for user {User}: no GroupToRole mapping matched their LDAP groups.",
+                ldapResult.Username);
 
             return DashboardAuthenticationResult.Fail(GenericFailureMessage);
         }
-        catch (Exception ex)
-        {
-            logger.LogError(ex, "Unexpected LDAP dashboard login error for user {User}.", normalizedUsername);
 
-            return DashboardAuthenticationResult.Fail(GenericFailureMessage);
-        }
-    }
-
-    /// <summary>Escapes special characters in LDAP filter strings.</summary>
-    /// <param name="value">The string value to escape.</param>
-    internal static string EscapeLdapFilter(string value)
-    {
-        StringBuilder builder = new(value.Length);
-        foreach (char character in value)
-        {
-            builder.Append(character switch
-            {
-                '\\' => @"\5c",
-                '*' => @"\2a",
-                '(' => @"\28",
-                ')' => @"\29",
-                '\0' => @"\00",
-                _ => character.ToString()
-            });
-        }
-
-        return builder.ToString();
+        return DashboardAuthenticationResult.Success(CreatePrincipal(
+            ldapResult.Username,
+            ldapResult.DisplayName,
+            ldapResult.Groups,
+            roles));
     }
 
     /// <summary>
-    /// Maps the user's LDAP groups to dashboard roles. A user can pick up
-    /// multiple roles; Admin and Viewer are the only legal values. Returns
-    /// an empty list when no group matches (caller rejects the login).
+    /// Builds the dashboard <see cref="ClaimsPrincipal"/> from the LDAP outcome.
     /// </summary>
-    /// <param name="groups">The collection of LDAP groups the user belongs to.</param>
-    /// <param name="groupToRole">The mapping from group names to dashboard role names.</param>
-    internal static IReadOnlyList<string> MapGroupsToRoles(
-        IEnumerable<string> groups,
-        IReadOnlyDictionary<string, string> groupToRole)
-    {
-        if (groupToRole.Count == 0)
-        {
-            return [];
-        }
-
-        HashSet<string> roles = new(StringComparer.Ordinal);
-        foreach (string group in groups)
-        {
-            string normalizedGroup = group.Trim();
-
-            // Lookup precedence (Server-040): the full literal group string is
-            // tried first; only if that misses do we fall back to the leading
-            // RDN value (e.g. "GwAdmin" extracted from
-            // "ou=GwAdmin,ou=groups,..."). The map's comparer is
-            // OrdinalIgnoreCase (see DashboardOptions.GroupToRole), so e.g.
-            // "GwAdmin" and "gwadmin" both match.
-            if (groupToRole.TryGetValue(normalizedGroup, out string? mapped)
-                || groupToRole.TryGetValue(ExtractFirstRdnValue(normalizedGroup), out mapped))
-            {
-                roles.Add(mapped);
-            }
-        }
-
-        return [.. roles];
-    }
-
-    /// <summary>Extracts the first RDN value from a distinguished name.</summary>
-    /// <param name="distinguishedName">The LDAP distinguished name.</param>
-    internal static string ExtractFirstRdnValue(string distinguishedName)
-    {
-        int equalsIndex = distinguishedName.IndexOf('=');
-        if (equalsIndex < 0)
-        {
-            return distinguishedName;
-        }
-
-        int valueStart = equalsIndex + 1;
-        int commaIndex = distinguishedName.IndexOf(',', valueStart);
-
-        return commaIndex > valueStart
-            ? distinguishedName[valueStart..commaIndex]
-            : distinguishedName[valueStart..];
-    }
-
-    private static Task BindServiceAccountAsync(
-        LdapConnection connection,
-        LdapOptions ldapOptions,
-        CancellationToken cancellationToken)
-    {
-        return Task.Run(
-            () => connection.Bind(ldapOptions.ServiceAccountDn, ldapOptions.ServiceAccountPassword),
-            cancellationToken);
-    }
-
-    private static async Task<LdapEntry?> SearchUserAsync(
-        LdapConnection connection,
-        LdapOptions ldapOptions,
-        string username,
-        CancellationToken cancellationToken)
-    {
-        string filter = $"({ldapOptions.UserNameAttribute}={EscapeLdapFilter(username)})";
-        ILdapSearchResults results = await Task.Run(
-                () => connection.Search(
-                    ldapOptions.SearchBase,
-                    LdapConnection.ScopeSub,
-                    filter,
-                    attrs: null,
-                    typesOnly: false),
-                cancellationToken)
-            .ConfigureAwait(false);
-
-        LdapEntry? entry = null;
-        while (results.HasMore())
-        {
-            LdapEntry next = results.Next();
-            if (entry is not null)
-            {
-                return null;
-            }
-
-            entry = next;
-        }
-
-        return entry;
-    }
-
-    private static string? ReadAttribute(LdapEntry entry, string attributeName)
-    {
-        return ReadLdapAttribute(entry, attributeName)?.StringValue;
-    }
-
-    private static IReadOnlyList<string> ReadAttributeValues(LdapEntry entry, string attributeName)
-    {
-        LdapAttribute? attribute = ReadLdapAttribute(entry, attributeName);
-        return attribute?.StringValueArray ?? [];
-    }
-
-    private static LdapAttribute? ReadLdapAttribute(LdapEntry entry, string attributeName)
-    {
-        return entry.GetAttribute(attributeName)
-            ?? entry.GetAttribute(attributeName.ToLowerInvariant())
-            ?? entry.GetAttribute(attributeName.ToUpperInvariant());
-    }
-
+    /// <param name="username">
+    /// The (trimmed) login name. Emitted as <see cref="ClaimTypes.NameIdentifier"/> (kept for
+    /// back-compat reads) and as the canonical <see cref="ZbClaimTypes.Username"/> ("zb:username").
+    /// </param>
+    /// <param name="displayName">
+    /// The user's display name. Emitted as <see cref="ZbClaimTypes.Name"/> (= <see cref="ClaimTypes.Name"/>
+    /// so <c>Identity.Name</c> resolves) and as <see cref="ZbClaimTypes.DisplayName"/> ("zb:displayname")
+    /// for cross-app consistency.
+    /// </param>
+    /// <param name="groups">
+    /// The user's LDAP groups, as returned by <see cref="ILdapAuthService"/>. NOTE
+    /// (review C1): these are <b>already-normalized short RDN names</b> (e.g.
+    /// <c>GwAdmin</c>), not raw distinguished names. The shared
+    /// <c>ZB.MOM.WW.Auth.Ldap</c> provider strips each group DN to its first RDN
+    /// value before returning it, so the <see cref="DashboardAuthenticationDefaults.LdapGroupClaimType"/>
+    /// claim carries the short name. This differs from the pre-cutover behaviour,
+    /// which surfaced the raw <c>memberOf</c> values (full DNs) on the claim; the
+    /// claim is informational only (no policy or UI reads its value — authorization
+    /// is role-based), so the shape change is non-breaking for dashboard consumers.
+    /// </param>
+    /// <param name="roles">The dashboard roles resolved from <paramref name="groups"/>.</param>
     private static ClaimsPrincipal CreatePrincipal(
         string username,
         string displayName,
@@ -261,11 +105,21 @@ public sealed class DashboardAuthenticator(
     {
         List<Claim> claims =
         [
+            // Keep NameIdentifier so any existing read-site that uses it continues to work.
             new Claim(ClaimTypes.NameIdentifier, username),
-            new Claim(ClaimTypes.Name, displayName),
+            // Canonical login-username claim (Task 1.5).
+            new Claim(ZbClaimTypes.Username, username),
+            // ZbClaimTypes.Name == ClaimTypes.Name — drives Identity.Name resolution.
+            new Claim(ZbClaimTypes.Name, displayName),
+            // Canonical display-name claim for cross-app consistency (Task 1.5).
+            new Claim(ZbClaimTypes.DisplayName, displayName),
         ];
 
-        claims.AddRange(roles.Select(role => new Claim(ClaimTypes.Role, role)));
+        // ZbClaimTypes.Role == ClaimTypes.Role — drives IsInRole and [Authorize(Roles=...)].
+        claims.AddRange(roles.Select(role => new Claim(ZbClaimTypes.Role, role)));
+        // Groups are short RDN names from ILdapAuthService (see param doc above), so
+        // this claim value is the short group name, not the original DN.
+        // LdapGroupClaimType is MxGateway-specific ("mxgateway:ldap_group") — no ZbClaimType for groups.
         claims.AddRange(groups.Select(group => new Claim(
             DashboardAuthenticationDefaults.LdapGroupClaimType,
             group)));
@@ -273,8 +127,8 @@ public sealed class DashboardAuthenticator(
         ClaimsIdentity claimsIdentity = new(
             claims,
             DashboardAuthenticationDefaults.AuthenticationScheme,
-            ClaimTypes.Name,
-            ClaimTypes.Role);
+            ZbClaimTypes.Name,
+            ZbClaimTypes.Role);
 
         return new ClaimsPrincipal(claimsIdentity);
     }

src/ZB.MOM.WW.MxGateway.Server/Dashboard/DashboardEndpointRouteBuilderExtensions.cs

@@ -1,7 +1,6 @@
 using System.Text.Encodings.Web;
 using Microsoft.AspNetCore.Antiforgery;
 using Microsoft.AspNetCore.Authentication;
-using Microsoft.AspNetCore.Http.HttpResults;
 using ZB.MOM.WW.MxGateway.Server.Configuration;
 using ZB.MOM.WW.MxGateway.Server.Dashboard.Components;
 using ZB.MOM.WW.MxGateway.Server.Dashboard.Hubs;
@@ -25,14 +24,19 @@ public static class DashboardEndpointRouteBuilderExtensions
             return endpoints;
         }
 
-        endpoints.MapGet(
-                "/login",
-                (HttpContext httpContext, IAntiforgery antiforgery) => GetLoginAsync(httpContext, antiforgery))
-            .AllowAnonymous()
-            .WithName("DashboardLogin");
-
+        // GET /login is served by the [AllowAnonymous] Blazor <Login> component
+        // (Components/Pages/Login.razor → @page "/login"), which renders the shared
+        // kit's <LoginCard>. Its [AllowAnonymous] attribute overrides the
+        // RequireAuthorization(ViewerPolicy) that MapRazorComponents<App>() applies,
+        // so the cookie scheme's LoginPath="/login" redirect resolves for anonymous users.
+        //
+        // The credential POST is mapped to /auth/login, NOT /login. The @page "/login"
+        // Razor Components endpoint matches ALL HTTP methods, so a MapPost("/login") shared
+        // the "/login" route with it and every POST threw AmbiguousMatchException (HTTP 500).
+        // A distinct /auth/login path (as ScadaBridge does) keeps the GET page and the POST
+        // handler on separate routes. The <LoginCard Action="/auth/login"> form posts here.
         endpoints.MapPost(
-                "/login",
+                "/auth/login",
                 (HttpContext httpContext, IAntiforgery antiforgery, IDashboardAuthenticator authenticator) =>
                     PostLoginAsync(httpContext, antiforgery, authenticator))
             .AllowAnonymous()
@@ -92,17 +96,6 @@ public static class DashboardEndpointRouteBuilderExtensions
         return endpoints;
     }
 
