docs(index): HistorianGateway store-forward now FasterLog-backed; refresh test count (702/681)

docs: refresh HistorianGateway + GalaxyRepository status in index
HistorianGateway is now pushed to gitea (gitea.dohertylan.com/dohertj2/historiangw), and ZB.MOM.WW.GalaxyRepository is published to the Gitea feed and consumed as a PackageReference (no longer a cross-repo ProjectReference). Updates the sister-project row, the component table, and the GalaxyRepository narrative; test figure 584 green -> 590 total (584 on macOS).
2026-06-24 11:19:56 -04:00 · 2026-06-24 07:28:25 -04:00 · 2026-06-24 06:45:10 -04:00 · 2026-06-24 00:41:29 -04:00 · 2026-06-23 20:36:28 -04:00 · 2026-06-23 20:34:32 -04:00
49 changed files with 6455 additions and 29 deletions
@@ -6,12 +6,13 @@ This file provides guidance to Claude Code (claude.ai/code) when working with co

 `scadaproj` is primarily an umbrella/index workspace that aggregates a family of
 related SCADA / OT / Wonderware / OPC UA "sister projects" that live as **sibling
-directories under `~/Desktop/`**. It now also **hosts five pieces of source itself** —
+directories under `~/Desktop/`**. It now also **hosts six pieces of source itself** —
 the shared [`ZB.MOM.WW.Auth/`](ZB.MOM.WW.Auth/) library, the shared
 [`ZB.MOM.WW.Theme/`](ZB.MOM.WW.Theme/) UI kit, the shared
 [`ZB.MOM.WW.Health/`](ZB.MOM.WW.Health/) health-check library, the shared
-[`ZB.MOM.WW.Telemetry/`](ZB.MOM.WW.Telemetry/) observability library, and the shared
-[`ZB.MOM.WW.Configuration/`](ZB.MOM.WW.Configuration/) config-validation library — all the realized output of their
+[`ZB.MOM.WW.Telemetry/`](ZB.MOM.WW.Telemetry/) observability library, the shared
+[`ZB.MOM.WW.Configuration/`](ZB.MOM.WW.Configuration/) config-validation library, and the new
+[`ZB.MOM.WW.GalaxyRepository/`](ZB.MOM.WW.GalaxyRepository/) Galaxy browse library — all the realized output of their
 respective component normalizations (see [Component normalization](#component-normalization)).
 The point of this file is to give a high-level scan of each sister project — its purpose,
 location, stack, and primary commands — so a fresh Claude Code session can orient across
@@ -30,9 +31,10 @@ own `CLAUDE.md` for the full picture. See [Refreshing this index](#refreshing-th

 | Project | Location | Stack | Repo | Summary |
 |---|---|---|---|---|
-| **OtOpcUa** | `~/Desktop/OtOpcUa` | .NET 10, OPC UA, gRPC | `gitea.dohertylan.com/dohertj2/lmxopcua` | OPC UA server that exposes AVEVA System Platform (Wonderware) Galaxy tags as an OPC UA address space. Galaxy access flows through an in-process `GalaxyDriver` → gRPC → the **mxaccessgw** gateway. |
+| **OtOpcUa** | `~/Desktop/OtOpcUa` | .NET 10, OPC UA, gRPC | `gitea.dohertylan.com/dohertj2/lmxopcua` | OPC UA server that exposes industrial data sources under a **unified Equipment-based address space** — native-protocol drivers (Modbus, S7, AB CIP/Legacy, TwinCAT, FOCAS, OpcUaClient) **and AVEVA System Platform (Wonderware) Galaxy, now a standard Equipment-kind driver** (the old SystemPlatform mirror / alias-tag model was retired ~2026-06-12). Galaxy access flows through the in-process `GalaxyDriver` → gRPC → the **mxaccessgw** gateway. Surfaces live read + authorized write, native OPC UA Part 9 alarms, and server-side HistoryRead. |
 | **MxAccessGateway** (`mxaccessgw`) | `~/Desktop/MxAccessGateway` | .NET 10 gateway (x64) + .NET 4.8 worker (**x86**), gRPC | `gitea.dohertylan.com/dohertj2/mxaccessgw` | gRPC gateway giving modern clients full MXAccess parity without loading 32-bit COM. Two-process: gateway (ASP.NET Core gRPC + Blazor dashboard) + per-session x86 worker that owns the MXAccess COM STA. **OtOpcUa depends on this.** |
 | **ScadaBridge** | `~/Desktop/ScadaBridge` | .NET 10, Akka.NET, Docker | _git_ | Full implementation of the distributed SCADA platform — hub-and-spoke (1 central cluster + N site clusters). Projects prefixed `ZB.MOM.WW.ScadaBridge.*`; solution `ZB.MOM.WW.ScadaBridge.slnx`. Ships `src/`, `tests/`, `docker/` topology, and the design docs that are the spec. |
+| **HistorianGateway** | `~/Desktop/HistorianGateway` | .NET 10 x64, gRPC, Blazor | `gitea.dohertylan.com/dohertj2/historiangw` | Single-process gRPC sidecar exposing (1) full read/write API to the AVEVA Historian (5 gRPC services; 15 retrieval modes; historical/backfill writes; tag-config lifecycle; SQL live-value path; store-forward + redundancy resilience; all default-disabled) and (2) read-only Galaxy object-hierarchy browse via the shared `ZB.MOM.WW.GalaxyRepository` lib (consumed as a Gitea-feed package). No COM, no x86 worker. Dashboard on `:5220` (HTTP/1.1); gRPC h2c on `:5221`. Vendors `AVEVA.Historian.Client` from `histsdk`. Store-forward uses a crash-safe FasterLog append-only outbox (`Microsoft.FASTER.Core` 2.6.5; `CommitMode` PerEntry/Periodic), not SQLite. 702 tests total — 681 green on macOS; the env-gated live historian + Galaxy integration suite (21 tests) skips without a live server. |

 ## Cross-project relationships

@@ -84,8 +86,10 @@ the gateway uses `MxGateway.*`). The common subject is **AVEVA System Platform (
  `GalaxyRepositoryClient` for the static hierarchy, and an MXAccess session
  (`MxCommand`/`MxEvent` protos) for live read/write/subscribe. A `DeployWatcher` polls the
  gateway's deploy-event signal to rebuild the OPC UA address space on Galaxy redeploy.
-  OtOpcUa's job is purely a **protocol bridge**: it republishes Galaxy as an OPC UA address
-  space for *any* OPC UA client.
+  OtOpcUa's job is a **protocol bridge**: it republishes Galaxy — now bound as a *standard
+  Equipment-kind driver* alongside its native-protocol drivers, not a special SystemPlatform
+  mirror — as an OPC UA address space (live values, Part 9 alarms, HistoryRead) for *any* OPC
+  UA client.
 - **ScadaBridge → OPC UA** (OPC UA client). ScadaBridge's DCL has an OPC UA adapter that
  collects data and mirrors native OPC UA Alarms & Conditions. OtOpcUa is exactly such a
  server, so ScadaBridge can ingest Wonderware data **indirectly via OtOpcUa**.
@@ -101,15 +105,21 @@ the gateway uses `MxGateway.*`). The common subject is **AVEVA System Platform (
 - ScadaBridge has **two paths** to the same Wonderware data: (1) OPC UA → OtOpcUa →
  gateway, or (2) MxGateway adapter → gateway directly. Path 1 gives standards-based OPC UA
  decoupling; path 2 gives a more direct/native feed.
+- **HistorianGateway is a new, independent sidecar** (no runtime coupling to the three above).
+  It reaches the Historian via its vendored gRPC client and the Galaxy Repository SQL DB directly,
+  not through `mxaccessgw`. It consumes the shared `ZB.MOM.WW.GalaxyRepository` lib
+  (cross-repo `ProjectReference`). Any client that needs Historian data or Galaxy browse can
+  target HistorianGateway independently; it is not a dependency of OtOpcUa or ScadaBridge today.
 - Coupling is loose: each repo references the others only as **sibling context** (the
  `## Sister Projects` note in ScadaBridge's own `CLAUDE.md` lists `MxAccessGateway` and
  `OtOpcUa` with their Gitea URLs but states they are *not part of its solution*).
 - **The break surface is the wire contracts, not code.** Because coupling is by network
  protocol, the things that break across repo boundaries are: the gateway's `.proto` files
-  (`mxaccess_gateway.proto`, `mxaccess_worker.proto`, `galaxy_repository.proto`), and the
-  OPC UA address-space shape OtOpcUa publishes (browse paths, node IDs, A&C alarm model).
-  Changes to any of these must be coordinated across the affected repos — a green build in
-  one repo does not prove the others still interoperate.
+  (`mxaccess_gateway.proto`, `mxaccess_worker.proto`, `galaxy_repository.proto`), the
+  `historian_gateway.v1` proto (HistorianGateway's own contract), and the OPC UA address-space
+  shape OtOpcUa publishes (browse paths, node IDs, A&C alarm model). Changes to any of these
+  must be coordinated across the affected repos — a green build in one repo does not prove the
+  others still interoperate.

 ## Component normalization

@@ -126,6 +136,7 @@ each project's **code-verified current state**, and the **gaps** between. See
 | Observability (metrics / traces / logs) | Built (lib `0.1.0`) | Shared `ZB.MOM.WW.Telemetry` lib + `.Serilog` | [`components/observability/`](components/observability/) | [`ZB.MOM.WW.Telemetry/`](ZB.MOM.WW.Telemetry/) |
 | Config + validation (options / startup validation) | Adopted (lib `0.1.0`; all 3 apps, local) | Shared `ZB.MOM.WW.Configuration` lib | [`components/configuration/`](components/configuration/) | [`ZB.MOM.WW.Configuration/`](ZB.MOM.WW.Configuration/) |
 | Audit (event model + writer seam) | Adopted (lib `0.1.0`; all 3 apps, merged to **local default** main/master + **pushed to origin** (gitea)) | Shared `ZB.MOM.WW.Audit` lib | [`components/audit/`](components/audit/) | [`ZB.MOM.WW.Audit/`](ZB.MOM.WW.Audit/) |
+| Galaxy Repository (object-hierarchy SQL browse + gRPC service) | Built (lib `0.1.0`, **published to the Gitea feed**; consumed by HistorianGateway as a feed `PackageReference`) | Shared `ZB.MOM.WW.GalaxyRepository` lib | _(design in histsdk + design doc 2026-06-23)_ | [`ZB.MOM.WW.GalaxyRepository/`](ZB.MOM.WW.GalaxyRepository/) |

 The auth component is fully populated: a normalized [`spec`](components/auth/spec/SPEC.md), a
 proposed [`shared-contract`](components/auth/shared-contract/ZB.MOM.WW.Auth.md), three
@@ -261,6 +272,25 @@ migration, MSSQL-verified). Phase 3 wires `Actor` from the Auth principal at aut
 Build/test from `ZB.MOM.WW.Audit/`: `dotnet test`. Consumer matrix: all three apps consume the single
 `ZB.MOM.WW.Audit` package (OtOpcUa, MxAccessGateway, ScadaBridge — DEEP-adopted as the canonical record).

+The Galaxy Repository component normalizes the **Galaxy object-hierarchy SQL browse + reusable gRPC service**
+that was previously embedded in `mxaccessgw`. Shared = canonical `galaxy_repository.v1` proto (wire-compatible
+with `mxaccessgw`'s existing contract so OtOpcUa's `GalaxyRepositoryClient` is unaffected), the SQL browse
+provider (`HierarchySql` / `AttributesSql` validated reverse-engineered queries), in-memory hierarchy cache +
+snapshot + deploy-poll refresh `BackgroundService`, `GalaxyHierarchyProjector`, and `AddZbGalaxyRepository` /
+`MapZbGalaxyRepository` DI extension. Left per-consumer = section path, subtree auth filtering, and any
+app-specific paging defaults.
+
+The shared library is **built and lives in this repo** at [`ZB.MOM.WW.GalaxyRepository/`](ZB.MOM.WW.GalaxyRepository/)
+(.NET 10; single package `ZB.MOM.WW.GalaxyRepository`; `dotnet pack` → 1 nupkg @ 0.1.0, **published to
+the Gitea NuGet feed** `gitea.dohertylan.com/api/packages/dohertj2/nuget`). The design doc is at
+[`docs/plans/2026-06-23-historian-gateway-design.md`](docs/plans/2026-06-23-historian-gateway-design.md) (§10, component 1).
+**Consumed by HistorianGateway** as a `PackageReference` from that Gitea feed, pinned at `0.1.0` (originally a
+cross-repo `ProjectReference` to this scadaproj tree; switched to the feed package 2026-06-24).
+**mxaccessgw adoption is a tracked follow-on** — once adopted, mxaccessgw's inline Galaxy browse code is replaced
+by the shared lib (the `galaxy_repository.v1` wire contract is already identical, so OtOpcUa and ScadaBridge
+clients are unaffected). Build/test from `ZB.MOM.WW.GalaxyRepository/`: `dotnet test`.
+Consumer matrix: HistorianGateway (initial); mxaccessgw (follow-on adoption).
+
 ## Per-project primary commands

 Run these from inside each project directory (not from `scadaproj`).
@@ -282,9 +312,17 @@ dotnet run   --project src/MxGateway.Server/MxGateway.Server.csproj
 dotnet build ZB.MOM.WW.ScadaBridge.slnx
 bash docker/deploy.sh        # rebuild + redeploy the 8-node cluster
 cd infra && docker compose up -d   # local test services (SQL, OPC UA, SMTP, REST, Traefik) — LDAP is NOT here
+
+# HistorianGateway  (~/Desktop/HistorianGateway)
+dotnet build ZB.MOM.WW.HistorianGateway.slnx
+dotnet test  ZB.MOM.WW.HistorianGateway.slnx   # unit + golden; live integration tests skip without env vars
+dotnet run --project src/ZB.MOM.WW.HistorianGateway.Server/ZB.MOM.WW.HistorianGateway.Server.csproj
+# dashboard on :5220, gRPC h2c on :5221
+# Live integration (need HISTORIAN_GRPC_HOST + HISTORIAN_GRPC_WRITE_SANDBOX_TAG + GALAXY_SQL_CONNSTR set)
+dotnet test ZB.MOM.WW.HistorianGateway.slnx --filter "Category=LiveIntegration"
 ```

-> **Shared GLAuth (all three apps):** LDAP auth for every local dev/test stack is provided by a
+> **Shared GLAuth (all three apps + HistorianGateway):** LDAP auth for every local dev/test stack is provided by a
 > single `zb-shared-glauth` container on the Linux fixture host **`10.100.0.35:3893`**
 > (`baseDN dc=zb,dc=local`, Transport=None). Source of truth and deploy runbook:
 > [`scadaproj/infra/glauth/`](infra/glauth/) (`config.toml` + `docker-compose.yml` + `README.md`).
@@ -0,0 +1,11 @@
+<Project>
+  <PropertyGroup>
+    <TargetFramework>net10.0</TargetFramework>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <LangVersion>latest</LangVersion>
+    <Version>0.1.0</Version>
+    <ManagePackageVersionsCentrally>true</ManagePackageVersionsCentrally>
+    <GenerateDocumentationFile>true</GenerateDocumentationFile>
+  </PropertyGroup>
+</Project>
@@ -0,0 +1,24 @@
+<Project>
+
+  <PropertyGroup>
+    <ManagePackageVersionsCentrally>true</ManagePackageVersionsCentrally>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <!-- Library -->
+    <PackageVersion Include="Microsoft.Data.SqlClient" Version="6.0.2" />
+    <PackageVersion Include="Grpc.AspNetCore" Version="2.76.0" />
+    <!-- Google.Protobuf and Grpc.Tools must be >= the minimums Grpc.AspNetCore 2.76.0 requires -->
+    <PackageVersion Include="Google.Protobuf" Version="3.31.1" />
+    <PackageVersion Include="Microsoft.Extensions.Hosting.Abstractions" Version="10.0.0" />
+    <PackageVersion Include="Microsoft.Extensions.Options.ConfigurationExtensions" Version="10.0.0" />
+    <PackageVersion Include="Grpc.Tools" Version="2.76.0" />
+
+    <!-- Test -->
+    <PackageVersion Include="xunit" Version="2.9.3" />
+    <PackageVersion Include="xunit.runner.visualstudio" Version="3.1.4" />
+    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.14.1" />
+    <PackageVersion Include="coverlet.collector" Version="6.0.4" />
+  </ItemGroup>
+
+</Project>
@@ -0,0 +1,8 @@
+<Solution>
+  <Folder Name="/src/">
+    <Project Path="src/ZB.MOM.WW.GalaxyRepository/ZB.MOM.WW.GalaxyRepository.csproj" />
+  </Folder>
+  <Folder Name="/tests/">
+    <Project Path="tests/ZB.MOM.WW.GalaxyRepository.Tests/ZB.MOM.WW.GalaxyRepository.Tests.csproj" />
+  </Folder>
+</Solution>
@@ -0,0 +1,71 @@
+using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Routing;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Options;
+using ZB.MOM.WW.GalaxyRepository.Grpc;
+
+namespace ZB.MOM.WW.GalaxyRepository.DependencyInjection;
+
+/// <summary>
+///     Dependency-injection and endpoint-routing extensions that register the reusable
+///     Galaxy Repository services and map the canonical gRPC service. A consuming gateway
+///     calls <see cref="AddZbGalaxyRepository"/> during service registration and
+///     <see cref="MapZbGalaxyRepository"/> while building its endpoint pipeline.
+/// </summary>
+public static class GalaxyRepositoryServiceCollectionExtensions
+{
+    /// <summary>
+    ///     Registers the Galaxy Repository SQL provider, shared hierarchy cache, deploy
+    ///     notifier, on-disk snapshot store, and the background refresh service, binding
+    ///     <see cref="GalaxyRepositoryOptions"/> from the supplied configuration section.
+    /// </summary>
+    /// <param name="services">The service collection to add registrations to.</param>
+    /// <param name="configuration">The application configuration root.</param>
+    /// <param name="sectionPath">
+    ///     The configuration section path to bind <see cref="GalaxyRepositoryOptions"/> from
+    ///     (for example <c>MxGateway:Galaxy</c> or <c>HistorianGateway:Galaxy</c>).
+    /// </param>
+    /// <returns>The service collection for chaining.</returns>
+    public static IServiceCollection AddZbGalaxyRepository(
+        this IServiceCollection services,
+        IConfiguration configuration,
+        string sectionPath)
+    {
+        ArgumentNullException.ThrowIfNull(services);
+        ArgumentNullException.ThrowIfNull(configuration);
+        ArgumentException.ThrowIfNullOrWhiteSpace(sectionPath);
+
+        // Bind only — this shared lib ships no validator, so a .ValidateOnStart() here
+        // would be a silent no-op. The consuming application owns option validation
+        // (e.g. the sidecar's ConfigPreflight / validated-options layer).
+        services
+            .AddOptions<GalaxyRepositoryOptions>()
+            .Bind(configuration.GetSection(sectionPath));
+
+        services.AddSingleton(sp =>
+            new GalaxyRepository(sp.GetRequiredService<IOptions<GalaxyRepositoryOptions>>().Value));
+        services.AddSingleton<IGalaxyRepository>(sp => sp.GetRequiredService<GalaxyRepository>());
+
+        services.AddSingleton<IGalaxyDeployNotifier, GalaxyDeployNotifier>();
+        services.AddSingleton<IGalaxyHierarchySnapshotStore, GalaxyHierarchySnapshotStore>();
+        services.AddSingleton<IGalaxyHierarchyCache, GalaxyHierarchyCache>();
+        services.AddHostedService<GalaxyHierarchyRefreshService>();
+
+        return services;
+    }
+
+    /// <summary>
+    ///     Maps the canonical <see cref="GalaxyRepositoryGrpcService"/> onto the consuming
+    ///     application's endpoint pipeline. Call after <see cref="AddZbGalaxyRepository"/> and
+    ///     after gRPC has been added to the application's services.
