Phase 3 PR 37 — End-to-end live-stack Galaxy smoke test. Closes the code side of LMX follow-up #5; once OtOpcUaGalaxyHost is installed + started on the dev box, the suite exercises the full topology GalaxyProxyDriver in-process → named-pipe IPC → running OtOpcUaGalaxyHost Windows service → MxAccessGalaxyBackend → live MXAccess runtime → real deployed Galaxy objects. Never spawns the Host process itself — connects to the already-running service per project_galaxy_host_service.md, which is the only way to exercise the production COM-apartment + service-account + pipe-ACL configuration.

LiveStackConfig resolves the pipe name + per-install shared secret from two sources in order: OTOPCUA_GALAXY_PIPE + OTOPCUA_GALAXY_SECRET env vars first (for CI / benchwork overrides), then the service's per-process Environment registry values under HKLM\SYSTEM\CurrentControlSet\Services\OtOpcUaGalaxyHost (what Install-Services.ps1 writes at install time). Registry read requires the test host to run elevated on most boxes — the skip message says so explicitly so operators see the right remediation. Hard-coded secrets are deliberately avoided: the installer generates 32 fresh random bytes per install, a committed secret would diverge from production the moment the service is re-installed.
LiveStackFixture is an IAsyncLifetime that (1) runs AvevaPrerequisites.CheckAllAsync with CheckGalaxyHostPipe=true + CheckHistorian=false — produces a structured PrerequisiteReport whose SkipReason is the exact operator-facing 'here's what you need to fix' text, (2) resolves LiveStackConfig and surfaces a clear skip when the secret isn't discoverable, (3) instantiates GalaxyProxyDriver + calls InitializeAsync (the IPC handshake), capturing a skip with the exception detail + common-cause hints (secret mismatch, SID not in pipe ACL, Host's backend couldn't connect to ZB) rather than letting a NullRef cascade through every subsequent test. SkipIfUnavailable() translates the captured SkipReason into Assert.Skip at the top of every fact so tests read as cleanly-skipped with a visible reason, not silently-passed or crashed.
LiveStackSmokeTests (5 facts, Collection=LiveStack, Category=LiveGalaxy): Fixture_initialized_successfully (cheapest possible end-to-end assertion — if this passes, the IPC handshake worked); Driver_reports_Healthy_after_IPC_handshake (DriverHealth.State post-connect); DiscoverAsync_returns_at_least_one_variable_from_live_galaxy (captures every Variable() call from DiscoverAsync via CapturingAddressSpaceBuilder and asserts > 0 — zero here usually means the Host couldn't read ZB, the skip message names OTOPCUA_GALAXY_ZB_CONN to check); GetHostStatuses_reports_at_least_one_platform (IHostConnectivityProbe surface — zero means the probe loop hasn't fired or no Platform is deployed locally); Can_read_a_discovered_variable_from_live_galaxy (reads the first discovered attribute's full reference, asserts status != BadInternalError — Galaxy's Uncertain-quality-until-first-Engine-scan is intentionally NOT treated as failure since it depends on runtime state that varies across test runs). Read-only by design; writes need an agreed scratch tag to avoid mutating a process-critical attribute — deferred to a follow-up PR that reuses this fixture.
CapturingAddressSpaceBuilder is a minimal IAddressSpaceBuilder that flattens every Variable() call into a list so tests can inspect what discovery produced without booting the full OPC UA node-manager stack; alarm annotation + property calls are no-ops. Scoped private to the test class.
Galaxy.Proxy.Tests csproj gains a ProjectReference to Driver.Galaxy.TestSupport (PR 36) for AvevaPrerequisites. The NU1702 warning about the Host project being net48-referenced-by-net10 is pre-existing from the HostSubprocessParityTests — Proxy.Tests only needs the Host EXE path for that parity scenario, not type surface.
Test run on THIS machine (OtOpcUaGalaxyHost not yet installed): Skipped! Failed 0, Passed 0, Skipped 5 — each skip message includes the full prerequisites report pointing at the missing service. Once the service is installed + started (scripts\install\Install-Services.ps1), the 5 facts will execute against live Galaxy. Proxy.Tests Unit: 17 pass / 0 fail (unchanged — new tests are Category=LiveGalaxy, separate suite). Full Proxy build clean. Memory already captures the 'live tests run via already-running service, don't spawn' convention (project_galaxy_host_service.md).
lmx-followups.md #5 updated: status is 'IN PROGRESS' across PRs 36 + 37 with the explicit remaining work (install + start services, subscribe-and-receive, write round-trip).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

ZB.MOM.WW.OtOpcUa.slnx

@@ -21,6 +21,7 @@
         <Project Path="tests/ZB.MOM.WW.OtOpcUa.Admin.Tests/ZB.MOM.WW.OtOpcUa.Admin.Tests.csproj"/>
         <Project Path="tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Shared.Tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Shared.Tests.csproj"/>
         <Project Path="tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host.Tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host.Tests.csproj"/>
+        <Project Path="tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport.csproj"/>
         <Project Path="tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Proxy.Tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Proxy.Tests.csproj"/>
         <Project Path="tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.E2E/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.E2E.csproj"/>
         <Project Path="tests/ZB.MOM.WW.OtOpcUa.Driver.Modbus.Tests/ZB.MOM.WW.OtOpcUa.Driver.Modbus.Tests.csproj"/>

docs/v2/lmx-followups.md

@@ -9,19 +9,18 @@ rough priority order.
 
 ## 1. Proxy-side `IHistoryProvider` for `ReadAtTime` / `ReadEvents`
 
-**Status**: Host-side IPC shipped (PR 10 + PR 11). Proxy consumer not written.
+**Status**: Capability surface complete (PR 35). OPC UA HistoryRead service-handler
+wiring in `DriverNodeManager` remains as the next step; integration-test still
+pending.
 
-PR 10 added `HistoryReadAtTimeRequest/Response` on the IPC wire and
-`MxAccessGalaxyBackend.HistoryReadAtTimeAsync` delegates to
-`HistorianDataSource.ReadAtTimeAsync`. PR 11 did the same for events
-(`HistoryReadEventsRequest/Response` + `GalaxyHistoricalEvent`). The Proxy
-side (`GalaxyProxyDriver`) doesn't call those yet — `Core.Abstractions.IHistoryProvider`
-only exposes `ReadRawAsync` + `ReadProcessedAsync`.
+PR 35 extended `IHistoryProvider` with `ReadAtTimeAsync` + `ReadEventsAsync`
+(default throwing implementations so existing impls keep compiling), added the
+`HistoricalEvent` + `HistoricalEventsResult` records to
+`Core.Abstractions`, and implemented both methods in `GalaxyProxyDriver` on top
+of the PR 10 / PR 11 IPC messages. Wire-to-domain mapping (`ToHistoricalEvent`)
+is unit-tested for field fidelity, null-preservation, and `DateTimeKind.Utc`.
 
-**To do**:
-- Extend `IHistoryProvider` with `ReadAtTimeAsync(string, DateTime[], …)` and
-  `ReadEventsAsync(string?, DateTime, DateTime, int, …)`.
-- `GalaxyProxyDriver` calls the new IPC message kinds.
+**Remaining**:
 - `DriverNodeManager` wires the new capability methods onto `HistoryRead`
   `AtTime` + `Events` service handlers.
 - Integration test: OPC UA client calls `HistoryReadAtTime` / `HistoryReadEvents`,
@@ -78,18 +77,36 @@ drive a full OPC UA session with username/password, then read an
 `IHostConnectivityProbe`-style "whoami" node to verify the role surfaced).
 That needs a test-only address-space node and is a separate PR.
 
-## 5. Full Galaxy live-service smoke test against the merged v2 stack
+## 5. Full Galaxy live-service smoke test against the merged v2 stack — **IN PROGRESS (PRs 36 + 37)**
 
-**Status**: Individual pieces have live smoke tests (PR 5 MXAccess, PR 13
-probe manager, PR 14 alarm tracker), but the full loop — OPC UA client →
-`OtOpcUaServer` → `GalaxyProxyDriver` (in-process) → named-pipe to
-Galaxy.Host subprocess → live MXAccess runtime → real Galaxy objects — has
-no single end-to-end smoke test.
+PR 36 shipped the prerequisites helper (`AvevaPrerequisites`) that probes
+every dependency a live smoke test needs and produces actionable skip
+messages.
 
-**To do**:
-- Test that spawns the full topology, discovers a deployed Galaxy object,
-  subscribes to one of its attributes, writes a value back, and asserts the
-  write round-tripped through MXAccess. Skip when ArchestrA isn't running.
+PR 37 shipped the live-stack smoke test project structure:
+`tests/Driver.Galaxy.Proxy.Tests/LiveStack/` with `LiveStackFixture` (connects
+to the *already-running* `OtOpcUaGalaxyHost` Windows service via named pipe;
+never spawns the Host process) and `LiveStackSmokeTests` covering:
+
+- Fixture initializes successfully (IPC handshake succeeds end-to-end).
+- Driver reports `DriverState.Healthy` post-handshake.
+- `DiscoverAsync` returns at least one variable from the live Galaxy.
+- `GetHostStatuses` reports at least one Platform/AppEngine host.
+- `ReadAsync` on a discovered variable round-trips through
+  Proxy → Host pipe → MXAccess → back without a BadInternalError.
+
+Shared secret + pipe name resolve from `OTOPCUA_GALAXY_SECRET` /
+`OTOPCUA_GALAXY_PIPE` env vars, falling back to reading the service's
+registry-stored Environment values (requires elevated test host).
+
+**Remaining**:
+- Install + run the `OtOpcUaGalaxyHost` + `OtOpcUa` services on the dev box
+  (`scripts/install/Install-Services.ps1`) so the skip-on-unready tests
+  actually execute and the smoke PR lands green.
+- Subscribe-and-receive-data-change fact (needs a known tag that actually
+  ticks; deferred until operators confirm a scratch tag exists).
+- Write-and-roundtrip fact (needs a test-only UDA or agreed scratch tag
+  so we can't accidentally mutate a process-critical value).
 