-    private static Task<ContentHttpResult> GetLoginAsync(
-        HttpContext httpContext,
-        IAntiforgery antiforgery)
-    {
-        string returnUrl = SanitizeReturnUrl(httpContext.Request.Query["returnUrl"].ToString());
-
-        return Task.FromResult(TypedResults.Content(
-            RenderLoginPage(httpContext, antiforgery, returnUrl, failureMessage: null),
-            "text/html"));
-    }
-
     private static async Task<IResult> PostLoginAsync(
         HttpContext httpContext,
         IAntiforgery antiforgery,
@@ -124,10 +117,13 @@ public static class DashboardEndpointRouteBuilderExtensions
 
         if (!result.Succeeded || result.Principal is null)
         {
-            return TypedResults.Content(
-                RenderLoginPage(httpContext, antiforgery, returnUrl, result.FailureMessage),
-                "text/html",
-                statusCode: StatusCodes.Status401Unauthorized);
+            // Round-trip the failure back to the anonymous Blazor /login page, carrying
+            // the (sanitized) returnUrl so a successful retry still lands on the target.
+            string failureMessage = result.FailureMessage
+                ?? "The username or password is invalid, or the user is not authorized.";
+            return Results.Redirect(
+                $"/login?error={Uri.EscapeDataString(failureMessage)}"
+                + $"&returnUrl={Uri.EscapeDataString(returnUrl)}");
         }
 
         await httpContext
@@ -158,42 +154,6 @@ public static class DashboardEndpointRouteBuilderExtensions
         return Results.LocalRedirect("/login");
     }
 
-    private static string RenderLoginPage(
-        HttpContext httpContext,
-        IAntiforgery antiforgery,
-        string returnUrl,
-        string? failureMessage)
-    {
-        AntiforgeryTokenSet tokens = antiforgery.GetAndStoreTokens(httpContext);
-        string requestToken = tokens.RequestToken ?? string.Empty;
-        string alert = string.IsNullOrWhiteSpace(failureMessage)
-            ? string.Empty
-            : $"<p class=\"alert alert-danger\" role=\"alert\">{HtmlEncoder.Default.Encode(failureMessage)}</p>";
-
-        string body = $"""
-            <section class="dashboard-login">
-                {alert}
-                <form method="post" action="/login" class="card login-card">
-                    <div class="card-body">
-                        <input name="{tokens.FormFieldName}" type="hidden" value="{HtmlEncoder.Default.Encode(requestToken)}" />
-                        <input name="returnUrl" type="hidden" value="{HtmlEncoder.Default.Encode(returnUrl)}" />
-                        <div class="mb-3">
-                            <label for="username" class="form-label">Username</label>
-                            <input id="username" name="username" type="text" autocomplete="username" class="form-control" />
-                        </div>
-                        <div class="mb-3">
-                            <label for="password" class="form-label">Password</label>
-                            <input id="password" name="password" type="password" autocomplete="current-password" class="form-control" />
-                        </div>
-                        <button type="submit" class="btn btn-primary">Sign in</button>
-                    </div>
-                </form>
-            </section>
-            """;
-
-        return RenderPage("Dashboard Sign In", heading: null, body);
-    }
-
     private static string RenderPage(string title, string body)
         => RenderPage(title, heading: title, body);
 
@@ -215,7 +175,8 @@ public static class DashboardEndpointRouteBuilderExtensions
                 <meta name="viewport" content="width=device-width, initial-scale=1" />
                 <title>{HtmlEncoder.Default.Encode(title)}</title>
                 <link rel="stylesheet" href="/lib/bootstrap/css/bootstrap.min.css" />
-                <link rel="stylesheet" href="/css/theme.css" />
+                <link rel="stylesheet" href="/_content/ZB.MOM.WW.Theme/css/theme.css" />
+                <link rel="stylesheet" href="/_content/ZB.MOM.WW.Theme/css/layout.css" />
                 <link rel="stylesheet" href="/css/site.css" />
             </head>
             <body class="dashboard-body">

src/ZB.MOM.WW.MxGateway.Server/Dashboard/DashboardGroupRoleMapper.cs

@@ -0,0 +1,31 @@
+using Microsoft.Extensions.Options;
+using ZB.MOM.WW.Auth.Abstractions.Roles;
+using ZB.MOM.WW.MxGateway.Server.Configuration;
+
+namespace ZB.MOM.WW.MxGateway.Server.Dashboard;
+
+/// <summary>
+/// Shared-Auth <see cref="IGroupRoleMapper{TRole}"/> seam over the dashboard's
+/// LDAP-group → role mapping. Roles are plain strings
+/// (<see cref="DashboardRoles.Admin"/> / <see cref="DashboardRoles.Viewer"/>),
+/// so <c>TRole</c> is <see cref="string"/>. The mapping rules (full-DN first,
+/// leading-RDN fallback, case-insensitive) live in
+/// <see cref="DashboardGroupRoleMapping"/>, shared with
+/// <see cref="DashboardAuthenticator"/> so behaviour stays identical.
+/// </summary>
+/// <param name="options">Gateway options supplying the dashboard GroupToRole map.</param>
+public sealed class DashboardGroupRoleMapper(IOptions<GatewayOptions> options)
+    : IGroupRoleMapper<string>
+{
+    /// <inheritdoc />
+    public Task<GroupRoleMapping<string>> MapAsync(
+        IReadOnlyList<string> groups,
+        CancellationToken ct)
+    {
+        IReadOnlyList<string> roles = DashboardGroupRoleMapping.MapGroupsToRoles(
+            groups,
+            options.Value.Dashboard.GroupToRole);
+
+        return Task.FromResult(new GroupRoleMapping<string>(roles, Scope: null));
+    }
+}

src/ZB.MOM.WW.MxGateway.Server/Dashboard/DashboardGroupRoleMapping.cs

@@ -0,0 +1,79 @@
+namespace ZB.MOM.WW.MxGateway.Server.Dashboard;
+
+/// <summary>
+/// Single source of truth for mapping a user's LDAP groups to dashboard roles.
+/// Both <see cref="DashboardAuthenticator"/> (the existing login flow) and
+/// <see cref="DashboardGroupRoleMapper"/> (the shared-Auth
+/// <see cref="ZB.MOM.WW.Auth.Abstractions.Roles.IGroupRoleMapper{TRole}"/> seam)
+/// delegate here so the precedence and case rules stay identical.
+/// </summary>
+internal static class DashboardGroupRoleMapping
+{
+    /// <summary>
+    /// Maps the user's LDAP groups to dashboard roles. A user can pick up
+    /// multiple roles; Admin and Viewer are the only legal values. Returns
+    /// an empty list when no group matches (caller rejects the login).
+    /// </summary>
+    /// <param name="groups">The collection of LDAP groups the user belongs to.</param>
+    /// <param name="groupToRole">The mapping from group names to dashboard role names.</param>
+    internal static IReadOnlyList<string> MapGroupsToRoles(
+        IEnumerable<string> groups,
+        IReadOnlyDictionary<string, string> groupToRole)
+    {
+        if (groupToRole.Count == 0)
+        {
+            return [];
+        }
+
+        HashSet<string> roles = new(StringComparer.Ordinal);
+        foreach (string group in groups)
+        {
+            string normalizedGroup = group.Trim();
+
+            // Lookup precedence (Server-040): the full literal group string is
+            // tried first; only if that misses do we fall back to the leading
+            // RDN value (e.g. "GwAdmin" extracted from
+            // "ou=GwAdmin,ou=groups,..."). The map's comparer is
+            // OrdinalIgnoreCase (see DashboardOptions.GroupToRole), so e.g.
+            // "GwAdmin" and "gwadmin" both match.
+            //
+            // Review C1: with the shared ZB.MOM.WW.Auth.Ldap provider, groups
+            // arrive here already stripped to short RDN names (the library calls
+            // FirstRdnValue before returning them). So through the live login path
+            // the full-string branch only ever sees short names and the RDN
+            // fallback is effectively a no-op — they collapse to the same key.
+            // The fallback is retained because this mapping is also reachable
+            // directly via the IGroupRoleMapper<string> seam (DashboardGroupRoleMapper),
+            // where a caller could still pass a full DN. CONSEQUENCE: configuring a
+            // full-DN GroupToRole *key* (e.g. "ou=GwAdmin,ou=groups,...") is
+            // UNSUPPORTED with the shared library — the incoming group is a short
+            // name, so it will never equal a full-DN key. Keep GroupToRole keys as
+            // short group names.
+            if (groupToRole.TryGetValue(normalizedGroup, out string? mapped)
+                || groupToRole.TryGetValue(ExtractFirstRdnValue(normalizedGroup), out mapped))
+            {
+                roles.Add(mapped);
+            }
+        }
+
+        return [.. roles];
+    }
+
+    /// <summary>Extracts the first RDN value from a distinguished name.</summary>
+    /// <param name="distinguishedName">The LDAP distinguished name.</param>
+    internal static string ExtractFirstRdnValue(string distinguishedName)
+    {
+        int equalsIndex = distinguishedName.IndexOf('=');
+        if (equalsIndex < 0)
+        {
+            return distinguishedName;
+        }
+
+        int valueStart = equalsIndex + 1;
+        int commaIndex = distinguishedName.IndexOf(',', valueStart);
+
+        return commaIndex > valueStart
+            ? distinguishedName[valueStart..commaIndex]
+            : distinguishedName[valueStart..];
+    }
+}

src/ZB.MOM.WW.MxGateway.Server/Dashboard/DashboardRoles.cs

@@ -8,8 +8,10 @@ public static class DashboardRoles
 {
     /// <summary>
     /// Read-write access: API-key CRUD, settings, any state-changing UI.
+    /// Canonical role value (Task 1.7); formerly <c>"Admin"</c> — pure value
+    /// rename, the operations this role authorizes are unchanged.
     /// </summary>
-    public const string Admin = "Admin";
+    public const string Admin = "Administrator";
 
     /// <summary>
     /// Read-only access: all pages render but write affordances are hidden.

src/ZB.MOM.WW.MxGateway.Server/Dashboard/DashboardServiceCollectionExtensions.cs

@@ -1,8 +1,12 @@
 using Microsoft.AspNetCore.Authentication;
 using Microsoft.AspNetCore.Authentication.Cookies;
 using Microsoft.AspNetCore.Authorization;
+using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.Options;
+using ZB.MOM.WW.Auth.Abstractions.Roles;
+using ZB.MOM.WW.Auth.AspNetCore;
 using ZB.MOM.WW.MxGateway.Server.Configuration;
+using ZB.MOM.WW.MxGateway.Server.Security.Audit;
 
 namespace ZB.MOM.WW.MxGateway.Server.Dashboard;
 