+    /// </summary>
+    /// <param name="endpoints">The endpoint route builder to map the gRPC service onto.</param>
+    /// <returns>The endpoint route builder for chaining.</returns>
+    public static IEndpointRouteBuilder MapZbGalaxyRepository(this IEndpointRouteBuilder endpoints)
+    {
+        ArgumentNullException.ThrowIfNull(endpoints);
+        endpoints.MapGrpcService<GalaxyRepositoryGrpcService>();
+        return endpoints;
+    }
+}
@@ -0,0 +1,41 @@
+namespace ZB.MOM.WW.GalaxyRepository;
+
+/// <summary>One row from <see cref="GalaxyRepository.GetAttributesAsync"/>.</summary>
+public sealed class GalaxyAttributeRow
+{
+    /// <summary>Gets the Galaxy object identifier.</summary>
+    public int GobjectId { get; init; }
+
+    /// <summary>Gets the tag name.</summary>
+    public string TagName { get; init; } = string.Empty;
+
+    /// <summary>Gets the attribute name.</summary>
+    public string AttributeName { get; init; } = string.Empty;
+
+    /// <summary>Gets the full tag reference.</summary>
+    public string FullTagReference { get; init; } = string.Empty;
+
+    /// <summary>Gets the MXAccess data type code.</summary>
+    public int MxDataType { get; init; }
+
+    /// <summary>Gets the data type name.</summary>
+    public string? DataTypeName { get; init; }
+
+    /// <summary>Gets a value indicating whether this is an array.</summary>
+    public bool IsArray { get; init; }
+
+    /// <summary>Gets the array dimension, if applicable.</summary>
+    public int? ArrayDimension { get; init; }
+
+    /// <summary>Gets the MXAccess attribute category code.</summary>
+    public int MxAttributeCategory { get; init; }
+
+    /// <summary>Gets the security classification code.</summary>
+    public int SecurityClassification { get; init; }
+
+    /// <summary>Gets a value indicating whether this is historized.</summary>
+    public bool IsHistorized { get; init; }
+
+    /// <summary>Gets a value indicating whether this is an alarm.</summary>
+    public bool IsAlarm { get; init; }
+}
@@ -0,0 +1,19 @@
+using ZB.MOM.WW.GalaxyRepository.Grpc;
+
+namespace ZB.MOM.WW.GalaxyRepository;
+
+/// <summary>
+///     Result of one <see cref="GalaxyBrowseProjector.ProjectChildren"/> call. Holds a
+///     materialized page of direct children for the requested parent, along with a
+///     parallel-indexed <see cref="ChildHasChildren"/> hint and the total post-filter
+///     sibling count for paging.
+/// </summary>
+/// <param name="Children">The page of direct children, sorted areas-first then by display name.</param>
+/// <param name="ChildHasChildren">Parallel array indicating whether each child has at least one matching descendant under the same filter set.</param>
+/// <param name="TotalChildCount">Total matching direct children of the parent (post-filter).</param>
+/// <param name="FilterSignature">Stable signature of the filter and parent selector, used to bind page tokens.</param>
+public sealed record GalaxyBrowseChildrenResult(
+    IReadOnlyList<GalaxyObject> Children,
+    IReadOnlyList<bool> ChildHasChildren,
+    int TotalChildCount,
+    string FilterSignature);
@@ -0,0 +1,281 @@
+using System.Collections.Concurrent;
+using System.Runtime.CompilerServices;
+using System.Security.Cryptography;
+using System.Text;
+using Grpc.Core;
+using ZB.MOM.WW.GalaxyRepository.Grpc;
+
+namespace ZB.MOM.WW.GalaxyRepository;
+
+/// <summary>
+///     Projects one level of children of a parent object out of an immutable
+///     <see cref="GalaxyHierarchyCacheEntry"/>. Pure and side-effect free. Memoizes the
+///     filtered child list per cache-entry instance so repeated paging is an O(pageSize)
+///     slice rather than an O(siblings) filter scan per page. The memo is keyed on the
+///     immutable cache entry, so when the cache publishes a new entry the stale memo
+///     becomes unreachable and is reclaimed with it.
+/// </summary>
+public static class GalaxyBrowseProjector
+{
+    private static readonly ConditionalWeakTable<
+        GalaxyHierarchyCacheEntry,
+        ConcurrentDictionary<string, FilteredChildren>> FilteredChildrenCache = new();
+
+    /// <summary>Projects one page of direct children of the resolved parent.</summary>
+    /// <param name="entry">The Galaxy hierarchy cache entry to query.</param>
+    /// <param name="request">The browse-children request.</param>
+    /// <param name="browseSubtreeGlobs">Optional API-key browse-subtree constraints.</param>
+    /// <param name="offset">Zero-based offset into the filtered child list.</param>
+    /// <param name="pageSize">Maximum number of children to return.</param>
+    public static GalaxyBrowseChildrenResult ProjectChildren(
+        GalaxyHierarchyCacheEntry entry,
+        BrowseChildrenRequest request,
+        IReadOnlyList<string>? browseSubtreeGlobs,
+        int offset,
+        int pageSize)
+    {
+        ArgumentNullException.ThrowIfNull(entry);
+        ArgumentNullException.ThrowIfNull(request);
+        if (offset < 0)
+        {
+            throw new ArgumentOutOfRangeException(nameof(offset), offset, "Offset must be greater than or equal to zero.");
+        }
+        if (pageSize <= 0)
+        {
+            throw new ArgumentOutOfRangeException(nameof(pageSize), pageSize, "Page size must be greater than zero.");
+        }
+
+        int parentId = ResolveParentId(entry, request);
+        string filterSignature = ComputeFilterSignature(request, browseSubtreeGlobs, parentId);
+        FilteredChildren filtered = GetFilteredChildren(entry, request, browseSubtreeGlobs, parentId, filterSignature);
+
+        bool includeAttributes = IncludeAttributes(request);
+        int end = (int)Math.Min((long)offset + pageSize, filtered.Children.Count);
+        List<GalaxyObject> page = new(Math.Max(0, end - offset));
+        List<bool> hasChildren = new(Math.Max(0, end - offset));
+        for (int index = offset; index < end; index++)
+        {
+            page.Add(CloneObject(filtered.Children[index].Object, includeAttributes));
+            hasChildren.Add(filtered.HasMatchingDescendant[index]);
+        }
+
+        return new GalaxyBrowseChildrenResult(page, hasChildren, filtered.Children.Count, filterSignature);
+    }
+
+    /// <summary>
+    ///     Resolves the request's parent oneof to a gobject id, throwing
+    ///     <see cref="RpcException"/> with <see cref="StatusCode.NotFound"/> when the
+    ///     parent does not exist. Public so the gRPC handler can compute the same
+    ///     parent id (needed for the page-token signature) without reimplementing the
+    ///     resolution rules.
+    /// </summary>
+    /// <param name="entry">The Galaxy hierarchy cache entry to query.</param>
+    /// <param name="request">The browse-children request.</param>
+    public static int ResolveParentId(GalaxyHierarchyCacheEntry entry, BrowseChildrenRequest request)
+    {
+        switch (request.ParentCase)
+        {
+            case BrowseChildrenRequest.ParentOneofCase.None:
+                return 0;
+            case BrowseChildrenRequest.ParentOneofCase.ParentGobjectId:
+                if (request.ParentGobjectId == 0)
+                {
+                    return 0;
+                }
+                if (!entry.Index.ObjectViewsById.ContainsKey(request.ParentGobjectId))
+                {
+                    throw new RpcException(new Status(StatusCode.NotFound, "BrowseChildren parent was not found."));
+                }
+                return request.ParentGobjectId;
+            case BrowseChildrenRequest.ParentOneofCase.ParentTagName:
+            {
+                if (!entry.Index.ObjectViewsByTagName.TryGetValue(request.ParentTagName, out GalaxyObjectView? match))
+                {
+                    throw new RpcException(new Status(StatusCode.NotFound, "BrowseChildren parent was not found."));
+                }
+                return match.Object.GobjectId;
+            }
+            case BrowseChildrenRequest.ParentOneofCase.ParentContainedPath:
+            {
+                if (!entry.Index.ObjectViewsByContainedPath.TryGetValue(request.ParentContainedPath, out GalaxyObjectView? match))
+                {
+                    throw new RpcException(new Status(StatusCode.NotFound, "BrowseChildren parent was not found."));
+                }
+                return match.Object.GobjectId;
+            }
+            default:
+                return 0;
+        }
+    }
+
+    private static FilteredChildren GetFilteredChildren(
+        GalaxyHierarchyCacheEntry entry,
+        BrowseChildrenRequest request,
+        IReadOnlyList<string>? browseSubtreeGlobs,
+        int parentId,
+        string filterSignature)
+    {
+        ConcurrentDictionary<string, FilteredChildren> memo =
+            FilteredChildrenCache.GetValue(entry, static _ => new ConcurrentDictionary<string, FilteredChildren>(StringComparer.Ordinal));
+
+        return memo.GetOrAdd(
+            filterSignature,
+            static (_, state) =>
+            {
+                IReadOnlyDictionary<int, IReadOnlyList<GalaxyObjectView>> map = state.Entry.Index.ChildrenByParent;
+                IReadOnlyList<GalaxyObjectView> directChildren = map.TryGetValue(state.ParentId, out IReadOnlyList<GalaxyObjectView>? list)
+                    ? list
+                    : Array.Empty<GalaxyObjectView>();
+
+                List<GalaxyObjectView> matched = [];
+                List<bool> hasMatching = [];
+                foreach (GalaxyObjectView view in directChildren)
+                {
+                    if (!MatchesBrowseSubtrees(view, state.BrowseSubtreeGlobs))
+                    {
+                        continue;
+                    }
+                    if (!MatchesFilters(view.Object, state.Request))
+                    {
+                        // Even if the direct child itself fails the filter, a matching
+                        // descendant should still surface its ancestor — but only when
+                        // there is one. Mirror the dashboard browse-tree semantics: if a
+                        // descendant matches, include the parent with has-children true.
+                        if (HasMatchingDescendant(view, state.Entry.Index, state.Request, state.BrowseSubtreeGlobs))
+                        {
+                            matched.Add(view);
+                            hasMatching.Add(true);
+                        }
+                        continue;
+                    }
+                    matched.Add(view);
+                    hasMatching.Add(HasMatchingDescendant(view, state.Entry.Index, state.Request, state.BrowseSubtreeGlobs));
+                }
+
+                return new FilteredChildren(matched, hasMatching);
+            },
+            (Entry: entry, ParentId: parentId, Request: request, BrowseSubtreeGlobs: browseSubtreeGlobs));
+    }
+
+    private static bool HasMatchingDescendant(
+        GalaxyObjectView parent,
+        GalaxyHierarchyIndex index,
+        BrowseChildrenRequest request,
+        IReadOnlyList<string>? browseSubtreeGlobs)
+    {
+        if (!index.ChildrenByParent.TryGetValue(parent.Object.GobjectId, out IReadOnlyList<GalaxyObjectView>? children))
+        {
+            return false;
+        }
+
+        // Defend against pathological cycles in Galaxy data (e.g. a corrupt A→B→A chain).
+        // BuildContainedPath uses the same visited-id pattern; mirror it so this walk
+        // terminates even when ChildrenByParent forms a cycle.
+        HashSet<int> visited = new() { parent.Object.GobjectId };
+        Stack<GalaxyObjectView> stack = new();
+        foreach (GalaxyObjectView child in children)
+        {
+            if (visited.Add(child.Object.GobjectId))
+            {
+                stack.Push(child);
+            }
+        }
+        while (stack.Count > 0)
+        {
+            GalaxyObjectView candidate = stack.Pop();
+            if (MatchesBrowseSubtrees(candidate, browseSubtreeGlobs)
+                && MatchesFilters(candidate.Object, request))
+            {
+                return true;
+            }
+            if (index.ChildrenByParent.TryGetValue(candidate.Object.GobjectId, out IReadOnlyList<GalaxyObjectView>? grandchildren))
+            {
+                foreach (GalaxyObjectView grandchild in grandchildren)
+                {
+                    if (visited.Add(grandchild.Object.GobjectId))
+                    {
+                        stack.Push(grandchild);
+                    }
+                }
+            }
+        }
+        return false;
+    }
+
+    private static bool MatchesBrowseSubtrees(GalaxyObjectView view, IReadOnlyList<string>? browseSubtreeGlobs)
+    {
+        return browseSubtreeGlobs is null
+            || browseSubtreeGlobs.Count == 0
+            || browseSubtreeGlobs.Any(glob => GalaxyGlobMatcher.IsMatch(view.ContainedPath, glob));
+    }
+
+    private static bool MatchesFilters(GalaxyObject obj, BrowseChildrenRequest request)
+    {
+        if (request.CategoryIds.Count > 0 && !request.CategoryIds.Contains(obj.CategoryId))
+        {
+            return false;
+        }
+        foreach (string templateFilter in request.TemplateChainContains)
+        {
+            if (!obj.TemplateChain.Any(template => template.Contains(templateFilter, StringComparison.OrdinalIgnoreCase)))
+            {
+                return false;
+            }
+        }
+        if (!string.IsNullOrWhiteSpace(request.TagNameGlob)
+            && !GalaxyGlobMatcher.IsMatch(obj.TagName, request.TagNameGlob))
+        {
+            return false;
+        }
+        if (request.AlarmBearingOnly && !obj.Attributes.Any(attribute => attribute.IsAlarm))
+        {
+            return false;
+        }
+        if (request.HistorizedOnly && !obj.Attributes.Any(attribute => attribute.IsHistorized))
+        {
+            return false;
+        }
+        return true;
+    }
+
+    private static bool IncludeAttributes(BrowseChildrenRequest request)
+    {
+        return !request.HasIncludeAttributes || request.IncludeAttributes;
+    }
+
+    private static GalaxyObject CloneObject(GalaxyObject source, bool includeAttributes)
+    {
+        GalaxyObject clone = source.Clone();
+        if (!includeAttributes)
+        {
+            clone.Attributes.Clear();
+        }
+        return clone;
+    }
+
+    /// <summary>Computes a stable filter signature for memoization purposes.</summary>
+    /// <param name="request">The browse-children request.</param>
+    /// <param name="browseSubtreeGlobs">Optional API-key browse-subtree constraints.</param>
+    /// <param name="parentId">Resolved parent gobject id (0 for roots).</param>
+    public static string ComputeFilterSignature(
+        BrowseChildrenRequest request,
+        IReadOnlyList<string>? browseSubtreeGlobs,
+        int parentId)
+    {
+        StringBuilder builder = new();
+        builder.Append("parent=").Append(parentId.ToString(System.Globalization.CultureInfo.InvariantCulture));
+        builder.Append("|cat=").AppendJoin(',', request.CategoryIds.Order());
+        builder.Append("|tpl=").AppendJoin(',', request.TemplateChainContains.Order(StringComparer.OrdinalIgnoreCase));
+        builder.Append("|glob=").Append(request.TagNameGlob);
+        builder.Append("|attrs=").Append(request.HasIncludeAttributes ? request.IncludeAttributes.ToString() : "unset");
+        builder.Append("|alarm=").Append(request.AlarmBearingOnly);
+        builder.Append("|hist=").Append(request.HistorizedOnly);
+        builder.Append("|browse=").AppendJoin(',', (browseSubtreeGlobs ?? Array.Empty<string>()).Order(StringComparer.OrdinalIgnoreCase));
+        byte[] hash = SHA256.HashData(Encoding.UTF8.GetBytes(builder.ToString()));
+        return Convert.ToHexString(hash, 0, 12);
+    }
+
+    private sealed record FilteredChildren(
+        IReadOnlyList<GalaxyObjectView> Children,
+        IReadOnlyList<bool> HasMatchingDescendant);
+}
@@ -0,0 +1,18 @@
+namespace ZB.MOM.WW.GalaxyRepository;
+
+/// <summary>Freshness state of the shared Galaxy hierarchy cache entry.</summary>
+public enum GalaxyCacheStatus
+{
+    /// <summary>Cache has never completed a refresh.</summary>
+    Unknown = 0,
+
+    /// <summary>Cache holds data from a recent successful refresh.</summary>
+    Healthy = 1,
+
+    /// <summary>Cache holds data, but the most recent refresh attempt failed
+    /// or no successful refresh has happened within the staleness threshold.</summary>
+    Stale = 2,
+
+    /// <summary>Latest refresh failed and no prior data is available.</summary>
+    Unavailable = 3,
+}
@@ -0,0 +1,19 @@
+namespace ZB.MOM.WW.GalaxyRepository;
+
+/// <summary>
+///     A single Galaxy deploy notification. Published by <see cref="GalaxyHierarchyCache"/>
+///     whenever a refresh detects that <c>galaxy.time_of_last_deploy</c> has changed (or on
+///     the first successful refresh). Consumed by <see cref="IGalaxyDeployNotifier"/>
+///     subscribers (the streaming gRPC RPC).
+/// </summary>
+/// <param name="Sequence">Monotonically increasing per process start; gaps indicate dropped events.</param>
+/// <param name="ObservedAt">Server wall-clock when the cache observed the deploy.</param>
+/// <param name="TimeOfLastDeploy">The <c>galaxy.time_of_last_deploy</c> value, or <see langword="null"/> when the Galaxy table reports none.</param>
+/// <param name="ObjectCount">Number of objects in the hierarchy at the time of the event.</param>
+/// <param name="AttributeCount">Number of attributes in the hierarchy at the time of the event.</param>
+public sealed record GalaxyDeployEventInfo(
+    long Sequence,
+    DateTimeOffset ObservedAt,
+    DateTimeOffset? TimeOfLastDeploy,
+    int ObjectCount,
+    int AttributeCount);
@@ -0,0 +1,79 @@
+using System.Collections.Concurrent;
+using System.Runtime.CompilerServices;
+using System.Threading.Channels;
+
+namespace ZB.MOM.WW.GalaxyRepository;
+
+/// <summary>
+///     Channel-based fan-out of Galaxy deploy events to streaming gRPC subscribers. Each
+///     subscriber gets a private bounded channel so a slow client cannot back-pressure
+///     other subscribers or the publisher. When a subscriber's channel is full the oldest
+///     event is dropped — clients use the sequence field to detect gaps.
+/// </summary>
+public sealed class GalaxyDeployNotifier : IGalaxyDeployNotifier
+{
+    private const int SubscriberQueueCapacity = 16;
+
+    private readonly ConcurrentDictionary<Guid, Channel<GalaxyDeployEventInfo>> _subscribers = new();
+    private GalaxyDeployEventInfo? _latest;
+
+    /// <summary>
+    /// The most recent deploy event, or null if none has been published.
+    /// </summary>
+    public GalaxyDeployEventInfo? Latest => Volatile.Read(ref _latest);
+
+    /// <inheritdoc />
+    public void Publish(GalaxyDeployEventInfo info)
+    {
+        ArgumentNullException.ThrowIfNull(info);
+
+        Volatile.Write(ref _latest, info);
+
+        foreach (Channel<GalaxyDeployEventInfo> channel in _subscribers.Values)
+        {
+            // BoundedChannelFullMode.DropOldest -> writes never wait; we only fail if the
+            // channel was completed by the subscriber side, which we ignore.
+            channel.Writer.TryWrite(info);
+        }
+    }
+
+    /// <inheritdoc />
+    public async IAsyncEnumerable<GalaxyDeployEventInfo> SubscribeAsync(
+        [EnumeratorCancellation] CancellationToken cancellationToken)
+    {
+        Guid subscriberId = Guid.NewGuid();
+        Channel<GalaxyDeployEventInfo> channel = Channel.CreateBounded<GalaxyDeployEventInfo>(
+            new BoundedChannelOptions(SubscriberQueueCapacity)
+            {
+                FullMode = BoundedChannelFullMode.DropOldest,
+                SingleReader = true,
+                SingleWriter = false,
+            });
+
+        _subscribers[subscriberId] = channel;
+
+        // Bootstrap: emit the latest known event so subscribers don't need to wait for
+        // the next deploy to know current state.
+        GalaxyDeployEventInfo? bootstrap = Volatile.Read(ref _latest);
+        if (bootstrap is not null)
+        {
+            channel.Writer.TryWrite(bootstrap);
+        }
+
+        try
+        {
+            while (await channel.Reader.WaitToReadAsync(cancellationToken).ConfigureAwait(false))
+            {
+                while (channel.Reader.TryRead(out GalaxyDeployEventInfo? next))
+                {
+                    yield return next;
+                }
+            }
+        }
+        finally
+        {
+            _subscribers.TryRemove(subscriberId, out _);
+            channel.Writer.TryComplete();
+        }
+    }
+}
@@ -0,0 +1,131 @@
+using System.Collections.Concurrent;
+using System.Text;
+using System.Text.RegularExpressions;
+
+namespace ZB.MOM.WW.GalaxyRepository;
+
+/// <summary>
+///     Anchored, case-insensitive glob matcher (<c>*</c> and <c>?</c> wildcards) used by the
+///     hierarchy and browse projectors to filter object tag names and browse subtrees.
