src/Core/ZB.MOM.WW.OtOpcUa.Core.Abstractions/DriverTypeNames.cs

@@ -58,6 +58,9 @@ public static class DriverTypeNames
     /// <summary>MQTT / Sparkplug B broker-subscription driver.</summary>
     public const string Mqtt = "Mqtt";
 
+    /// <summary>MTConnect Agent driver — read-only HTTP/XML over an Agent's probe/current/sample surface.</summary>
+    public const string MTConnect = "MTConnect";
+
     /// <summary>
     ///     Every driver-type string declared above, for callers that need to enumerate
     ///     the full set (e.g. validation of an authored <c>DriverType</c>).
@@ -75,5 +78,6 @@ public static class DriverTypeNames
         Calculation,
         Sql,
         Mqtt,
+        MTConnect,
     ];
 }

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.MTConnect/MTConnectDriver.cs

@@ -386,7 +386,12 @@ public sealed class MTConnectDriver : IDriver, IReadable, ISubscribable, ITagDis
     public string DriverInstanceId => _driverInstanceId;
 
     /// <inheritdoc/>
-    public string DriverType => "MTConnect";
+    /// <remarks>
+    ///     Sourced from the <see cref="DriverTypeNames"/> constant rather than a literal — the
+    ///     repo-wide fix for the historical <c>TwinCat</c>/<c>Focas</c> drift, where a driver's own
+    ///     spelling diverged from the constant every dispatch map keys off.
+    /// </remarks>
+    public string DriverType => DriverTypeNames.MTConnect;
 
     /// <summary>
     ///     The live <c>dataItemId → snapshot</c> map that backs the <b>subscription</b> surface:

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.MTConnect/MTConnectDriverFactoryExtensions.cs

@@ -45,13 +45,16 @@ public static class MTConnectDriverFactoryExtensions
     ///     The <c>DriverInstance.DriverType</c> value this factory answers to.
     /// </summary>
     /// <remarks>
-    ///     Kept identical to <see cref="MTConnectDriver.DriverType"/> — the registry key and the
+    ///     <b>Aliased to <see cref="DriverTypeNames.MTConnect"/>, not a literal.</b> The registry key,
-    ///     instance's self-reported type must agree or the runtime would look the driver up under a
+    ///     the instance's self-reported <see cref="MTConnectDriver.DriverType"/>, the probe's
-    ///     name it never registered. Task 16 adds the matching <c>DriverTypeNames.MTConnect</c>
+    ///     <c>DriverType</c>, and the constant every dispatch map keys off are therefore the same
-    ///     constant (the repo's convention is that dispatch maps key off those constants) and wires
+    ///     symbol — the repo-wide fix for the historical <c>TwinCat</c>/<c>Focas</c> drift, where a
-    ///     the Host registration + guard test; this literal is what that constant must equal.
+    ///     driver's own spelling silently diverged from the constant and dispatch maps missed it.
+    ///     Retained as a named const (rather than deleted in favour of the constant) so the existing
+    ///     factory callers and the sibling <c>*DriverFactoryExtensions.DriverTypeName</c> convention
+    ///     keep working; it is now an alias with no independent value.
     /// </remarks>
-    public const string DriverTypeName = "MTConnect";
+    public const string DriverTypeName = DriverTypeNames.MTConnect;
 
     /// <summary>
     ///     Register the MTConnect factory with the driver registry. The optional

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.MTConnect/MTConnectDriverProbe.cs

@@ -86,7 +86,12 @@ public sealed class MTConnectDriverProbe : IDriverProbe
     }
 
     /// <inheritdoc />
-    public string DriverType => "MTConnect";
+    /// <remarks>
+    ///     Sourced from the <see cref="DriverTypeNames"/> constant, not a literal — the probe is
+    ///     looked up by <c>AdminOperationsActor</c> under this key, so a drift from the constant
+    ///     silently disables the Test Connect button rather than failing anything at build time.
+    /// </remarks>
+    public string DriverType => DriverTypeNames.MTConnect;
 
     /// <summary>Minimal probe-only config shape. Deliberately independent of the factory DTO — see the type remarks.</summary>
     private sealed class MTConnectProbeConfigDto

src/Server/ZB.MOM.WW.OtOpcUa.Host/Drivers/DriverFactoryBootstrap.cs

@@ -20,6 +20,7 @@ using GalaxyProbe    = Driver.Galaxy.GalaxyDriverProbe;
 using CalculationProbe = Driver.Calculation.CalculationDriverProbe;
 using SqlProbe       = Driver.Sql.SqlDriverProbe;
 using MqttProbe      = Driver.Mqtt.MqttDriverProbe;
+using MTConnectProbe = Driver.MTConnect.MTConnectDriverProbe;
 