@@ -15,11 +19,25 @@ public static class DashboardServiceCollectionExtensions
     /// Registers all dashboard services, authentication, and Razor components.
     /// </summary>
     /// <param name="services">Service collection to register services.</param>
-    public static IServiceCollection AddGatewayDashboard(this IServiceCollection services)
+    /// <param name="configuration">
+    /// Application configuration, used to bind the shared LDAP provider's options
+    /// from the <c>MxGateway:Ldap</c> section.
+    /// </param>
+    public static IServiceCollection AddGatewayDashboard(
+        this IServiceCollection services,
+        IConfiguration configuration)
     {
+        // Dashboard logins delegate bind/search to the shared ZB.MOM.WW.Auth.Ldap
+        // provider. Its LdapOptions bind straight from MxGateway:Ldap (the gateway's
+        // LdapOptions field names match the shared options: Transport / AllowInsecure /
+        // SearchBase / ServiceAccount* / *Attribute). AddZbLdapAuth also adds a
+        // ValidateOnStart() so an insecure-transport misconfiguration fails fast at boot.
+        services.AddZbLdapAuth(configuration, "MxGateway:Ldap");
+
         services.AddSingleton<IDashboardSnapshotService, DashboardSnapshotService>();
         services.AddSingleton<IDashboardLiveDataService, DashboardLiveDataService>();
         services.AddSingleton<IDashboardAuthenticator, DashboardAuthenticator>();
+        services.AddSingleton<IGroupRoleMapper<string>, DashboardGroupRoleMapper>();
         services.AddSingleton<DashboardApiKeyAuthorization>();
         services.AddSingleton<IDashboardApiKeyManagementService, DashboardApiKeyManagementService>();
         services.AddSingleton<IDashboardSessionAdminService, DashboardSessionAdminService>();
@@ -30,6 +48,7 @@ public static class DashboardServiceCollectionExtensions
         services.AddHostedService<Hubs.DashboardSnapshotPublisher>();
         services.AddHostedService<Hubs.AlarmsHubPublisher>();
         services.AddHttpContextAccessor();
+        services.AddSingleton<IAuditActorAccessor, HttpAuditActorAccessor>();
         services.AddAntiforgery();
         services.AddCascadingAuthenticationState();
         services.AddRazorComponents()
@@ -40,29 +59,42 @@ public static class DashboardServiceCollectionExtensions
             .AddAuthentication(DashboardAuthenticationDefaults.AuthenticationScheme)
             .AddCookie(DashboardAuthenticationDefaults.AuthenticationScheme, cookieOptions =>
             {
+                // Hardened defaults (HttpOnly, SameSite=Strict, SecurePolicy, SlidingExpiration,
+                // ExpireTimeSpan) via the shared ZbCookieDefaults.Apply. requireHttps is set to
+                // its default (true / Always) here and overridden per-environment by the
+                // PostConfigure below; the 8-hour idle timeout is preserved (not the 30-min default).
+                ZbCookieDefaults.Apply(cookieOptions, requireHttps: true, idleTimeout: TimeSpan.FromHours(8));
+                // Cookie name, path, and redirect paths are MxGateway-specific — set after Apply
+                // so they are never overwritten by the shared helper (Apply intentionally skips name).
+                // This is the canonical default; it is overridden per-environment from
+                // DashboardOptions.CookieName by the PostConfigure below.
                 cookieOptions.Cookie.Name = DashboardAuthenticationDefaults.CookieName;
-                cookieOptions.Cookie.HttpOnly = true;
-                cookieOptions.Cookie.SameSite = SameSiteMode.Strict;
-                // SecurePolicy is bound via PostConfigure below so it can honour
-                // DashboardOptions.RequireHttpsCookie (default Always; dev HTTP
-                // deployments set RequireHttpsCookie=false to use SameAsRequest).
                 cookieOptions.Cookie.Path = "/";
                 cookieOptions.LoginPath = "/login";
                 cookieOptions.LogoutPath = "/logout";
                 cookieOptions.AccessDeniedPath = "/denied";
-                cookieOptions.ExpireTimeSpan = TimeSpan.FromHours(8);
-                cookieOptions.SlidingExpiration = true;
             })
             .AddScheme<AuthenticationSchemeOptions, HubTokenAuthenticationHandler>(
                 DashboardAuthenticationDefaults.HubAuthenticationScheme,
                 _ => { });
 
+        // Honour DashboardOptions.RequireHttpsCookie (default true / Always; set false for dev
+        // HTTP deployments → SameAsRequest) and the optional per-environment cookie-name
+        // override. Both run after the inline AddCookie config above, so they win.
         services.AddOptions<CookieAuthenticationOptions>(DashboardAuthenticationDefaults.AuthenticationScheme)
             .Configure<IOptions<GatewayOptions>>((cookieOptions, gatewayOptions) =>
             {
                 cookieOptions.Cookie.SecurePolicy = gatewayOptions.Value.Dashboard.RequireHttpsCookie
                     ? CookieSecurePolicy.Always
                     : CookieSecurePolicy.SameAsRequest;
+
+                // Config-driven cookie name (MxGateway:Dashboard:CookieName). Null/blank keeps
+                // the canonical default set above, so a misconfiguration cannot unname the cookie.
+                var cookieName = gatewayOptions.Value.Dashboard.CookieName;
+                if (!string.IsNullOrWhiteSpace(cookieName))
+                {
+                    cookieOptions.Cookie.Name = cookieName;
+                }
             });
 
         services.AddAuthorization(authorization =>

src/ZB.MOM.WW.MxGateway.Server/Dashboard/DashboardSnapshotService.cs

@@ -2,6 +2,7 @@ using System.Runtime.CompilerServices;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Logging.Abstractions;
 using Microsoft.Extensions.Options;
+using ZB.MOM.WW.Auth.Abstractions.ApiKeys;
 using ZB.MOM.WW.MxGateway.Server.Configuration;
 using ZB.MOM.WW.MxGateway.Server.Galaxy;
 using ZB.MOM.WW.MxGateway.Server.Metrics;
@@ -242,7 +243,7 @@ public sealed class DashboardSnapshotService : IDashboardSnapshotService
                     KeyId: key.KeyId,
                     DisplayName: key.DisplayName,
                     Scopes: key.Scopes,
-                    Constraints: key.Constraints,
+                    Constraints: ApiKeyConstraintSerializer.Deserialize(key.ConstraintsJson),
                     CreatedUtc: key.CreatedUtc,
                     LastUsedUtc: key.LastUsedUtc,
                     RevokedUtc: key.RevokedUtc))

src/ZB.MOM.WW.MxGateway.Server/Diagnostics/AuthStoreHealthCheck.cs

@@ -0,0 +1,40 @@
+using Microsoft.Data.Sqlite;
+using Microsoft.Extensions.Diagnostics.HealthChecks;
+using ZB.MOM.WW.Auth.ApiKeys.Sqlite;
+
+namespace ZB.MOM.WW.MxGateway.Server.Diagnostics;
+
+/// <summary>
+/// Readiness probe: verifies the SQLite authentication store is reachable. The gateway
+/// authenticates every gRPC call against this store, so its reachability gates readiness.
+/// </summary>
+public sealed class AuthStoreHealthCheck : IHealthCheck
+{
+    private readonly AuthSqliteConnectionFactory _connectionFactory;
+
+    public AuthStoreHealthCheck(AuthSqliteConnectionFactory connectionFactory) =>
+        _connectionFactory = connectionFactory ?? throw new ArgumentNullException(nameof(connectionFactory));
+
+    public async Task<HealthCheckResult> CheckHealthAsync(
+        HealthCheckContext context,
+        CancellationToken cancellationToken = default)
+    {
+        try
+        {
+            await using SqliteConnection connection =
+                await _connectionFactory.OpenConnectionAsync(cancellationToken).ConfigureAwait(false);
+            await using SqliteCommand command = connection.CreateCommand();
+            command.CommandText = "SELECT 1;";
+            await command.ExecuteScalarAsync(cancellationToken).ConfigureAwait(false);
+            return HealthCheckResult.Healthy("Auth store is reachable.");
+        }
+        catch (OperationCanceledException) when (cancellationToken.IsCancellationRequested)
+        {
+            throw;
+        }
+        catch (Exception ex)
+        {
+            return HealthCheckResult.Unhealthy("Auth store is unreachable.", ex);
+        }
+    }
+}

src/ZB.MOM.WW.MxGateway.Server/Diagnostics/GatewayLogRedactorAdapter.cs

@@ -1,64 +0,0 @@
-using ZB.MOM.WW.Telemetry.Serilog;
-
-namespace ZB.MOM.WW.MxGateway.Server.Diagnostics;
-
-/// <summary>
-/// Bridges the gateway's <see cref="GatewayLogRedactor"/> policy onto the shared
-/// <see cref="ILogRedactor"/> seam consumed by <c>ZB.MOM.WW.Telemetry.Serilog</c>'s redaction
-/// enricher. Applied to every Serilog log event before it reaches a sink, it masks the same
-/// secrets the original MEL-scope path masked: API-key bearer tokens / client identities
-/// (<c>mxgw_*</c>) and command values for credential-bearing MXAccess commands. All masking
-/// decisions delegate to <see cref="GatewayLogRedactor"/> — this type adds no new policy.
-/// </summary>
-public sealed class GatewayLogRedactorAdapter : ILogRedactor
-{
-    /// <summary>Property name carrying a client identity / authorization header value.</summary>
-    private const string ClientIdentityProperty = "ClientIdentity";
-
-    /// <summary>Property name carrying a raw authorization header value.</summary>
-    private const string AuthorizationProperty = "Authorization";
-
-    /// <summary>Property name carrying the MXAccess command method, used to gate value redaction.</summary>
-    private const string CommandMethodProperty = "CommandMethod";
-
-    /// <summary>Property name carrying a command payload value that may bear credentials.</summary>
-    private const string CommandValueProperty = "CommandValue";
-
-    /// <summary>
-    /// Masks any sensitive values in <paramref name="properties"/> in place using the shared
-    /// <see cref="GatewayLogRedactor"/> policy. Identity/authorization properties have their API-key
-    /// secret stripped; a command value is redacted when its associated command method bears
-    /// credentials.
-    /// </summary>
-    /// <param name="properties">The mutable log-event property dictionary for the current event.</param>
-    public void Redact(IDictionary<string, object?> properties)
-    {
-        ArgumentNullException.ThrowIfNull(properties);
-
-        RedactIdentity(properties, ClientIdentityProperty);
-        RedactIdentity(properties, AuthorizationProperty);
-        RedactCommandValue(properties);
-    }
-
-    private static void RedactIdentity(IDictionary<string, object?> properties, string propertyName)
-    {
-        if (properties.TryGetValue(propertyName, out object? value) && value is string identity)
-        {
-            properties[propertyName] = GatewayLogRedactor.RedactClientIdentity(identity);
-        }
-    }
-
-    private static void RedactCommandValue(IDictionary<string, object?> properties)
-    {
-        if (!properties.TryGetValue(CommandValueProperty, out object? value) || value is null)
-        {
-            return;
-        }
-
-        string? commandMethod = properties.TryGetValue(CommandMethodProperty, out object? method)
-            ? method as string
-            : null;
-
-        properties[CommandValueProperty] = GatewayLogRedactor.RedactCommandValue(commandMethod, value);
-    }
-}

src/ZB.MOM.WW.MxGateway.Server/Diagnostics/GatewayLogRedactorSeam.cs

@@ -0,0 +1,28 @@
+using ZB.MOM.WW.Telemetry.Serilog;
+
+namespace ZB.MOM.WW.MxGateway.Server.Diagnostics;
+
+/// <summary>
+/// Adapts the static <see cref="GatewayLogRedactor"/> to the shared <see cref="ILogRedactor"/> seam
+/// so the telemetry RedactionEnricher masks API-key/credential material on every log event.
+/// </summary>
+public sealed class GatewayLogRedactorSeam : ILogRedactor
+{
+    private static readonly string[] IdentityKeys = ["ClientIdentity", "authorization", "Authorization"];
+
+    /// <summary>
+    /// Masks API-key/credential material in known identity-bearing log properties.
+    /// </summary>
+    /// <param name="properties">The log event property dictionary to redact in place.</param>
+    public void Redact(IDictionary<string, object?> properties)
+    {
+        ArgumentNullException.ThrowIfNull(properties);
+        foreach (var key in IdentityKeys)
+        {
+            if (properties.TryGetValue(key, out var value) && value is string s)
+            {
+                properties[key] = GatewayLogRedactor.RedactClientIdentity(s);
+            }
+        }
+    }
+}

src/ZB.MOM.WW.MxGateway.Server/Diagnostics/GatewayLoggerExtensions.cs

@@ -0,0 +1,20 @@
+using Microsoft.Extensions.Logging;
+
+namespace ZB.MOM.WW.MxGateway.Server.Diagnostics;
+
+public static class GatewayLoggerExtensions
+{
+    /// <summary>Begins a gateway log scope with the specified scope properties.</summary>
+    /// <param name="logger">Logger used for diagnostic output.</param>
+    /// <param name="scope">Scope properties to apply.</param>
+    /// <returns>A disposable that ends the scope when disposed.</returns>
+    public static IDisposable? BeginGatewayScope(
+        this ILogger logger,
+        GatewayLogScope scope)
+    {
+        ArgumentNullException.ThrowIfNull(logger);
+        ArgumentNullException.ThrowIfNull(scope);
+
+        return logger.BeginScope(scope.ToDictionary());
+    }
+}

src/ZB.MOM.WW.MxGateway.Server/Diagnostics/GatewayRequestLoggingMiddlewareExtensions.cs