+///     Compiled regexes are cached and the cache is bounded so an unbounded stream of distinct
+///     client-supplied globs cannot grow memory without limit.
+/// </summary>
+public static class GalaxyGlobMatcher
+{
+    /// <summary>
+    ///     Maximum number of compiled-regex entries retained in <see cref="RegexCache"/>.
+    ///     The cache is keyed by glob pattern and patterns flow in from two sources:
+    ///     admin-controlled API-key constraints (naturally bounded) and the
+    ///     client-supplied <c>DiscoverHierarchyRequest.TagNameGlob</c> (unbounded — a
+    ///     client can iterate through generated names and create millions of distinct
+    ///     globs over the process lifetime). Capping the cache bounds memory while
+    ///     keeping the hot working set hit-cached.
+    /// </summary>
+    internal const int RegexCacheCapacity = 256;
+
+    /// <summary>
+    ///     Bounded compiled-regex cache keyed by glob pattern. <c>IsMatch</c> is called
+    ///     once per object per <c>DiscoverHierarchy</c>/<c>WatchDeployEvents</c>
+    ///     evaluation, so the same handful of glob patterns are translated
+    ///     repeatedly; caching avoids rebuilding and recompiling the regex on every
+    ///     call. Beyond <see cref="RegexCacheCapacity"/> entries the oldest insertion
+    ///     is evicted so a client cannot grow the cache without bound by submitting
+    ///     unique patterns. Eviction is approximate (FIFO over insertion order, not
+    ///     true LRU) because we only need the bound, not exact recency tracking.
+    /// </summary>
+    private static readonly ConcurrentDictionary<string, Regex> RegexCache = new(StringComparer.Ordinal);
+
+    /// <summary>
+    ///     Insertion-order queue used to evict the oldest cache entry when the cache
+    ///     exceeds <see cref="RegexCacheCapacity"/>. A separate queue keeps the
+    ///     <see cref="RegexCache"/> reads lock-free; the lock below only guards the
+    ///     eviction path.
+    /// </summary>
+    private static readonly ConcurrentQueue<string> InsertionOrder = new();
+    private static readonly object EvictionLock = new();
+
+    /// <summary>
+    ///     Current cache size, exposed for tests asserting the cap is honoured.
+    /// </summary>
+    internal static int CurrentCacheSize => RegexCache.Count;
+
+    /// <summary>Determines whether a value matches a glob pattern (with * and ? wildcards).</summary>
+    /// <param name="value">The value to test against the glob pattern.</param>
+    /// <param name="glob">The glob pattern with * and ? wildcards.</param>
+    public static bool IsMatch(string value, string glob)
+    {
+        if (string.IsNullOrWhiteSpace(glob))
+        {
+            return true;
+        }
+
+        return GetOrCreateRegex(glob).IsMatch(value ?? string.Empty);
+    }
+
+    private static Regex GetOrCreateRegex(string glob)
+    {
+        if (RegexCache.TryGetValue(glob, out Regex? existing))
+        {
+            return existing;
+        }
+
+        Regex compiled = new(
+            BuildRegex(glob),
+            RegexOptions.CultureInvariant | RegexOptions.IgnoreCase | RegexOptions.Compiled,
+            TimeSpan.FromMilliseconds(100));
+
+        // GetOrAdd atomically returns whichever instance is in the cache after the
+        // call — either the locally-compiled regex (we won the race) or the regex
+        // another thread inserted (we lost). It also avoids the TryAdd-then-indexer
+        // pattern where the key could be evicted between the failed TryAdd and the
+        // indexer read, producing a KeyNotFoundException under contention near the cap.
+        Regex result = RegexCache.GetOrAdd(glob, compiled);
+        if (ReferenceEquals(result, compiled))
+        {
+            // We were the inserter — track for FIFO eviction and bound the cache.
+            InsertionOrder.Enqueue(glob);
+            EvictIfOverCapacity();
+        }
+        return result;
+    }
+
+    private static void EvictIfOverCapacity()
+    {
+        if (RegexCache.Count <= RegexCacheCapacity)
+        {
+            return;
+        }
+
+        // Serialize eviction so two threads do not race past the cap together.
+        lock (EvictionLock)
+        {
+            while (RegexCache.Count > RegexCacheCapacity && InsertionOrder.TryDequeue(out string? oldest))
+            {
+                RegexCache.TryRemove(oldest, out _);
+            }
+        }
+    }
+
+    private static string BuildRegex(string glob)
+    {
+        StringBuilder builder = new("^", glob.Length + 2);
+        foreach (char character in glob)
+        {
+            switch (character)
+            {
+                case '*':
+                    builder.Append(".*");
+                    break;
+                case '?':
+                    builder.Append('.');
+                    break;
+                default:
+                    builder.Append(Regex.Escape(character.ToString()));
+                    break;
+            }
+        }
+
+        builder.Append('$');
+        return builder.ToString();
+    }
+}
@@ -0,0 +1,365 @@
+using Microsoft.Extensions.Logging;
+using ZB.MOM.WW.GalaxyRepository.Grpc;
+
+namespace ZB.MOM.WW.GalaxyRepository;
+
+/// <summary>
+///     Server-side cache of Galaxy Repository browse data. All gRPC clients share the same
+///     entry — the materialized object list is produced once per refresh and reused across
+///     requests. Refreshes are deploy-time gated: every tick queries
+///     <c>galaxy.time_of_last_deploy</c> (cheap), and the heavy hierarchy + attributes rowsets
+///     are pulled only when that timestamp has advanced.
+///     Each successful heavy refresh is persisted to disk through
+///     <see cref="IGalaxyHierarchySnapshotStore"/>; the first refresh restores that
+///     snapshot (as <see cref="GalaxyCacheStatus.Stale"/>) so clients can browse
+///     last-known data when the Galaxy database is unreachable on a cold start.
+/// </summary>
+public sealed class GalaxyHierarchyCache : IGalaxyHierarchyCache, IDisposable
+{
+    private static readonly TimeSpan StaleThreshold = TimeSpan.FromMinutes(5);
+
+    private readonly IGalaxyRepository _repository;
+    private readonly IGalaxyDeployNotifier _notifier;
+    private readonly IGalaxyHierarchySnapshotStore? _snapshotStore;
+    private readonly TimeProvider _timeProvider;
+    private readonly ILogger<GalaxyHierarchyCache>? _logger;
+    private readonly TaskCompletionSource _firstLoad = new(TaskCreationOptions.RunContinuationsAsynchronously);
+    private readonly SemaphoreSlim _refreshGate = new(1, 1);
+    private GalaxyHierarchyCacheEntry _current = GalaxyHierarchyCacheEntry.Empty;
+    private bool _restoreAttempted;
+
+    /// <summary>Initializes a new instance of the <see cref="GalaxyHierarchyCache"/> class.</summary>
+    /// <param name="repository">Galaxy Repository client for SQL queries.</param>
+    /// <param name="notifier">Galaxy deploy event notifier.</param>
+    /// <param name="timeProvider">Provider for current time; defaults to system time.</param>
+    /// <param name="logger">Optional logger for diagnostic output.</param>
+    /// <param name="snapshotStore">
+    ///     Optional on-disk snapshot store. When supplied, the cache persists each
+    ///     successful refresh and restores the last snapshot on first load.
+    /// </param>
+    public GalaxyHierarchyCache(
+        IGalaxyRepository repository,
+        IGalaxyDeployNotifier notifier,
+        TimeProvider? timeProvider = null,
+        ILogger<GalaxyHierarchyCache>? logger = null,
+        IGalaxyHierarchySnapshotStore? snapshotStore = null)
+    {
+        _repository = repository;
+        _notifier = notifier;
+        _timeProvider = timeProvider ?? TimeProvider.System;
+        _logger = logger;
+        _snapshotStore = snapshotStore;
+    }
+
+    /// <summary>Gets the current Galaxy hierarchy cache entry with projected status.</summary>
+    public GalaxyHierarchyCacheEntry Current
+    {
+        get
+        {
+            GalaxyHierarchyCacheEntry snapshot = Volatile.Read(ref _current);
+            GalaxyCacheStatus projected = ProjectStatus(snapshot);
+            return projected == snapshot.Status
+                ? snapshot
+                : snapshot with { Status = projected };
+        }
+    }
+
+    /// <summary>Refreshes the Galaxy hierarchy cache if the deploy time has advanced.</summary>
+    /// <param name="cancellationToken">Token to cancel the asynchronous operation.</param>
+    /// <returns>Asynchronous task representing the refresh operation.</returns>
+    public async Task RefreshAsync(CancellationToken cancellationToken)
+    {
+        await _refreshGate.WaitAsync(cancellationToken).ConfigureAwait(false);
+        try
+        {
+            await RefreshCoreAsync(cancellationToken).ConfigureAwait(false);
+        }
+        finally
+        {
+            _refreshGate.Release();
+        }
+    }
+
+    /// <summary>Waits for the Galaxy hierarchy cache to complete its first load.</summary>
+    /// <param name="cancellationToken">Token to cancel the asynchronous operation.</param>
+    /// <returns>Asynchronous task representing the wait operation.</returns>
+    public Task WaitForFirstLoadAsync(CancellationToken cancellationToken)
+    {
+        return _firstLoad.Task.WaitAsync(cancellationToken);
+    }
+
+    /// <summary>
+    ///     Disposes the refresh gate. As a DI singleton the cache is disposed once at host
+    ///     shutdown, after the refresh <see cref="GalaxyHierarchyRefreshService"/> has stopped,
+    ///     so no in-flight refresh can be holding the gate.
+    /// </summary>
+    public void Dispose()
+    {
+        _refreshGate.Dispose();
+    }
+
+    private async Task RefreshCoreAsync(CancellationToken cancellationToken)
+    {
+        // First refresh only: seed the cache from the on-disk snapshot before
+        // querying SQL, so a cold start with an unreachable Galaxy database can
+        // still serve last-known browse data. Runs under the refresh gate.
+        if (!_restoreAttempted)
+        {
+            _restoreAttempted = true;
+            await TryRestoreFromDiskAsync(cancellationToken).ConfigureAwait(false);
+        }
+
+        GalaxyHierarchyCacheEntry previous = Volatile.Read(ref _current);
+        DateTimeOffset queriedAt = _timeProvider.GetUtcNow();
+
+        try
+        {
+            DateTime? deployRaw = await _repository.GetLastDeployTimeAsync(cancellationToken).ConfigureAwait(false);
+            DateTimeOffset? deployTime = deployRaw.HasValue
+                ? new DateTimeOffset(DateTime.SpecifyKind(deployRaw.Value, DateTimeKind.Utc))
+                : null;
+
+            bool hasPriorData = previous.HasData;
+            bool deployChanged = !hasPriorData || deployTime != previous.LastDeployTime;
+
+            if (!deployChanged)
+            {
+                // No deploy change — skip heavy queries; just bump LastSuccessAt.
+                GalaxyHierarchyCacheEntry refreshed = previous with
+                {
+                    Status = GalaxyCacheStatus.Healthy,
+                    LastQueriedAt = queriedAt,
+                    LastSuccessAt = queriedAt,
+                    LastError = null,
+                };
+                Volatile.Write(ref _current, refreshed);
+                _firstLoad.TrySetResult();
+                return;
+            }
+
+            Task<List<GalaxyHierarchyRow>> hierarchyTask = _repository.GetHierarchyAsync(cancellationToken);
+            Task<List<GalaxyAttributeRow>> attributesTask = _repository.GetAttributesAsync(cancellationToken);
+            await Task.WhenAll(hierarchyTask, attributesTask).ConfigureAwait(false);
+
+            List<GalaxyHierarchyRow> hierarchy = hierarchyTask.Result;
+            List<GalaxyAttributeRow> attributes = attributesTask.Result;
+
+            long nextSequence = previous.Sequence + 1;
+            GalaxyHierarchyCacheEntry next = BuildEntry(
+                status: GalaxyCacheStatus.Healthy,
+                sequence: nextSequence,
+                lastQueriedAt: queriedAt,
+                lastSuccessAt: queriedAt,
+                lastDeployTime: deployTime,
+                lastError: null,
+                hierarchy: hierarchy,
+                attributes: attributes);
+
+            Volatile.Write(ref _current, next);
+            _firstLoad.TrySetResult();
+
+            _notifier.Publish(new GalaxyDeployEventInfo(
+                Sequence: nextSequence,
+                ObservedAt: queriedAt,
+                TimeOfLastDeploy: deployTime,
+                ObjectCount: hierarchy.Count,
+                AttributeCount: attributes.Count));
+
+            await PersistSnapshotAsync(deployTime, queriedAt, hierarchy, attributes, cancellationToken).ConfigureAwait(false);
+        }
+        catch (OperationCanceledException) when (cancellationToken.IsCancellationRequested)
+        {
+            throw;
+        }
+        catch (Exception exception)
+        {
+            // Catch every non-cancellation failure — not just SqlException /
+            // InvalidOperationException. A TimeoutException or Win32Exception
+            // from connection establishment, or another DbException subtype,
+            // must still degrade gracefully to Stale/Unavailable and complete
+            // _firstLoad rather than escape and fault the refresh BackgroundService.
+            _logger?.LogWarning(exception, "Galaxy hierarchy cache refresh failed.");
+            GalaxyHierarchyCacheEntry failed = previous with
+            {
+                Status = previous.HasData ? GalaxyCacheStatus.Stale : GalaxyCacheStatus.Unavailable,
+                LastQueriedAt = queriedAt,
+                LastError = exception.Message,
+            };
+            Volatile.Write(ref _current, failed);
+            _firstLoad.TrySetResult();
+        }
+    }
+
+    /// <summary>
+    ///     Materializes a complete <see cref="GalaxyHierarchyCacheEntry"/> from raw
+    ///     hierarchy and attribute rowsets. Shared by the live refresh path and the
+    ///     on-disk restore path so both produce an identical object list and index.
+    /// </summary>
+    private static GalaxyHierarchyCacheEntry BuildEntry(
+        GalaxyCacheStatus status,
+        long sequence,
+        DateTimeOffset? lastQueriedAt,
+        DateTimeOffset? lastSuccessAt,
+        DateTimeOffset? lastDeployTime,
+        string? lastError,
+        IReadOnlyList<GalaxyHierarchyRow> hierarchy,
+        IReadOnlyList<GalaxyAttributeRow> attributes)
+    {
+        IReadOnlyList<GalaxyObject> objects = BuildObjects(hierarchy, attributes);
+        GalaxyHierarchyIndex index = GalaxyHierarchyIndex.Build(objects);
+
+        int areaCount = hierarchy.Count(row => row.IsArea);
+        int historized = attributes.Count(row => row.IsHistorized);
+        int alarms = attributes.Count(row => row.IsAlarm);
+
+        return new GalaxyHierarchyCacheEntry(
+            Status: status,
+            Sequence: sequence,
+            LastQueriedAt: lastQueriedAt,
+            LastSuccessAt: lastSuccessAt,
+            LastDeployTime: lastDeployTime,
+            LastError: lastError,
+            Objects: objects,
+            Index: index,
+            ObjectCount: hierarchy.Count,
+            AreaCount: areaCount,
+            AttributeCount: attributes.Count,
+            HistorizedAttributeCount: historized,
+            AlarmAttributeCount: alarms);
+    }
+
+    /// <summary>
+    ///     Seeds the cache from the on-disk snapshot when no live data has loaded yet.
+    ///     The restored entry is marked <see cref="GalaxyCacheStatus.Stale"/> — it is
+    ///     last-known data, not live. A later refresh that observes the same deploy
+    ///     time promotes it to healthy; one that observes a newer deploy replaces it.
+    /// </summary>
+    private async Task TryRestoreFromDiskAsync(CancellationToken cancellationToken)
+    {
+        if (_snapshotStore is null)
+        {
+            return;
+        }
+
+        if (Volatile.Read(ref _current).HasData)
+        {
+            return;
+        }
+
+        GalaxyHierarchySnapshot? snapshot;
+        try
+        {
+            snapshot = await _snapshotStore.TryLoadAsync(cancellationToken).ConfigureAwait(false);
+        }
+        catch (OperationCanceledException) when (cancellationToken.IsCancellationRequested)
+        {
+            throw;
+        }
+        catch (Exception exception)
+        {
+            _logger?.LogWarning(exception, "Failed to restore the Galaxy hierarchy from the on-disk snapshot.");
+            return;
+        }
+
+        if (snapshot is null)
+        {
+            return;
+        }
+
+        long sequence = Volatile.Read(ref _current).Sequence + 1;
+        GalaxyHierarchyCacheEntry restored = BuildEntry(
+            status: GalaxyCacheStatus.Stale,
+            sequence: sequence,
+            lastQueriedAt: snapshot.SavedAt,
+            lastSuccessAt: snapshot.SavedAt,
+            lastDeployTime: snapshot.LastDeployTime,
+            lastError: null,
+            hierarchy: snapshot.Hierarchy,
+            attributes: snapshot.Attributes);
+        Volatile.Write(ref _current, restored);
+
+        // Restored data is a valid completed first load: unblock callers waiting on
+        // the bootstrap gate immediately, rather than making them wait out the full
+        // wait budget for a live query that — when the database is unreachable, the
+        // scenario this restore exists for — may not return for seconds.
+        _firstLoad.TrySetResult();
+
+        _notifier.Publish(new GalaxyDeployEventInfo(
+            Sequence: sequence,
+            ObservedAt: _timeProvider.GetUtcNow(),
+            TimeOfLastDeploy: snapshot.LastDeployTime,
+            ObjectCount: snapshot.Hierarchy.Count,
+            AttributeCount: snapshot.Attributes.Count));
+
+        _logger?.LogInformation(
+            "Restored Galaxy hierarchy from on-disk snapshot saved {SavedAt:o}: {ObjectCount} objects, {AttributeCount} attributes (status Stale until the Galaxy database confirms).",
+            snapshot.SavedAt,
+            snapshot.Hierarchy.Count,
+            snapshot.Attributes.Count);
+    }
+
+    /// <summary>
+    ///     Persists a successful refresh to disk. Persistence failures are logged and
+    ///     swallowed — a cache that cannot write its backup is still fully usable.
+    /// </summary>
+    private async Task PersistSnapshotAsync(
+        DateTimeOffset? deployTime,
+        DateTimeOffset savedAt,
+        IReadOnlyList<GalaxyHierarchyRow> hierarchy,
+        IReadOnlyList<GalaxyAttributeRow> attributes,
+        CancellationToken cancellationToken)
+    {
+        if (_snapshotStore is null)
+        {
+            return;
+        }
+
+        try
+        {
+            await _snapshotStore.SaveAsync(
+                new GalaxyHierarchySnapshot(deployTime, savedAt, hierarchy, attributes),
+                cancellationToken).ConfigureAwait(false);
+        }
+        catch (OperationCanceledException) when (cancellationToken.IsCancellationRequested)
+        {
+            // The refresh was cancelled (service shutdown) before the write finished.
+            // That is not a persistence failure — do not log it as a warning.
+        }
+        catch (Exception exception)
+        {
+            _logger?.LogWarning(exception, "Failed to persist the Galaxy hierarchy snapshot to disk.");
+        }
+    }
+
+    private static IReadOnlyList<GalaxyObject> BuildObjects(
+        IReadOnlyList<GalaxyHierarchyRow> hierarchy,
+        IReadOnlyList<GalaxyAttributeRow> attributes)
+    {
+        Dictionary<int, List<GalaxyAttributeRow>> attributesByGobjectId = attributes
+            .GroupBy(a => a.GobjectId)
+            .ToDictionary(g => g.Key, g => g.ToList());
+
+        List<GalaxyObject> objects = new(hierarchy.Count);
+        foreach (GalaxyHierarchyRow row in hierarchy)
+        {
+            objects.Add(GalaxyProtoMapper.MapObject(row, attributesByGobjectId));
+        }
+        return objects;
+    }
+
+    private GalaxyCacheStatus ProjectStatus(GalaxyHierarchyCacheEntry snapshot)
+    {
+        if (snapshot.Status is GalaxyCacheStatus.Unknown or GalaxyCacheStatus.Unavailable)
+        {
+            return snapshot.Status;
+        }
+
+        if (snapshot.LastSuccessAt is { } success
+            && _timeProvider.GetUtcNow() - success > StaleThreshold)
+        {
+            return GalaxyCacheStatus.Stale;
+        }
+
+        return snapshot.Status;
+    }
+}
@@ -0,0 +1,56 @@
+using ZB.MOM.WW.GalaxyRepository.Grpc;
+
+namespace ZB.MOM.WW.GalaxyRepository;
+
+/// <summary>
+///     Immutable snapshot of the Galaxy Repository browse data held by
+///     <see cref="GalaxyHierarchyCache"/>. Multiple gRPC clients share the same
+///     materialized object list and precomputed hierarchy index.