 /// <summary>
 ///     Wires every cross-platform driver assembly's <c>Register(registry, loggerFactory)</c>
@@ -126,6 +127,7 @@ public static class DriverFactoryBootstrap
         services.TryAddEnumerable(ServiceDescriptor.Singleton<IDriverProbe, CalculationProbe>());
         services.TryAddEnumerable(ServiceDescriptor.Singleton<IDriverProbe, SqlProbe>());
         services.TryAddEnumerable(ServiceDescriptor.Singleton<IDriverProbe, MqttProbe>());
+        services.TryAddEnumerable(ServiceDescriptor.Singleton<IDriverProbe, MTConnectProbe>());
 
         return services;
     }
@@ -149,6 +151,13 @@ public static class DriverFactoryBootstrap
         Driver.Galaxy.GalaxyDriverFactoryExtensions.Register(registry, secretResolver, loggerFactory);
         Driver.Modbus.ModbusDriverFactoryExtensions.Register(registry, loggerFactory);
         Driver.Mqtt.MqttDriverFactoryExtensions.Register(registry, loggerFactory);
+        // Tier A (the Register default): fully managed — HttpClient + System.Xml.Linq, no native SDK,
+        // no COM. Tier C is the only tier that arms process-level recycle (MemoryRecycle hard-breach /
+        // ScheduledRecycleScheduler), which would be wrong here: the driver is in-process and killing
+        // it kills every OPC UA session. The long-lived /sample stream does not argue for a slower
+        // tier either — SubscribeAsync returns synchronously after starting the pump on a background
+        // task, so the Tier A 5s Subscribe budget never covers the stream's lifetime.
+        Driver.MTConnect.MTConnectDriverFactoryExtensions.Register(registry, loggerFactory);
         Driver.OpcUaClient.OpcUaClientDriverFactoryExtensions.Register(registry, loggerFactory, secretResolver);
         Driver.S7.S7DriverFactoryExtensions.Register(registry);
         Driver.Sql.SqlDriverFactoryExtensions.Register(registry, loggerFactory);

src/Server/ZB.MOM.WW.OtOpcUa.Host/ZB.MOM.WW.OtOpcUa.Host.csproj

@@ -75,6 +75,7 @@
         <ProjectReference Include="..\..\Drivers\ZB.MOM.WW.OtOpcUa.Driver.Historian.Gateway\ZB.MOM.WW.OtOpcUa.Driver.Historian.Gateway.csproj"/>
         <ProjectReference Include="..\..\Drivers\ZB.MOM.WW.OtOpcUa.Driver.Modbus\ZB.MOM.WW.OtOpcUa.Driver.Modbus.csproj"/>
         <ProjectReference Include="..\..\Drivers\ZB.MOM.WW.OtOpcUa.Driver.Mqtt\ZB.MOM.WW.OtOpcUa.Driver.Mqtt.csproj"/>
+        <ProjectReference Include="..\..\Drivers\ZB.MOM.WW.OtOpcUa.Driver.MTConnect\ZB.MOM.WW.OtOpcUa.Driver.MTConnect.csproj"/>
         <ProjectReference Include="..\..\Drivers\ZB.MOM.WW.OtOpcUa.Driver.OpcUaClient\ZB.MOM.WW.OtOpcUa.Driver.OpcUaClient.csproj"/>
         <ProjectReference Include="..\..\Drivers\ZB.MOM.WW.OtOpcUa.Driver.S7\ZB.MOM.WW.OtOpcUa.Driver.S7.csproj"/>
         <ProjectReference Include="..\..\Drivers\ZB.MOM.WW.OtOpcUa.Driver.Sql\ZB.MOM.WW.OtOpcUa.Driver.Sql.csproj"/>

tests/Core/ZB.MOM.WW.OtOpcUa.Core.Abstractions.Tests/ZB.MOM.WW.OtOpcUa.Core.Abstractions.Tests.csproj

@@ -38,6 +38,7 @@
         <ProjectReference Include="..\..\..\src\Drivers\ZB.MOM.WW.OtOpcUa.Driver.Galaxy\ZB.MOM.WW.OtOpcUa.Driver.Galaxy.csproj"/>
         <ProjectReference Include="..\..\..\src\Drivers\ZB.MOM.WW.OtOpcUa.Driver.Calculation\ZB.MOM.WW.OtOpcUa.Driver.Calculation.csproj"/>
         <ProjectReference Include="..\..\..\src\Drivers\ZB.MOM.WW.OtOpcUa.Driver.Sql\ZB.MOM.WW.OtOpcUa.Driver.Sql.csproj"/>
+        <ProjectReference Include="..\..\..\src\Drivers\ZB.MOM.WW.OtOpcUa.Driver.MTConnect\ZB.MOM.WW.OtOpcUa.Driver.MTConnect.csproj"/>
         <!-- Ships no driver factory (it is a historian backend, not an Equipment driver), so the
              DriverTypeNames guard skips it — but it does hard-code OPC UA status constants, which
              puts it in StatusCodeParityTests' scope. -->

tests/Server/ZB.MOM.WW.OtOpcUa.Host.IntegrationTests/DriverProbeRegistrationTests.cs

@@ -32,6 +32,7 @@ public sealed class DriverProbeRegistrationTests
         "OpcUaClient",
         "GalaxyMxGateway",
         "Calculation",           // v3 Batch 2 pseudo-driver; CalculationProbe registered in DriverFactoryBootstrap
+        "MTConnect",             // MTConnectProbe — read-only Agent driver; probe issues a bare GET /probe
     ];
 
     [Fact]