@@ -1,5 +1,4 @@
 using Microsoft.Extensions.Primitives;
-using Serilog.Context;
 
 namespace ZB.MOM.WW.MxGateway.Server.Diagnostics;
 
@@ -18,12 +17,7 @@ public static class GatewayRequestLoggingMiddlewareExtensions
     /// <summary>Header name for the command method name.</summary>
     public const string CommandMethodHeaderName = "x-command-method";
 
-    /// <summary>
-    /// Adds gateway request logging middleware that reads the correlation headers and pushes them
-    /// as Serilog <see cref="LogContext"/> properties for the duration of the request. The pushed
-    /// properties (SessionId / WorkerProcessId / CorrelationId / CommandMethod / ClientIdentity)
-    /// are disposed when the request completes; the shared redaction enricher masks any secrets.
-    /// </summary>
+    /// <summary>Adds gateway request logging scope middleware that reads correlation headers and redacts sensitive data.</summary>
     /// <param name="app">Application builder.</param>
     public static IApplicationBuilder UseGatewayRequestLoggingScope(this IApplicationBuilder app)
     {
@@ -31,56 +25,21 @@ public static class GatewayRequestLoggingMiddlewareExtensions
 
         return app.Use(async (context, next) =>
         {
-            GatewayLogScope scope = new(
+            ILogger logger = context.RequestServices
+                .GetRequiredService<ILoggerFactory>()
+                .CreateLogger("MxGateway.Request");
+
+            using IDisposable? scope = logger.BeginGatewayScope(new GatewayLogScope(
                 SessionId: ReadHeader(context, SessionIdHeaderName),
                 WorkerProcessId: ReadInt32Header(context, WorkerProcessIdHeaderName),
                 CorrelationId: ReadUInt64Header(context, CorrelationIdHeaderName),
                 CommandMethod: ReadHeader(context, CommandMethodHeaderName),
-                ClientIdentity: ReadHeader(context, "authorization"));
-
-            using IDisposable correlationScope = PushCorrelationProperties(scope);
+                ClientIdentity: ReadHeader(context, "authorization")));
 
             await next(context);
         });
     }
 
-    /// <summary>
-    /// Pushes the populated <paramref name="scope"/> properties onto the Serilog
-    /// <see cref="LogContext"/>, returning a single disposable that pops them all when the request
-    /// completes. Only the properties present in <see cref="GatewayLogScope.ToDictionary"/> (which
-    /// already applies the client-identity redaction policy) are pushed.
-    /// </summary>
-    /// <param name="scope">The correlation properties for the current request.</param>
-    /// <returns>A disposable that removes the pushed properties on disposal.</returns>
-    private static IDisposable PushCorrelationProperties(GatewayLogScope scope)
-    {
-        Stack<IDisposable> pushed = new();
-
-        foreach (KeyValuePair<string, object?> property in scope.ToDictionary())
-        {
-            pushed.Push(LogContext.PushProperty(property.Key, property.Value));
-        }
-
-        return new CorrelationPropertyScope(pushed);
-    }
-
-    /// <summary>
-    /// Disposes the pushed <see cref="LogContext"/> property bindings in reverse order, restoring
-    /// the ambient context to its pre-request state.
-    /// </summary>
-    private sealed class CorrelationPropertyScope(Stack<IDisposable> bindings) : IDisposable
-    {
-        private readonly Stack<IDisposable> _bindings = bindings;
-
-        public void Dispose()
-        {
-            while (_bindings.Count > 0)
-            {
-                _bindings.Pop().Dispose();
-            }
-        }
-    }
-
     private static string? ReadHeader(HttpContext context, string headerName)
     {
         return context.Request.Headers.TryGetValue(headerName, out StringValues values)

src/ZB.MOM.WW.MxGateway.Server/Galaxy/GalaxyAlarmAttributeRow.cs

@@ -0,0 +1,36 @@
+namespace ZB.MOM.WW.MxGateway.Server.Galaxy;
+
+/// <summary>
+///     One alarm-bearing attribute discovered by
+///     <see cref="GalaxyRepository.GetAlarmAttributesAsync"/>: an attribute whose owning
+///     object configures an <c>AlarmExtension</c> primitive (the same
+///     <c>is_alarm</c> detection used by <see cref="GalaxyRepository.GetAttributesAsync"/>).
+///     Used to build the subtag-fallback watch-list.
+/// </summary>
+public sealed class GalaxyAlarmAttributeRow
+{
+    /// <summary>
+    ///     Gets the alarm-bearing attribute reference (e.g. <c>Tank01.Level.HiHi</c>),
+    ///     matching the <c>full_tag_reference</c> projection of
+    ///     <see cref="GalaxyRepository.GetAttributesAsync"/>.
+    /// </summary>
+    public string FullTagReference { get; init; } = string.Empty;
+
+    /// <summary>
+    ///     Gets the owning object reference (e.g. <c>Tank01</c>). This is the Galaxy
+    ///     <c>tag_name</c> — the segment that precedes the first attribute dot in
+    ///     <see cref="FullTagReference"/>.
+    /// </summary>
+    public string SourceObjectReference { get; init; } = string.Empty;
+
+    /// <summary>
+    ///     Gets the writable ack-comment attribute address.
+    ///     <para>
+    ///     The Galaxy Repository schema does not expose an ack-comment subtag address
+    ///     directly, so this is always <see cref="string.Empty"/> here. The watch-list
+    ///     resolver (a later task) composes the concrete address from configuration plus
+    ///     <see cref="SourceObjectReference"/> / <see cref="FullTagReference"/>.
+    ///     </para>
+    /// </summary>
+    public string AckCommentSubtag { get; init; } = string.Empty;
+}

src/ZB.MOM.WW.MxGateway.Server/Galaxy/GalaxyRepository.cs

@@ -114,6 +114,56 @@ public sealed class GalaxyRepository(GalaxyRepositoryOptions options) : IGalaxyR
         return rows;
     }
 
+    /// <summary>
+    ///     Retrieves only the alarm-bearing attributes for the subtag-fallback watch-list.
+    ///     Alarm detection is identical to <see cref="GetAttributesAsync"/>: a row is
+    ///     alarm-bearing when its owning object configures an <c>AlarmExtension</c>
+    ///     primitive (the same <c>is_alarm</c> projection, here applied as a SQL filter).
+    /// </summary>
+    /// <param name="ct">Token to cancel the asynchronous operation.</param>
+    public async Task<List<GalaxyAlarmAttributeRow>> GetAlarmAttributesAsync(CancellationToken ct = default)
+    {
+        List<GalaxyAlarmAttributeRow> rows = new();
+
+        using SqlConnection conn = new(options.ConnectionString);
+        await conn.OpenAsync(ct).ConfigureAwait(false);
+
+        using SqlCommand cmd = new(AlarmAttributesSql, conn) { CommandTimeout = options.CommandTimeoutSeconds };
+        using SqlDataReader reader = await cmd.ExecuteReaderAsync(ct).ConfigureAwait(false);
+
+        while (await reader.ReadAsync(ct).ConfigureAwait(false))
+        {
+            rows.Add(MapAlarmRow(
+                fullTagReference: reader.GetString(0),
+                sourceObjectReference: reader.GetString(1)));
+        }
+        return rows;
+    }
+
+    /// <summary>
+    ///     Maps a raw alarm-attribute reader row to a <see cref="GalaxyAlarmAttributeRow"/>.
+    ///     <para>
+    ///     <paramref name="sourceObjectReference"/> is the Galaxy <c>tag_name</c> (the
+    ///     owning object), and <paramref name="fullTagReference"/> is
+    ///     <c>tag_name + '.' + attribute_name</c> — the same composition the
+    ///     <c>full_tag_reference</c> projection of <see cref="AttributesSql"/> produces.
+    ///     <see cref="GalaxyAlarmAttributeRow.AckCommentSubtag"/> is left empty here; the
+    ///     schema does not expose an ack-comment address and the watch-list resolver
+    ///     composes it later.
+    ///     </para>
+    ///     Exposed internally so the derivation can be unit-tested without a database.
+    /// </summary>
+    /// <param name="fullTagReference">The alarm-bearing attribute reference.</param>
+    /// <param name="sourceObjectReference">The owning object reference (tag name).</param>
+    internal static GalaxyAlarmAttributeRow MapAlarmRow(
+        string fullTagReference,
+        string sourceObjectReference) => new()
+        {
+            FullTagReference = fullTagReference,
+            SourceObjectReference = sourceObjectReference,
+            AckCommentSubtag = string.Empty,
+        };
+
     private const string HierarchySql = @"
 ;WITH template_chain AS (
     SELECT g.gobject_id AS instance_gobject_id, t.gobject_id AS template_gobject_id,
@@ -248,5 +298,71 @@ SELECT
 FROM ranked r
 LEFT JOIN data_type dt ON dt.mx_data_type = r.mx_data_type
 WHERE r.rn = 1
+ORDER BY r.tag_name, r.attribute_name";
+
+    // Alarm-only discovery for the subtag-fallback watch-list. This deliberately reuses the
+    // exact candidate/ranked CTE structure and the same `AlarmExtension`-based is_alarm
+    // detection as AttributesSql so the two queries cannot drift: a row qualifies only when
+    // its user attribute (src_pri 0) anchors an `AlarmExtension` primitive on the owning
+    // object. It projects just what the watch-list needs — full_tag_reference (tag_name +
+    // '.' + attribute_name, matching AttributesSql) and the owning object's tag_name as
+    // source_object_reference. The array `[]` suffix is intentionally omitted: an
+    // alarm-bearing attribute is a scalar anchor, not an array body.
+    private const string AlarmAttributesSql = @"
+;WITH deployed_package_chain AS (
+    SELECT g.gobject_id, p.package_id, p.derived_from_package_id, 0 AS depth
+    FROM gobject g
+    INNER JOIN package p ON p.package_id = g.deployed_package_id
+    WHERE g.is_template = 0 AND g.deployed_package_id <> 0
+    UNION ALL
+    SELECT dpc.gobject_id, p.package_id, p.derived_from_package_id, dpc.depth + 1
+    FROM deployed_package_chain dpc
+    INNER JOIN package p ON p.package_id = dpc.derived_from_package_id
+    WHERE dpc.derived_from_package_id <> 0 AND dpc.depth < 10
+),
+candidate AS (
+    SELECT
+        dpc.gobject_id, g.tag_name, da.attribute_name, dpc.depth, 0 AS src_pri
+    FROM deployed_package_chain dpc
+    INNER JOIN dynamic_attribute da ON da.package_id = dpc.package_id
+    INNER JOIN gobject g ON g.gobject_id = dpc.gobject_id
+    INNER JOIN template_definition td ON td.template_definition_id = g.template_definition_id
+    WHERE td.category_id IN (1, 3, 4, 10, 11, 13, 17, 24, 26)
+        AND da.attribute_name NOT LIKE '[_]%'
+        AND da.attribute_name NOT LIKE '%.Description'
+        AND da.mx_attribute_category IN (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 24)
+    UNION ALL
+    SELECT
+        dpc.gobject_id, g.tag_name,
+        CASE WHEN pi.primitive_name IS NULL OR pi.primitive_name = ''
+             THEN ad.attribute_name
+             ELSE pi.primitive_name + '.' + ad.attribute_name END AS attribute_name,
+        dpc.depth, 1 AS src_pri
+    FROM deployed_package_chain dpc
+    INNER JOIN primitive_instance pi ON pi.package_id = dpc.package_id
+    INNER JOIN attribute_definition ad ON ad.primitive_definition_id = pi.primitive_definition_id
+    INNER JOIN gobject g ON g.gobject_id = dpc.gobject_id
+    INNER JOIN template_definition td ON td.template_definition_id = g.template_definition_id
+    WHERE td.category_id IN (1, 3, 4, 10, 11, 13, 17, 24, 26)
+        AND ad.attribute_name NOT LIKE '[_]%'
+        AND ad.attribute_name NOT LIKE '%.Description'
+),
+ranked AS (
+    SELECT c.*, ROW_NUMBER() OVER (
+        PARTITION BY c.gobject_id, c.attribute_name ORDER BY c.src_pri, c.depth) AS rn
+    FROM candidate c
+)
+SELECT
+    r.tag_name + '.' + r.attribute_name AS full_tag_reference,
+    r.tag_name AS source_object_reference
+FROM ranked r
+WHERE r.rn = 1
+    AND r.src_pri = 0
+    AND EXISTS (
+        SELECT 1 FROM deployed_package_chain dpc2
+        INNER JOIN primitive_instance pi ON pi.package_id = dpc2.package_id AND pi.primitive_name = r.attribute_name
+        INNER JOIN primitive_definition pd ON pd.primitive_definition_id = pi.primitive_definition_id AND pd.primitive_name = 'AlarmExtension'
+        WHERE dpc2.gobject_id = r.gobject_id
+    )
 ORDER BY r.tag_name, r.attribute_name";
 }