+/// </summary>
+/// <param name="Status">The cache freshness state at the time the entry was produced.</param>
+/// <param name="Sequence">Monotonically increasing per process start; bumped on each heavy refresh.</param>
+/// <param name="LastQueriedAt">UTC wall-clock of the most recent refresh attempt.</param>
+/// <param name="LastSuccessAt">UTC wall-clock of the most recent successful refresh.</param>
+/// <param name="LastDeployTime">The <c>galaxy.time_of_last_deploy</c> the data was pulled at.</param>
+/// <param name="LastError">The most recent refresh error message, or <see langword="null"/>.</param>
+/// <param name="Objects">The materialized Galaxy object list.</param>
+/// <param name="Index">Precomputed lookup structures over <paramref name="Objects"/>.</param>
+/// <param name="ObjectCount">Number of objects in the hierarchy.</param>
+/// <param name="AreaCount">Number of area objects in the hierarchy.</param>
+/// <param name="AttributeCount">Number of attributes across all objects.</param>
+/// <param name="HistorizedAttributeCount">Number of historized attributes.</param>
+/// <param name="AlarmAttributeCount">Number of alarm-bearing attributes.</param>
+public sealed record GalaxyHierarchyCacheEntry(
+    GalaxyCacheStatus Status,
+    long Sequence,
+    DateTimeOffset? LastQueriedAt,
+    DateTimeOffset? LastSuccessAt,
+    DateTimeOffset? LastDeployTime,
+    string? LastError,
+    IReadOnlyList<GalaxyObject> Objects,
+    GalaxyHierarchyIndex Index,
+    int ObjectCount,
+    int AreaCount,
+    int AttributeCount,
+    int HistorizedAttributeCount,
+    int AlarmAttributeCount)
+{
+    /// <summary>Gets an empty Galaxy hierarchy cache entry.</summary>
+    public static GalaxyHierarchyCacheEntry Empty { get; } = new(
+        Status: GalaxyCacheStatus.Unknown,
+        Sequence: 0,
+        LastQueriedAt: null,
+        LastSuccessAt: null,
+        LastDeployTime: null,
+        LastError: null,
+        Objects: Array.Empty<GalaxyObject>(),
+        Index: GalaxyHierarchyIndex.Empty,
+        ObjectCount: 0,
+        AreaCount: 0,
+        AttributeCount: 0,
+        HistorizedAttributeCount: 0,
+        AlarmAttributeCount: 0);
+
+    /// <summary>Gets a value indicating whether the cache entry contains usable data.</summary>
+    public bool HasData => Status is GalaxyCacheStatus.Healthy or GalaxyCacheStatus.Stale;
+}
@@ -0,0 +1,206 @@
+using ZB.MOM.WW.GalaxyRepository.Grpc;
+
+namespace ZB.MOM.WW.GalaxyRepository;
+
+/// <summary>
+///     Precomputed lookup structures over a materialized Galaxy object list. Built once per
+///     cache entry so browse/discover handlers can resolve roots/parents by id, tag name, or
+///     contained path in O(1), enumerate direct children, and resolve tag addresses to objects
+///     or attributes without rescanning the full object list.
+/// </summary>
+public sealed class GalaxyHierarchyIndex
+{
+    private GalaxyHierarchyIndex(
+        IReadOnlyList<GalaxyObjectView> objectViews,
+        IReadOnlyDictionary<int, GalaxyObjectView> objectViewsById,
+        IReadOnlyDictionary<string, GalaxyTagLookup> tagsByAddress,
+        IReadOnlyDictionary<int, IReadOnlyList<GalaxyObjectView>> childrenByParent,
+        IReadOnlyDictionary<string, GalaxyObjectView> objectViewsByTagName,
+        IReadOnlyDictionary<string, GalaxyObjectView> objectViewsByContainedPath)
+    {
+        ObjectViews = objectViews;
+        ObjectViewsById = objectViewsById;
+        TagsByAddress = tagsByAddress;
+        ChildrenByParent = childrenByParent;
+        ObjectViewsByTagName = objectViewsByTagName;
+        ObjectViewsByContainedPath = objectViewsByContainedPath;
+    }
+
+    /// <summary>Gets an empty Galaxy hierarchy index.</summary>
+    public static GalaxyHierarchyIndex Empty { get; } = new(
+        Array.Empty<GalaxyObjectView>(),
+        new Dictionary<int, GalaxyObjectView>(),
+        new Dictionary<string, GalaxyTagLookup>(StringComparer.OrdinalIgnoreCase),
+        new Dictionary<int, IReadOnlyList<GalaxyObjectView>>(),
+        new Dictionary<string, GalaxyObjectView>(StringComparer.OrdinalIgnoreCase),
+        new Dictionary<string, GalaxyObjectView>(StringComparer.OrdinalIgnoreCase));
+
+    /// <summary>Gets the object views.</summary>
+    public IReadOnlyList<GalaxyObjectView> ObjectViews { get; }
+
+    /// <summary>Gets the object views indexed by gobject id.</summary>
+    public IReadOnlyDictionary<int, GalaxyObjectView> ObjectViewsById { get; }
+
+    /// <summary>Gets tags indexed by address.</summary>
+    public IReadOnlyDictionary<string, GalaxyTagLookup> TagsByAddress { get; }
+
+    /// <summary>Gets direct children grouped by parent gobject id. Root objects (no parent, or self-parented) live under key 0. Each list is sorted areas-first, then by display name (OrdinalIgnoreCase).</summary>
+    public IReadOnlyDictionary<int, IReadOnlyList<GalaxyObjectView>> ChildrenByParent { get; }
+
+    /// <summary>Gets object views indexed by <see cref="GalaxyObject.TagName"/> (OrdinalIgnoreCase). Lets browse/discover handlers resolve parents/roots by tag name in O(1) instead of scanning <see cref="ObjectViews"/>.</summary>
+    public IReadOnlyDictionary<string, GalaxyObjectView> ObjectViewsByTagName { get; }
+
+    /// <summary>Gets object views indexed by contained path (OrdinalIgnoreCase). Lets browse/discover handlers resolve parents/roots by path in O(1) instead of scanning <see cref="ObjectViews"/>.</summary>
+    public IReadOnlyDictionary<string, GalaxyObjectView> ObjectViewsByContainedPath { get; }
+
+    /// <summary>Builds a Galaxy hierarchy index from the given objects.</summary>
+    /// <param name="objects">The Galaxy objects to index.</param>
+    /// <returns>A new Galaxy hierarchy index.</returns>
+    public static GalaxyHierarchyIndex Build(IReadOnlyList<GalaxyObject> objects)
+    {
+        if (objects.Count == 0)
+        {
+            return Empty;
+        }
+
+        Dictionary<int, GalaxyObject> objectsById = new();
+        foreach (GalaxyObject obj in objects)
+        {
+            objectsById.TryAdd(obj.GobjectId, obj);
+        }
+
+        List<GalaxyObjectView> views = new(objects.Count);
+        Dictionary<int, GalaxyObjectView> viewsById = new();
+        Dictionary<string, GalaxyTagLookup> tagsByAddress = new(StringComparer.OrdinalIgnoreCase);
+        Dictionary<string, GalaxyObjectView> viewsByTagName = new(StringComparer.OrdinalIgnoreCase);
+        Dictionary<string, GalaxyObjectView> viewsByContainedPath = new(StringComparer.OrdinalIgnoreCase);
+
+        foreach (GalaxyObject obj in objects)
+        {
+            string path = BuildContainedPath(obj, objectsById);
+            int depth = string.IsNullOrWhiteSpace(path) ? 0 : path.Count(character => character == '/');
+            GalaxyObjectView view = new(obj, path, depth);
+            views.Add(view);
+            viewsById.TryAdd(obj.GobjectId, view);
+
+            if (!string.IsNullOrWhiteSpace(obj.TagName))
+            {
+                tagsByAddress.TryAdd(obj.TagName, new GalaxyTagLookup(obj, Attribute: null, path));
+                viewsByTagName.TryAdd(obj.TagName, view);
+            }
+
+            if (!string.IsNullOrWhiteSpace(path))
+            {
+                viewsByContainedPath.TryAdd(path, view);
+            }
+
+            foreach (GalaxyAttribute attribute in obj.Attributes)
+            {
+                if (!string.IsNullOrWhiteSpace(attribute.FullTagReference))
+                {
+                    tagsByAddress.TryAdd(attribute.FullTagReference, new GalaxyTagLookup(obj, attribute, path));
+                }
+            }
+        }
+
+        Dictionary<int, List<GalaxyObjectView>> childrenByParent = new();
+        foreach (GalaxyObjectView view in views)
+        {
+            int parentKey = view.Object.ParentGobjectId;
+            // Treat self-parented (corrupt) rows as roots.
+            if (parentKey == view.Object.GobjectId)
+            {
+                parentKey = 0;
+            }
+            // Re-root orphans whose parent object is absent from the set (e.g. a deleted or
+            // never-loaded container area). Otherwise they bucket under a phantom parent id
+            // that is never reached from the root, so they vanish from browse entirely.
+            else if (parentKey != 0 && !objectsById.ContainsKey(parentKey))
+            {
+                parentKey = 0;
+            }
+            if (!childrenByParent.TryGetValue(parentKey, out List<GalaxyObjectView>? bucket))
+            {
+                bucket = [];
+                childrenByParent[parentKey] = bucket;
+            }
+            bucket.Add(view);
+        }
+
+        foreach (List<GalaxyObjectView> bucket in childrenByParent.Values)
+        {
+            bucket.Sort(CompareByAreaThenDisplayName);
+        }
+
+        Dictionary<int, IReadOnlyList<GalaxyObjectView>> readOnlyChildren = new(childrenByParent.Count);
+        foreach (KeyValuePair<int, List<GalaxyObjectView>> kvp in childrenByParent)
+        {
+            readOnlyChildren[kvp.Key] = kvp.Value;
+        }
+
+        return new GalaxyHierarchyIndex(
+            views,
+            viewsById,
+            tagsByAddress,
+            readOnlyChildren,
+            viewsByTagName,
+            viewsByContainedPath);
+    }
+
+    private static string BuildContainedPath(
+        GalaxyObject obj,
+        IReadOnlyDictionary<int, GalaxyObject> objectsById)
+    {
+        Stack<string> names = new();
+        HashSet<int> seen = [];
+        GalaxyObject? current = obj;
+        while (current is not null && seen.Add(current.GobjectId))
+        {
+            names.Push(ResolvePathSegment(current));
+            current = current.ParentGobjectId != 0
+                && objectsById.TryGetValue(current.ParentGobjectId, out GalaxyObject? parent)
+                    ? parent
+                    : null;
+        }
+
+        return string.Join('/', names.Where(name => !string.IsNullOrWhiteSpace(name)));
+    }
+
+    private static string ResolvePathSegment(GalaxyObject obj)
+    {
+        if (!string.IsNullOrWhiteSpace(obj.ContainedName))
+        {
+            return obj.ContainedName;
+        }
+
+        if (!string.IsNullOrWhiteSpace(obj.BrowseName))
+        {
+            return obj.BrowseName;
+        }
+
+        return obj.TagName;
+    }
+
+    private static int CompareByAreaThenDisplayName(GalaxyObjectView left, GalaxyObjectView right)
+    {
+        if (left.Object.IsArea != right.Object.IsArea)
+        {
+            return left.Object.IsArea ? -1 : 1;
+        }
+        return string.Compare(DisplayNameOf(left), DisplayNameOf(right), StringComparison.OrdinalIgnoreCase);
+    }
+
+    private static string DisplayNameOf(GalaxyObjectView view)
+    {
+        GalaxyObject obj = view.Object;
+        if (!string.IsNullOrWhiteSpace(obj.BrowseName))
+        {
+            return obj.BrowseName;
+        }
+        if (!string.IsNullOrWhiteSpace(obj.ContainedName))
+        {
+            return obj.ContainedName;
+        }
+        return obj.TagName;
+    }
+}
@@ -0,0 +1,317 @@
+using System.Collections.Concurrent;
+using System.Runtime.CompilerServices;
+using System.Security.Cryptography;
+using System.Text;
+using Grpc.Core;
+using ZB.MOM.WW.GalaxyRepository.Grpc;
+
+namespace ZB.MOM.WW.GalaxyRepository;
+
+/// <summary>
+///     Projects a <c>DiscoverHierarchy</c> request against an immutable
+///     <see cref="GalaxyHierarchyCacheEntry"/>: applies the root/depth/category/template/glob
+///     filters, pages the result, and memoizes the filtered list per cache-entry instance so
+///     paging is O(pageSize) rather than O(total) per page. Pure and side-effect free.
+/// </summary>
+public static class GalaxyHierarchyProjector
+{
+    /// <summary>
+    ///     Per-cache-entry memo of filtered, ordered <see cref="GalaxyObjectView"/> lists
+    ///     keyed by filter signature. Without it, paging through a large hierarchy
+    ///     re-applies every filter and re-scans the full <see cref="GalaxyHierarchyIndex.ObjectViews"/>
+    ///     collection on every page — O(total) per page, O(total²/pageSize) end-to-end.
+    ///     With it, the first page builds the filtered list and each subsequent page is an
+    ///     O(pageSize) slice. The table is keyed on the immutable cache-entry instance, so
+    ///     when the cache publishes a new entry the stale memo becomes unreachable and is
+    ///     reclaimed with it — no explicit invalidation needed.
+    /// </summary>
+    private static readonly ConditionalWeakTable<GalaxyHierarchyCacheEntry, ConcurrentDictionary<string, IReadOnlyList<GalaxyObjectView>>> FilteredViewCache = new();
+
+    /// <summary>Projects a discovery request against a cache entry and returns all matching objects.</summary>
+    /// <param name="entry">The Galaxy hierarchy cache entry.</param>
+    /// <param name="request">The discovery hierarchy request.</param>
+    /// <param name="browseSubtreeGlobs">Optional glob patterns to filter browse subtrees.</param>
+    public static GalaxyHierarchyQueryResult Project(
+        GalaxyHierarchyCacheEntry entry,
+        DiscoverHierarchyRequest request,
+        IReadOnlyList<string>? browseSubtreeGlobs = null)
+    {
+        return Project(
+            entry,
+            request,
+            browseSubtreeGlobs,
+            offset: 0,
+            pageSize: int.MaxValue);
+    }
+
+    /// <summary>Projects a discovery request with paging against a cache entry and returns a page of matching objects.</summary>
+    /// <param name="entry">The Galaxy hierarchy cache entry.</param>
+    /// <param name="request">The discovery hierarchy request.</param>
+    /// <param name="browseSubtreeGlobs">Optional glob patterns to filter browse subtrees.</param>
+    /// <param name="offset">The zero-based offset into the result set.</param>
+    /// <param name="pageSize">The maximum number of results to return.</param>
+    public static GalaxyHierarchyQueryResult Project(
+        GalaxyHierarchyCacheEntry entry,
+        DiscoverHierarchyRequest request,
+        IReadOnlyList<string>? browseSubtreeGlobs,
+        int offset,
+        int pageSize)
+    {
+        ArgumentNullException.ThrowIfNull(entry);
+        ArgumentNullException.ThrowIfNull(request);
+        if (offset < 0)
+        {
+            throw new ArgumentOutOfRangeException(nameof(offset), offset, "Offset must be greater than or equal to zero.");
+        }
+
+        if (pageSize <= 0)
+        {
+            throw new ArgumentOutOfRangeException(nameof(pageSize), pageSize, "Page size must be greater than zero.");
+        }
+
+        int? maxDepth = request.MaxDepth;
+        if (maxDepth < 0)
+        {
+            throw new RpcException(new Status(
+                StatusCode.InvalidArgument,
+                "DiscoverHierarchy max_depth must be greater than or equal to zero when provided."));
+        }
+
+        string filterSignature = ComputeFilterSignature(request, browseSubtreeGlobs);
+        IReadOnlyList<GalaxyObjectView> matchedViews = GetFilteredViews(
+            entry,
+            request,
+            browseSubtreeGlobs,
+            maxDepth,
+            filterSignature);
+
+        bool includeAttributes = IncludeAttributes(request);
+        List<GalaxyObject> page = new(Math.Min(pageSize, Math.Max(0, matchedViews.Count - offset)));
+        int end = (int)Math.Min((long)offset + pageSize, matchedViews.Count);
+        for (int index = offset; index < end; index++)
+        {
+            page.Add(CloneObject(matchedViews[index].Object, includeAttributes));
+        }
+
+        return new GalaxyHierarchyQueryResult(
+            page,
+            matchedViews.Count,
+            filterSignature);
+    }
+
+    private static IReadOnlyList<GalaxyObjectView> GetFilteredViews(
+        GalaxyHierarchyCacheEntry entry,
+        DiscoverHierarchyRequest request,
+        IReadOnlyList<string>? browseSubtreeGlobs,
+        int? maxDepth,
+        string filterSignature)
+    {
+        // ResolveRoot can throw RpcException(NotFound); run it before consulting the
+        // memo so a bad root surfaces consistently regardless of cache state.