 ## 6. Second driver instance on the same server — **DONE (PR 32)**
 

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

@@ -30,6 +30,52 @@ public interface IHistoryProvider
         TimeSpan interval,
         HistoryAggregateType aggregate,
         CancellationToken cancellationToken);
+
+    /// <summary>
+    ///     Read one sample per requested timestamp — OPC UA HistoryReadAtTime service. The
+    ///     driver interpolates (or returns the prior-boundary sample) when no exact match
+    ///     exists. Optional; drivers that can't interpolate throw <see cref="NotSupportedException"/>.
+    /// </summary>
+    /// <remarks>
+    ///     Default implementation throws. Drivers opt in by overriding; keeps existing
+    ///     <c>IHistoryProvider</c> implementations compiling without forcing a ReadAtTime path
+    ///     they may not have a backend for.
+    /// </remarks>
+    Task<HistoryReadResult> ReadAtTimeAsync(
+        string fullReference,
+        IReadOnlyList<DateTime> timestampsUtc,
+        CancellationToken cancellationToken)
+        => throw new NotSupportedException(
+            $"{GetType().Name} does not implement ReadAtTimeAsync. " +
+            "Drivers whose backends support at-time reads override this method.");
+
+    /// <summary>
+    ///     Read historical alarm/event records — OPC UA HistoryReadEvents service. Distinct
+    ///     from the live event stream — historical rows come from an event historian (Galaxy's
+    ///     Alarm Provider history log, etc.) rather than the driver's active subscription.
+    /// </summary>
+    /// <param name="sourceName">
+    ///     Optional filter: null means "all sources", otherwise restrict to events from that
+    ///     source-object name. Drivers may ignore the filter if the backend doesn't support it.
+    /// </param>
+    /// <param name="startUtc">Inclusive lower bound on <c>EventTimeUtc</c>.</param>
+    /// <param name="endUtc">Exclusive upper bound on <c>EventTimeUtc</c>.</param>
+    /// <param name="maxEvents">Upper cap on returned events — the driver's backend enforces this.</param>
+    /// <param name="cancellationToken">Request cancellation.</param>
+    /// <remarks>
+    ///     Default implementation throws. Only drivers with an event historian (Galaxy via the
+    ///     Wonderware Alarm &amp; Events log) override. Modbus / the OPC UA Client driver stay
+    ///     with the default and let callers see <c>BadHistoryOperationUnsupported</c>.
+    /// </remarks>
+    Task<HistoricalEventsResult> ReadEventsAsync(
+        string? sourceName,
+        DateTime startUtc,
+        DateTime endUtc,
+        int maxEvents,
+        CancellationToken cancellationToken)
+        => throw new NotSupportedException(
+            $"{GetType().Name} does not implement ReadEventsAsync. " +
+            "Drivers whose backends have an event historian override this method.");
 }
 
 /// <summary>Result of a HistoryRead call.</summary>
@@ -48,3 +94,29 @@ public enum HistoryAggregateType
     Total,
     Count,
 }
+
+/// <summary>
+///     One row returned by <see cref="IHistoryProvider.ReadEventsAsync"/> — a historical
+///     alarm/event record, not the OPC UA live-event stream. Fields match the minimum set the
+///     Server needs to populate a <c>HistoryEventFieldList</c> for HistoryReadEvents responses.
+/// </summary>
+/// <param name="EventId">Stable unique id for the event — driver-specific format.</param>
+/// <param name="SourceName">Source object that emitted the event. May differ from the <c>sourceName</c> filter the caller passed (fuzzy matches).</param>
+/// <param name="EventTimeUtc">Process-side timestamp — when the event actually occurred.</param>
+/// <param name="ReceivedTimeUtc">Historian-side timestamp — when the historian persisted the row; may lag <paramref name="EventTimeUtc"/> by the historian's buffer flush cadence.</param>
+/// <param name="Message">Human-readable message text.</param>
+/// <param name="Severity">OPC UA severity (1-1000). Drivers map their native priority scale onto this range.</param>
+public sealed record HistoricalEvent(
+    string EventId,
+    string? SourceName,
+    DateTime EventTimeUtc,
+    DateTime ReceivedTimeUtc,
+    string? Message,
+    ushort Severity);
+
+/// <summary>Result of a <see cref="IHistoryProvider.ReadEventsAsync"/> call.</summary>
+/// <param name="Events">Events in chronological order by <c>EventTimeUtc</c>.</param>
+/// <param name="ContinuationPoint">Opaque token for the next call when more events are available; null when complete.</param>
+public sealed record HistoricalEventsResult(
+    IReadOnlyList<HistoricalEvent> Events,
+    byte[]? ContinuationPoint);

src/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Proxy/GalaxyProxyDriver.cs

@@ -339,6 +339,64 @@ public sealed class GalaxyProxyDriver(GalaxyProxyOptions options)
         return new HistoryReadResult(samples, ContinuationPoint: null);
     }
 
+    public async Task<HistoryReadResult> ReadAtTimeAsync(
+        string fullReference, IReadOnlyList<DateTime> timestampsUtc, CancellationToken cancellationToken)
+    {
+        var client = RequireClient();
+        var resp = await client.CallAsync<HistoryReadAtTimeRequest, HistoryReadAtTimeResponse>(
+            MessageKind.HistoryReadAtTimeRequest,
+            new HistoryReadAtTimeRequest
+            {
+                SessionId = _sessionId,
+                TagReference = fullReference,
+                TimestampsUtcUnixMs = [.. timestampsUtc.Select(t => new DateTimeOffset(t, TimeSpan.Zero).ToUnixTimeMilliseconds())],
+            },
+            MessageKind.HistoryReadAtTimeResponse,
+            cancellationToken);
+
+        if (!resp.Success)
+            throw new InvalidOperationException($"Galaxy.Host HistoryReadAtTime failed: {resp.Error}");
+
+        // ReadAtTime returns one sample per requested timestamp in the same order — the Host
+        // pads with bad-quality snapshots when a timestamp can't be interpolated, so response
+        // length matches request length exactly. We trust that contract rather than
+        // re-aligning here, because the Host is the source-of-truth for interpolation policy.
+        IReadOnlyList<DataValueSnapshot> samples = [.. resp.Values.Select(ToSnapshot)];
+        return new HistoryReadResult(samples, ContinuationPoint: null);
+    }
+
+    public async Task<HistoricalEventsResult> ReadEventsAsync(
+        string? sourceName, DateTime startUtc, DateTime endUtc, int maxEvents, CancellationToken cancellationToken)
+    {
+        var client = RequireClient();
+        var resp = await client.CallAsync<HistoryReadEventsRequest, HistoryReadEventsResponse>(
+            MessageKind.HistoryReadEventsRequest,
+            new HistoryReadEventsRequest
+            {
+                SessionId = _sessionId,
+                SourceName = sourceName,
+                StartUtcUnixMs = new DateTimeOffset(startUtc, TimeSpan.Zero).ToUnixTimeMilliseconds(),
+                EndUtcUnixMs = new DateTimeOffset(endUtc, TimeSpan.Zero).ToUnixTimeMilliseconds(),
+                MaxEvents = maxEvents,
+            },
+            MessageKind.HistoryReadEventsResponse,
+            cancellationToken);
+
+        if (!resp.Success)
+            throw new InvalidOperationException($"Galaxy.Host HistoryReadEvents failed: {resp.Error}");
+
+        IReadOnlyList<HistoricalEvent> events = [.. resp.Events.Select(ToHistoricalEvent)];
+        return new HistoricalEventsResult(events, ContinuationPoint: null);
+    }
+
+    internal static HistoricalEvent ToHistoricalEvent(GalaxyHistoricalEvent wire) => new(
+        EventId: wire.EventId,
+        SourceName: wire.SourceName,
+        EventTimeUtc: DateTimeOffset.FromUnixTimeMilliseconds(wire.EventTimeUtcUnixMs).UtcDateTime,
+        ReceivedTimeUtc: DateTimeOffset.FromUnixTimeMilliseconds(wire.ReceivedTimeUtcUnixMs).UtcDateTime,
+        Message: wire.DisplayText,
+        Severity: wire.Severity);
+
     /// <summary>
     ///     Maps the OPC UA Part 13 aggregate enum onto the Wonderware Historian
     ///     AnalogSummaryQuery column names consumed by <c>HistorianDataSource.ReadAggregateAsync</c>.

tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host.Tests/AvevaPrerequisitesLiveTests.cs

@@ -0,0 +1,127 @@
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using Shouldly;
+using Xunit;
+using Xunit.Abstractions;
+using ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host.Tests
+{
+    /// <summary>
+    ///     Exercises <see cref="AvevaPrerequisites"/> against the live dev box so the helper
+    ///     itself gets integration coverage — i.e. "do the probes return Pass for things that
+    ///     really are Pass?" as validated against this machine's known-installed topology.
+    ///     Category <c>LiveGalaxy</c> so CI / clean dev boxes skip cleanly.
+    /// </summary>
+    [Trait("Category", "LiveGalaxy")]
+    public sealed class AvevaPrerequisitesLiveTests
+    {
+        private readonly ITestOutputHelper _output;
+
+        public AvevaPrerequisitesLiveTests(ITestOutputHelper output) => _output = output;
+
+        [Fact]
+        public async Task CheckAll_on_live_box_reports_Framework_install()
+        {
+            var report = await AvevaPrerequisites.CheckAllAsync();
+            _output.WriteLine(report.ToString());
+            report.Checks.ShouldContain(c =>
+                c.Name == "registry:ArchestrA.Framework" && c.Status == PrerequisiteStatus.Pass,
+                "ArchestrA Framework registry root should be found on this machine.");
+        }
+
+        [Fact]
+        public async Task CheckAll_on_live_box_reports_aaBootstrap_running()
+        {
+            var report = await AvevaPrerequisites.CheckAllAsync();
+            var bootstrap = report.Checks.FirstOrDefault(c => c.Name == "service:aaBootstrap");
+            bootstrap.ShouldNotBeNull();
+            bootstrap.Status.ShouldBe(PrerequisiteStatus.Pass,
+                $"aaBootstrap must be Running for any live-Galaxy test to work — detail: {bootstrap.Detail}");
+        }
+
+        [Fact]
+        public async Task CheckAll_on_live_box_reports_aaGR_running()
+        {
+            var report = await AvevaPrerequisites.CheckAllAsync();
+            var gr = report.Checks.FirstOrDefault(c => c.Name == "service:aaGR");
+            gr.ShouldNotBeNull();
+            gr.Status.ShouldBe(PrerequisiteStatus.Pass,
+                $"aaGR (Galaxy Repository) must be Running — detail: {gr.Detail}");
+        }
+
+        [Fact]
+        public async Task CheckAll_on_live_box_reports_MxAccess_COM_registered()
+        {
+            var report = await AvevaPrerequisites.CheckAllAsync();
+            var com = report.Checks.FirstOrDefault(c => c.Name == "com:LMXProxy");
+            com.ShouldNotBeNull();
+            com.Status.ShouldBe(PrerequisiteStatus.Pass,
+                $"LMXProxy.LMXProxyServer ProgID must resolve to an InprocServer32 DLL — detail: {com.Detail}");
+        }
+
+        [Fact]
+        public async Task CheckRepositoryOnly_on_live_box_reports_ZB_reachable()
+        {
+            var report = await AvevaPrerequisites.CheckRepositoryOnlyAsync(ct: CancellationToken.None);
+            var zb = report.Checks.FirstOrDefault(c => c.Name == "sql:ZB");
+            zb.ShouldNotBeNull();
+            zb.Status.ShouldBe(PrerequisiteStatus.Pass,
+                $"ZB database must be reachable via SQL Server Windows auth — detail: {zb.Detail}");
+        }
+
+        [Fact]
+        public async Task CheckRepositoryOnly_on_live_box_reports_non_zero_deployed_objects()
+        {
+            // This box has 49 deployed objects per the research; we just assert > 0 so adding/
+            // removing objects doesn't break the test.
+            var report = await AvevaPrerequisites.CheckRepositoryOnlyAsync();
+            var deployed = report.Checks.FirstOrDefault(c => c.Name == "sql:ZB.deployedObjects");
+            deployed.ShouldNotBeNull();
+            deployed.Status.ShouldBe(PrerequisiteStatus.Pass,
+                $"At least one deployed gobject should exist — detail: {deployed.Detail}");
+        }
+
+        [Fact]
+        public async Task Aveva_side_is_ready_on_this_machine()
+        {
+            // Narrower than "livetest ready" — our own services (OtOpcUa / OtOpcUaGalaxyHost)
+            // may not be installed on a developer's box while they're actively iterating on
+            // them, but the AVEVA side (Framework / Galaxy Repository / MXAccess COM /
+            // SQL / core services) should always be up on a machine with System Platform
+            // installed. This assertion is what gates live-Galaxy tests that go straight to
+            // the Galaxy Repository without routing through our stack.
+            var report = await AvevaPrerequisites.CheckAllAsync(
+                new AvevaPrerequisites.Options { CheckGalaxyHostPipe = false });
+            _output.WriteLine(report.ToString());
+            _output.WriteLine(report.Warnings ?? "no warnings");
+
+            // Enumerate AVEVA-side failures (if any) for an actionable assertion message.
+            var avevaFails = report.Checks
+                .Where(c => c.Status == PrerequisiteStatus.Fail &&
+                            c.Category != PrerequisiteCategory.OtOpcUaService)
+                .ToList();
+            report.IsAvevaSideReady.ShouldBeTrue(
+                avevaFails.Count == 0
+                    ? "unexpected state"
+                    : "AVEVA-side failures: " + string.Join(" ; ",
+                        avevaFails.Select(f => $"{f.Name}: {f.Detail}")));
+        }
+
+        [Fact]
+        public async Task Report_captures_OtOpcUa_services_state_even_when_not_installed()
+        {
+            // The helper reports the status of OtOpcUaGalaxyHost + OtOpcUa services even if
+            // they're not installed yet — absence is itself an actionable signal. This test
+            // doesn't assert Pass/Fail on those services (their state depends on what's
+            // installed when the test runs) — it only asserts the helper EMITTED the rows,
+            // so nobody can ship a prerequisite check that silently omits our own services.
+            var report = await AvevaPrerequisites.CheckAllAsync();
+
+            report.Checks.ShouldContain(c => c.Name == "service:OtOpcUaGalaxyHost");
+            report.Checks.ShouldContain(c => c.Name == "service:OtOpcUa");
+            report.Checks.ShouldContain(c => c.Name == "service:GLAuth");
+        }
+    }
+}

tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host.Tests/GalaxyRepositoryLiveSmokeTests.cs

@@ -6,6 +6,7 @@ using Xunit;
 using ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host.Backend;
 using ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host.Backend.Galaxy;
 using ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Shared.Contracts;
+using ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport;
 
 namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host.Tests
 {
@@ -16,6 +17,11 @@ namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host.Tests
     ///     SQL the v1 Host uses, proving the lift is byte-for-byte equivalent at the
     ///     <c>DiscoverHierarchyResponse</c> shape.
     /// </summary>
+    /// <remarks>
+    ///     Since PR 36, skip logic is delegated to <see cref="AvevaPrerequisites.CheckRepositoryOnlyAsync"/>
+    ///     so operators see exactly why a test skipped ("ZB db not found" vs "SQL Server
+    ///     unreachable") instead of a silent return.
+    /// </remarks>
     [Trait("Category", "LiveGalaxy")]
     public sealed class GalaxyRepositoryLiveSmokeTests
     {
@@ -26,15 +32,20 @@ namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host.Tests
             CommandTimeoutSeconds = 10,
         };
 
+        private static async Task<string?> RepositorySkipReasonAsync()
+        {
+            using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(4));
+            var report = await AvevaPrerequisites.CheckRepositoryOnlyAsync(
+                DevZbOptions().ConnectionString, cts.Token);
+            return report.SkipReason;
+        }
+
         private static async Task<bool> ZbReachableAsync()
         {
-            try
-            {
-                var repo = new GalaxyRepository(DevZbOptions());
-                using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(3));
-                return await repo.TestConnectionAsync(cts.Token);
-            }
-            catch { return false; }
+            // Legacy silent-skip adapter — keeps the existing tests compiling while
+            // gradually migrating to the Skip-with-reason pattern. Returns true when the
+            // prerequisite check has no Fail entries.
+            return (await RepositorySkipReasonAsync()) is null;
         }
 
         [Fact]

tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host.Tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host.Tests.csproj

@@ -23,6 +23,7 @@
 
     <ItemGroup>
         <ProjectReference Include="..\..\src\ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host\ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host.csproj"/>
+        <ProjectReference Include="..\ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport\ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport.csproj"/>
         <Reference Include="System.ServiceProcess"/>
         <!-- IMxProxy's delegate signatures mention ArchestrA.MxAccess.MXSTATUS_PROXY, so tests
              implementing the interface must resolve that type at compile time. -->

tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Proxy.Tests/HistoricalEventMappingTests.cs

@@ -0,0 +1,81 @@
+using Shouldly;
+using Xunit;
+using ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Proxy;
+using ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Shared.Contracts;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Proxy.Tests;
+
+/// <summary>
+///     Pins <see cref="GalaxyProxyDriver.ToHistoricalEvent"/> — the wire-to-domain mapping
+///     from <see cref="GalaxyHistoricalEvent"/> (MessagePack-annotated IPC contract,
+///     Unix-ms timestamps) to <c>Core.Abstractions.HistoricalEvent</c> (domain record,
+///     <see cref="DateTime"/> timestamps). Added in PR 35 alongside the new
+///     <c>IHistoryProvider.ReadEventsAsync</c> method.
+/// </summary>
+[Trait("Category", "Unit")]
+public sealed class HistoricalEventMappingTests
+{
+    [Fact]
+    public void Maps_every_field_from_wire_to_domain_record()
+    {
+        var wire = new GalaxyHistoricalEvent
+        {
+            EventId = "evt-42",
+            SourceName = "Tank1.HiAlarm",
+            EventTimeUtcUnixMs = 1_700_000_000_000L, // 2023-11-14T22:13:20.000Z
+            ReceivedTimeUtcUnixMs = 1_700_000_000_500L,
+            DisplayText = "High level reached",
+            Severity = 750,
+        };
+
+        var domain = GalaxyProxyDriver.ToHistoricalEvent(wire);
+
+        domain.EventId.ShouldBe("evt-42");
+        domain.SourceName.ShouldBe("Tank1.HiAlarm");
+        domain.EventTimeUtc.ShouldBe(new DateTime(2023, 11, 14, 22, 13, 20, DateTimeKind.Utc));
+        domain.ReceivedTimeUtc.ShouldBe(new DateTime(2023, 11, 14, 22, 13, 20, 500, DateTimeKind.Utc));
+        domain.Message.ShouldBe("High level reached");
+        domain.Severity.ShouldBe((ushort)750);
+    }
+
+    [Fact]
+    public void Preserves_null_SourceName_and_DisplayText()
+    {
+        // Historical rows from the Galaxy event historian often omit source or message for
+        // system events (e.g. time sync). The mapping must preserve null — callers use it to
+        // distinguish system events from alarm events.
+        var wire = new GalaxyHistoricalEvent
+        {
+            EventId = "sys-1",
+            SourceName = null,
+            EventTimeUtcUnixMs = 0,
+            ReceivedTimeUtcUnixMs = 0,
+            DisplayText = null,
+            Severity = 1,
+        };
+
+        var domain = GalaxyProxyDriver.ToHistoricalEvent(wire);
+
+        domain.SourceName.ShouldBeNull();
+        domain.Message.ShouldBeNull();
+    }
+
+    [Fact]
+    public void EventTime_and_ReceivedTime_are_produced_as_DateTimeKind_Utc()
+    {
+        // Unix-ms timestamps come off the wire timezone-agnostic; the mapping must tag the
+        // resulting DateTime as Utc so downstream serializers (JSON, OPC UA types) don't apply
+        // an unexpected local-time offset.
+        var wire = new GalaxyHistoricalEvent
+        {
+            EventId = "e",
+            EventTimeUtcUnixMs = 1_000L,
+            ReceivedTimeUtcUnixMs = 2_000L,
+        };
+
+        var domain = GalaxyProxyDriver.ToHistoricalEvent(wire);
+
+        domain.EventTimeUtc.Kind.ShouldBe(DateTimeKind.Utc);
+        domain.ReceivedTimeUtc.Kind.ShouldBe(DateTimeKind.Utc);
+    }
+}

tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Proxy.Tests/LiveStack/LiveStackConfig.cs

@@ -0,0 +1,75 @@
+using System.Runtime.InteropServices;
+using System.Runtime.Versioning;
+using Microsoft.Win32;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Proxy.Tests.LiveStack;
+
+/// <summary>
+///     Resolves the pipe name + shared secret the live <see cref="GalaxyProxyDriver"/> needs
+///     to connect to a running <c>OtOpcUaGalaxyHost</c> Windows service. Two sources are
+///     consulted, first match wins:
+///     <list type="number">
+///         <item>Explicit env vars (<c>OTOPCUA_GALAXY_PIPE</c>, <c>OTOPCUA_GALAXY_SECRET</c>) — lets CI / benchwork override.</item>
+///         <item>The service's per-process <c>Environment</c> registry values under
+///               <c>HKLM\SYSTEM\CurrentControlSet\Services\OtOpcUaGalaxyHost</c> — what
+///               <c>Install-Services.ps1</c> writes at install time. Requires the test to run as a
+///               principal with read access to that registry key (typically Administrators).</item>
+///     </list>
+/// </summary>
+/// <remarks>
+///     Explicitly NOT baked-in-to-source: the shared secret is rotated per install (the
+///     installer generates 32 random bytes and stores the base64 string). A hard-coded secret
+///     in tests would diverge from production the moment someone re-installed the service.
+/// </remarks>
+public sealed record LiveStackConfig(string PipeName, string SharedSecret, string? Source)
+{
+    public const string EnvPipeName = "OTOPCUA_GALAXY_PIPE";
+    public const string EnvSharedSecret = "OTOPCUA_GALAXY_SECRET";
+    public const string ServiceRegistryKey =
+        @"SYSTEM\CurrentControlSet\Services\OtOpcUaGalaxyHost";
+    public const string DefaultPipeName = "OtOpcUaGalaxy";
+
+    public static LiveStackConfig? Resolve()
+    {
+        var envPipe = Environment.GetEnvironmentVariable(EnvPipeName);
+        var envSecret = Environment.GetEnvironmentVariable(EnvSharedSecret);
+        if (!string.IsNullOrWhiteSpace(envPipe) && !string.IsNullOrWhiteSpace(envSecret))
+            return new LiveStackConfig(envPipe, envSecret, "env vars");
+
+        if (!RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+            return null;
+
+        return FromServiceRegistry();
+    }
+
+    [SupportedOSPlatform("windows")]
+    private static LiveStackConfig? FromServiceRegistry()
+    {
+        try
+        {
+            using var key = Registry.LocalMachine.OpenSubKey(ServiceRegistryKey);
+            if (key is null) return null;
+            var env = key.GetValue("Environment") as string[];
+            if (env is null || env.Length == 0) return null;
+
+            string? pipe = null, secret = null;
+            foreach (var line in env)
+            {
+                var eq = line.IndexOf('=');
+                if (eq <= 0) continue;
+                var name = line[..eq];
+                var value = line[(eq + 1)..];
+                if (name.Equals(EnvPipeName, StringComparison.OrdinalIgnoreCase)) pipe = value;
+                else if (name.Equals(EnvSharedSecret, StringComparison.OrdinalIgnoreCase)) secret = value;
+            }
+
+            if (string.IsNullOrWhiteSpace(secret)) return null;
+            return new LiveStackConfig(pipe ?? DefaultPipeName, secret, "service registry");
+        }
+        catch
+        {
+            // Access denied / key missing / malformed — caller gets null and surfaces a Skip.
+            return null;
+        }
+    }
+}

tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Proxy.Tests/LiveStack/LiveStackFixture.cs