src/ZB.MOM.WW.MxGateway.Server/Galaxy/IGalaxyRepository.cs

@@ -27,4 +27,12 @@ public interface IGalaxyRepository
     /// <summary>Retrieves all attributes for Galaxy objects from the repository.</summary>
     /// <param name="ct">Token to cancel the asynchronous operation.</param>
     Task<List<GalaxyAttributeRow>> GetAttributesAsync(CancellationToken ct = default);
+
+    /// <summary>
+    ///     Retrieves only the alarm-bearing attributes (those whose owning object
+    ///     configures an <c>AlarmExtension</c> primitive) for building the
+    ///     subtag-fallback watch-list.
+    /// </summary>
+    /// <param name="ct">Token to cancel the asynchronous operation.</param>
+    Task<List<GalaxyAlarmAttributeRow>> GetAlarmAttributesAsync(CancellationToken ct = default);
 }

src/ZB.MOM.WW.MxGateway.Server/GatewayApplication.cs

@@ -1,5 +1,8 @@
+using System.Security.Cryptography.X509Certificates;
 using Microsoft.AspNetCore.Hosting.StaticWebAssets;
-using Serilog;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Logging.Configuration;
+using ZB.MOM.WW.Health;
 using ZB.MOM.WW.MxGateway.Contracts;
 using ZB.MOM.WW.MxGateway.Server.Alarms;
 using ZB.MOM.WW.MxGateway.Server.Configuration;
@@ -12,6 +15,7 @@ using ZB.MOM.WW.MxGateway.Server.Security.Authentication;
 using ZB.MOM.WW.MxGateway.Server.Security.Authorization;
 using ZB.MOM.WW.MxGateway.Server.Sessions;
 using ZB.MOM.WW.MxGateway.Server.Workers;
+using ZB.MOM.WW.Telemetry;
 using ZB.MOM.WW.Telemetry.Serilog;
 
 namespace ZB.MOM.WW.MxGateway.Server;
@@ -33,10 +37,7 @@ public static class GatewayApplication
         WebApplicationBuilder builder = CreateBuilder(args);
         WebApplication app = builder.Build();
 
-        // Push the per-request correlation properties (via Serilog LogContext) before the
-        // request-logging middleware emits its completion event, so those properties appear on it.
         app.UseGatewayRequestLoggingScope();
-        app.UseSerilogRequestLogging();
         app.UseStaticFiles();
         app.UseAuthentication();
         app.UseAuthorization();
@@ -60,47 +61,68 @@ public static class GatewayApplication
         });
         StaticWebAssetsLoader.UseStaticWebAssets(builder.Environment, builder.Configuration);
 
-        ConfigureSerilog(builder);
+        ConfigureSelfSignedTls(builder);
 
-        builder.Services.AddGatewayConfiguration();
-        builder.Services.AddSqliteAuthStore();
+        builder.AddZbSerilog(o => o.ServiceName = "mxgateway");
+
+        builder.Services.AddGatewayConfiguration(builder.Configuration);
+        builder.Services.AddSqliteAuthStore(builder.Configuration);
         builder.Services.AddGatewayGrpcAuthorization();
-        builder.Services.AddHealthChecks();
+        builder.Services.AddHealthChecks()
+            .AddTypeActivatedCheck<AuthStoreHealthCheck>(
+                "auth-store",
+                failureStatus: null,
+                tags: new[] { ZbHealthTags.Ready });
         builder.Services.AddSingleton<GatewayMetrics>();
+        builder.AddZbTelemetry(o =>
+        {
+            o.ServiceName = "mxgateway";
+            o.Meters = [GatewayMetrics.MeterName]; // "MxGateway.Server" — name unchanged
+            if (Enum.TryParse<ZbExporter>(builder.Configuration["MxGateway:Telemetry:Exporter"], ignoreCase: true, out var exporter))
+                o.Exporter = exporter;
+            var otlp = builder.Configuration["MxGateway:Telemetry:OtlpEndpoint"];
+            if (!string.IsNullOrWhiteSpace(otlp))
+                o.OtlpEndpoint = otlp;
+        });
+        builder.Services.AddSingleton<ILogRedactor, GatewayLogRedactorSeam>();
         builder.Services.AddSingleton<MxAccessGrpcMapper>();
         builder.Services.AddSingleton<MxAccessGrpcRequestValidator>();
         builder.Services.AddSingleton<IEventStreamService, EventStreamService>();
         builder.Services.AddWorkerProcessLauncher();
         builder.Services.AddGatewaySessions();
         builder.Services.AddGatewayAlarms();
-        builder.Services.AddGatewayDashboard();
+        builder.Services.AddGatewayDashboard(builder.Configuration);
         builder.Services.AddGalaxyRepository();
 
         return builder;
     }
 
-    /// <summary>
-    /// Replaces the default Microsoft.Extensions.Logging provider with the shared
-    /// <c>ZB.MOM.WW.Telemetry.Serilog</c> bootstrap (<see cref="ZbSerilogExtensions.AddZbSerilog"/>).
-    /// Sinks and minimum level come from the <c>Serilog</c> configuration section; identity
-    /// (<c>SiteId</c>/<c>NodeRole</c>) is read from <c>MxGateway:Telemetry</c> when present.
-    /// Also registers the project's <see cref="ILogRedactor"/> adapter so the shared redaction
-    /// enricher masks gateway secrets on every event.
-    /// </summary>
-    /// <param name="builder">The web application builder being configured.</param>
-    private static void ConfigureSerilog(WebApplicationBuilder builder)
+    private static void ConfigureSelfSignedTls(WebApplicationBuilder builder)
     {
-        string? siteId = builder.Configuration["MxGateway:Telemetry:SiteId"];
-        string? nodeRole = builder.Configuration["MxGateway:Telemetry:NodeRole"];
-
-        builder.Services.AddSingleton<ILogRedactor, GatewayLogRedactorAdapter>();
-
-        builder.AddZbSerilog(options =>
+        if (!Security.Tls.KestrelTlsInspector.RequiresGeneratedCertificate(builder.Configuration))
         {
-            options.ServiceName = "mxgateway";
-            options.SiteId = string.IsNullOrWhiteSpace(siteId) ? null : siteId;
-            options.NodeRole = string.IsNullOrWhiteSpace(nodeRole) ? null : nodeRole;
+            return;
+        }
+
+        Configuration.TlsOptions tlsOptions =
+            builder.Configuration.GetSection("MxGateway:Tls").Get<Configuration.TlsOptions>()
+            ?? new Configuration.TlsOptions();
+
+        using ILoggerFactory loggerFactory = LoggerFactory.Create(logging =>
+        {
+            logging.AddConfiguration(builder.Configuration.GetSection("Logging"));
+            logging.AddConsole();
         });
+        Security.Tls.SelfSignedCertificateProvider provider = new(
+            tlsOptions,
+            loggerFactory.CreateLogger<Security.Tls.SelfSignedCertificateProvider>(),
+            TimeProvider.System);
+
+        X509Certificate2 certificate = provider.LoadOrCreate();
+        builder.WebHost.ConfigureKestrel(options =>
+            // The certificate is intentionally owned by Kestrel for the application
+            // lifetime; it is not disposed here.
+            options.ConfigureHttpsDefaults(https => https.ServerCertificate = certificate));
     }
 
     private static string ResolveContentRootPath()
@@ -167,13 +189,8 @@ public static class GatewayApplication
     {
         endpoints.MapStaticAssets(ResolveStaticAssetsManifestPath());
 
-        endpoints.MapGet(
-                "/health/live",
-                () => Results.Ok(new GatewayHealthReply(
-                    Status: "Healthy",
-                    DefaultBackend: GatewayContractInfo.DefaultBackendName,
-                    WorkerProtocolVersion: GatewayContractInfo.WorkerProtocolVersion)))
-            .WithName("LiveHealth");
+        endpoints.MapZbHealth();
+        endpoints.MapZbMetrics();
 
         endpoints.MapGrpcService<MxAccessGatewayService>();
         endpoints.MapGrpcService<GalaxyRepositoryGrpcService>();

src/ZB.MOM.WW.MxGateway.Server/Metrics/GatewayMetrics.cs

@@ -1,11 +1,12 @@
 using System.Collections.Concurrent;
 using System.Diagnostics.Metrics;
+using System.Globalization;
 
 namespace ZB.MOM.WW.MxGateway.Server.Metrics;
 
 public sealed class GatewayMetrics : IDisposable
 {
-    public const string MeterName = "MxGateway.Server";
+    public const string MeterName = "ZB.MOM.WW.MxGateway";
 
     private readonly object _syncRoot = new();
     private readonly Meter _meter;
@@ -22,6 +23,7 @@ public sealed class GatewayMetrics : IDisposable
     private readonly Counter<long> _heartbeatFailuresCounter;
     private readonly Counter<long> _streamDisconnectsCounter;
     private readonly Counter<long> _retryAttemptsCounter;
+    private readonly Counter<long> _alarmProviderSwitchesCounter;
     private readonly Histogram<double> _workerStartupLatencyHistogram;
     private readonly Histogram<double> _commandLatencyHistogram;
     private readonly Histogram<double> _eventStreamSendLatencyHistogram;
@@ -34,6 +36,7 @@ public sealed class GatewayMetrics : IDisposable
     private int _workersRunning;
     private int _workerEventQueueDepth;
     private int _grpcEventStreamQueueDepth;
+    private int _alarmProviderMode;
     private long _sessionsOpened;
     private long _sessionsClosed;
     private long _commandsStarted;
@@ -68,14 +71,16 @@ public sealed class GatewayMetrics : IDisposable
         _heartbeatFailuresCounter = _meter.CreateCounter<long>("mxgateway.heartbeats.failed");
         _streamDisconnectsCounter = _meter.CreateCounter<long>("mxgateway.grpc.streams.disconnected");
         _retryAttemptsCounter = _meter.CreateCounter<long>("mxgateway.retries.attempted");
-        _workerStartupLatencyHistogram = _meter.CreateHistogram<double>("mxgateway.workers.startup.duration", "ms");
-        _commandLatencyHistogram = _meter.CreateHistogram<double>("mxgateway.commands.duration", "ms");
-        _eventStreamSendLatencyHistogram = _meter.CreateHistogram<double>("mxgateway.events.stream_send.duration", "ms");
+        _alarmProviderSwitchesCounter = _meter.CreateCounter<long>("mxgateway.alarms.provider_switches");
+        _workerStartupLatencyHistogram = _meter.CreateHistogram<double>("mxgateway.workers.startup.duration", "s");
+        _commandLatencyHistogram = _meter.CreateHistogram<double>("mxgateway.commands.duration", "s");
+        _eventStreamSendLatencyHistogram = _meter.CreateHistogram<double>("mxgateway.events.stream_send.duration", "s");
 