+        IReadOnlyList<GalaxyObjectView> views = entry.Index.ObjectViews;
+        GalaxyObjectView? root = ResolveRoot(request, entry.Index);
+
+        ConcurrentDictionary<string, IReadOnlyList<GalaxyObjectView>> memo =
+            FilteredViewCache.GetValue(entry, static _ => new ConcurrentDictionary<string, IReadOnlyList<GalaxyObjectView>>(StringComparer.Ordinal));
+
+        return memo.GetOrAdd(
+            filterSignature,
+            static (_, state) =>
+            {
+                List<GalaxyObjectView> matched = [];
+                foreach (GalaxyObjectView view in state.Views)
+                {
+                    if (MatchesRoot(view, state.Root, state.MaxDepth)
+                        && MatchesBrowseSubtrees(view, state.BrowseSubtreeGlobs)
+                        && MatchesFilters(view.Object, state.Request))
+                    {
+                        matched.Add(view);
+                    }
+                }
+
+                return matched;
+            },
+            (Views: views, Root: root, MaxDepth: maxDepth, BrowseSubtreeGlobs: browseSubtreeGlobs, Request: request));
+    }
+
+    /// <summary>Finds an object in the hierarchy by its tag address.</summary>
+    /// <param name="entry">The Galaxy hierarchy cache entry.</param>
+    /// <param name="tagAddress">The tag address to search for.</param>
+    public static GalaxyObject? FindObjectForTag(
+        GalaxyHierarchyCacheEntry entry,
+        string tagAddress)
+    {
+        if (string.IsNullOrWhiteSpace(tagAddress))
+        {
+            return null;
+        }
+
+        return entry.Index.TagsByAddress.TryGetValue(tagAddress, out GalaxyTagLookup? lookup)
+            ? lookup.Object
+            : null;
+    }
+
+    /// <summary>Finds an attribute in the hierarchy by its tag address.</summary>
+    /// <param name="entry">The Galaxy hierarchy cache entry.</param>
+    /// <param name="tagAddress">The tag address to search for.</param>
+    public static GalaxyAttribute? FindAttributeForTag(
+        GalaxyHierarchyCacheEntry entry,
+        string tagAddress)
+    {
+        if (string.IsNullOrWhiteSpace(tagAddress))
+        {
+            return null;
+        }
+
+        return entry.Index.TagsByAddress.TryGetValue(tagAddress, out GalaxyTagLookup? lookup)
+            ? lookup.Attribute
+            : null;
+    }
+
+    /// <summary>Gets the contained path for an object by its gobject ID.</summary>
+    /// <param name="entry">The Galaxy hierarchy cache entry.</param>
+    /// <param name="gobjectId">The Galaxy object ID.</param>
+    public static string GetContainedPath(
+        GalaxyHierarchyCacheEntry entry,
+        int gobjectId)
+    {
+        return entry.Index.ObjectViewsById.TryGetValue(gobjectId, out GalaxyObjectView? view)
+            ? view.ContainedPath
+            : string.Empty;
+    }
+
+    private static GalaxyObjectView? ResolveRoot(
+        DiscoverHierarchyRequest request,
+        GalaxyHierarchyIndex index)
+    {
+        GalaxyObjectView? root = request.RootCase switch
+        {
+            DiscoverHierarchyRequest.RootOneofCase.None => null,
+            DiscoverHierarchyRequest.RootOneofCase.RootGobjectId =>
+                index.ObjectViewsById.TryGetValue(request.RootGobjectId, out GalaxyObjectView? byId) ? byId : null,
+            DiscoverHierarchyRequest.RootOneofCase.RootTagName =>
+                index.ObjectViewsByTagName.TryGetValue(request.RootTagName, out GalaxyObjectView? byTag) ? byTag : null,
+            DiscoverHierarchyRequest.RootOneofCase.RootContainedPath =>
+                index.ObjectViewsByContainedPath.TryGetValue(request.RootContainedPath, out GalaxyObjectView? byPath) ? byPath : null,
+            _ => null,
+        };
+
+        if (request.RootCase != DiscoverHierarchyRequest.RootOneofCase.None && root is null)
+        {
+            throw new RpcException(new Status(StatusCode.NotFound, "DiscoverHierarchy root was not found."));
+        }
+
+        return root;
+    }
+
+    private static bool MatchesRoot(
+        GalaxyObjectView view,
+        GalaxyObjectView? root,
+        int? maxDepth)
+    {
+        if (root is null)
+        {
+            return true;
+        }
+
+        bool isRoot = view.Object.GobjectId == root.Object.GobjectId;
+        bool isDescendant = view.ContainedPath.StartsWith(root.ContainedPath + "/", StringComparison.OrdinalIgnoreCase);
+        if (!isRoot && !isDescendant)
+        {
+            return false;
+        }
+
+        return maxDepth is null || view.Depth - root.Depth <= maxDepth.Value;
+    }
+
+    private static bool MatchesBrowseSubtrees(
+        GalaxyObjectView view,
+        IReadOnlyList<string>? browseSubtreeGlobs)
+    {
+        return browseSubtreeGlobs is null
+            || browseSubtreeGlobs.Count == 0
+            || browseSubtreeGlobs.Any(glob => GalaxyGlobMatcher.IsMatch(view.ContainedPath, glob));
+    }
+
+    private static bool MatchesFilters(
+        GalaxyObject obj,
+        DiscoverHierarchyRequest request)
+    {
+        if (request.CategoryIds.Count > 0 && !request.CategoryIds.Contains(obj.CategoryId))
+        {
+            return false;
+        }
+
+        foreach (string templateFilter in request.TemplateChainContains)
+        {
+            if (!obj.TemplateChain.Any(template => template.Contains(templateFilter, StringComparison.OrdinalIgnoreCase)))
+            {
+                return false;
+            }
+        }
+
+        if (!string.IsNullOrWhiteSpace(request.TagNameGlob)
+            && !GalaxyGlobMatcher.IsMatch(obj.TagName, request.TagNameGlob))
+        {
+            return false;
+        }
+
+        if (request.AlarmBearingOnly && !obj.Attributes.Any(attribute => attribute.IsAlarm))
+        {
+            return false;
+        }
+
+        if (request.HistorizedOnly && !obj.Attributes.Any(attribute => attribute.IsHistorized))
+        {
+            return false;
+        }
+
+        return true;
+    }
+
+    private static bool IncludeAttributes(DiscoverHierarchyRequest request)
+    {
+        return !request.HasIncludeAttributes || request.IncludeAttributes;
+    }
+
+    private static GalaxyObject CloneObject(GalaxyObject source, bool includeAttributes)
+    {
+        GalaxyObject clone = source.Clone();
+        if (!includeAttributes)
+        {
+            clone.Attributes.Clear();
+        }
+
+        return clone;
+    }
+
+    /// <summary>Computes a stable filter signature for memoization purposes.</summary>
+    /// <param name="request">The discovery hierarchy request.</param>
+    /// <param name="browseSubtreeGlobs">Optional glob patterns to filter browse subtrees.</param>
+    public static string ComputeFilterSignature(
+        DiscoverHierarchyRequest request,
+        IReadOnlyList<string>? browseSubtreeGlobs)
+    {
+        StringBuilder builder = new();
+        builder.Append("root=").Append(request.RootCase).Append('|');
+        builder.Append(request.RootCase switch
+        {
+            DiscoverHierarchyRequest.RootOneofCase.RootGobjectId => request.RootGobjectId.ToString(
+                System.Globalization.CultureInfo.InvariantCulture),
+            DiscoverHierarchyRequest.RootOneofCase.RootTagName => request.RootTagName,
+            DiscoverHierarchyRequest.RootOneofCase.RootContainedPath => request.RootContainedPath,
+            _ => string.Empty,
+        });
+        builder.Append("|max=").Append(request.MaxDepth?.ToString(System.Globalization.CultureInfo.InvariantCulture) ?? "");
+        builder.Append("|cat=").AppendJoin(',', request.CategoryIds.Order());
+        builder.Append("|tpl=").AppendJoin(',', request.TemplateChainContains.Order(StringComparer.OrdinalIgnoreCase));
+        builder.Append("|glob=").Append(request.TagNameGlob);
+        builder.Append("|attrs=").Append(request.HasIncludeAttributes ? request.IncludeAttributes.ToString() : "unset");
+        builder.Append("|alarm=").Append(request.AlarmBearingOnly);
+        builder.Append("|hist=").Append(request.HistorizedOnly);
+        builder.Append("|browse=").AppendJoin(',', (browseSubtreeGlobs ?? Array.Empty<string>()).Order(StringComparer.OrdinalIgnoreCase));
+
+        byte[] hash = SHA256.HashData(Encoding.UTF8.GetBytes(builder.ToString()));
+        return Convert.ToHexString(hash, 0, 12);
+    }
+}
@@ -0,0 +1,16 @@
+using ZB.MOM.WW.GalaxyRepository.Grpc;
+
+namespace ZB.MOM.WW.GalaxyRepository;
+
+/// <summary>
+///     Result of one <see cref="GalaxyHierarchyProjector.Project(GalaxyHierarchyCacheEntry, DiscoverHierarchyRequest, System.Collections.Generic.IReadOnlyList{string}, int, int)"/>
+///     call: a materialized page of matching objects, the total post-filter object count, and
+///     the stable filter signature used to bind page tokens.
+/// </summary>
+/// <param name="Objects">The page of matching objects.</param>
+/// <param name="TotalObjectCount">Total matching objects across the whole hierarchy (post-filter).</param>
+/// <param name="FilterSignature">Stable signature of the filter set, used to bind page tokens.</param>
+public sealed record GalaxyHierarchyQueryResult(
+    IReadOnlyList<GalaxyObject> Objects,
+    int TotalObjectCount,
+    string FilterSignature);
@@ -0,0 +1,62 @@
+using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+
+namespace ZB.MOM.WW.GalaxyRepository;
+
+/// <summary>Background service that periodically refreshes the Galaxy Repository hierarchy cache off the request path.</summary>
+public sealed class GalaxyHierarchyRefreshService(
+    IGalaxyHierarchyCache cache,
+    IOptions<GalaxyRepositoryOptions> options,
+    ILogger<GalaxyHierarchyRefreshService> logger,
+    TimeProvider? timeProvider = null) : BackgroundService
+{
+    private readonly TimeProvider _timeProvider = timeProvider ?? TimeProvider.System;
+
+    /// <inheritdoc />
+    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
+    {
+        TimeSpan interval = TimeSpan.FromSeconds(Math.Max(1, options.Value.DashboardRefreshIntervalSeconds));
+
+        try
+        {
+            await cache.RefreshAsync(stoppingToken).ConfigureAwait(false);
+        }
+        catch (OperationCanceledException) when (stoppingToken.IsCancellationRequested)
+        {
+            return;
+        }
+        catch (Exception exception)
+        {
+            // A transient first-load failure (e.g. a TimeoutException or
+            // Win32Exception from connection establishment, or a DbException
+            // subtype the cache does not catch) must not fault this
+            // BackgroundService and stop the whole host. The cache records
+            // its own Unavailable/Stale status; the periodic tick below retries.
+            logger.LogWarning(exception, "Initial Galaxy hierarchy cache load failed; will retry on the refresh interval.");
+        }
+
+        using PeriodicTimer timer = new(interval, _timeProvider);
+        try
+        {
+            while (await timer.WaitForNextTickAsync(stoppingToken).ConfigureAwait(false))
+            {
+                try
+                {
+                    await cache.RefreshAsync(stoppingToken).ConfigureAwait(false);
+                }
+                catch (OperationCanceledException) when (stoppingToken.IsCancellationRequested)
+                {
+                    return;
+                }
+                catch (Exception exception)
+                {
+                    logger.LogWarning(exception, "Galaxy hierarchy cache refresh tick failed.");
+                }
+            }
+        }
+        catch (OperationCanceledException) when (stoppingToken.IsCancellationRequested)
+        {
+        }
+    }
+}
@@ -0,0 +1,35 @@
+namespace ZB.MOM.WW.GalaxyRepository;
+
+/// <summary>
+///     One row from <see cref="GalaxyRepository.GetHierarchyAsync"/>: a deployed Galaxy
+///     <c>gobject</c> with its hierarchy parent and template-derivation chain.
+/// </summary>
+public sealed class GalaxyHierarchyRow
+{
+    /// <summary>Gets the Galaxy object identifier.</summary>
+    public int GobjectId { get; init; }
+
+    /// <summary>Gets the tag name.</summary>
+    public string TagName { get; init; } = string.Empty;
+
+    /// <summary>Gets the contained name.</summary>
+    public string ContainedName { get; init; } = string.Empty;
+
+    /// <summary>Gets the browse name.</summary>
+    public string BrowseName { get; init; } = string.Empty;
+
+    /// <summary>Gets the parent Galaxy object identifier.</summary>
+    public int ParentGobjectId { get; init; }
+
+    /// <summary>Gets a value indicating whether this is an area.</summary>
+    public bool IsArea { get; init; }
+
+    /// <summary>Gets the category identifier.</summary>
+    public int CategoryId { get; init; }
+
+    /// <summary>Gets the Galaxy object identifier of the host.</summary>
+    public int HostedByGobjectId { get; init; }
+
+    /// <summary>Gets the template derivation chain.</summary>
+    public IReadOnlyList<string> TemplateChain { get; init; } = Array.Empty<string>();
+}
@@ -0,0 +1,24 @@
+namespace ZB.MOM.WW.GalaxyRepository;
+
+/// <summary>
+///     A serializable point-in-time copy of the Galaxy Repository browse data.
+///     Holds the raw hierarchy and attribute rowsets — not the materialized
+///     protobuf objects — so the restore path runs the exact same
+///     materialization as a live refresh. Persisted by
+///     <see cref="IGalaxyHierarchySnapshotStore"/> after a successful refresh
+///     and reloaded at startup when the Galaxy database is unreachable.
+/// </summary>
+/// <param name="LastDeployTime">
+///     The <c>galaxy.time_of_last_deploy</c> the rowsets were pulled at, or
+///     <see langword="null"/> when the Galaxy table reported no deploy. A later
+///     live refresh that observes this same timestamp can promote the restored
+///     entry to healthy without re-running the heavy queries.
+/// </param>
+/// <param name="SavedAt">UTC wall-clock when the snapshot was written to disk.</param>
+/// <param name="Hierarchy">The persisted object-hierarchy rowset.</param>
+/// <param name="Attributes">The persisted attribute rowset.</param>
+public sealed record GalaxyHierarchySnapshot(
+    DateTimeOffset? LastDeployTime,
+    DateTimeOffset SavedAt,
+    IReadOnlyList<GalaxyHierarchyRow> Hierarchy,
+    IReadOnlyList<GalaxyAttributeRow> Attributes);
@@ -0,0 +1,152 @@
+using System.Text.Json;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+
+namespace ZB.MOM.WW.GalaxyRepository;
+
+/// <summary>
+///     JSON-file implementation of <see cref="IGalaxyHierarchySnapshotStore"/>.
+///     Writes the on-disk snapshot atomically (temp file + rename) so a crash
+///     mid-write can never leave a torn file, and ignores files whose schema
+///     version it does not recognize. When
+///     <see cref="GalaxyRepositoryOptions.PersistSnapshot"/> is <see langword="false"/>
+///     — or <see cref="GalaxyRepositoryOptions.SnapshotCachePath"/> is empty —
+///     both operations are no-ops. The snapshot path is fully consumer-supplied;
+///     this store imposes no platform-specific default, so it is cross-platform.
+/// </summary>
+public sealed class GalaxyHierarchySnapshotStore : IGalaxyHierarchySnapshotStore, IDisposable
+{
+    /// <summary>
+    ///     On-disk format version. Bump this whenever the persisted shape changes
+    ///     in a way an older or newer consumer cannot read; a mismatched file is
+    ///     ignored rather than misparsed.
+    /// </summary>
+    private const int CurrentSchemaVersion = 1;
+
+    private static readonly JsonSerializerOptions SerializerOptions = new()
+    {
+        WriteIndented = false,
+    };
+
+    private readonly string? _path;
+    private readonly TimeSpan _writeTimeout;
+    private readonly ILogger<GalaxyHierarchySnapshotStore>? _logger;
+    private readonly SemaphoreSlim _ioGate = new(1, 1);
+
+    /// <summary>Initializes a new instance of the <see cref="GalaxyHierarchySnapshotStore"/> class.</summary>
+    /// <param name="options">Galaxy repository options carrying the snapshot path and enable flag.</param>
+    /// <param name="logger">Optional logger for diagnostic output.</param>
+    public GalaxyHierarchySnapshotStore(
+        IOptions<GalaxyRepositoryOptions> options,
+        ILogger<GalaxyHierarchySnapshotStore>? logger = null)
+    {
+        GalaxyRepositoryOptions value = options.Value;
+        _path = value.PersistSnapshot && !string.IsNullOrWhiteSpace(value.SnapshotCachePath)
+            ? value.SnapshotCachePath
+            : null;
+        _writeTimeout = TimeSpan.FromSeconds(Math.Max(1, value.CommandTimeoutSeconds));
+        _logger = logger;
+    }
+
+    /// <inheritdoc />
+    public async Task SaveAsync(GalaxyHierarchySnapshot snapshot, CancellationToken cancellationToken)
+    {
+        ArgumentNullException.ThrowIfNull(snapshot);
+        if (_path is null)
+        {
+            return;
+        }
+
+        PersistedFile file = new(CurrentSchemaVersion, snapshot);
+
+        await _ioGate.WaitAsync(cancellationToken).ConfigureAwait(false);
+        try
+        {
+            // Bound the write so a stuck disk — e.g. a SnapshotCachePath on an
+            // unresponsive network share — cannot stall the caller. On the cache
+            // refresh path that would otherwise pin the whole refresh loop.
+            using CancellationTokenSource writeCts = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken);
+            writeCts.CancelAfter(_writeTimeout);
+
+            string? directory = Path.GetDirectoryName(_path);
+            if (!string.IsNullOrEmpty(directory))
+            {
+                Directory.CreateDirectory(directory);
+            }
+
+            string tempPath = _path + ".tmp";
+            await using (FileStream stream = new(tempPath, FileMode.Create, FileAccess.Write, FileShare.None))
+            {
+                await JsonSerializer.SerializeAsync(stream, file, SerializerOptions, writeCts.Token).ConfigureAwait(false);
+            }
+
+            File.Move(tempPath, _path, overwrite: true);
+            _logger?.LogDebug(
+                "Persisted Galaxy hierarchy snapshot to {Path} ({ObjectCount} objects, {AttributeCount} attributes).",
+                _path,
+                snapshot.Hierarchy.Count,
+                snapshot.Attributes.Count);
+        }
+        finally
+        {
+            _ioGate.Release();
+        }
+    }
+
+    /// <inheritdoc />
+    public async Task<GalaxyHierarchySnapshot?> TryLoadAsync(CancellationToken cancellationToken)
+    {
+        if (_path is null || !File.Exists(_path))
+        {
+            return null;
+        }
+
+        await _ioGate.WaitAsync(cancellationToken).ConfigureAwait(false);
+        try
+        {
+            PersistedFile? file;
+            await using (FileStream stream = new(_path, FileMode.Open, FileAccess.Read, FileShare.Read))
+            {
+                file = await JsonSerializer.DeserializeAsync<PersistedFile>(
+                    stream, SerializerOptions, cancellationToken).ConfigureAwait(false);
+            }
+
+            if (file is null || file.SchemaVersion != CurrentSchemaVersion || file.Snapshot is null)
+            {
+                _logger?.LogWarning(
+                    "Ignoring Galaxy hierarchy snapshot at {Path}: unrecognized or empty schema version.",
+                    _path);
+                return null;
+            }
+
+            return file.Snapshot;
+        }
+        catch (Exception exception) when (exception is JsonException or IOException or UnauthorizedAccessException)
+        {
+            // A corrupt, truncated, locked, or access-denied snapshot file is an
+            // expected failure mode for a disk cache — honor the Try contract and
+            // return null rather than throwing.
+            _logger?.LogWarning(
+                exception,
+                "Ignoring Galaxy hierarchy snapshot at {Path}: the file is unreadable or not valid JSON.",
+                _path);
+            return null;
+        }
+        finally
+        {
+            _ioGate.Release();
+        }
+    }
+
+    /// <summary>
+    ///     Disposes the I/O gate. As a DI singleton the store is disposed once at host
+    ///     shutdown, by which point no save/load is in flight.
+    /// </summary>
+    public void Dispose()
+    {
+        _ioGate.Dispose();
+    }
+
+    /// <summary>On-disk envelope: a schema version plus the snapshot payload.</summary>
+    private sealed record PersistedFile(int SchemaVersion, GalaxyHierarchySnapshot? Snapshot);
+}
@@ -0,0 +1,16 @@
+using ZB.MOM.WW.GalaxyRepository.Grpc;
+
+namespace ZB.MOM.WW.GalaxyRepository;
+
+/// <summary>
+///     A <see cref="GalaxyObject"/> paired with its computed contained path and hierarchy
+///     depth. Materialized once per cache entry by <see cref="GalaxyHierarchyIndex"/> so
+///     browse/discover projection can filter and page without recomputing paths.
+/// </summary>
+/// <param name="Object">The projected Galaxy object.</param>
+/// <param name="ContainedPath">The slash-delimited contained path from the hierarchy root.</param>
+/// <param name="Depth">The number of path segments from the root (zero for top-level objects).</param>
+public sealed record GalaxyObjectView(
+    GalaxyObject Object,
+    string ContainedPath,
+    int Depth);
@@ -0,0 +1,76 @@
+using ZB.MOM.WW.GalaxyRepository.Grpc;
+
+namespace ZB.MOM.WW.GalaxyRepository;
+
+/// <summary>
+///     Maps <see cref="GalaxyHierarchyRow"/> + <see cref="GalaxyAttributeRow"/> rows produced
+///     by <see cref="GalaxyRepository"/> into <c>galaxy_repository.v1</c> proto messages.
+///     Pure function, separated so it can be unit-tested without a SQL connection.