@@ -0,0 +1,120 @@
+using System.Threading;
+using System.Threading.Tasks;
+using Xunit;
+using ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Proxy.Tests.LiveStack;
+
+/// <summary>
+///     Connects a single <see cref="GalaxyProxyDriver"/> to the already-running
+///     <c>OtOpcUaGalaxyHost</c> Windows service for the lifetime of a test class. Uses
+///     <see cref="AvevaPrerequisites"/> to decide whether to proceed; on failure,
+///     <see cref="SkipReason"/> is populated and each test calls <see cref="SkipIfUnavailable"/>
+///     to translate that into <c>Assert.Skip</c>.
+/// </summary>
+/// <remarks>
+///     <para>
+///         <b>Does NOT spawn the Host process.</b> Production deploys <c>OtOpcUaGalaxyHost</c>
+///         as a standalone Windows service — spawning a second instance from a test would
+///         bypass the COM-apartment + service-account setup and fail differently than
+///         production (see <c>project_galaxy_host_service.md</c> memory).
+///     </para>
+///     <para>
+///         <b>Shared-secret handling</b>: read from <see cref="LiveStackConfig"/> — env vars
+///         first, then the service's registry-stored <c>Environment</c> values. Requires
+///         the test process to have read access to
+///         <c>HKLM\SYSTEM\CurrentControlSet\Services\OtOpcUaGalaxyHost</c>; on a dev box
+///         that typically means running the test host elevated, or exporting
+///         <c>OTOPCUA_GALAXY_SECRET</c> out-of-band.
+///     </para>
+/// </remarks>
+public sealed class LiveStackFixture : IAsyncLifetime
+{
+    public GalaxyProxyDriver? Driver { get; private set; }
+
+    public string? SkipReason { get; private set; }
+
+    public PrerequisiteReport? PrerequisiteReport { get; private set; }
+
+    public LiveStackConfig? Config { get; private set; }
+
+    public async ValueTask InitializeAsync()
+    {
+        // 1. AVEVA + OtOpcUa service state — actionable diagnostic if anything is missing.
+        using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(10));
+        PrerequisiteReport = await AvevaPrerequisites.CheckAllAsync(
+            new AvevaPrerequisites.Options { CheckGalaxyHostPipe = true, CheckHistorian = false },
+            cts.Token);
+
+        if (!PrerequisiteReport.IsLivetestReady)
+        {
+            SkipReason = PrerequisiteReport.SkipReason;
+            return;
+        }
+
+        // 2. Secret / pipe-name resolution. If the service is running but we can't discover its
+        //    env vars from registry (non-elevated test host), a clear message beats a silent
+        //    connect-rejected failure 10 seconds later.
+        Config = LiveStackConfig.Resolve();
+        if (Config is null)
+        {
+            SkipReason =
+                $"Cannot resolve shared secret. Set {LiveStackConfig.EnvSharedSecret} (and optionally " +
+                $"{LiveStackConfig.EnvPipeName}) in the environment, or run the test host elevated so it " +
+                $"can read HKLM\\{LiveStackConfig.ServiceRegistryKey}\\Environment.";
+            return;
+        }
+
+        // 3. Connect. InitializeAsync does the pipe connect + handshake; a 5-second
+        //    ConnectTimeout gives enough headroom for a service that just started.
+        Driver = new GalaxyProxyDriver(new GalaxyProxyOptions
+        {
+            DriverInstanceId = "live-stack-smoke",
+            PipeName = Config.PipeName,
+            SharedSecret = Config.SharedSecret,
+            ConnectTimeout = TimeSpan.FromSeconds(5),
+        });
+
+        try
+        {
+            await Driver.InitializeAsync(driverConfigJson: "{}", CancellationToken.None);
+        }
+        catch (Exception ex)
+        {
+            SkipReason =
+                $"Connected to named pipe '{Config.PipeName}' but GalaxyProxyDriver.InitializeAsync failed: " +
+                $"{ex.GetType().Name}: {ex.Message}. Common causes: shared secret mismatch (rotated after last install), " +
+                $"service account SID not in pipe ACL (installer sets OTOPCUA_ALLOWED_SID to the service account — " +
+                $"test must run as that user), or Host's backend couldn't connect to ZB.";
+            Driver.Dispose();
+            Driver = null;
+            return;
+        }
+    }
+
+    public async ValueTask DisposeAsync()
+    {
+        if (Driver is not null)
+        {
+            try { await Driver.ShutdownAsync(CancellationToken.None); } catch { /* best-effort */ }
+            Driver.Dispose();
+        }
+    }
+
+    /// <summary>
+    ///     Translate <see cref="SkipReason"/> into <c>Assert.Skip</c>. Tests call this at the
+    ///     top of every fact so a fixture init failure shows up as a cleanly-skipped test with
+    ///     the full prerequisites report, not a cascading NullReferenceException on
+    ///     <see cref="Driver"/>.
+    /// </summary>
+    public void SkipIfUnavailable()
+    {
+        if (SkipReason is not null) Assert.Skip(SkipReason);
+    }
+}
+
+[CollectionDefinition(Name)]
+public sealed class LiveStackCollection : ICollectionFixture<LiveStackFixture>
+{
+    public const string Name = "LiveStack";
+}

tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Proxy.Tests/LiveStack/LiveStackSmokeTests.cs

@@ -0,0 +1,147 @@
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using Shouldly;
+using Xunit;
+using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Proxy.Tests.LiveStack;
+
+/// <summary>
+///     End-to-end smoke against the installed <c>OtOpcUaGalaxyHost</c> Windows service.
+///     Closes LMX follow-up #5 — exercises the full topology: <see cref="GalaxyProxyDriver"/>
+///     in-process → named-pipe IPC → <c>OtOpcUaGalaxyHost</c> service → <c>MxAccessGalaxyBackend</c> →
+///     live MXAccess runtime → real Galaxy objects + attributes.
+/// </summary>
+/// <remarks>
+///     <para>
+///         <b>Preconditions</b> (all checked by <see cref="LiveStackFixture"/>, surfaced via
+///         <c>Assert.Skip</c> when missing):
+///     </para>
+///     <list type="bullet">
+///         <item>AVEVA System Platform installed + Platform deployed.</item>
+///         <item><c>aaBootstrap</c> / <c>aaGR</c> / <c>NmxSvc</c> / <c>MSSQLSERVER</c> running.</item>
+///         <item>MXAccess COM server registered.</item>
+///         <item>ZB database exists with at least one deployed gobject.</item>
+///         <item><c>OtOpcUaGalaxyHost</c> service installed + running (named pipe accepting connections).</item>
+///         <item>Shared secret discoverable via <c>OTOPCUA_GALAXY_SECRET</c> env var or the
+///               service's registry Environment values (test host typically needs to be elevated
+///               to read the latter).</item>
+///         <item>Test process runs as the account listed in the service's pipe ACL
+///               (<c>OTOPCUA_ALLOWED_SID</c>, typically the service account per decision #76).</item>
+///     </list>
+///     <para>
+///         Tests here are deliberately read-only. Writes against live Galaxy attributes are a
+///         separate concern — they need a test-only UDA or an agreed scratch tag so they can't
+///         accidentally mutate a process-critical value. Adding a write test is a follow-up
+///         PR that reuses this fixture.
+///     </para>
+/// </remarks>
+[Trait("Category", "LiveGalaxy")]
+[Collection(LiveStackCollection.Name)]
+public sealed class LiveStackSmokeTests(LiveStackFixture fixture)
+{
+    [Fact]
+    public void Fixture_initialized_successfully()
+    {
+        fixture.SkipIfUnavailable();
+        // If the fixture init succeeded, Driver is non-null and InitializeAsync completed.
+        // This is the cheapest possible assertion that the IPC handshake worked end-to-end;
+        // every other test in this class depends on it.
+        fixture.Driver.ShouldNotBeNull();
+        fixture.Config.ShouldNotBeNull();
+        fixture.PrerequisiteReport.ShouldNotBeNull();
+        fixture.PrerequisiteReport!.IsLivetestReady.ShouldBeTrue(fixture.PrerequisiteReport.SkipReason);
+    }
+
+    [Fact]
+    public void Driver_reports_Healthy_after_IPC_handshake()
+    {
+        fixture.SkipIfUnavailable();
+        var health = fixture.Driver!.GetHealth();
+        health.State.ShouldBe(DriverState.Healthy,
+            $"Expected Healthy after successful IPC connect; Reason={health.LastError}");
+    }
+
+    [Fact]
+    public async Task DiscoverAsync_returns_at_least_one_variable_from_live_galaxy()
+    {
+        fixture.SkipIfUnavailable();
+        var builder = new CapturingAddressSpaceBuilder();
+        using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(30));
+        await fixture.Driver!.DiscoverAsync(builder, cts.Token);
+
+        builder.Variables.Count.ShouldBeGreaterThan(0,
+            "Live Galaxy has > 0 deployed objects per the prereq check — at least one variable must be discovered. " +
+            "Zero usually means the Host couldn't read ZB (check OTOPCUA_GALAXY_ZB_CONN in the service Environment).");
+
+        // Every discovered attribute must carry a non-empty FullName so the OPC UA server can
+        // route reads/writes back. Regression guard — PR 19 normalized this across drivers.
+        builder.Variables.ShouldAllBe(v => !string.IsNullOrEmpty(v.AttributeInfo.FullName));
+    }
+
+    [Fact]
+    public void GetHostStatuses_reports_at_least_one_platform()
+    {
+        fixture.SkipIfUnavailable();
+        var statuses = fixture.Driver!.GetHostStatuses();
+        statuses.Count.ShouldBeGreaterThan(0,
+            "Live Galaxy must report at least one Platform/AppEngine host via IHostConnectivityProbe. " +
+            "Zero means the Host's probe loop hasn't completed its first tick or the Platform isn't deployed locally.");
+
+        // Host names are driver-opaque to the Core but non-empty by contract.
+        statuses.ShouldAllBe(h => !string.IsNullOrEmpty(h.HostName));
+    }
+
+    [Fact]
+    public async Task Can_read_a_discovered_variable_from_live_galaxy()
+    {
+        fixture.SkipIfUnavailable();
+        var builder = new CapturingAddressSpaceBuilder();
+        using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(30));
+        await fixture.Driver!.DiscoverAsync(builder, cts.Token);
+        builder.Variables.Count.ShouldBeGreaterThan(0);
+
+        // Pick the first discovered variable. Read-only smoke — we don't assert on Value,
+        // only that a ReadAsync round-trip through Proxy → Host pipe → MXAccess → back
+        // returns a snapshot with a non-BadInternalError status. Galaxy attributes default to
+        // Uncertain quality until the Engine's first scan publishes them, which is fine here.
+        var full = builder.Variables[0].AttributeInfo.FullName;
+        var snapshots = await fixture.Driver!.ReadAsync([full], cts.Token);
+
+        snapshots.Count.ShouldBe(1);
+        var snap = snapshots[0];
+        snap.StatusCode.ShouldNotBe(0x80020000u,
+            $"Read returned BadInternalError for {full} — the Host couldn't fulfil the request. " +
+            $"Investigate: the Host service's logs at {System.Environment.GetFolderPath(System.Environment.SpecialFolder.CommonApplicationData)}\\OtOpcUa\\Galaxy\\logs.");
+    }
+
+    /// <summary>
+    ///     Minimal <see cref="IAddressSpaceBuilder"/> implementation that captures every
+    ///     Variable() call into a flat list so tests can inspect what discovery produced
+    ///     without running the full OPC UA node-manager stack.
+    /// </summary>
+    private sealed class CapturingAddressSpaceBuilder : IAddressSpaceBuilder
+    {
+        public List<(string BrowseName, DriverAttributeInfo AttributeInfo)> Variables { get; } = [];
+
+        public IAddressSpaceBuilder Folder(string browseName, string displayName) => this;
+        public IVariableHandle Variable(string browseName, string displayName, DriverAttributeInfo attributeInfo)
+        {
+            Variables.Add((browseName, attributeInfo));
+            return new NoopHandle(attributeInfo.FullName);
+        }
+        public void AddProperty(string browseName, DriverDataType dataType, object? value) { }
+
+        private sealed class NoopHandle(string fullReference) : IVariableHandle
+        {
+            public string FullReference { get; } = fullReference;
+            public IAlarmConditionSink MarkAsAlarmCondition(AlarmConditionInfo info) => new NoopSink();
+            private sealed class NoopSink : IAlarmConditionSink
+            {
+                public void OnTransition(AlarmEventArgs args) { }
+            }
+        }
+    }
+}

tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Proxy.Tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Proxy.Tests.csproj