         _meter.CreateObservableGauge("mxgateway.sessions.open", GetOpenSessions);
         _meter.CreateObservableGauge("mxgateway.workers.running", GetWorkersRunning);
         _meter.CreateObservableGauge("mxgateway.events.worker_queue.depth", GetWorkerEventQueueDepth);
         _meter.CreateObservableGauge("mxgateway.events.grpc_stream_queue.depth", GetGrpcEventStreamQueueDepth);
+        _meter.CreateObservableGauge("mxgateway.alarms.provider_mode", GetAlarmProviderMode);
     }
 
     /// <summary>
@@ -144,7 +149,7 @@ public sealed class GatewayMetrics : IDisposable
             _workersRunning++;
         }
 
-        _workerStartupLatencyHistogram.Record(startupDuration.TotalMilliseconds);
+        _workerStartupLatencyHistogram.Record(startupDuration.TotalSeconds);
     }
 
     /// <summary>
@@ -208,7 +213,7 @@ public sealed class GatewayMetrics : IDisposable
 
         KeyValuePair<string, object?> methodTag = new("method", method);
         _commandsSucceededCounter.Add(1, methodTag);
-        _commandLatencyHistogram.Record(duration.TotalMilliseconds, methodTag);
+        _commandLatencyHistogram.Record(duration.TotalSeconds, methodTag);
     }
 
     /// <summary>
@@ -228,7 +233,7 @@ public sealed class GatewayMetrics : IDisposable
         KeyValuePair<string, object?> methodTag = new("method", method);
         KeyValuePair<string, object?> categoryTag = new("category", category);
         _commandsFailedCounter.Add(1, methodTag, categoryTag);
-        _commandLatencyHistogram.Record(duration.TotalMilliseconds, methodTag, categoryTag);
+        _commandLatencyHistogram.Record(duration.TotalSeconds, methodTag, categoryTag);
     }
 
     /// <summary>
@@ -255,7 +260,7 @@ public sealed class GatewayMetrics : IDisposable
     public void RecordEventStreamSend(string family, TimeSpan duration)
     {
         _eventStreamSendLatencyHistogram.Record(
-            duration.TotalMilliseconds,
+            duration.TotalSeconds,
             new KeyValuePair<string, object?>("family", family));
     }
 
@@ -377,6 +382,26 @@ public sealed class GatewayMetrics : IDisposable
         _retryAttemptsCounter.Add(1, new KeyValuePair<string, object?>("area", area));
     }
 
+    /// <summary>
+    /// Records that the alarm provider switched modes and updates the current provider mode gauge.
+    /// </summary>
+    /// <param name="fromMode">Provider mode before the switch (1=alarmmgr, 2=subtag, 0=unknown).</param>
+    /// <param name="toMode">Provider mode after the switch (1=alarmmgr, 2=subtag, 0=unknown).</param>
+    /// <param name="reason">Human-readable reason for the switch.</param>
+    public void AlarmProviderSwitched(int fromMode, int toMode, string reason)
+    {
+        lock (_syncRoot)
+        {
+            _alarmProviderMode = toMode;
+        }
+
+        _alarmProviderSwitchesCounter.Add(
+            1,
+            new KeyValuePair<string, object?>("from", fromMode.ToString(CultureInfo.InvariantCulture)),
+            new KeyValuePair<string, object?>("to", toMode.ToString(CultureInfo.InvariantCulture)),
+            new KeyValuePair<string, object?>("reason", reason));
+    }
+
     /// <summary>
     /// Returns a snapshot of all current metric values.
     /// </summary>
@@ -455,6 +480,14 @@ public sealed class GatewayMetrics : IDisposable
         }
     }
 
+    private int GetAlarmProviderMode()
+    {
+        lock (_syncRoot)
+        {
+            return _alarmProviderMode;
+        }
+    }
+
     private static void Increment(Dictionary<string, long> values, string key)
     {
         values.TryGetValue(key, out long currentValue);

src/ZB.MOM.WW.MxGateway.Server/Security/Audit/CanonicalAuditWriter.cs

@@ -0,0 +1,42 @@
+using ZB.MOM.WW.Audit;
+
+namespace ZB.MOM.WW.MxGateway.Server.Security.Audit;
+
+/// <summary>
+/// Best-effort <see cref="IAuditWriter"/> over the MxGateway-owned
+/// <see cref="SqliteCanonicalAuditStore"/>. It honours the canonical
+/// <see cref="IAuditWriter"/> contract: a failed audit write is swallowed and logged
+/// rather than propagated, so it can never abort the user-facing action that produced it.
+/// </summary>
+/// <remarks>
+/// This is the single sink through which ALL MxGateway audit flows — the library admin
+/// verbs (via <see cref="CanonicalForwardingApiKeyAuditStore"/>) and the gateway's own
+/// dashboard / constraint-denial producers, which write canonical events directly. The
+/// best-effort wrapping here also closes the gap that the library's
+/// <c>SqliteApiKeyAuditStore.AppendAsync</c> propagated exceptions.
+/// </remarks>
+public sealed class CanonicalAuditWriter(
+    SqliteCanonicalAuditStore store,
+    ILogger<CanonicalAuditWriter> logger) : IAuditWriter
+{
+    /// <inheritdoc />
+    public async Task WriteAsync(AuditEvent auditEvent, CancellationToken cancellationToken = default)
+    {
+        ArgumentNullException.ThrowIfNull(auditEvent);
+
+        try
+        {
+            await store.InsertAsync(auditEvent, cancellationToken).ConfigureAwait(false);
+        }
+        catch (Exception exception)
+        {
+            // Best-effort: a failed audit write must never abort the action that produced it.
+            // Swallow everything (including OperationCanceledException) and log for diagnosis.
+            logger.LogWarning(
+                exception,
+                "Failed to persist audit event {EventId} (action {Action}); audit write is best-effort and was suppressed.",
+                auditEvent.EventId,
+                auditEvent.Action);
+        }
+    }
+}

src/ZB.MOM.WW.MxGateway.Server/Security/Audit/CanonicalForwardingApiKeyAuditStore.cs

@@ -0,0 +1,143 @@
+using System.Text.Json;
+using ZB.MOM.WW.Audit;
+using ZB.MOM.WW.Auth.Abstractions.ApiKeys;
+
+namespace ZB.MOM.WW.MxGateway.Server.Security.Audit;
+
+/// <summary>
+/// Adapter that overrides the shared library's <see cref="IApiKeyAuditStore"/> so that
+/// library-emitted API-key audit events (CLI / admin verbs from
+/// <c>ApiKeyAdminCommands</c>) are canonicalized onto <see cref="AuditEvent"/> and routed
+/// through the gateway's <see cref="IAuditWriter"/> into the canonical
+/// <c>audit_event</c> store.
+/// </summary>
+/// <remarks>
+/// Overriding the registered <see cref="IApiKeyAuditStore"/> is the ONLY way to
+/// canonicalize the library-internal <c>ApiKeyAdminCommands</c> events, since that type
+/// cannot be edited. <see cref="ListRecentAsync"/> reads back from the canonical store
+/// and maps each <see cref="AuditEvent"/> to an <see cref="ApiKeyAuditEntry"/> so the
+/// existing dashboard "recent audit" view (and the CLI/store tests) keep working through
+/// this same seam, unchanged.
+/// <para>
+/// The library's own <c>api_key_audit</c> table is left in place but UNUSED — nothing
+/// writes to it once this adapter overrides the library's <c>SqliteApiKeyAuditStore</c>
+/// registration.
+/// </para>
+/// </remarks>
+public sealed class CanonicalForwardingApiKeyAuditStore(
+    IAuditWriter auditWriter,
+    SqliteCanonicalAuditStore store) : IApiKeyAuditStore
+{
+    /// <summary>The canonical <see cref="AuditEvent.Category"/> assigned to API-key events.</summary>
+    public const string ApiKeyCategory = "ApiKey";
+
+    /// <summary>Actor used for the library's keyless <c>init-db</c> event.</summary>
+    private const string SystemActor = "system";
+
+    /// <summary>Actor used for any other keyless (CLI-originated) library event.</summary>
+    private const string CliActor = "cli";
+
+    /// <summary>The library event type that denotes a constraint denial.</summary>
+    private const string ConstraintDeniedEventType = "constraint-denied";
+
+    /// <summary>The library's keyless schema-init event type.</summary>
+    private const string InitDbEventType = "init-db";
+
+    /// <inheritdoc />
+    public async Task AppendAsync(ApiKeyAuditEntry entry, CancellationToken ct)
+    {
+        ArgumentNullException.ThrowIfNull(entry);
+
+        AuditEvent auditEvent = new()
+        {
+            EventId = Guid.NewGuid(),
+            OccurredAtUtc = entry.CreatedUtc,
+            // Keyless library events: init-db is system-originated; any other keyless event
+            // is a CLI/admin verb run without an authenticated principal.
+            Actor = entry.KeyId
+                ?? (entry.EventType == InitDbEventType ? SystemActor : CliActor),
+            Action = entry.EventType,
+            Outcome = entry.EventType == ConstraintDeniedEventType
+                ? AuditOutcome.Denied
+                : AuditOutcome.Success,
+            Category = ApiKeyCategory,
+            Target = entry.KeyId,
+            SourceNode = entry.RemoteAddress,
+            CorrelationId = null,
+            DetailsJson = WrapDetails(entry.Details),
+        };
+
+        // Best-effort: IAuditWriter swallows/logs failures, so this never throws.
+        await auditWriter.WriteAsync(auditEvent, ct).ConfigureAwait(false);
+    }
+
+    /// <inheritdoc />
+    public async Task<IReadOnlyList<ApiKeyAuditEntry>> ListRecentAsync(int limit, CancellationToken ct)
+    {
+        IReadOnlyList<AuditEvent> events = await store.ListRecentAsync(limit, ct).ConfigureAwait(false);
+
+        ApiKeyAuditEntry[] entries = new ApiKeyAuditEntry[events.Count];
+        for (int index = 0; index < events.Count; index++)
+        {
+            AuditEvent auditEvent = events[index];
+            entries[index] = new ApiKeyAuditEntry(
+                KeyId: auditEvent.Actor switch
+                {
+                    // Keyless library events were mapped to the system/cli sentinel actors on the
+                    // way in; map them back to a null KeyId so the dashboard view is faithful.
+                    SystemActor or CliActor => null,
+                    string actor => actor,
+                },
+                EventType: auditEvent.Action,
+                RemoteAddress: auditEvent.SourceNode,
+                CreatedUtc: auditEvent.OccurredAtUtc,
+                Details: UnwrapDetails(auditEvent.DetailsJson));
+        }
+
+        return entries;
+    }
+
+    /// <summary>
+    /// Wraps a free-form library detail string into the canonical
+    /// <c>{"detail": "&lt;escaped&gt;"}</c> JSON envelope, or null when there is no detail.
+    /// </summary>
+    private static string? WrapDetails(string? details)
+    {
+        if (details is null)
+        {
+            return null;
+        }
+
+        return JsonSerializer.Serialize(new Dictionary<string, string> { ["detail"] = details });
+    }
+
+    /// <summary>
+    /// Unwraps the canonical detail envelope back to the original free-form string. Falls
+    /// back to the raw JSON when it is not a recognised <c>{"detail": ...}</c> envelope, so
+    /// directly-emitted canonical events (whose DetailsJson is richer) still surface text.
+    /// </summary>
+    private static string? UnwrapDetails(string? detailsJson)
+    {
+        if (string.IsNullOrEmpty(detailsJson))
+        {
+            return null;
+        }
+
+        try
+        {
+            using JsonDocument document = JsonDocument.Parse(detailsJson);
+            if (document.RootElement.ValueKind == JsonValueKind.Object
+                && document.RootElement.TryGetProperty("detail", out JsonElement detail)
+                && detail.ValueKind == JsonValueKind.String)
+            {
+                return detail.GetString();
+            }
+        }
+        catch (JsonException)
+        {
+            // Not JSON we recognise; surface the raw payload below.
+        }
+
+        return detailsJson;
+    }
+}