+/// </summary>
+public static class GalaxyProtoMapper
+{
+    /// <summary>Maps Galaxy hierarchy and attribute rows to Galaxy object protos.</summary>
+    /// <param name="hierarchy">Hierarchy rows from Galaxy Repository.</param>
+    /// <param name="attributes">Attribute rows from Galaxy Repository.</param>
+    public static IEnumerable<GalaxyObject> MapHierarchy(
+        IReadOnlyList<GalaxyHierarchyRow> hierarchy,
+        IReadOnlyList<GalaxyAttributeRow> attributes)
+    {
+        Dictionary<int, List<GalaxyAttributeRow>> attributesByGobjectId = attributes
+            .GroupBy(a => a.GobjectId)
+            .ToDictionary(g => g.Key, g => g.ToList());
+
+        foreach (GalaxyHierarchyRow row in hierarchy)
+        {
+            yield return MapObject(row, attributesByGobjectId);
+        }
+    }
+
+    /// <summary>Maps a Galaxy hierarchy row to a Galaxy object proto.</summary>
+    /// <param name="row">Hierarchy row from Galaxy Repository.</param>
+    /// <param name="attributesByGobjectId">Attributes indexed by gobject ID.</param>
+    public static GalaxyObject MapObject(
+        GalaxyHierarchyRow row,
+        IReadOnlyDictionary<int, List<GalaxyAttributeRow>> attributesByGobjectId)
+    {
+        GalaxyObject obj = new()
+        {
+            GobjectId = row.GobjectId,
+            TagName = row.TagName,
+            ContainedName = row.ContainedName,
+            BrowseName = row.BrowseName,
+            ParentGobjectId = row.ParentGobjectId,
+            IsArea = row.IsArea,
+            CategoryId = row.CategoryId,
+            HostedByGobjectId = row.HostedByGobjectId,
+        };
+        obj.TemplateChain.AddRange(row.TemplateChain);
+
+        if (attributesByGobjectId.TryGetValue(row.GobjectId, out List<GalaxyAttributeRow>? attrs))
+        {
+            foreach (GalaxyAttributeRow attr in attrs)
+            {
+                obj.Attributes.Add(MapAttribute(attr));
+            }
+        }
+
+        return obj;
+    }
+
+    /// <summary>Maps a Galaxy attribute row to a Galaxy attribute proto.</summary>
+    /// <param name="row">Attribute row from Galaxy Repository.</param>
+    public static GalaxyAttribute MapAttribute(GalaxyAttributeRow row) => new()
+    {
+        AttributeName = row.AttributeName,
+        FullTagReference = row.FullTagReference,
+        MxDataType = row.MxDataType,
+        DataTypeName = row.DataTypeName ?? string.Empty,
+        IsArray = row.IsArray,
+        ArrayDimension = row.ArrayDimension ?? 0,
+        ArrayDimensionPresent = row.ArrayDimension.HasValue,
+        MxAttributeCategory = row.MxAttributeCategory,
+        SecurityClassification = row.SecurityClassification,
+        IsHistorized = row.IsHistorized,
+        IsAlarm = row.IsAlarm,
+    };
+}
@@ -0,0 +1,257 @@
+using Microsoft.Data.SqlClient;
+
+namespace ZB.MOM.WW.GalaxyRepository;
+
+/// <summary>
+///     SQL access to the AVEVA System Platform Galaxy Repository database.
+///     <para>
+///     <see cref="HierarchySql" /> is the query originally ported from the OtOpcUa
+///     project. <see cref="AttributesSql" /> has diverged: it additionally enumerates the
+///     built-in attributes contributed by each object's primitives (from
+///     <c>attribute_definition</c> via <c>primitive_instance</c>), so engine/platform objects
+///     and extension sub-attributes (e.g. <c>TestAlarm001.Acked</c>) are surfaced. The
+///     OtOpcUa query is not kept in sync.
+///     </para>
+/// </summary>
+public sealed class GalaxyRepository(GalaxyRepositoryOptions options) : IGalaxyRepository
+{
+    /// <summary>Tests the connection to the Galaxy Repository database.</summary>
+    /// <param name="ct">Token to cancel the asynchronous operation.</param>
+    public async Task<bool> TestConnectionAsync(CancellationToken ct = default)
+    {
+        try
+        {
+            using SqlConnection conn = new(options.ConnectionString);
+            await conn.OpenAsync(ct).ConfigureAwait(false);
+            using SqlCommand cmd = new("SELECT 1", conn) { CommandTimeout = options.CommandTimeoutSeconds };
+            object? result = await cmd.ExecuteScalarAsync(ct).ConfigureAwait(false);
+            return result is int i && i == 1;
+        }
+        catch (SqlException) { return false; }
+        catch (InvalidOperationException) { return false; }
+    }
+
+    /// <summary>Retrieves the last deployment time from the Galaxy Repository.</summary>
+    /// <param name="ct">Token to cancel the asynchronous operation.</param>
+    public async Task<DateTime?> GetLastDeployTimeAsync(CancellationToken ct = default)
+    {
+        using SqlConnection conn = new(options.ConnectionString);
+        await conn.OpenAsync(ct).ConfigureAwait(false);
+        using SqlCommand cmd = new("SELECT time_of_last_deploy FROM galaxy", conn)
+        { CommandTimeout = options.CommandTimeoutSeconds };
+        object? result = await cmd.ExecuteScalarAsync(ct).ConfigureAwait(false);
+        return result is DateTime dt ? dt : null;
+    }
+
+    /// <summary>Retrieves the complete hierarchy of Galaxy objects from the repository.</summary>
+    /// <param name="ct">Token to cancel the asynchronous operation.</param>
+    public async Task<List<GalaxyHierarchyRow>> GetHierarchyAsync(CancellationToken ct = default)
+    {
+        List<GalaxyHierarchyRow> rows = new();
+
+        using SqlConnection conn = new(options.ConnectionString);
+        await conn.OpenAsync(ct).ConfigureAwait(false);
+
+        using SqlCommand cmd = new(HierarchySql, conn) { CommandTimeout = options.CommandTimeoutSeconds };
+        using SqlDataReader reader = await cmd.ExecuteReaderAsync(ct).ConfigureAwait(false);
+
+        while (await reader.ReadAsync(ct).ConfigureAwait(false))
+        {
+            string templateChainRaw = reader.IsDBNull(8) ? string.Empty : reader.GetString(8);
+            string[] templateChain = templateChainRaw.Length == 0
+                ? Array.Empty<string>()
+                : templateChainRaw.Split(['|'], StringSplitOptions.RemoveEmptyEntries)
+                    .Select(s => s.Trim())
+                    .Where(s => s.Length > 0)
+                    .ToArray();
+
+            rows.Add(new GalaxyHierarchyRow
+            {
+                GobjectId = Convert.ToInt32(reader.GetValue(0)),
+                TagName = reader.GetString(1),
+                ContainedName = reader.IsDBNull(2) ? string.Empty : reader.GetString(2),
+                BrowseName = reader.GetString(3),
+                ParentGobjectId = Convert.ToInt32(reader.GetValue(4)),
+                IsArea = Convert.ToInt32(reader.GetValue(5)) == 1,
+                CategoryId = Convert.ToInt32(reader.GetValue(6)),
+                HostedByGobjectId = Convert.ToInt32(reader.GetValue(7)),
+                TemplateChain = templateChain,
+            });
+        }
+        return rows;
+    }
+
+    /// <summary>Retrieves all attributes for Galaxy objects from the repository.</summary>
+    /// <param name="ct">Token to cancel the asynchronous operation.</param>
+    public async Task<List<GalaxyAttributeRow>> GetAttributesAsync(CancellationToken ct = default)
+    {
+        List<GalaxyAttributeRow> rows = new();
+
+        using SqlConnection conn = new(options.ConnectionString);
+        await conn.OpenAsync(ct).ConfigureAwait(false);
+
+        using SqlCommand cmd = new(AttributesSql, conn) { CommandTimeout = options.CommandTimeoutSeconds };
+        using SqlDataReader reader = await cmd.ExecuteReaderAsync(ct).ConfigureAwait(false);
+
+        while (await reader.ReadAsync(ct).ConfigureAwait(false))
+        {
+            rows.Add(new GalaxyAttributeRow
+            {
+                GobjectId = Convert.ToInt32(reader.GetValue(0)),
+                TagName = reader.GetString(1),
+                AttributeName = reader.GetString(2),
+                FullTagReference = reader.GetString(3),
+                MxDataType = Convert.ToInt32(reader.GetValue(4)),
+                DataTypeName = reader.IsDBNull(5) ? null : reader.GetString(5),
+                IsArray = Convert.ToInt32(reader.GetValue(6)) == 1,
+                ArrayDimension = reader.IsDBNull(7) ? null : Convert.ToInt32(reader.GetValue(7)),
+                MxAttributeCategory = Convert.ToInt32(reader.GetValue(8)),
+                SecurityClassification = Convert.ToInt32(reader.GetValue(9)),
+                IsHistorized = Convert.ToInt32(reader.GetValue(10)) == 1,
+                IsAlarm = Convert.ToInt32(reader.GetValue(11)) == 1,
+            });
+        }
+        return rows;
+    }
+
+    // Area objects (category 13) are returned even when undeployed (deployed_package_id = 0):
+    // they are organizational/model nodes that group deployed objects, so excluding them
+    // orphans every area whose containing area is not itself deployed. All non-area objects
+    // still require deployment. Orphans left by a missing/deleted parent area are re-rooted
+    // by GalaxyHierarchyIndex.Build so nothing disappears from browse.
+    private const string HierarchySql = @"
+;WITH template_chain AS (
+    SELECT g.gobject_id AS instance_gobject_id, t.gobject_id AS template_gobject_id,
+           t.tag_name AS template_tag_name, t.derived_from_gobject_id, 0 AS depth
+    FROM gobject g
+    INNER JOIN gobject t ON t.gobject_id = g.derived_from_gobject_id
+    WHERE g.is_template = 0 AND g.deployed_package_id <> 0 AND g.derived_from_gobject_id <> 0
+    UNION ALL
+    SELECT tc.instance_gobject_id, t.gobject_id, t.tag_name, t.derived_from_gobject_id, tc.depth + 1
+    FROM template_chain tc
+    INNER JOIN gobject t ON t.gobject_id = tc.derived_from_gobject_id
+    WHERE tc.derived_from_gobject_id <> 0 AND tc.depth < 10
+)
+SELECT DISTINCT
+    g.gobject_id,
+    g.tag_name,
+    g.contained_name,
+    CASE WHEN g.contained_name IS NULL OR g.contained_name = ''
+         THEN g.tag_name
+         ELSE g.contained_name
+    END AS browse_name,
+    CASE WHEN g.contained_by_gobject_id = 0
+         THEN g.area_gobject_id
+         ELSE g.contained_by_gobject_id
+    END AS parent_gobject_id,
+    CASE WHEN td.category_id = 13
+         THEN 1
+         ELSE 0
+    END AS is_area,
+    td.category_id AS category_id,
+    g.hosted_by_gobject_id AS hosted_by_gobject_id,
+    ISNULL(
+        STUFF((
+            SELECT '|' + tc.template_tag_name
+            FROM template_chain tc
+            WHERE tc.instance_gobject_id = g.gobject_id
+            ORDER BY tc.depth
+            FOR XML PATH('')
+        ), 1, 1, ''),
+        ''
+    ) AS template_chain
+FROM gobject g
+INNER JOIN template_definition td
+    ON g.template_definition_id = td.template_definition_id
+WHERE td.category_id IN (1, 3, 4, 10, 11, 13, 17, 24, 26)
+    AND g.is_template = 0
+    AND (g.deployed_package_id <> 0 OR td.category_id = 13)
+ORDER BY parent_gobject_id, g.tag_name";
+
+    // Unlike HierarchySql, this query has diverged from the OtOpcUa original. It returns two
+    // kinds of attribute: user-configured dynamic attributes (the original `dynamic_attribute`
+    // body, src_pri 0) and the built-in attributes every object inherits from its primitives
+    // (`attribute_definition` joined through `primitive_instance`, src_pri 1). Built-in
+    // attributes are why engine/platform objects and extension sub-attributes such as
+    // `TestAlarm001.Acked` show up at all. Built-in rows carry no category filter (the
+    // `attribute_definition` category numbering differs from `dynamic_attribute`'s — only the
+    // `_`-prefix and `.Description` name exclusions apply) and are never flagged
+    // `is_historized`/`is_alarm`: those flags describe a user attribute that anchors an
+    // extension, not the extension's machinery leaves.
+    private const string AttributesSql = @"
+;WITH deployed_package_chain AS (
+    SELECT g.gobject_id, p.package_id, p.derived_from_package_id, 0 AS depth
+    FROM gobject g
+    INNER JOIN package p ON p.package_id = g.deployed_package_id
+    WHERE g.is_template = 0 AND g.deployed_package_id <> 0
+    UNION ALL
+    SELECT dpc.gobject_id, p.package_id, p.derived_from_package_id, dpc.depth + 1
+    FROM deployed_package_chain dpc
+    INNER JOIN package p ON p.package_id = dpc.derived_from_package_id
+    WHERE dpc.derived_from_package_id <> 0 AND dpc.depth < 10
+),
+candidate AS (
+    SELECT
+        dpc.gobject_id, g.tag_name, da.attribute_name, da.mx_data_type, da.is_array,
+        CASE WHEN da.is_array = 1
+             THEN CONVERT(int, CONVERT(varbinary(2),
+                  SUBSTRING(da.mx_value, 15, 2) + SUBSTRING(da.mx_value, 13, 2), 2))
+             ELSE NULL END AS array_dimension,
+        da.mx_attribute_category, da.security_classification, dpc.depth, 0 AS src_pri
+    FROM deployed_package_chain dpc
+    INNER JOIN dynamic_attribute da ON da.package_id = dpc.package_id
+    INNER JOIN gobject g ON g.gobject_id = dpc.gobject_id
+    INNER JOIN template_definition td ON td.template_definition_id = g.template_definition_id
+    WHERE td.category_id IN (1, 3, 4, 10, 11, 13, 17, 24, 26)
+        AND da.attribute_name NOT LIKE '[_]%'
+        AND da.attribute_name NOT LIKE '%.Description'
+        AND da.mx_attribute_category IN (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 24)
+    UNION ALL
+    SELECT
+        dpc.gobject_id, g.tag_name,
+        CASE WHEN pi.primitive_name IS NULL OR pi.primitive_name = ''
+             THEN ad.attribute_name
+             ELSE pi.primitive_name + '.' + ad.attribute_name END AS attribute_name,
+        ad.mx_data_type, ad.is_array,
+        CASE WHEN ad.is_array = 1
+             THEN CONVERT(int, CONVERT(varbinary(2),
+                  SUBSTRING(ad.mx_value, 15, 2) + SUBSTRING(ad.mx_value, 13, 2), 2))
+             ELSE NULL END AS array_dimension,
+        ad.mx_attribute_category, ad.security_classification, dpc.depth, 1 AS src_pri
+    FROM deployed_package_chain dpc
+    INNER JOIN primitive_instance pi ON pi.package_id = dpc.package_id
+    INNER JOIN attribute_definition ad ON ad.primitive_definition_id = pi.primitive_definition_id
+    INNER JOIN gobject g ON g.gobject_id = dpc.gobject_id
+    INNER JOIN template_definition td ON td.template_definition_id = g.template_definition_id
+    WHERE td.category_id IN (1, 3, 4, 10, 11, 13, 17, 24, 26)
+        AND ad.attribute_name NOT LIKE '[_]%'
+        AND ad.attribute_name NOT LIKE '%.Description'
+),
+ranked AS (
+    SELECT c.*, ROW_NUMBER() OVER (
+        PARTITION BY c.gobject_id, c.attribute_name ORDER BY c.src_pri, c.depth) AS rn
+    FROM candidate c
+)
+SELECT
+    r.gobject_id, r.tag_name, r.attribute_name,
+    r.tag_name + '.' + r.attribute_name
+        + CASE WHEN r.is_array = 1 THEN '[]' ELSE '' END AS full_tag_reference,
+    r.mx_data_type, dt.description AS data_type_name, r.is_array, r.array_dimension,
+    r.mx_attribute_category, r.security_classification,
+    CASE WHEN r.src_pri = 0 AND EXISTS (
+        SELECT 1 FROM deployed_package_chain dpc2
+        INNER JOIN primitive_instance pi ON pi.package_id = dpc2.package_id AND pi.primitive_name = r.attribute_name
+        INNER JOIN primitive_definition pd ON pd.primitive_definition_id = pi.primitive_definition_id AND pd.primitive_name = 'HistoryExtension'
+        WHERE dpc2.gobject_id = r.gobject_id
+    ) THEN 1 ELSE 0 END AS is_historized,
+    CASE WHEN r.src_pri = 0 AND EXISTS (
+        SELECT 1 FROM deployed_package_chain dpc2
+        INNER JOIN primitive_instance pi ON pi.package_id = dpc2.package_id AND pi.primitive_name = r.attribute_name
+        INNER JOIN primitive_definition pd ON pd.primitive_definition_id = pi.primitive_definition_id AND pd.primitive_name = 'AlarmExtension'
+        WHERE dpc2.gobject_id = r.gobject_id
+    ) THEN 1 ELSE 0 END AS is_alarm
+FROM ranked r
+LEFT JOIN data_type dt ON dt.mx_data_type = r.mx_data_type
+WHERE r.rn = 1
+ORDER BY r.tag_name, r.attribute_name";
+}
@@ -0,0 +1,55 @@
+namespace ZB.MOM.WW.GalaxyRepository;
+
+/// <summary>
+///     Connection settings for the AVEVA System Platform Galaxy Repository database.
+///     <para>
+///     <see cref="SectionName"/> is a generic default; the DI extension accepts an explicit
+///     configuration section path so a consumer can bind from its own section (e.g.
+///     <c>HistorianGateway:Galaxy</c>).
+///     </para>
+/// </summary>
+public sealed class GalaxyRepositoryOptions
+{
+    /// <summary>
+    ///     Generic default configuration section name. The DI extension accepts an explicit
+    ///     section path, so a consumer may bind from a different section (e.g.
+    ///     <c>HistorianGateway:Galaxy</c>).
+    /// </summary>
+    public const string SectionName = "GalaxyRepository";
+
+    /// <summary>
+    ///     Default SQL Server connection string for the Galaxy Repository database.
+    ///     Single source of truth shared with the integration-test fallback so the
+    ///     production default and the live-test default cannot drift.
+    /// </summary>
+    public const string DefaultConnectionString =
+        "Server=localhost;Database=ZB;Integrated Security=True;TrustServerCertificate=True;Encrypt=False;";
+
+    /// <summary>The SQL Server connection string for the Galaxy Repository database.</summary>
+    public string ConnectionString { get; init; } = DefaultConnectionString;
+
+    /// <summary>The timeout in seconds for SQL commands executed against the Galaxy Repository.</summary>
+    public int CommandTimeoutSeconds { get; init; } = 60;
+
+    /// <summary>
+    ///     Interval (seconds) between background refreshes of the dashboard Galaxy summary
+    ///     cache. SQL is hit at most once per interval regardless of dashboard render rate.
+    /// </summary>
+    public int DashboardRefreshIntervalSeconds { get; init; } = 30;
+
+    /// <summary>
+    ///     Whether the latest successful Galaxy browse dataset is persisted to disk. When
+    ///     enabled, the cache reloads that snapshot at startup so clients can still browse
+    ///     last-known data while the Galaxy database is unreachable.
+    /// </summary>
+    public bool PersistSnapshot { get; init; } = true;
+
+    /// <summary>
+    ///     File path for the persisted Galaxy browse snapshot. Ignored when
+    ///     <see cref="PersistSnapshot"/> is <see langword="false"/>. There is no built-in
+    ///     default path — the consumer supplies a cross-platform-friendly path appropriate to
+    ///     its host. When left empty and <see cref="PersistSnapshot"/> is enabled, the
+    ///     snapshot store (a later task) decides where to write.
+    /// </summary>
+    public string SnapshotCachePath { get; init; } = string.Empty;
+}
@@ -0,0 +1,16 @@
+using ZB.MOM.WW.GalaxyRepository.Grpc;
+
+namespace ZB.MOM.WW.GalaxyRepository;
+
+/// <summary>
+///     Resolution result for a tag address: the owning <see cref="GalaxyObject"/>, the
+///     specific <see cref="GalaxyAttribute"/> when the address names an attribute (otherwise
+///     <see langword="null"/>), and the object's contained path.
+/// </summary>
+/// <param name="Object">The Galaxy object that owns the looked-up address.</param>
+/// <param name="Attribute">The matched attribute, or <see langword="null"/> when the address names an object.</param>
+/// <param name="ContainedPath">The owning object's contained path.</param>
+public sealed record GalaxyTagLookup(
+    GalaxyObject Object,
+    GalaxyAttribute? Attribute,
+    string ContainedPath);
@@ -0,0 +1,329 @@
+using Google.Protobuf.WellKnownTypes;
+using Grpc.Core;
+using ProtoGalaxyRepository = ZB.MOM.WW.GalaxyRepository.Grpc.GalaxyRepository;
+
+namespace ZB.MOM.WW.GalaxyRepository.Grpc;
+
+/// <summary>
+///     Reusable gRPC surface that exposes the Galaxy Repository to clients. Hosted by any
+///     consuming gateway (e.g. MxAccessGateway or the HistorianGateway sidecar) via
+///     <see cref="DependencyInjection.GalaxyRepositoryServiceCollectionExtensions.MapZbGalaxyRepository"/>.
+///     <para>
+///     <c>DiscoverHierarchy</c> and <c>GetLastDeployTime</c> serve from
+///     <see cref="IGalaxyHierarchyCache"/> so many clients share a single SQL pull.