@@ -22,6 +22,7 @@
     <ItemGroup>
         <ProjectReference Include="..\..\src\ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Proxy\ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Proxy.csproj"/>
         <ProjectReference Include="..\..\src\ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host\ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host.csproj"/>
+        <ProjectReference Include="..\ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport\ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport.csproj"/>
     </ItemGroup>
 
     <ItemGroup>

tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport/AvevaPrerequisites.cs

@@ -0,0 +1,163 @@
+using ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport.Probes;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport;
+
+/// <summary>
+///     Entry point for live-AVEVA test fixtures. Runs every relevant probe and returns a
+///     <see cref="PrerequisiteReport"/> whose <c>SkipReason</c> feeds <c>Assert.Skip</c> when
+///     the environment isn't set up. Non-Windows hosts get a single aggregated Skip row per
+///     category instead of a flood of individual skips.
+/// </summary>
+/// <remarks>
+///     <para><b>Call shape</b>:</para>
+///     <code>
+///         var report = await AvevaPrerequisites.CheckAllAsync();
+///         if (report.SkipReason is not null) Assert.Skip(report.SkipReason);
+///     </code>
+///     <para><b>Categories in rough order of 'would I want to know first?'</b>:</para>
+///     <list type="number">
+///         <item>Environment — process bitness, OS platform, RPCSS up.</item>
+///         <item>AvevaInstall — Framework registry, install paths, no pending reboot.</item>
+///         <item>AvevaCoreService — aaBootstrap / aaGR / NmxSvc running.</item>
+///         <item>MxAccessCom — LMXProxy.LMXProxyServer ProgID → CLSID → file-on-disk.</item>
+///         <item>GalaxyRepository — SQL reachable, ZB exists, deployed-object count.</item>
+///         <item>OtOpcUaService — our two Windows services + GLAuth.</item>
+///         <item>AvevaSoftService — aaLogger etc., warn only.</item>
+///         <item>AvevaHistorian — aahClientAccessPoint etc., optional.</item>
+///     </list>
+///     <para><b>What's NOT checked here</b>: end-to-end subscribe / read / write against a real
+///     Galaxy tag. That's the job of the live-smoke tests this helper gates — the helper just
+///     tells them whether running is worthwhile.</para>
+/// </remarks>
+public static class AvevaPrerequisites
+{
+    // -------- Individual service lists (kept as data so tests can inspect / override) --------
+
+    /// <summary>Services whose absence means live-Galaxy tests can't run at all.</summary>
+    internal static readonly (string Name, string Purpose)[] CoreServices =
+    [
+        ("aaBootstrap", "master service that starts the Platform process + brokers aa* communication"),
+        ("aaGR", "Galaxy Repository host — mediates IDE / runtime access to ZB"),
+        ("NmxSvc", "Network Message Exchange — MXAccess + Bootstrap transport"),
+        ("MSSQLSERVER", "SQL Server instance that hosts the ZB database"),
+    ];
+
+    /// <summary>Warn-but-don't-fail AVEVA services.</summary>
+    internal static readonly (string Name, string Purpose)[] SoftServices =
+    [
+        ("aaLogger", "ArchestrA Logger — diagnostic log receiver; stack runs without it but error visibility suffers"),
+        ("aaUserValidator", "OS user/group auth for ArchestrA security; only required when Galaxy security mode isn't 'Open'"),
+        ("aaGlobalDataCacheMonitorSvr", "cross-platform global data cache; single-node dev boxes run fine without it"),
+    ];
+
+    /// <summary>Optional AVEVA Historian services — only required for HistoryRead IPC paths.</summary>
+    internal static readonly (string Name, string Purpose)[] HistorianServices =
+    [
+        ("aahClientAccessPoint", "AVEVA Historian Client Access Point — HistoryRead IPC endpoint"),
+        ("aahGateway", "AVEVA Historian Gateway"),
+    ];
+
+    /// <summary>OtOpcUa-stack Windows services + third-party deps we manage.</summary>
+    internal static readonly (string Name, string Purpose, bool HardRequired)[] OtOpcUaServices =
+    [
+        ("OtOpcUaGalaxyHost", "Galaxy.Host out-of-process service (net48 x86, STA + MXAccess)", true),
+        ("OtOpcUa", "Main OPC UA server service (hosts Proxy + DriverHost + Admin-facing DB publisher)", false),
+        ("GLAuth", "LDAP server (dev only) — glauth.exe on localhost:3893", false),
+    ];
+
+    // -------- Orchestrator --------
+
+    public static async Task<PrerequisiteReport> CheckAllAsync(
+        Options? options = null, CancellationToken ct = default)
+    {
+        options ??= new Options();
+        var checks = new List<PrerequisiteCheck>();
+
+        // Environment
+        checks.Add(MxAccessComProbe.CheckProcessBitness());
+
+        // AvevaInstall — registry + files
+        checks.Add(RegistryProbe.CheckFrameworkInstalled());
+        checks.Add(RegistryProbe.CheckPlatformDeployed());
+        checks.Add(RegistryProbe.CheckRebootPending());
+
+        // AvevaCoreService
+        foreach (var (name, purpose) in CoreServices)
+            checks.Add(ServiceProbe.Check(name, PrerequisiteCategory.AvevaCoreService, hardRequired: true, whatItDoes: purpose));
+
+        // MxAccessCom
+        checks.Add(MxAccessComProbe.Check());
+
+        // GalaxyRepository
+        checks.Add(await SqlProbe.CheckZbDatabaseAsync(options.SqlConnectionString, ct));
+        // Deployed-object count only makes sense if the DB check passed.
+        if (checks[checks.Count - 1].Status == PrerequisiteStatus.Pass)
+            checks.Add(await SqlProbe.CheckDeployedObjectCountAsync(options.SqlConnectionString, ct));
+
+        // OtOpcUaService
+        foreach (var (name, purpose, hard) in OtOpcUaServices)
+            checks.Add(ServiceProbe.Check(name, PrerequisiteCategory.OtOpcUaService, hardRequired: hard, whatItDoes: purpose));
+        if (options.CheckGalaxyHostPipe)
+            checks.Add(await NamedPipeProbe.CheckGalaxyHostPipeAsync(options.GalaxyHostPipeName, ct));
+
+        // AvevaSoftService
+        foreach (var (name, purpose) in SoftServices)
+            checks.Add(ServiceProbe.Check(name, PrerequisiteCategory.AvevaSoftService, hardRequired: false, whatItDoes: purpose));
+
+        // AvevaHistorian
+        if (options.CheckHistorian)
+        {
+            foreach (var (name, purpose) in HistorianServices)
+                checks.Add(ServiceProbe.Check(name, PrerequisiteCategory.AvevaHistorian, hardRequired: false, whatItDoes: purpose));
+        }
+
+        return new PrerequisiteReport(checks);
+    }
+
+    /// <summary>
+    ///     Narrower check for tests that only need the Galaxy Repository (SQL) path — don't
+    ///     pay the cost of probing every aa* service when the test only reads gobject rows.
+    /// </summary>
+    public static async Task<PrerequisiteReport> CheckRepositoryOnlyAsync(
+        string? sqlConnectionString = null, CancellationToken ct = default)
+    {
+        var checks = new List<PrerequisiteCheck>
+        {
+            await SqlProbe.CheckZbDatabaseAsync(sqlConnectionString, ct),
+        };
+        if (checks[0].Status == PrerequisiteStatus.Pass)
+            checks.Add(await SqlProbe.CheckDeployedObjectCountAsync(sqlConnectionString, ct));
+        return new PrerequisiteReport(checks);
+    }
+
+    /// <summary>
+    ///     Narrower check for the named-pipe endpoint — tests that drive the full Proxy
+    ///     against a live Galaxy.Host service don't need the SQL or AVEVA-internal probes
+    ///     (the Host does that work internally; we just need the pipe to accept).
+    /// </summary>
+    public static async Task<PrerequisiteReport> CheckGalaxyHostPipeOnlyAsync(
+        string? pipeName = null, CancellationToken ct = default)
+    {
+        var checks = new List<PrerequisiteCheck>
+        {
+            await NamedPipeProbe.CheckGalaxyHostPipeAsync(pipeName, ct),
+        };
+        return new PrerequisiteReport(checks);
+    }
+
+    /// <summary>Knobs for <see cref="CheckAllAsync"/>.</summary>
+    public sealed class Options
+    {
+        /// <summary>SQL Server connection string — defaults to Windows-auth <c>localhost\ZB</c>.</summary>
+        public string? SqlConnectionString { get; init; }
+
+        /// <summary>Named-pipe endpoint for OtOpcUaGalaxyHost — defaults to <c>OtOpcUaGalaxy</c>.</summary>
+        public string? GalaxyHostPipeName { get; init; }
+
+        /// <summary>Include the named-pipe probe. Off by default — it's a seconds-long TCP-like probe and some tests don't need it.</summary>
+        public bool CheckGalaxyHostPipe { get; init; } = true;
+
+        /// <summary>Include Historian service probes. Off by default — Historian is optional.</summary>
+        public bool CheckHistorian { get; init; } = false;
+    }
+}

tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport/Net48Polyfills.cs

@@ -0,0 +1,26 @@
+#if NET48
+// Polyfills for C# 9+ language features that the helper uses but that net48 BCL doesn't
+// provide. Keeps the sources single-target-free at the language level — the same .cs files
+// build on both frameworks without preprocessor guards in the callsites.
+
+namespace System.Runtime.CompilerServices
+{
+    /// <summary>Required by C# 9 <c>init</c>-only setters and <c>record</c> types.</summary>
+    internal static class IsExternalInit { }
+}
+
+namespace System.Runtime.Versioning
+{
+    /// <summary>
+    ///     Minimal shim for the .NET 5+ <c>SupportedOSPlatformAttribute</c>. Pure marker for the
+    ///     compiler on net10; on net48 we still want the attribute to exist so the same
+    ///     <c>[SupportedOSPlatform("windows")]</c> source compiles. The attribute is internal
+    ///     and attribute-targets-everything to minimize surface.
+    /// </summary>
+    [AttributeUsage(AttributeTargets.All, Inherited = false, AllowMultiple = true)]
+    internal sealed class SupportedOSPlatformAttribute(string platformName) : Attribute
+    {
+        public string PlatformName { get; } = platformName;
+    }
+}
+#endif

tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport/PrerequisiteCheck.cs

@@ -0,0 +1,44 @@
+namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport;
+
+/// <summary>One prerequisite probe's outcome. <see cref="AvevaPrerequisites"/> returns many of these.</summary>
+/// <param name="Name">Short diagnostic id — e.g. <c>service:aaBootstrap</c>, <c>sql:ZB</c>, <c>registry:ArchestrA.Framework</c>.</param>
+/// <param name="Category">Which subsystem the probe belongs to — lets callers filter (e.g. "Historian warns don't gate the core Galaxy smoke").</param>
+/// <param name="Status">Outcome.</param>
+/// <param name="Detail">One-line specific message an operator can act on — <c>"aaGR not installed — install the Galaxy Repository role from the System Platform setup"</c> beats <c>"failed"</c>.</param>
+public sealed record PrerequisiteCheck(
+    string Name,
+    PrerequisiteCategory Category,
+    PrerequisiteStatus Status,
+    string Detail);
+
+public enum PrerequisiteStatus
+{
+    /// <summary>Prerequisite is met; no action needed.</summary>
+    Pass,
+    /// <summary>Soft dependency missing — stack still runs but some feature (e.g. logging) is degraded.</summary>
+    Warn,
+    /// <summary>Hard dependency missing — live tests can't proceed; <see cref="PrerequisiteReport.SkipReason"/> surfaces this.</summary>
+    Fail,
+    /// <summary>Probe wasn't applicable in this environment (e.g. non-Windows host, Historian not installed).</summary>
+    Skip,
+}
+
+public enum PrerequisiteCategory
+{
+    /// <summary>Platform sanity — process bitness, OS platform, DCOM/RPCSS.</summary>
+    Environment,
+    /// <summary>Hard-required AVEVA Windows services (aaBootstrap, aaGR, NmxSvc).</summary>
+    AvevaCoreService,
+    /// <summary>Soft-required AVEVA Windows services (aaLogger, aaUserValidator) — warn only.</summary>
+    AvevaSoftService,
+    /// <summary>ArchestrA Framework install markers (registry + files).</summary>
+    AvevaInstall,
+    /// <summary>MXAccess COM server registration + file on disk.</summary>
+    MxAccessCom,
+    /// <summary>SQL Server reachability + ZB database presence + deployed-object count.</summary>
+    GalaxyRepository,
+    /// <summary>Historian services (optional — only required for HistoryRead IPC paths).</summary>
+    AvevaHistorian,
+    /// <summary>OtOpcUa-side services (OtOpcUa, OtOpcUaGalaxyHost) + third-party deps (GLAuth).</summary>
+    OtOpcUaService,
+}

tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport/PrerequisiteReport.cs

@@ -0,0 +1,94 @@
+using System.Text;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport;
+
+/// <summary>
+///     Aggregated result of an <see cref="AvevaPrerequisites.CheckAll"/> run. Test fixtures
+///     typically call <see cref="SkipReason"/> to produce the argument for xUnit's
+///     <c>Assert.Skip</c> when any hard dependency failed.
+/// </summary>
+public sealed class PrerequisiteReport
+{
+    public IReadOnlyList<PrerequisiteCheck> Checks { get; }
+
+    public PrerequisiteReport(IEnumerable<PrerequisiteCheck> checks)
+    {
+        Checks = [.. checks];
+    }
+
+    /// <summary>True when every probe is Pass / Warn / Skip — no Fail entries.</summary>
+    public bool IsLivetestReady => !Checks.Any(c => c.Status == PrerequisiteStatus.Fail);
+
+    /// <summary>
+    ///     True when only the AVEVA-side probes pass — ignores failures in the
+    ///     <see cref="PrerequisiteCategory.OtOpcUaService"/> category. Lets a live-test gate
+    ///     say "AVEVA is ready even if the v2 services aren't installed yet" without
+    ///     conflating the two. Useful for tests that exercise Galaxy directly (e.g.
+    ///     <see cref="GalaxyRepositoryLiveSmokeTests"/>) rather than through our stack.
+    /// </summary>
+    public bool IsAvevaSideReady =>
+        !Checks.Any(c => c.Status == PrerequisiteStatus.Fail && c.Category != PrerequisiteCategory.OtOpcUaService);
+
+    /// <summary>
+    ///     Multi-line message for <c>Assert.Skip</c> when a hard dependency isn't met. Returns
+    ///     null when <see cref="IsLivetestReady"/> is true.
+    /// </summary>
+    public string? SkipReason
+    {
+        get
+        {
+            var fails = Checks.Where(c => c.Status == PrerequisiteStatus.Fail).ToList();
+            if (fails.Count == 0) return null;
+
+            var sb = new StringBuilder();
+            sb.AppendLine($"Live-AVEVA prerequisites not met ({fails.Count} failed):");
+            foreach (var f in fails)
+                sb.AppendLine($"  • [{f.Category}] {f.Name} — {f.Detail}");
+            sb.Append("Run `Get-Service aa*` / `sqlcmd -S localhost -d ZB -E -Q \"SELECT 1\"` to triage.");
+            return sb.ToString();
+        }
+    }
+
+    /// <summary>
+    ///     Human-readable summary of warnings — caller decides whether to log or ignore. Useful
+    ///     when a live test does pass but an operator should know their environment is degraded.
+    /// </summary>
+    public string? Warnings
+    {
+        get
+        {
+            var warns = Checks.Where(c => c.Status == PrerequisiteStatus.Warn).ToList();
+            if (warns.Count == 0) return null;
+
+            var sb = new StringBuilder();
+            sb.AppendLine($"AVEVA prerequisites with warnings ({warns.Count}):");
+            foreach (var w in warns)
+                sb.AppendLine($"  • [{w.Category}] {w.Name} — {w.Detail}");
+            return sb.ToString();
+        }
+    }
+
+    /// <summary>
+    ///     Throw <see cref="InvalidOperationException"/> if any <paramref name="categories"/>
+    ///     contain a Fail — useful when a specific test needs, say, Galaxy Repository but doesn't
+    ///     care about Historian. Call before <c>Assert.Skip</c> if you want to be strict.
+    /// </summary>
+    public void RequireCategories(params PrerequisiteCategory[] categories)
+    {
+        var set = categories.ToHashSet();
+        var fails = Checks.Where(c => c.Status == PrerequisiteStatus.Fail && set.Contains(c.Category)).ToList();
+        if (fails.Count == 0) return;
+
+        var detail = string.Join("; ", fails.Select(f => $"{f.Name}: {f.Detail}"));
+        throw new InvalidOperationException($"Required prerequisite categories failed: {detail}");
+    }
+
+    public override string ToString()
+    {
+        var sb = new StringBuilder();
+        sb.AppendLine($"PrerequisiteReport: {Checks.Count} checks");
+        foreach (var c in Checks)
+            sb.AppendLine($"  [{c.Status,-4}] {c.Category}/{c.Name}: {c.Detail}");
+        return sb.ToString();
+    }
+}

tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport/Probes/MxAccessComProbe.cs

@@ -0,0 +1,102 @@
+using System.Runtime.InteropServices;
+using System.Runtime.Versioning;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport.Probes;
+
+/// <summary>
+///     Confirms MXAccess COM server registration by resolving the
+///     <c>LMXProxy.LMXProxyServer</c> ProgID to its CLSID, then checking that the CLSID's
+///     32-bit <c>InprocServer32</c> entry points at a file that exists on disk.
+/// </summary>
+/// <remarks>
+///     A common failure mode on partial installs: ProgID is registered but the CLSID
+///     InprocServer32 DLL is missing (previous install uninstalled but registry orphan remains).
+///     This probe surfaces that case with an actionable message instead of the
+///     <c>0x80040154 REGDB_E_CLASSNOTREG</c> you'd see from a late COM activation failure.
+/// </remarks>
+public static class MxAccessComProbe
+{
+    public const string ProgId = "LMXProxy.LMXProxyServer";
+    public const string VersionedProgId = "LMXProxy.LMXProxyServer.1";
+
+    public static PrerequisiteCheck Check()
+    {
+        if (!RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+        {
+            return new PrerequisiteCheck("com:LMXProxy", PrerequisiteCategory.MxAccessCom,
+                PrerequisiteStatus.Skip, "COM registration probes only run on Windows.");
+        }
+        return CheckWindows();
+    }
+
+    [SupportedOSPlatform("windows")]
+    private static PrerequisiteCheck CheckWindows()
+    {
+        try
+        {
+            var (clsid, dll) = RegistryProbe.ResolveProgIdToInproc(ProgId);
+            if (clsid is null)
+            {
+                return new PrerequisiteCheck("com:LMXProxy", PrerequisiteCategory.MxAccessCom,
+                    PrerequisiteStatus.Fail,
+                    $"ProgID {ProgId} not registered — MXAccess COM server isn't installed. " +
+                    $"Install System Platform's MXAccess component and re-run.");
+            }
+
+            if (string.IsNullOrWhiteSpace(dll))
+            {
+                return new PrerequisiteCheck("com:LMXProxy", PrerequisiteCategory.MxAccessCom,
+                    PrerequisiteStatus.Fail,
+                    $"ProgID {ProgId} → CLSID {clsid} but InprocServer32 is empty. " +
+                    $"Registry is orphaned; re-register with: regsvr32 /s LmxProxy.dll (from an elevated cmd in the Framework bin dir).");
+            }
+
+            // Resolve the recorded path — sometimes registered as a bare filename that the COM
+            // runtime resolves via the current process's DLL-search path. Accept either an
+            // absolute path that exists, or a bare filename whose resolution we can't verify
+            // without loading it (treat as Pass-with-note).
+            if (Path.IsPathRooted(dll))
+            {
+                if (!File.Exists(dll))
+                {
+                    return new PrerequisiteCheck("com:LMXProxy", PrerequisiteCategory.MxAccessCom,
+                        PrerequisiteStatus.Fail,
+                        $"ProgID {ProgId} → CLSID {clsid} → InprocServer32 {dll}, but the file is missing. " +
+                        $"Re-install the Framework or restore from backup.");
+                }
+                return new PrerequisiteCheck("com:LMXProxy", PrerequisiteCategory.MxAccessCom,
+                    PrerequisiteStatus.Pass,
+                    $"ProgID {ProgId} → {dll} (file exists).");
+            }
+
+            return new PrerequisiteCheck("com:LMXProxy", PrerequisiteCategory.MxAccessCom,
+                PrerequisiteStatus.Pass,
+                $"ProgID {ProgId} → {dll} (bare filename — relies on PATH resolution at COM activation time).");
+        }
+        catch (Exception ex)
+        {
+            return new PrerequisiteCheck("com:LMXProxy", PrerequisiteCategory.MxAccessCom,
+                PrerequisiteStatus.Warn,
+                $"Probe failed: {ex.GetType().Name}: {ex.Message}");
+        }
+    }
+
+    /// <summary>
+    ///     Warn when running as a 64-bit process — MXAccess COM activation will fail with
+    ///     <c>0x80040154</c> regardless of registration state. The production drivers run net48
+    ///     x86; xunit hosts run 64-bit by default so this often surfaces first.
+    /// </summary>
+    public static PrerequisiteCheck CheckProcessBitness()
+    {
+        if (Environment.Is64BitProcess)
+        {
+            return new PrerequisiteCheck("env:ProcessBitness", PrerequisiteCategory.Environment,
+                PrerequisiteStatus.Warn,
+                "Test host is 64-bit. Direct MXAccess COM activation would fail with REGDB_E_CLASSNOTREG (0x80040154); " +
+                "the production driver workaround is to run Galaxy.Host as a 32-bit process. Tests that only " +
+                "talk to the Host service over the named pipe aren't affected.");
+        }
+        return new PrerequisiteCheck("env:ProcessBitness", PrerequisiteCategory.Environment,
+            PrerequisiteStatus.Pass, "Test host is 32-bit.");
+    }
+}

tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport/Probes/NamedPipeProbe.cs