src/ZB.MOM.WW.MxGateway.Server/Security/Audit/HttpAuditActorAccessor.cs

@@ -0,0 +1,51 @@
+using System.Security.Claims;
+using ZB.MOM.WW.Auth.AspNetCore;
+
+namespace ZB.MOM.WW.MxGateway.Server.Security.Audit;
+
+/// <summary>
+/// HTTP-context-backed implementation of <see cref="IAuditActorAccessor"/> that reads the
+/// dashboard operator's identity from the current <see cref="IHttpContextAccessor"/>.
+/// </summary>
+/// <remarks>
+/// Claim resolution order:
+/// <list type="number">
+///   <item><see cref="ZbClaimTypes.Username"/> ("zb:username") — the canonical LDAP login name.</item>
+///   <item><see cref="ClaimsPrincipal.Identity"/>.<see cref="System.Security.Principal.IIdentity.Name"/> — framework fallback (= <see cref="ZbClaimTypes.Name"/> = <see cref="ClaimTypes.Name"/> = display name).</item>
+///   <item><see cref="ZbClaimTypes.Name"/> — explicit fallback matching the claim emitted by <c>DashboardAuthenticator.CreatePrincipal</c>.</item>
+/// </list>
+/// Returns <see langword="null"/> when there is no HTTP context or the user is not authenticated.
+/// </remarks>
+public sealed class HttpAuditActorAccessor(IHttpContextAccessor httpContextAccessor) : IAuditActorAccessor
+{
+    /// <inheritdoc />
+    public string? CurrentActor
+    {
+        get
+        {
+            ClaimsPrincipal? user = httpContextAccessor.HttpContext?.User;
+            if (user?.Identity?.IsAuthenticated != true)
+            {
+                return null;
+            }
+
+            // Prefer the canonical login-username claim (set by DashboardAuthenticator).
+            string? username = user.FindFirstValue(ZbClaimTypes.Username);
+            if (!string.IsNullOrWhiteSpace(username))
+            {
+                return username;
+            }
+
+            // Framework fallback: Identity.Name is driven by the ClaimsIdentity nameClaimType,
+            // which DashboardAuthenticator sets to ZbClaimTypes.Name (= ClaimTypes.Name = display name).
+            string? identityName = user.Identity?.Name;
+            if (!string.IsNullOrWhiteSpace(identityName))
+            {
+                return identityName;
+            }
+
+            // Final explicit fallback — ZbClaimTypes.Name claim value directly.
+            return user.FindFirstValue(ZbClaimTypes.Name);
+        }
+    }
+}

src/ZB.MOM.WW.MxGateway.Server/Security/Audit/IAuditActorAccessor.cs

@@ -0,0 +1,18 @@
+namespace ZB.MOM.WW.MxGateway.Server.Security.Audit;
+
+/// <summary>
+/// Returns the current actor name for use in audit events.
+/// </summary>
+/// <remarks>
+/// Implementations resolve the actor from the ambient request context. For the dashboard
+/// this is the authenticated LDAP operator; for non-HTTP contexts (gRPC, CLI) the caller
+/// provides the actor directly and this seam is not used.
+/// </remarks>
+public interface IAuditActorAccessor
+{
+    /// <summary>
+    /// Gets the current actor's username, or <see langword="null"/> when there is no
+    /// authenticated principal in scope (e.g. an anonymous or unauthenticated request).
+    /// </summary>
+    string? CurrentActor { get; }
+}

src/ZB.MOM.WW.MxGateway.Server/Security/Audit/SqliteCanonicalAuditStore.cs

@@ -0,0 +1,138 @@
+using System.Globalization;
+using Microsoft.Data.Sqlite;
+using ZB.MOM.WW.Audit;
+using ZB.MOM.WW.Auth.ApiKeys.Sqlite;
+
+namespace ZB.MOM.WW.MxGateway.Server.Security.Audit;
+
+/// <summary>
+/// MxGateway-owned, append-only SQLite store for canonical
+/// <see cref="AuditEvent"/>s. It writes to a NEW <c>audit_event</c> table in the
+/// SAME database file as the shared <c>ZB.MOM.WW.Auth.ApiKeys</c> stores: both share
+/// the library's <see cref="AuthSqliteConnectionFactory"/> (so they target the same
+/// <c>ApiKeyOptions.SqlitePath</c> with the same WAL/busy-timeout connection config).
+/// </summary>
+/// <remarks>
+/// This store is the canonical sink for ALL MxGateway audit. The library's own
+/// <c>api_key_audit</c> table is left in place but UNUSED after adoption — the library's
+/// <c>IApiKeyAuditStore</c> registration is overridden by
+/// <see cref="CanonicalForwardingApiKeyAuditStore"/>, which forwards onto this store via
+/// <see cref="CanonicalAuditWriter"/>. The library's <c>schema_version</c> /
+/// <c>api_key_audit</c> tables are not touched here; the <c>audit_event</c> table is
+/// created idempotently (<c>CREATE TABLE IF NOT EXISTS</c>) on each write so it
+/// self-bootstraps regardless of migration ordering.
+/// </remarks>
+public sealed class SqliteCanonicalAuditStore(AuthSqliteConnectionFactory connectionFactory)
+{
+    private const string CreateTableSql =
+        """
+        CREATE TABLE IF NOT EXISTS audit_event (
+            event_id        TEXT PRIMARY KEY,
+            occurred_at_utc TEXT NOT NULL,
+            actor           TEXT NOT NULL,
+            action          TEXT NOT NULL,
+            outcome         TEXT NOT NULL,
+            category        TEXT NULL,
+            target          TEXT NULL,
+            source_node     TEXT NULL,
+            correlation_id  TEXT NULL,
+            details_json    TEXT NULL
+        );
+        """;
+
+    /// <summary>Inserts a canonical audit event into the <c>audit_event</c> table.</summary>
+    /// <param name="auditEvent">The canonical event to persist.</param>
+    /// <param name="cancellationToken">Token to observe for cancellation.</param>
+    public async Task InsertAsync(AuditEvent auditEvent, CancellationToken cancellationToken)
+    {
+        ArgumentNullException.ThrowIfNull(auditEvent);
+
+        await using SqliteConnection connection =
+            await connectionFactory.OpenConnectionAsync(cancellationToken).ConfigureAwait(false);
+
+        await EnsureTableAsync(connection, cancellationToken).ConfigureAwait(false);
+
+        await using SqliteCommand command = connection.CreateCommand();
+        command.CommandText =
+            """
+            INSERT INTO audit_event
+                (event_id, occurred_at_utc, actor, action, outcome,
+                 category, target, source_node, correlation_id, details_json)
+            VALUES
+                ($event_id, $occurred_at_utc, $actor, $action, $outcome,
+                 $category, $target, $source_node, $correlation_id, $details_json);
+            """;
+        command.Parameters.AddWithValue("$event_id", auditEvent.EventId.ToString());
+        command.Parameters.AddWithValue("$occurred_at_utc", auditEvent.OccurredAtUtc.ToString("O", CultureInfo.InvariantCulture));
+        command.Parameters.AddWithValue("$actor", auditEvent.Actor);
+        command.Parameters.AddWithValue("$action", auditEvent.Action);
+        command.Parameters.AddWithValue("$outcome", auditEvent.Outcome.ToString());
+        command.Parameters.AddWithValue("$category", (object?)auditEvent.Category ?? DBNull.Value);
+        command.Parameters.AddWithValue("$target", (object?)auditEvent.Target ?? DBNull.Value);
+        command.Parameters.AddWithValue("$source_node", (object?)auditEvent.SourceNode ?? DBNull.Value);
+        command.Parameters.AddWithValue("$correlation_id", (object?)auditEvent.CorrelationId?.ToString() ?? DBNull.Value);
+        command.Parameters.AddWithValue("$details_json", (object?)auditEvent.DetailsJson ?? DBNull.Value);
+
+        await command.ExecuteNonQueryAsync(cancellationToken).ConfigureAwait(false);
+    }
+
+    /// <summary>Returns the most recent canonical audit events, newest first.</summary>
+    /// <param name="limit">Maximum number of events to return.</param>
+    /// <param name="cancellationToken">Token to observe for cancellation.</param>
+    public async Task<IReadOnlyList<AuditEvent>> ListRecentAsync(int limit, CancellationToken cancellationToken)
+    {
+        if (limit <= 0)
+        {
+            return [];
+        }
+
+        await using SqliteConnection connection =
+            await connectionFactory.OpenConnectionAsync(cancellationToken).ConfigureAwait(false);
+
+        await EnsureTableAsync(connection, cancellationToken).ConfigureAwait(false);
+
+        await using SqliteCommand command = connection.CreateCommand();
+        command.CommandText =
+            """
+            SELECT event_id, occurred_at_utc, actor, action, outcome,
+                   category, target, source_node, correlation_id, details_json
+            FROM audit_event
+            ORDER BY rowid DESC
+            LIMIT $limit;
+            """;
+        command.Parameters.AddWithValue("$limit", limit);
+
+        List<AuditEvent> events = [];
+
+        await using SqliteDataReader reader = await command.ExecuteReaderAsync(cancellationToken).ConfigureAwait(false);
+
+        while (await reader.ReadAsync(cancellationToken).ConfigureAwait(false))
+        {
+            events.Add(new AuditEvent
+            {
+                EventId = Guid.Parse(reader.GetString(0)),
+                OccurredAtUtc = ParseUtc(reader.GetString(1)),
+                Actor = reader.GetString(2),
+                Action = reader.GetString(3),
+                Outcome = Enum.Parse<AuditOutcome>(reader.GetString(4)),
+                Category = reader.IsDBNull(5) ? null : reader.GetString(5),
+                Target = reader.IsDBNull(6) ? null : reader.GetString(6),
+                SourceNode = reader.IsDBNull(7) ? null : reader.GetString(7),
+                CorrelationId = reader.IsDBNull(8) ? null : Guid.Parse(reader.GetString(8)),
+                DetailsJson = reader.IsDBNull(9) ? null : reader.GetString(9),
+            });
+        }
+
+        return events;
+    }
+
+    private static async Task EnsureTableAsync(SqliteConnection connection, CancellationToken cancellationToken)
+    {
+        await using SqliteCommand command = connection.CreateCommand();
+        command.CommandText = CreateTableSql;
+        await command.ExecuteNonQueryAsync(cancellationToken).ConfigureAwait(false);
+    }
+
+    private static DateTimeOffset ParseUtc(string value) =>
+        DateTimeOffset.Parse(value, CultureInfo.InvariantCulture, DateTimeStyles.RoundtripKind);
+}

src/ZB.MOM.WW.MxGateway.Server/Security/Authentication/ApiKeyAdminCliRunner.cs

@@ -1,15 +1,19 @@
 using System.Text.Json;
+using ZB.MOM.WW.Auth.Abstractions.ApiKeys;
+using ZB.MOM.WW.Auth.ApiKeys.Admin;
 
 namespace ZB.MOM.WW.MxGateway.Server.Security.Authentication;
 