+///     <c>WatchDeployEvents</c> streams events from <see cref="IGalaxyDeployNotifier"/>.
+///     <c>TestConnection</c> remains a direct SQL probe since callers use it as a health check.
+///     </para>
+///     <para>
+///     This service applies <b>no</b> per-identity browse-subtree filtering — the full
+///     hierarchy is projected (<c>null</c> subtree globs). Authorization (including any
+///     subtree scoping) is the responsibility of the hosting gateway's interceptor layer.
+///     </para>
+/// </summary>
+/// <param name="repository">Direct SQL surface used by <c>TestConnection</c>.</param>
+/// <param name="cache">Shared hierarchy cache that <c>DiscoverHierarchy</c>/<c>BrowseChildren</c>/<c>GetLastDeployTime</c> serve from.</param>
+/// <param name="notifier">Deploy-event source streamed by <c>WatchDeployEvents</c>.</param>
+public sealed class GalaxyRepositoryGrpcService(
+    IGalaxyRepository repository,
+    IGalaxyHierarchyCache cache,
+    IGalaxyDeployNotifier notifier) : ProtoGalaxyRepository.GalaxyRepositoryBase
+{
+    private static readonly TimeSpan FirstLoadWaitBudget = TimeSpan.FromSeconds(5);
+    private const int DefaultDiscoverPageSize = 1000;
+    private const int MaxDiscoverPageSize = 5000;
+    private const int DefaultBrowsePageSize = 500;
+    // MaxBrowsePageSize reuses MaxDiscoverPageSize (5000) — same cap.
+
+    /// <inheritdoc />
+    public override async Task<TestConnectionReply> TestConnection(
+        TestConnectionRequest request,
+        ServerCallContext context)
+    {
+        bool ok = await repository.TestConnectionAsync(context.CancellationToken).ConfigureAwait(false);
+        return new TestConnectionReply { Ok = ok };
+    }
+
+    /// <inheritdoc />
+    public override async Task<GetLastDeployTimeReply> GetLastDeployTime(
+        GetLastDeployTimeRequest request,
+        ServerCallContext context)
+    {
+        await WaitForCacheBootstrap(context.CancellationToken).ConfigureAwait(false);
+        GalaxyHierarchyCacheEntry entry = cache.Current;
+
+        if (!entry.HasData)
+        {
+            throw new RpcException(new Status(
+                StatusCode.Unavailable,
+                ResolveUnavailableMessage(entry)));
+        }
+
+        GetLastDeployTimeReply reply = new() { Present = entry.LastDeployTime.HasValue };
+        if (entry.LastDeployTime.HasValue)
+        {
+            reply.TimeOfLastDeploy = Timestamp.FromDateTimeOffset(entry.LastDeployTime.Value);
+        }
+        return reply;
+    }
+
+    /// <inheritdoc />
+    public override async Task<DiscoverHierarchyReply> DiscoverHierarchy(
+        DiscoverHierarchyRequest request,
+        ServerCallContext context)
+    {
+        await WaitForCacheBootstrap(context.CancellationToken).ConfigureAwait(false);
+        GalaxyHierarchyCacheEntry entry = cache.Current;
+
+        if (!entry.HasData)
+        {
+            throw new RpcException(new Status(
+                StatusCode.Unavailable,
+                ResolveUnavailableMessage(entry)));
+        }
+
+        int pageSize = ResolvePageSize(request.PageSize);
+        // The shared library applies no per-identity subtree scoping; the hosting
+        // gateway enforces authorization at its interceptor layer.
+        string filterSignature = GalaxyHierarchyProjector.ComputeFilterSignature(request, browseSubtreeGlobs: null);
+        PageToken pageToken = ParsePageToken(request.PageToken, entry.Sequence, filterSignature);
+        GalaxyHierarchyQueryResult query = GalaxyHierarchyProjector.Project(
+            entry,
+            request,
+            browseSubtreeGlobs: null,
+            pageToken.Offset,
+            pageSize);
+        int offset = pageToken.Offset;
+        if (offset > query.TotalObjectCount)
+        {
+            throw new RpcException(new Status(
+                StatusCode.InvalidArgument,
+                "DiscoverHierarchy page_token is outside the current hierarchy."));
+        }
+
+        DiscoverHierarchyReply reply = new()
+        {
+            TotalObjectCount = query.TotalObjectCount,
+        };
+        reply.Objects.Add(query.Objects);
+
+        int nextOffset = offset + query.Objects.Count;
+        if (nextOffset < query.TotalObjectCount)
+        {
+            reply.NextPageToken = FormatPageToken(entry.Sequence, query.FilterSignature, nextOffset);
+        }
+
+        return reply;
+    }
+
+    /// <inheritdoc />
+    public override async Task<BrowseChildrenReply> BrowseChildren(
+        BrowseChildrenRequest request,
+        ServerCallContext context)
+    {
+        await WaitForCacheBootstrap(context.CancellationToken).ConfigureAwait(false);
+        GalaxyHierarchyCacheEntry entry = cache.Current;
+
+        if (!entry.HasData)
+        {
+            throw new RpcException(new Status(
+                StatusCode.Unavailable,
+                ResolveUnavailableMessage(entry)));
+        }
+
+        int pageSize = ResolveBrowsePageSize(request.PageSize);
+
+        // Resolve the parent id once so the page-token signature can include it
+        // and the projector sees the same resolved id when memoizing. The projector
+        // re-resolves internally; with the by-name/by-path indexes on
+        // GalaxyHierarchyIndex that second call is O(1), so the redundancy is cheap
+        // and keeps the projector self-contained.
+        int parentId = GalaxyBrowseProjector.ResolveParentId(entry, request);
+        string filterSignature = GalaxyBrowseProjector.ComputeFilterSignature(
+            request, browseSubtreeGlobs: null, parentId);
+        PageToken pageToken = ParsePageToken(request.PageToken, entry.Sequence, filterSignature);
+
+        GalaxyBrowseChildrenResult result = GalaxyBrowseProjector.ProjectChildren(
+            entry,
+            request,
+            browseSubtreeGlobs: null,
+            pageToken.Offset,
+            pageSize);
+
+        if (pageToken.Offset > result.TotalChildCount)
+        {
+            throw new RpcException(new Status(
+                StatusCode.InvalidArgument,
+                "BrowseChildren page_token is outside the current children set."));
+        }
+
+        BrowseChildrenReply reply = new()
+        {
+            TotalChildCount = result.TotalChildCount,
+            CacheSequence = (ulong)entry.Sequence,
+        };
+        reply.Children.Add(result.Children);
+        reply.ChildHasChildren.Add(result.ChildHasChildren);
+
+        int nextOffset = pageToken.Offset + result.Children.Count;
+        if (nextOffset < result.TotalChildCount)
+        {
+            reply.NextPageToken = FormatPageToken(entry.Sequence, result.FilterSignature, nextOffset);
+        }
+
+        return reply;
+    }
+
+    /// <inheritdoc />
+    public override async Task WatchDeployEvents(
+        WatchDeployEventsRequest request,
+        IServerStreamWriter<DeployEvent> responseStream,
+        ServerCallContext context)
+    {
+        DateTimeOffset? lastSeen = request.LastSeenDeployTime?.ToDateTimeOffset();
+
+        await foreach (GalaxyDeployEventInfo info in notifier
+            .SubscribeAsync(context.CancellationToken)
+            .ConfigureAwait(false))
+        {
+            // Suppress the initial bootstrap event when the client already knows about
+            // this deploy time. We only suppress the first one — subsequent events fire
+            // on actual changes, so they always pass.
+            if (lastSeen is { } seen && info.TimeOfLastDeploy == seen)
+            {
+                lastSeen = null;
+                continue;
+            }
+            lastSeen = null;
+
+            await responseStream.WriteAsync(MapDeployEvent(info), context.CancellationToken).ConfigureAwait(false);
+        }
+    }
+
+    private async Task WaitForCacheBootstrap(CancellationToken cancellationToken)
+    {
+        if (cache.Current.HasData || cache.Current.Status == GalaxyCacheStatus.Unavailable)
+        {
+            return;
+        }
+
+        using CancellationTokenSource budget = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken);
+        budget.CancelAfter(FirstLoadWaitBudget);
+        try
+        {
+            await cache.WaitForFirstLoadAsync(budget.Token).ConfigureAwait(false);
+        }
+        catch (OperationCanceledException) when (cancellationToken.IsCancellationRequested)
+        {
+            throw;
+        }
+        catch (OperationCanceledException)
+        {
+            // Budget elapsed; fall through and let the caller see the current
+            // (possibly Unknown/Unavailable) entry.
+        }
+    }
+
+    private static DeployEvent MapDeployEvent(GalaxyDeployEventInfo info)
+    {
+        DeployEvent ev = new()
+        {
+            Sequence = (ulong)info.Sequence,
+            ObservedAt = Timestamp.FromDateTimeOffset(info.ObservedAt),
+            ObjectCount = info.ObjectCount,
+            AttributeCount = info.AttributeCount,
+            TimeOfLastDeployPresent = info.TimeOfLastDeploy.HasValue,
+        };
+        if (info.TimeOfLastDeploy.HasValue)
+        {
+            ev.TimeOfLastDeploy = Timestamp.FromDateTimeOffset(info.TimeOfLastDeploy.Value);
+        }
+        return ev;
+    }
+
+    private static string ResolveUnavailableMessage(GalaxyHierarchyCacheEntry entry) => entry.Status switch
+    {
+        GalaxyCacheStatus.Unknown => "Galaxy cache has not completed its initial load yet.",
+        GalaxyCacheStatus.Unavailable => "Galaxy repository is unavailable.",
+        _ => "Galaxy cache has no data available.",
+    };
+
+    private static int ResolvePageSize(int requestedPageSize)
+    {
+        if (requestedPageSize < 0)
+        {
+            throw new RpcException(new Status(
+                StatusCode.InvalidArgument,
+                "DiscoverHierarchy page_size must be greater than zero when provided."));
+        }
+
+        int pageSize = requestedPageSize == 0 ? DefaultDiscoverPageSize : requestedPageSize;
+        return Math.Min(pageSize, MaxDiscoverPageSize);
+    }
+
+    private static int ResolveBrowsePageSize(int requested)
+    {
+        if (requested < 0)
+        {
+            throw new RpcException(new Status(
+                StatusCode.InvalidArgument,
+                "BrowseChildren page_size must be greater than zero when provided."));
+        }
+        int pageSize = requested == 0 ? DefaultBrowsePageSize : requested;
+        return Math.Min(pageSize, MaxDiscoverPageSize);
+    }
+
+    private static string FormatPageToken(long sequence, string filterSignature, int offset)
+    {
+        return string.Concat(
+            sequence.ToString(System.Globalization.CultureInfo.InvariantCulture),
+            ":",
+            filterSignature,
+            ":",
+            offset.ToString(System.Globalization.CultureInfo.InvariantCulture));
+    }
+
+    private static PageToken ParsePageToken(string pageToken, long currentSequence, string currentFilterSignature)
+    {
+        if (string.IsNullOrWhiteSpace(pageToken))
+        {
+            return new PageToken(currentSequence, currentFilterSignature, Offset: 0);
+        }
+
+        string[] parts = pageToken.Split(':', count: 3);
+        if (parts.Length != 3
+            || !long.TryParse(
+                parts[0],
+                System.Globalization.NumberStyles.None,
+                System.Globalization.CultureInfo.InvariantCulture,
+                out long sequence)
+            || !int.TryParse(
+                parts[2],
+                System.Globalization.NumberStyles.None,
+                System.Globalization.CultureInfo.InvariantCulture,
+                out int offset)
+            || offset < 0)
+        {
+            throw new RpcException(new Status(
+                StatusCode.InvalidArgument,
+                "page_token is invalid."));
+        }
+
+        if (sequence != currentSequence)
+        {
+            throw new RpcException(new Status(
+                StatusCode.InvalidArgument,
+                "page_token is stale."));
+        }
+
+        if (!string.Equals(parts[1], currentFilterSignature, StringComparison.Ordinal))
+        {
+            throw new RpcException(new Status(
+                StatusCode.InvalidArgument,
+                "page_token does not match the current filters."));
+        }
+
+        return new PageToken(sequence, parts[1], offset);
+    }
+
+    private sealed record PageToken(long Sequence, string FilterSignature, int Offset);
+}
@@ -0,0 +1,17 @@
+namespace ZB.MOM.WW.GalaxyRepository;
+
+/// <summary>Publishes Galaxy repository deploy events to subscribers.</summary>
+public interface IGalaxyDeployNotifier
+{
+    /// <summary>The most recently published event, or null if no event has fired yet.</summary>
+    GalaxyDeployEventInfo? Latest { get; }
+
+    /// <summary>Publishes a deploy event to all current subscribers and stores it as Latest.</summary>
+    /// <param name="info">The deploy event to publish.</param>
+    void Publish(GalaxyDeployEventInfo info);
+
+    /// <summary>Subscribes to deploy events. The sequence yields the latest event first (if available) then streams new events as they fire.</summary>
+    /// <param name="cancellationToken">Token to cancel the asynchronous operation.</param>
+    /// <returns>Async enumerable of deploy events.</returns>
+    IAsyncEnumerable<GalaxyDeployEventInfo> SubscribeAsync(CancellationToken cancellationToken);
+}
@@ -0,0 +1,25 @@
+namespace ZB.MOM.WW.GalaxyRepository;
+
+/// <summary>Cache for Galaxy Repository hierarchy data.</summary>
+public interface IGalaxyHierarchyCache
+{
+    /// <summary>The latest cache entry. Status freshness is recomputed against the clock.</summary>
+    GalaxyHierarchyCacheEntry Current { get; }
+
+    /// <summary>
+    ///     Forces a refresh against the Galaxy Repository. Performs a cheap
+    ///     <c>time_of_last_deploy</c> probe first and only re-queries the heavy hierarchy +
+    ///     attributes rowsets when the deploy time has changed since the last successful
+    ///     refresh.
+    /// </summary>
+    /// <param name="cancellationToken">Token to cancel the asynchronous operation.</param>
+    Task RefreshAsync(CancellationToken cancellationToken);
+
+    /// <summary>
+    ///     Awaits the first completed refresh attempt (success or failure). Useful for
+    ///     gRPC handlers that want to serve from cache without returning Unavailable on the
+    ///     very first request after the service starts.
+    /// </summary>
+    /// <param name="cancellationToken">Token to cancel the asynchronous operation.</param>
+    Task WaitForFirstLoadAsync(CancellationToken cancellationToken);
+}
@@ -0,0 +1,28 @@
+namespace ZB.MOM.WW.GalaxyRepository;
+
+/// <summary>
+///     Persists the latest Galaxy Repository browse dataset to disk and reloads
+///     it at startup. Lets <see cref="GalaxyHierarchyCache"/> serve last-known
+///     browse data when the Galaxy database is unreachable on a cold start.
+/// </summary>
+public interface IGalaxyHierarchySnapshotStore
+{
+    /// <summary>
+    ///     Writes <paramref name="snapshot"/> to disk, replacing any previous
+    ///     snapshot atomically. A no-op when snapshot persistence is disabled.
+    /// </summary>
+    /// <param name="snapshot">The browse dataset to persist.</param>
+    /// <param name="cancellationToken">Token to cancel the asynchronous operation.</param>
+    Task SaveAsync(GalaxyHierarchySnapshot snapshot, CancellationToken cancellationToken);
+
+    /// <summary>
+    ///     Reads the persisted Galaxy browse dataset.
+    /// </summary>
+    /// <param name="cancellationToken">Token to cancel the asynchronous operation.</param>
+    /// <returns>
+    ///     The persisted snapshot, or <see langword="null"/> when none exists,
+    ///     persistence is disabled, or the on-disk file uses an unrecognized
+    ///     schema version.
+    /// </returns>
+    Task<GalaxyHierarchySnapshot?> TryLoadAsync(CancellationToken cancellationToken);
+}
@@ -0,0 +1,26 @@
+namespace ZB.MOM.WW.GalaxyRepository;
+
+/// <summary>
+///     Abstraction over <see cref="GalaxyRepository"/>: the read-only SQL surface over the
+///     AVEVA System Platform Galaxy Repository database. Exists so consumers (and the cache
+///     layer, a later task) can be unit-tested against an in-memory fake without standing up a
+///     real <c>Microsoft.Data.SqlClient</c> <c>SqlConnection</c> against a bogus host/port.
+/// </summary>
+public interface IGalaxyRepository
+{
+    /// <summary>Tests the connection to the Galaxy Repository database.</summary>
+    /// <param name="ct">Token to cancel the asynchronous operation.</param>
+    Task<bool> TestConnectionAsync(CancellationToken ct = default);
+
+    /// <summary>Retrieves the last deployment time from the Galaxy Repository.</summary>
+    /// <param name="ct">Token to cancel the asynchronous operation.</param>
+    Task<DateTime?> GetLastDeployTimeAsync(CancellationToken ct = default);
+
+    /// <summary>Retrieves the complete hierarchy of Galaxy objects from the repository.</summary>
+    /// <param name="ct">Token to cancel the asynchronous operation.</param>
+    Task<List<GalaxyHierarchyRow>> GetHierarchyAsync(CancellationToken ct = default);
+
+    /// <summary>Retrieves all attributes for Galaxy objects from the repository.</summary>
+    /// <param name="ct">Token to cancel the asynchronous operation.</param>
+    Task<List<GalaxyAttributeRow>> GetAttributesAsync(CancellationToken ct = default);
+}
@@ -0,0 +1,190 @@
+syntax = "proto3";
+
+package galaxy_repository.v1;
+
+option csharp_namespace = "ZB.MOM.WW.GalaxyRepository.Grpc";
+
+import "google/protobuf/timestamp.proto";
+import "google/protobuf/wrappers.proto";
+
+// Wire-compatibility policy (ProtobufStyleGuide): this contract evolves
+// additively only. Never renumber or repurpose an existing field number or
+// enum value. When a field or enum value is removed, add a `reserved` range
+// (and `reserved` name) covering it in the same change so a future editor
+// cannot accidentally reuse the retired tag. There are no `reserved`
+// declarations today because no field or enum value has ever been removed.
+
+// Read-only browse over the AVEVA System Platform Galaxy Repository (ZB SQL
+// database). Lets clients enumerate the deployed object hierarchy and each
+// object's dynamic attributes so they know what tag references to subscribe
+// to via the MxAccessGateway service.
+service GalaxyRepository {
+  rpc TestConnection(TestConnectionRequest) returns (TestConnectionReply);
+  rpc GetLastDeployTime(GetLastDeployTimeRequest) returns (GetLastDeployTimeReply);
+  rpc DiscoverHierarchy(DiscoverHierarchyRequest) returns (DiscoverHierarchyReply);
+
+  // Server-stream of deploy events. The server emits the current state immediately
+  // on subscribe (so clients can bootstrap their cache without waiting for the next
+  // deploy), then emits one event each time the gateway's hierarchy cache observes
+  // a new galaxy.time_of_last_deploy. The sequence field is monotonically
+  // increasing per server start; gaps indicate the per-subscriber buffer dropped
+  // older events because the client was too slow.
+  rpc WatchDeployEvents(WatchDeployEventsRequest) returns (stream DeployEvent);
+
+  // Returns the direct children of a parent object (or the root objects when
+  // `parent` is unset). Designed for OPC UA-style lazy expand: clients walk
+  // one level at a time instead of paging the full hierarchy. Filters mirror
+  // DiscoverHierarchy exactly. Backed by the same shared hierarchy cache.
+  rpc BrowseChildren(BrowseChildrenRequest) returns (BrowseChildrenReply);
+}
+
+message TestConnectionRequest {}
+
+message TestConnectionReply {
+  bool ok = 1;
+}
+
+message GetLastDeployTimeRequest {}
+
+message GetLastDeployTimeReply {
+  bool present = 1;
+  google.protobuf.Timestamp time_of_last_deploy = 2;
+}
+
+message DiscoverHierarchyRequest {
+  // Maximum number of objects to return. The server applies its default when
+  // unset and rejects non-positive values.
+  int32 page_size = 1;
+  // Opaque token returned by a previous DiscoverHierarchy response.
+  string page_token = 2;
+  // Optional. When set, return only this object and its descendants.
+  // Empty = full hierarchy.