@@ -0,0 +1,59 @@
+using System.IO.Pipes;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport.Probes;
+
+/// <summary>
+///     Verifies the <c>OtOpcUaGalaxyHost</c> named-pipe endpoint is accepting connections —
+///     the handshake the Proxy performs at boot. A clean pipe connect without sending any
+///     framed message proves the Host service is listening; we disconnect immediately so we
+///     don't consume a session slot.
+/// </summary>
+/// <remarks>
+///     Default pipe name matches the installer script's <c>OTOPCUA_GALAXY_PIPE</c> default.
+///     Override when the Host service was installed with a non-default name (custom deployments).
+/// </remarks>
+public static class NamedPipeProbe
+{
+    public const string DefaultGalaxyHostPipeName = "OtOpcUaGalaxy";
+
+    public static async Task<PrerequisiteCheck> CheckGalaxyHostPipeAsync(
+        string? pipeName = null, CancellationToken ct = default)
+    {
+        pipeName ??= DefaultGalaxyHostPipeName;
+        try
+        {
+            using var client = new NamedPipeClientStream(
+                serverName: ".",
+                pipeName: pipeName,
+                direction: PipeDirection.InOut,
+                options: PipeOptions.Asynchronous);
+            using var cts = CancellationTokenSource.CreateLinkedTokenSource(ct);
+            cts.CancelAfter(TimeSpan.FromSeconds(2));
+            await client.ConnectAsync(cts.Token);
+
+            return new PrerequisiteCheck("pipe:OtOpcUaGalaxyHost", PrerequisiteCategory.OtOpcUaService,
+                PrerequisiteStatus.Pass,
+                $@"Pipe \\.\pipe\{pipeName} accepted a connection — OtOpcUaGalaxyHost is listening.");
+        }
+        catch (OperationCanceledException)
+        {
+            return new PrerequisiteCheck("pipe:OtOpcUaGalaxyHost", PrerequisiteCategory.OtOpcUaService,
+                PrerequisiteStatus.Fail,
+                $@"Pipe \\.\pipe\{pipeName} not connectable within 2s — OtOpcUaGalaxyHost service isn't running. " +
+                "Start with: sc.exe start OtOpcUaGalaxyHost");
+        }
+        catch (TimeoutException)
+        {
+            return new PrerequisiteCheck("pipe:OtOpcUaGalaxyHost", PrerequisiteCategory.OtOpcUaService,
+                PrerequisiteStatus.Fail,
+                $@"Pipe \\.\pipe\{pipeName} connect timed out — service may be starting or stuck. " +
+                "Check: sc.exe query OtOpcUaGalaxyHost");
+        }
+        catch (Exception ex)
+        {
+            return new PrerequisiteCheck("pipe:OtOpcUaGalaxyHost", PrerequisiteCategory.OtOpcUaService,
+                PrerequisiteStatus.Fail,
+                $@"Pipe \\.\pipe\{pipeName} connect failed: {ex.GetType().Name}: {ex.Message}");
+        }
+    }
+}

tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport/Probes/RegistryProbe.cs

@@ -0,0 +1,162 @@
+using System.Runtime.InteropServices;
+using System.Runtime.Versioning;
+using Microsoft.Win32;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport.Probes;
+
+/// <summary>
+///     Reads HKLM registry keys to confirm ArchestrA Framework / System Platform install
+///     markers. Matches the registered paths documented in
+///     <c>docs/v2/implementation/</c> — System Platform is 32-bit so keys live under
+///     <c>HKLM\SOFTWARE\WOW6432Node\ArchestrA\...</c>.
+/// </summary>
+public static class RegistryProbe
+{
+    // Canonical install roots per the research on our dev box (System Platform 2020 R2).
+    public const string ArchestrARootKey = @"SOFTWARE\WOW6432Node\ArchestrA";
+    public const string FrameworkKey = @"SOFTWARE\WOW6432Node\ArchestrA\Framework";
+    public const string PlatformKey = @"SOFTWARE\WOW6432Node\ArchestrA\Framework\Platform";
+    public const string MsiInstallKey = @"SOFTWARE\WOW6432Node\ArchestrA\MSIInstall";
+
+    public static PrerequisiteCheck CheckFrameworkInstalled()
+    {
+        if (!RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+        {
+            return new PrerequisiteCheck("registry:ArchestrA.Framework", PrerequisiteCategory.AvevaInstall,
+                PrerequisiteStatus.Skip, "Registry probes only run on Windows.");
+        }
+        return FrameworkInstalledWindows();
+    }
+
+    public static PrerequisiteCheck CheckPlatformDeployed()
+    {
+        if (!RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+        {
+            return new PrerequisiteCheck("registry:ArchestrA.Platform", PrerequisiteCategory.AvevaInstall,
+                PrerequisiteStatus.Skip, "Registry probes only run on Windows.");
+        }
+        return PlatformDeployedWindows();
+    }
+
+    public static PrerequisiteCheck CheckRebootPending()
+    {
+        if (!RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+        {
+            return new PrerequisiteCheck("registry:ArchestrA.RebootPending", PrerequisiteCategory.AvevaInstall,
+                PrerequisiteStatus.Skip, "Registry probes only run on Windows.");
+        }
+        return RebootPendingWindows();
+    }
+
+    [SupportedOSPlatform("windows")]
+    private static PrerequisiteCheck FrameworkInstalledWindows()
+    {
+        try
+        {
+            using var key = Registry.LocalMachine.OpenSubKey(FrameworkKey);
+            if (key is null)
+            {
+                return new PrerequisiteCheck("registry:ArchestrA.Framework", PrerequisiteCategory.AvevaInstall,
+                    PrerequisiteStatus.Fail,
+                    $"Missing {FrameworkKey} — ArchestrA Framework isn't installed. Install AVEVA System Platform from the setup media.");
+            }
+
+            var installPath = key.GetValue("InstallPath") as string;
+            var rootPath = key.GetValue("RootPath") as string;
+            if (string.IsNullOrWhiteSpace(installPath) || string.IsNullOrWhiteSpace(rootPath))
+            {
+                return new PrerequisiteCheck("registry:ArchestrA.Framework", PrerequisiteCategory.AvevaInstall,
+                    PrerequisiteStatus.Warn,
+                    $"Framework key exists but InstallPath/RootPath values missing — install may be incomplete.");
+            }
+
+            return new PrerequisiteCheck("registry:ArchestrA.Framework", PrerequisiteCategory.AvevaInstall,
+                PrerequisiteStatus.Pass,
+                $"Installed at {installPath} (RootPath {rootPath}).");
+        }
+        catch (Exception ex)
+        {
+            return new PrerequisiteCheck("registry:ArchestrA.Framework", PrerequisiteCategory.AvevaInstall,
+                PrerequisiteStatus.Warn,
+                $"Probe failed: {ex.GetType().Name}: {ex.Message}");
+        }
+    }
+
+    [SupportedOSPlatform("windows")]
+    private static PrerequisiteCheck PlatformDeployedWindows()
+    {
+        try
+        {
+            using var key = Registry.LocalMachine.OpenSubKey(PlatformKey);
+            var pfeConfig = key?.GetValue("PfeConfigOptions") as string;
+            if (string.IsNullOrWhiteSpace(pfeConfig))
+            {
+                return new PrerequisiteCheck("registry:ArchestrA.Platform.Deployed", PrerequisiteCategory.AvevaInstall,
+                    PrerequisiteStatus.Warn,
+                    $"No Platform object deployed locally (Platform\\PfeConfigOptions empty). MXAccess will connect but subscriptions will fail. Deploy a Platform from the IDE.");
+            }
+
+            // PfeConfigOptions format: "PlatformId=N,EngineId=N,EngineName=...,..."
+            // A non-deployed state leaves PlatformId=0 or the key empty.
+            if (pfeConfig.Contains("PlatformId=0,", StringComparison.OrdinalIgnoreCase))
+            {
+                return new PrerequisiteCheck("registry:ArchestrA.Platform.Deployed", PrerequisiteCategory.AvevaInstall,
+                    PrerequisiteStatus.Warn,
+                    $"Platform never deployed (PfeConfigOptions has PlatformId=0). Deploy a Platform from the IDE before running live tests.");
+            }
+
+            return new PrerequisiteCheck("registry:ArchestrA.Platform.Deployed", PrerequisiteCategory.AvevaInstall,
+                PrerequisiteStatus.Pass,
+                $"Platform deployed ({pfeConfig}).");
+        }
+        catch (Exception ex)
+        {
+            return new PrerequisiteCheck("registry:ArchestrA.Platform.Deployed", PrerequisiteCategory.AvevaInstall,
+                PrerequisiteStatus.Warn,
+                $"Probe failed: {ex.GetType().Name}: {ex.Message}");
+        }
+    }
+
+    [SupportedOSPlatform("windows")]
+    private static PrerequisiteCheck RebootPendingWindows()
+    {
+        try
+        {
+            using var key = Registry.LocalMachine.OpenSubKey(MsiInstallKey);
+            var rebootRequired = key?.GetValue("RebootRequired") as string;
+            if (string.Equals(rebootRequired, "True", StringComparison.OrdinalIgnoreCase))
+            {
+                return new PrerequisiteCheck("registry:ArchestrA.RebootPending", PrerequisiteCategory.AvevaInstall,
+                    PrerequisiteStatus.Warn,
+                    "An ArchestrA patch has been installed but the machine hasn't rebooted. Post-patch behavior is undefined until a reboot.");
+            }
+            return new PrerequisiteCheck("registry:ArchestrA.RebootPending", PrerequisiteCategory.AvevaInstall,
+                PrerequisiteStatus.Pass,
+                "No pending reboot flagged.");
+        }
+        catch (Exception ex)
+        {
+            return new PrerequisiteCheck("registry:ArchestrA.RebootPending", PrerequisiteCategory.AvevaInstall,
+                PrerequisiteStatus.Warn,
+                $"Probe failed: {ex.GetType().Name}: {ex.Message}");
+        }
+    }
+
+    /// <summary>
+    ///     Read the registered <see cref="ComProgIdCheck"/> CLSID for the given ProgID and
+    ///     resolve the 32-bit <c>InprocServer32</c> file path. Returns null when either is missing.
+    /// </summary>
+    [SupportedOSPlatform("windows")]
+    internal static (string? Clsid, string? InprocDllPath) ResolveProgIdToInproc(string progId)
+    {
+        using var progIdKey = Registry.ClassesRoot.OpenSubKey($@"{progId}\CLSID");
+        var clsid = progIdKey?.GetValue(null) as string;
+        if (string.IsNullOrWhiteSpace(clsid)) return (null, null);
+
+        // 32-bit COM server under Wow6432Node\CLSID\{guid}\InprocServer32 default value.
+        using var inproc = Registry.LocalMachine.OpenSubKey(
+            $@"SOFTWARE\Classes\WOW6432Node\CLSID\{clsid}\InprocServer32");
+        var dll = inproc?.GetValue(null) as string;
+        return (clsid, dll);
+    }
+}

tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport/Probes/ServiceProbe.cs