 /// <summary>
 /// Executes API key administration commands from the CLI.
 /// </summary>
-public sealed class ApiKeyAdminCliRunner(
-    IAuthStoreMigrator migrator,
-    IApiKeyAdminStore adminStore,
-    IApiKeyAuditStore auditStore,
-    IApiKeySecretHasher hasher)
+/// <remarks>
+/// The create/revoke/rotate/list/init-db verbs (secret generation, peppered hashing, token
+/// assembly and per-action audit) are delegated to the shared
+/// <see cref="ApiKeyAdminCommands"/>. This runner adapts the gateway's strongly-typed command and
+/// output DTOs (which carry <see cref="ApiKeyConstraints"/>) onto the library's JSON-based contract.
+/// </remarks>
+public sealed class ApiKeyAdminCliRunner(ApiKeyAdminCommands commands)
 {
     private static readonly JsonSerializerOptions JsonOptions = new()
     {
@@ -44,8 +48,7 @@ public sealed class ApiKeyAdminCliRunner(
 
     private async Task<ApiKeyAdminOutput> InitDbAsync(CancellationToken cancellationToken)
     {
-        await migrator.MigrateAsync(cancellationToken).ConfigureAwait(false);
-        await AppendAuditAsync(null, "init-db", null, cancellationToken).ConfigureAwait(false);
+        await commands.InitDbAsync(remoteAddress: null, cancellationToken).ConfigureAwait(false);
 
         return new ApiKeyAdminOutput("init-db", "initialized", null, []);
     }
@@ -54,33 +57,26 @@ public sealed class ApiKeyAdminCliRunner(
         ApiKeyAdminCommand command,
         CancellationToken cancellationToken)
     {
-        await migrator.MigrateAsync(cancellationToken).ConfigureAwait(false);
+        // The shared command set requires the schema to exist; init-db is idempotent.
+        await commands.InitDbAsync(remoteAddress: null, cancellationToken).ConfigureAwait(false);
 
         string keyId = Required(command.KeyId);
-        string secret = ApiKeySecretGenerator.Generate();
-        string apiKey = FormatApiKey(keyId, secret);
-
-        await adminStore.CreateAsync(
-                new ApiKeyCreateRequest(
-                    KeyId: keyId,
-                    KeyPrefix: $"mxgw_{keyId}",
-                    SecretHash: hasher.HashSecret(secret),
-                    DisplayName: Required(command.DisplayName),
-                    Scopes: command.Scopes,
-                    Constraints: command.Constraints,
-                    CreatedUtc: DateTimeOffset.UtcNow),
+        CreateKeyResult created = await commands.CreateKeyAsync(
+                keyId,
+                Required(command.DisplayName),
+                command.Scopes,
+                ApiKeyConstraintSerializer.Serialize(command.Constraints),
+                remoteAddress: null,
                 cancellationToken)
             .ConfigureAwait(false);
-        await AppendAuditAsync(keyId, "create-key", null, cancellationToken).ConfigureAwait(false);
 
-        return new ApiKeyAdminOutput("create-key", "created", apiKey, []);
+        return new ApiKeyAdminOutput("create-key", "created", created.Token, []);
     }
 
     private async Task<ApiKeyAdminOutput> ListKeysAsync(CancellationToken cancellationToken)
     {
-        await migrator.MigrateAsync(cancellationToken).ConfigureAwait(false);
-        IReadOnlyList<ApiKeyRecord> keys = await adminStore.ListAsync(cancellationToken).ConfigureAwait(false);
-        await AppendAuditAsync(null, "list-keys", null, cancellationToken).ConfigureAwait(false);
+        await commands.InitDbAsync(remoteAddress: null, cancellationToken).ConfigureAwait(false);
+        IReadOnlyList<ApiKeyListItem> keys = await commands.ListKeysAsync(cancellationToken).ConfigureAwait(false);
 
         return new ApiKeyAdminOutput(
             "list-keys",
@@ -93,35 +89,28 @@ public sealed class ApiKeyAdminCliRunner(
         ApiKeyAdminCommand command,
         CancellationToken cancellationToken)
     {
-        await migrator.MigrateAsync(cancellationToken).ConfigureAwait(false);
+        await commands.InitDbAsync(remoteAddress: null, cancellationToken).ConfigureAwait(false);
 
         string keyId = Required(command.KeyId);
-        bool revoked = await adminStore.RevokeAsync(keyId, DateTimeOffset.UtcNow, cancellationToken)
+        KeyActionResult result = await commands.RevokeKeyAsync(keyId, remoteAddress: null, cancellationToken)
             .ConfigureAwait(false);
 
-        await AppendAuditAsync(keyId, "revoke-key", revoked ? "revoked" : "not-found-or-already-revoked", cancellationToken)
-            .ConfigureAwait(false);
-
-        return new ApiKeyAdminOutput("revoke-key", revoked ? "revoked" : "not-found-or-already-revoked", null, []);
+        return new ApiKeyAdminOutput("revoke-key", result.Succeeded ? "revoked" : "not-found-or-already-revoked", null, []);
     }
 
     private async Task<ApiKeyAdminOutput> RotateKeyAsync(
         ApiKeyAdminCommand command,
         CancellationToken cancellationToken)
     {
-        await migrator.MigrateAsync(cancellationToken).ConfigureAwait(false);
+        await commands.InitDbAsync(remoteAddress: null, cancellationToken).ConfigureAwait(false);
 
         string keyId = Required(command.KeyId);
-        string secret = ApiKeySecretGenerator.Generate();
-        string apiKey = FormatApiKey(keyId, secret);
-
-        bool rotated = await adminStore.RotateAsync(keyId, hasher.HashSecret(secret), DateTimeOffset.UtcNow, cancellationToken)
+        CreateKeyResult rotated = await commands.RotateKeyAsync(keyId, remoteAddress: null, cancellationToken)
             .ConfigureAwait(false);
 
-        await AppendAuditAsync(keyId, "rotate-key", rotated ? "rotated" : "not-found", cancellationToken)
-            .ConfigureAwait(false);
+        bool succeeded = rotated.Token is not null;
 
-        return new ApiKeyAdminOutput("rotate-key", rotated ? "rotated" : "not-found", rotated ? apiKey : null, []);
+        return new ApiKeyAdminOutput("rotate-key", succeeded ? "rotated" : "not-found", rotated.Token, []);
     }
 
     private static async Task WriteOutputAsync(
@@ -150,40 +139,19 @@ public sealed class ApiKeyAdminCliRunner(
         }
     }
 
-    private async Task AppendAuditAsync(
-        string? keyId,
-        string eventType,
-        string? details,
-        CancellationToken cancellationToken)
-    {
-        await auditStore.AppendAsync(
-                new ApiKeyAuditEntry(
-                    KeyId: keyId,
-                    EventType: eventType,
-                    RemoteAddress: null,
-                    Details: details),
-                cancellationToken)
-            .ConfigureAwait(false);
-    }
-
-    private static ApiKeyAdminListedKey ToListedKey(ApiKeyRecord key)
+    private static ApiKeyAdminListedKey ToListedKey(ApiKeyListItem key)
     {
         return new ApiKeyAdminListedKey(
             KeyId: key.KeyId,
             KeyPrefix: key.KeyPrefix,
             DisplayName: key.DisplayName,
             Scopes: key.Scopes,
-            Constraints: key.Constraints,
+            Constraints: ApiKeyConstraintSerializer.Deserialize(key.ConstraintsJson),
             CreatedUtc: key.CreatedUtc,
             LastUsedUtc: key.LastUsedUtc,
             RevokedUtc: key.RevokedUtc);
     }
 
-    private static string FormatApiKey(string keyId, string secret)
-    {
-        return $"mxgw_{keyId}_{secret}";
-    }
-
     private static string Required(string? value)
     {
         return value ?? throw new InvalidOperationException("Required command value was not provided.");

src/ZB.MOM.WW.MxGateway.Server/Security/Authentication/ApiKeyAuditEntry.cs

@@ -1,7 +0,0 @@
-namespace ZB.MOM.WW.MxGateway.Server.Security.Authentication;
-
-public sealed record ApiKeyAuditEntry(
-    string? KeyId,
-    string EventType,
-    string? RemoteAddress,
-    string? Details);

src/ZB.MOM.WW.MxGateway.Server/Security/Authentication/ApiKeyAuditRecord.cs

@@ -1,9 +0,0 @@
-namespace ZB.MOM.WW.MxGateway.Server.Security.Authentication;
-
-public sealed record ApiKeyAuditRecord(
-    long AuditId,
-    string? KeyId,
-    string EventType,
-    string? RemoteAddress,
-    DateTimeOffset CreatedUtc,
-    string? Details);

src/ZB.MOM.WW.MxGateway.Server/Security/Authentication/ApiKeyCreateRequest.cs

@@ -1,10 +0,0 @@
-namespace ZB.MOM.WW.MxGateway.Server.Security.Authentication;
-
-public sealed record ApiKeyCreateRequest(
-    string KeyId,
-    string KeyPrefix,
-    byte[] SecretHash,
-    string DisplayName,
-    IReadOnlySet<string> Scopes,
-    ApiKeyConstraints Constraints,
-    DateTimeOffset CreatedUtc);

src/ZB.MOM.WW.MxGateway.Server/Security/Authentication/ApiKeyParser.cs

@@ -1,49 +0,0 @@
-namespace ZB.MOM.WW.MxGateway.Server.Security.Authentication;
-
-public sealed class ApiKeyParser : IApiKeyParser
-{
-    private const string BearerPrefix = "Bearer ";
-    private const string TokenPrefix = "mxgw_";
-
-    /// <summary>Attempts to parse a Bearer token from an Authorization header and extract the API key ID and secret.</summary>
-    /// <param name="authorizationHeader">Authorization header value to parse.</param>
-    /// <param name="apiKey">Parsed API key with ID and secret, or null if parsing failed.</param>
-    /// <returns>True if the header was successfully parsed; otherwise, false.</returns>
-    public bool TryParseAuthorizationHeader(string? authorizationHeader, out ParsedApiKey? apiKey)
-    {
-        apiKey = null;
-
-        if (string.IsNullOrWhiteSpace(authorizationHeader)
-            || !authorizationHeader.StartsWith(BearerPrefix, StringComparison.OrdinalIgnoreCase))
-        {
-            return false;
-        }
-
-        string token = authorizationHeader[BearerPrefix.Length..].Trim();
-
-        if (!token.StartsWith(TokenPrefix, StringComparison.OrdinalIgnoreCase))
-        {
-            return false;
-        }
-
-        string keyPayload = token[TokenPrefix.Length..];
-        int separatorIndex = keyPayload.IndexOf('_', StringComparison.Ordinal);
-
-        if (separatorIndex <= 0 || separatorIndex == keyPayload.Length - 1)
-        {
-            return false;
-        }
-
-        string keyId = keyPayload[..separatorIndex];
-        string secret = keyPayload[(separatorIndex + 1)..];
-
-        if (string.IsNullOrWhiteSpace(keyId) || string.IsNullOrWhiteSpace(secret))
-        {
-            return false;
-        }
-
-        apiKey = new ParsedApiKey(keyId, secret);
-
-        return true;
-    }
-}

src/ZB.MOM.WW.MxGateway.Server/Security/Authentication/ApiKeyPepperUnavailableException.cs

@@ -1,4 +0,0 @@
-namespace ZB.MOM.WW.MxGateway.Server.Security.Authentication;
-
-public sealed class ApiKeyPepperUnavailableException(string pepperSecretName)
-    : InvalidOperationException($"API key pepper secret '{pepperSecretName}' is not configured.");

src/ZB.MOM.WW.MxGateway.Server/Security/Authentication/ApiKeyRecord.cs

@@ -1,12 +0,0 @@
-namespace ZB.MOM.WW.MxGateway.Server.Security.Authentication;
-
-public sealed record ApiKeyRecord(
-    string KeyId,
-    string KeyPrefix,
-    byte[] SecretHash,
-    string DisplayName,
-    IReadOnlySet<string> Scopes,
-    ApiKeyConstraints Constraints,
-    DateTimeOffset CreatedUtc,
-    DateTimeOffset? LastUsedUtc,
-    DateTimeOffset? RevokedUtc);