@@ -0,0 +1,85 @@
+using System.Runtime.InteropServices;
+using System.Runtime.Versioning;
+using System.ServiceProcess;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport.Probes;
+
+/// <summary>
+///     Queries the Windows Service Control Manager to report whether a named service is
+///     installed, its current state, and its start type. Non-Windows hosts return Skip.
+/// </summary>
+public static class ServiceProbe
+{
+    public static PrerequisiteCheck Check(
+        string serviceName,
+        PrerequisiteCategory category,
+        bool hardRequired,
+        string whatItDoes)
+    {
+        if (!RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+        {
+            return new PrerequisiteCheck(
+                Name: $"service:{serviceName}",
+                Category: category,
+                Status: PrerequisiteStatus.Skip,
+                Detail: "Service probes only run on Windows.");
+        }
+
+        return CheckWindows(serviceName, category, hardRequired, whatItDoes);
+    }
+
+    [SupportedOSPlatform("windows")]
+    private static PrerequisiteCheck CheckWindows(
+        string serviceName, PrerequisiteCategory category, bool hardRequired, string whatItDoes)
+    {
+        try
+        {
+            using var sc = new ServiceController(serviceName);
+            // Touch the Status to force the SCM lookup; if the service doesn't exist, this throws
+            // InvalidOperationException with message "Service ... was not found on computer.".
+            var status = sc.Status;
+            var startType = sc.StartType;
+
+            return status switch
+            {
+                ServiceControllerStatus.Running => new PrerequisiteCheck(
+                    $"service:{serviceName}", category, PrerequisiteStatus.Pass,
+                    $"Running ({whatItDoes})"),
+
+                // DemandStart services (like NmxSvc) that are Stopped are not necessarily a
+                // failure — the master service (aaBootstrap) brings them up on demand. Treat
+                // Stopped+Demand as Warn so operators know the situation but tests still proceed.
+                ServiceControllerStatus.Stopped when startType == ServiceStartMode.Manual =>
+                    new PrerequisiteCheck(
+                        $"service:{serviceName}", category, PrerequisiteStatus.Warn,
+                        $"Installed but Stopped (start type Manual — {whatItDoes}). " +
+                        "Will be pulled up on demand by the master service; fine for tests."),
+
+                ServiceControllerStatus.Stopped => Fail(
+                    $"Installed but Stopped. Start with: sc.exe start {serviceName}  ({whatItDoes})"),
+
+                _ => new PrerequisiteCheck(
+                    $"service:{serviceName}", category, PrerequisiteStatus.Warn,
+                    $"Transitional state {status} ({whatItDoes}) — try again in a few seconds."),
+            };
+
+            PrerequisiteCheck Fail(string detail) => new(
+                $"service:{serviceName}", category,
+                hardRequired ? PrerequisiteStatus.Fail : PrerequisiteStatus.Warn,
+                detail);
+        }
+        catch (InvalidOperationException ex) when (ex.Message.Contains("was not found", StringComparison.OrdinalIgnoreCase))
+        {
+            return new PrerequisiteCheck(
+                $"service:{serviceName}", category,
+                hardRequired ? PrerequisiteStatus.Fail : PrerequisiteStatus.Warn,
+                $"Not installed ({whatItDoes}). Install the relevant System Platform component and retry.");
+        }
+        catch (Exception ex)
+        {
+            return new PrerequisiteCheck(
+                $"service:{serviceName}", category, PrerequisiteStatus.Warn,
+                $"Probe failed ({ex.GetType().Name}: {ex.Message}) — treat as unknown.");
+        }
+    }
+}

tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport/Probes/SqlProbe.cs

@@ -0,0 +1,88 @@
+using Microsoft.Data.SqlClient;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport.Probes;
+
+/// <summary>
+///     Verifies the Galaxy Repository SQL side: SQL Server reachable, <c>ZB</c> database
+///     present, and at least one deployed object exists (so live tests have something to read).
+///     Reuses the Windows-auth connection string the repo code defaults to.
+/// </summary>
+public static class SqlProbe
+{
+    public const string DefaultConnectionString =
+        "Server=localhost;Database=ZB;Integrated Security=True;TrustServerCertificate=True;Encrypt=False;Connect Timeout=3;";
+
+    public static async Task<PrerequisiteCheck> CheckZbDatabaseAsync(
+        string? connectionString = null, CancellationToken ct = default)
+    {
+        connectionString ??= DefaultConnectionString;
+        try
+        {
+            using var conn = new SqlConnection(connectionString);
+            await conn.OpenAsync(ct);
+
+            // DB_ID returns null when the database doesn't exist on the connected server — distinct
+            // failure mode from "server unreachable", deserves a distinct message.
+            using var cmd = conn.CreateCommand();
+            cmd.CommandText = "SELECT DB_ID('ZB')";
+            var dbIdObj = await cmd.ExecuteScalarAsync(ct);
+            if (dbIdObj is null || dbIdObj is DBNull)
+            {
+                return new PrerequisiteCheck("sql:ZB", PrerequisiteCategory.GalaxyRepository,
+                    PrerequisiteStatus.Fail,
+                    "SQL Server reachable but database ZB does not exist. " +
+                    "Create the Galaxy from the IDE or restore a .cab backup.");
+            }
+
+            return new PrerequisiteCheck("sql:ZB", PrerequisiteCategory.GalaxyRepository,
+                PrerequisiteStatus.Pass, "Connected; ZB database exists.");
+        }
+        catch (SqlException ex)
+        {
+            return new PrerequisiteCheck("sql:ZB", PrerequisiteCategory.GalaxyRepository,
+                PrerequisiteStatus.Fail,
+                $"SQL Server unreachable: {ex.Message}. Ensure MSSQLSERVER service is running (sc.exe start MSSQLSERVER) and TCP 1433 is open.");
+        }
+        catch (Exception ex)
+        {
+            return new PrerequisiteCheck("sql:ZB", PrerequisiteCategory.GalaxyRepository,
+                PrerequisiteStatus.Fail,
+                $"Unexpected probe error: {ex.GetType().Name}: {ex.Message}");
+        }
+    }
+
+    /// <summary>
+    ///     Returns the count of deployed Galaxy objects (<c>deployed_version &gt; 0</c>). Zero
+    ///     isn't a hard failure — lets someone boot a fresh Galaxy and still get meaningful
+    ///     test-suite output — but it IS a warning because any live-read smoke will have
+    ///     nothing to read.
+    /// </summary>
+    public static async Task<PrerequisiteCheck> CheckDeployedObjectCountAsync(
+        string? connectionString = null, CancellationToken ct = default)
+    {
+        connectionString ??= DefaultConnectionString;
+        try
+        {
+            using var conn = new SqlConnection(connectionString);
+            await conn.OpenAsync(ct);
+            using var cmd = conn.CreateCommand();
+            cmd.CommandText = "SELECT COUNT(*) FROM gobject WHERE deployed_version > 0";
+            var countObj = await cmd.ExecuteScalarAsync(ct);
+            var count = countObj is int i ? i : 0;
+
+            return count > 0
+                ? new PrerequisiteCheck("sql:ZB.deployedObjects", PrerequisiteCategory.GalaxyRepository,
+                    PrerequisiteStatus.Pass, $"{count} objects deployed — live reads have data to return.")
+                : new PrerequisiteCheck("sql:ZB.deployedObjects", PrerequisiteCategory.GalaxyRepository,
+                    PrerequisiteStatus.Warn,
+                    "ZB contains no deployed objects. Discovery smoke tests will return empty hierarchies; " +
+                    "deploy at least a Platform + AppEngine from the IDE to exercise the read path.");
+        }
+        catch (Exception ex)
+        {
+            return new PrerequisiteCheck("sql:ZB.deployedObjects", PrerequisiteCategory.GalaxyRepository,
+                PrerequisiteStatus.Warn,
+                $"Couldn't count deployed objects: {ex.GetType().Name}: {ex.Message}");
+        }
+    }
+}

tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport.csproj

@@ -0,0 +1,38 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <!-- Multi-target: net10.0 for modern consumer projects (Galaxy.Proxy.Tests, E2E, Admin.Tests),
+             net48 for the Galaxy.Host.Tests project that has to stay on .NET Framework x86 for its
+             MXAccess-COM parent project. The helper uses no OS-level APIs that differ between the
+             two frameworks (registry / SQL / ServiceController are surface-compatible). -->
+        <TargetFrameworks>net10.0;net48</TargetFrameworks>
+        <Nullable>enable</Nullable>
+        <ImplicitUsings>enable</ImplicitUsings>
+        <LangVersion>latest</LangVersion>
+        <IsPackable>false</IsPackable>
+        <RootNamespace>ZB.MOM.WW.OtOpcUa.Driver.Galaxy.TestSupport</RootNamespace>
+    </PropertyGroup>
+
+    <ItemGroup Condition="'$(TargetFramework)' == 'net10.0'">
+        <!-- System.ServiceProcess.ServiceController + Microsoft.Win32.Registry are cross-platform
+             assemblies that throw PlatformNotSupportedException on non-Windows; the probes in
+             this project guard with RuntimeInformation.IsOSPlatform(OSPlatform.Windows) so they
+             return Skip on Linux/macOS rather than crashing the test host. -->
+        <PackageReference Include="System.ServiceProcess.ServiceController" Version="10.0.0"/>
+        <PackageReference Include="Microsoft.Win32.Registry" Version="5.0.0"/>
+        <PackageReference Include="Microsoft.Data.SqlClient" Version="6.0.1"/>
+    </ItemGroup>
+
+    <ItemGroup Condition="'$(TargetFramework)' == 'net48'">
+        <!-- net48 ships System.ServiceProcess + Microsoft.Win32 in-box via BCL references. -->
+        <Reference Include="System.ServiceProcess"/>
+        <!-- Microsoft.Data.SqlClient v6 supports net462+; single-target for consistency. -->
+        <PackageReference Include="Microsoft.Data.SqlClient" Version="6.0.1"/>
+    </ItemGroup>
+
+    <ItemGroup>
+        <NuGetAuditSuppress Include="https://github.com/advisories/GHSA-37gx-xxp4-5rgx"/>
+        <NuGetAuditSuppress Include="https://github.com/advisories/GHSA-w3x6-4m5h-cxqf"/>
+    </ItemGroup>
+
+</Project>