+  oneof root {
+    int32 root_gobject_id = 3;
+    string root_tag_name = 4;
+    string root_contained_path = 5;
+  }
+  // Optional. Cap on descendant depth from root. Zero returns only the root.
+  // Unset means unlimited depth.
+  google.protobuf.Int32Value max_depth = 6;
+  // Optional object category id filters.
+  repeated int32 category_ids = 7;
+  // Optional case-insensitive substring filters against template names.
+  repeated string template_chain_contains = 8;
+  // Optional anchored, case-insensitive glob over object tag_name.
+  string tag_name_glob = 9;
+  // Optional. Unset or true includes attributes. False returns object skeletons.
+  optional bool include_attributes = 10;
+  // Optional. Return only objects with at least one alarm-bearing attribute.
+  bool alarm_bearing_only = 11;
+  // Optional. Return only objects with at least one historized attribute.
+  bool historized_only = 12;
+}
+
+message DiscoverHierarchyReply {
+  repeated GalaxyObject objects = 1;
+  // Non-empty when another page is available.
+  string next_page_token = 2;
+  // Total number of objects in the cached hierarchy at the time of the call.
+  int32 total_object_count = 3;
+}
+
+message WatchDeployEventsRequest {
+  // Optional. When set, the bootstrap event is suppressed if the cached deploy
+  // time matches this value. Future events are still emitted normally.
+  google.protobuf.Timestamp last_seen_deploy_time = 1;
+}
+
+message DeployEvent {
+  // Monotonically increasing per server start. Gaps indicate dropped events.
+  uint64 sequence = 1;
+  // Server wall-clock when the cache observed the deploy.
+  google.protobuf.Timestamp observed_at = 2;
+  // Galaxy.time_of_last_deploy. Absent only when the Galaxy table reports null.
+  google.protobuf.Timestamp time_of_last_deploy = 3;
+  bool time_of_last_deploy_present = 4;
+  int32 object_count = 5;
+  int32 attribute_count = 6;
+}
+
+message GalaxyObject {
+  int32 gobject_id = 1;
+  string tag_name = 2;
+  string contained_name = 3;
+  string browse_name = 4;
+  int32 parent_gobject_id = 5;
+  bool is_area = 6;
+  int32 category_id = 7;
+  int32 hosted_by_gobject_id = 8;
+  repeated string template_chain = 9;
+  repeated GalaxyAttribute attributes = 10;
+}
+
+message GalaxyAttribute {
+  string attribute_name = 1;
+  string full_tag_reference = 2;
+  // Raw Galaxy SQL `dbo.data_type` identifier, passed through unchanged.
+  // This is NOT a member of `mxaccess_gateway.v1.MxDataType` — Galaxy's
+  // type enumeration is distinct from MXAccess's wire data-type enum and
+  // the two must not be cast or compared. The GalaxyRepository service is
+  // metadata-only and deliberately does not share types with
+  // mxaccess_gateway.proto. See docs/GalaxyRepository.md.
+  int32 mx_data_type = 3;
+  // Human-readable name from Galaxy's `dbo.data_type` table (e.g. "Float",
+  // "Integer", "Boolean"). Free-form Galaxy text; not a stable enum.
+  string data_type_name = 4;
+  bool is_array = 5;
+  int32 array_dimension = 6;
+  bool array_dimension_present = 7;
+  // Raw Galaxy SQL attribute-category identifier, passed through unchanged.
+  // Galaxy-specific; not mapped to any gateway enum. See
+  // docs/GalaxyRepository.md.
+  int32 mx_attribute_category = 8;
+  // Raw Galaxy SQL security-classification identifier, passed through
+  // unchanged. Galaxy-specific; not mapped to any gateway enum. See
+  // docs/GalaxyRepository.md.
+  int32 security_classification = 9;
+  bool is_historized = 10;
+  bool is_alarm = 11;
+}
+
+message BrowseChildrenRequest {
+  // Parent selector. Empty oneof returns root objects (parent_gobject_id == 0).
+  oneof parent {
+    int32 parent_gobject_id = 1;
+    string parent_tag_name = 2;
+    string parent_contained_path = 3;
+  }
+
+  // Maximum number of direct children to return. Server default 500; cap 5000.
+  int32 page_size = 4;
+  // Opaque token returned by a previous BrowseChildren response. Bound to the
+  // cache sequence, parent selector, and the filter set; a mismatch returns
+  // InvalidArgument.
+  string page_token = 5;
+
+  // --- Filter parity with DiscoverHierarchy. AND-combined. ---
+  repeated int32 category_ids = 6;
+  repeated string template_chain_contains = 7;
+  string tag_name_glob = 8;
+  optional bool include_attributes = 9;
+  bool alarm_bearing_only = 10;
+  bool historized_only = 11;
+}
+
+message BrowseChildrenReply {
+  // Direct children matching the filter, sorted areas-first then by
+  // case-insensitive display name (same order as the dashboard tree).
+  repeated GalaxyObject children = 1;
+  // Non-empty when another page of siblings is available.
+  string next_page_token = 2;
+  // Total matching direct children of the parent (post-filter).
+  int32 total_child_count = 3;
+  // Parallel array, indexed with `children`. True when the child has at least
+  // one matching descendant under the same filter set. Lets a UI choose
+  // whether to draw an expand triangle without an extra round trip.
+  repeated bool child_has_children = 4;
+  // Cache sequence this reply was projected from. Clients may pass it back as
+  // part of the page_token contract. Mismatch on the next page -> InvalidArgument.
+  uint64 cache_sequence = 5;
+}
@@ -0,0 +1,30 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <IsPackable>true</IsPackable>
+    <PackageId>ZB.MOM.WW.GalaxyRepository</PackageId>
+    <Authors>ZB.MOM.WW</Authors>
+    <Description>Read-only Galaxy object-hierarchy browse library for the ZB.MOM.WW SCADA family. Provides a SQL provider for the Galaxy Repository database and a canonical gRPC service for exposing the hierarchy to modern .NET 10 clients — extracted from MxAccessGateway so any consumer can browse the Galaxy without loading 32-bit COM.</Description>
+    <PackageTags>galaxy;repository;browse;aveva;wonderware;system-platform;scada;grpc;sql;zb-mom-ww</PackageTags>
+    <PackageProjectUrl>https://gitea.dohertylan.com/dohertj2/zb-mom-ww-galaxyrepository</PackageProjectUrl>
+    <RepositoryUrl>https://gitea.dohertylan.com/dohertj2/zb-mom-ww-galaxyrepository</RepositoryUrl>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.Data.SqlClient" />
+    <PackageReference Include="Grpc.AspNetCore" />
+    <PackageReference Include="Google.Protobuf" />
+    <PackageReference Include="Microsoft.Extensions.Hosting.Abstractions" />
+    <PackageReference Include="Microsoft.Extensions.Options.ConfigurationExtensions" />
+    <PackageReference Include="Grpc.Tools">
+      <PrivateAssets>all</PrivateAssets>
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+    </PackageReference>
+  </ItemGroup>
+
+  <!-- Proto files are added in Task 2; the empty glob is intentional and builds cleanly. -->
+  <ItemGroup>
+    <Protobuf Include="Protos\*.proto" GrpcServices="Server" />
+  </ItemGroup>
+
+</Project>
@@ -0,0 +1,134 @@
+using System.Runtime.CompilerServices;
+using ZB.MOM.WW.GalaxyRepository;
+
+namespace ZB.MOM.WW.GalaxyRepository.Tests;
+
+/// <summary>
+///     In-memory <see cref="IGalaxyRepository"/> returning canned rowsets. Counts the heavy
+///     hierarchy/attribute reads so tests can assert deploy-gated skips, and can be flipped to
+///     throw so the failure path is exercisable.
+/// </summary>
+internal sealed class FakeGalaxyRepository : IGalaxyRepository
+{
+    private readonly IReadOnlyList<GalaxyHierarchyRow> _hierarchy;
+    private readonly IReadOnlyList<GalaxyAttributeRow> _attributes;
+
+    public FakeGalaxyRepository(
+        IReadOnlyList<GalaxyHierarchyRow> hierarchy,
+        IReadOnlyList<GalaxyAttributeRow> attributes,
+        DateTime? deployTime)
+    {
+        _hierarchy = hierarchy;
+        _attributes = attributes;
+        DeployTime = deployTime;
+    }
+
+    /// <summary>The deploy time returned by <see cref="GetLastDeployTimeAsync"/>; mutate to simulate a redeploy.</summary>
+    public DateTime? DeployTime { get; set; }
+
+    /// <summary>When set, every query throws this exception (simulates an unreachable database).</summary>
+    public Exception? ThrowOnQuery { get; set; }
+
+    public int HierarchyReadCount { get; private set; }
+
+    public int AttributeReadCount { get; private set; }
+
+    public Task<bool> TestConnectionAsync(CancellationToken ct = default) =>
+        ThrowOnQuery is null ? Task.FromResult(true) : throw ThrowOnQuery;
+
+    public Task<DateTime?> GetLastDeployTimeAsync(CancellationToken ct = default)
+    {
+        if (ThrowOnQuery is not null)
+        {
+            throw ThrowOnQuery;
+        }
+
+        return Task.FromResult(DeployTime);
+    }
+
+    public Task<List<GalaxyHierarchyRow>> GetHierarchyAsync(CancellationToken ct = default)
+    {
+        if (ThrowOnQuery is not null)
+        {
+            throw ThrowOnQuery;
+        }
+
+        HierarchyReadCount++;
+        return Task.FromResult(_hierarchy.ToList());
+    }
+
+    public Task<List<GalaxyAttributeRow>> GetAttributesAsync(CancellationToken ct = default)
+    {
+        if (ThrowOnQuery is not null)
+        {
+            throw ThrowOnQuery;
+        }
+
+        AttributeReadCount++;
+        return Task.FromResult(_attributes.ToList());
+    }
+}
+
+/// <summary>Records published deploy events so tests can assert publication.</summary>
+internal sealed class RecordingDeployNotifier : IGalaxyDeployNotifier
+{
+    public List<GalaxyDeployEventInfo> Published { get; } = [];
+
+    public GalaxyDeployEventInfo? Latest { get; private set; }
+
+    public void Publish(GalaxyDeployEventInfo info)
+    {
+        Published.Add(info);
+        Latest = info;
+    }
+
+    public async IAsyncEnumerable<GalaxyDeployEventInfo> SubscribeAsync(
+        [EnumeratorCancellation] CancellationToken cancellationToken)
+    {
+        if (Latest is { } latest)
+        {
+            yield return latest;
+        }
+
+        await Task.CompletedTask.ConfigureAwait(false);
+    }
+}
+
+/// <summary>
+///     In-memory <see cref="IGalaxyHierarchySnapshotStore"/>. Pre-seed <see cref="Snapshot"/>
+///     to exercise the restore path; reads <see cref="SaveAsync"/> back to assert persistence.
+/// </summary>
+internal sealed class FakeSnapshotStore : IGalaxyHierarchySnapshotStore
+{
+    public GalaxyHierarchySnapshot? Snapshot { get; set; }
+
+    public int SaveCount { get; private set; }
+
+    public int LoadCount { get; private set; }
+
+    public Task SaveAsync(GalaxyHierarchySnapshot snapshot, CancellationToken cancellationToken)
+    {
+        SaveCount++;
+        Snapshot = snapshot;
+        return Task.CompletedTask;
+    }
+
+    public Task<GalaxyHierarchySnapshot?> TryLoadAsync(CancellationToken cancellationToken)
+    {
+        LoadCount++;
+        return Task.FromResult(Snapshot);
+    }
+}
+
+/// <summary>
+///     A <see cref="TimeProvider"/> whose UTC clock is fixed (and advanceable) so the cache's
+///     staleness projection (which fires after a 5-minute threshold) is deterministic.
+/// </summary>
+internal sealed class StubTimeProvider(DateTimeOffset start) : TimeProvider
+{
+    private DateTimeOffset _now = start;
+
+    public override DateTimeOffset GetUtcNow() => _now;
+
+    public void Advance(TimeSpan delta) => _now += delta;
+}
@@ -0,0 +1,236 @@
+using ZB.MOM.WW.GalaxyRepository;
+
+namespace ZB.MOM.WW.GalaxyRepository.Tests;
+
+/// <summary>
+///     Tests for <see cref="GalaxyHierarchyCache"/> first-load, deploy-gating, snapshot
+///     restore, persistence, and status-transition behavior. Uses an in-memory
+///     <see cref="IGalaxyRepository"/> and snapshot store plus a fixed
+///     <see cref="StubTimeProvider"/> so no SQL is touched and no asserts are time-sensitive.
+/// </summary>
+public sealed class GalaxyHierarchyCacheTests
+{
+    private static readonly DateTimeOffset FixedNow = new(2026, 1, 1, 12, 0, 0, TimeSpan.Zero);
+    private static readonly DateTime DeployTime = new(2026, 1, 1, 0, 0, 0, DateTimeKind.Utc);
+
+    private static List<GalaxyHierarchyRow> SampleHierarchy() =>
+    [
+        new() { GobjectId = 1, TagName = "Area1", ContainedName = "Area1", BrowseName = "Area1", IsArea = true },
+        new() { GobjectId = 2, TagName = "Pump01", ContainedName = "Pump01", BrowseName = "Pump01", ParentGobjectId = 1 },
+    ];
+
+    private static List<GalaxyAttributeRow> SampleAttributes() =>
+    [
+        new() { GobjectId = 2, AttributeName = "PV", FullTagReference = "Pump01.PV", IsHistorized = true, IsAlarm = true },
+    ];
+
+    [Fact]
+    public async Task RefreshAsync_FirstLoad_PopulatesCurrentWithDataAndUnblocksWaitForFirstLoad()
+    {
+        FakeGalaxyRepository repository = new(SampleHierarchy(), SampleAttributes(), DeployTime);
+        RecordingDeployNotifier notifier = new();
+        using GalaxyHierarchyCache cache = new(repository, notifier, new StubTimeProvider(FixedNow));
+
+        // Before refresh, the gate is unset and there is no data.
+        Assert.False(cache.Current.HasData);
+        Assert.Equal(GalaxyCacheStatus.Unknown, cache.Current.Status);
+
+        await cache.RefreshAsync(CancellationToken.None);
+
+        // First load completes (does not hang) and Current now holds usable data.
+        await cache.WaitForFirstLoadAsync(new CancellationTokenSource(TimeSpan.FromSeconds(5)).Token);
+        GalaxyHierarchyCacheEntry current = cache.Current;
+        Assert.True(current.HasData);
+        Assert.Equal(GalaxyCacheStatus.Healthy, current.Status);
+        Assert.Equal(2, current.ObjectCount);
+        Assert.Equal(1, current.AreaCount);
+        Assert.Equal(1, current.AttributeCount);
+        Assert.Equal(1, current.HistorizedAttributeCount);
+        Assert.Equal(1, current.AlarmAttributeCount);
+
+        // The heavy queries ran exactly once and a deploy event was published.
+        Assert.Equal(1, repository.HierarchyReadCount);
+        Assert.Equal(1, repository.AttributeReadCount);
+        GalaxyDeployEventInfo published = Assert.Single(notifier.Published);
+        Assert.Equal(2, published.ObjectCount);
+        Assert.Equal(1, published.AttributeCount);
+    }
+
+    [Fact]
+    public async Task RefreshAsync_NoDeployChange_SkipsHeavyQueriesOnSecondRefresh()
+    {
+        FakeGalaxyRepository repository = new(SampleHierarchy(), SampleAttributes(), DeployTime);
+        using GalaxyHierarchyCache cache = new(repository, new RecordingDeployNotifier(), new StubTimeProvider(FixedNow));
+
+        await cache.RefreshAsync(CancellationToken.None);
+        await cache.RefreshAsync(CancellationToken.None);
+
+        // Deploy time unchanged => the heavy hierarchy/attribute reads happened only once.
+        Assert.Equal(1, repository.HierarchyReadCount);
+        Assert.Equal(1, repository.AttributeReadCount);
+        Assert.True(cache.Current.HasData);
+        Assert.Equal(GalaxyCacheStatus.Healthy, cache.Current.Status);
+    }
+
+    [Fact]
+    public async Task RefreshAsync_DeployAdvances_RebuildsAndBumpsSequence()
+    {
+        FakeGalaxyRepository repository = new(SampleHierarchy(), SampleAttributes(), DeployTime);
+        RecordingDeployNotifier notifier = new();
+        using GalaxyHierarchyCache cache = new(repository, notifier, new StubTimeProvider(FixedNow));
+
+        await cache.RefreshAsync(CancellationToken.None);
+        long firstSequence = cache.Current.Sequence;
+
+        repository.DeployTime = DeployTime.AddHours(1);
+        await cache.RefreshAsync(CancellationToken.None);
+
+        Assert.Equal(2, repository.HierarchyReadCount);
+        Assert.Equal(firstSequence + 1, cache.Current.Sequence);
+        Assert.Equal(2, notifier.Published.Count);
+    }
+
+    [Fact]
+    public async Task RefreshAsync_FirstQueryFailsNoPriorData_StatusUnavailableButFirstLoadStillCompletes()
+    {
+        FakeGalaxyRepository repository = new(SampleHierarchy(), SampleAttributes(), DeployTime)
+        {
+            ThrowOnQuery = new TimeoutException("galaxy db unreachable"),
+        };
+        using GalaxyHierarchyCache cache = new(repository, new RecordingDeployNotifier(), new StubTimeProvider(FixedNow));
+
+        await cache.RefreshAsync(CancellationToken.None);
+
+        // First load must complete so callers do not hang, even though the query failed.
+        await cache.WaitForFirstLoadAsync(new CancellationTokenSource(TimeSpan.FromSeconds(5)).Token);
+        Assert.False(cache.Current.HasData);
+        Assert.Equal(GalaxyCacheStatus.Unavailable, cache.Current.Status);
+        Assert.Contains("unreachable", cache.Current.LastError);
+    }
+
+    [Fact]
+    public async Task RefreshAsync_QueryFailsAfterPriorData_DegradesToStaleAndKeepsData()
+    {
+        FakeGalaxyRepository repository = new(SampleHierarchy(), SampleAttributes(), DeployTime);
+        using GalaxyHierarchyCache cache = new(repository, new RecordingDeployNotifier(), new StubTimeProvider(FixedNow));
+
+        await cache.RefreshAsync(CancellationToken.None);
+        Assert.True(cache.Current.HasData);
+
+        // A later refresh fails: data is retained but flagged Stale.
+        repository.DeployTime = DeployTime.AddHours(1);
+        repository.ThrowOnQuery = new InvalidOperationException("transient");
+        await cache.RefreshAsync(CancellationToken.None);
+
+        Assert.True(cache.Current.HasData);
+        Assert.Equal(GalaxyCacheStatus.Stale, cache.Current.Status);
+        Assert.Equal(2, cache.Current.ObjectCount);
+    }
+
+    [Fact]
+    public async Task Current_AfterStalenessThreshold_ProjectsHealthyToStale()
+    {
+        FakeGalaxyRepository repository = new(SampleHierarchy(), SampleAttributes(), DeployTime);
+        StubTimeProvider clock = new(FixedNow);
+        using GalaxyHierarchyCache cache = new(repository, new RecordingDeployNotifier(), clock);
+
+        await cache.RefreshAsync(CancellationToken.None);
+        Assert.Equal(GalaxyCacheStatus.Healthy, cache.Current.Status);
+
+        // Advance past the 5-minute staleness threshold with no successful refresh.
+        clock.Advance(TimeSpan.FromMinutes(6));
+
+        Assert.Equal(GalaxyCacheStatus.Stale, cache.Current.Status);
+        // Data is still present — Stale means "old", not "gone".
+        Assert.True(cache.Current.HasData);
+    }
+
+    [Fact]
+    public async Task RefreshAsync_PersistsSnapshotAfterSuccessfulHeavyRefresh()
+    {
+        FakeGalaxyRepository repository = new(SampleHierarchy(), SampleAttributes(), DeployTime);
+        FakeSnapshotStore store = new();
+        using GalaxyHierarchyCache cache = new(
+            repository, new RecordingDeployNotifier(), new StubTimeProvider(FixedNow), logger: null, snapshotStore: store);
+
+        await cache.RefreshAsync(CancellationToken.None);
+
+        Assert.Equal(1, store.SaveCount);
+        Assert.NotNull(store.Snapshot);
+        Assert.Equal(2, store.Snapshot!.Hierarchy.Count);
+        Assert.Single(store.Snapshot.Attributes);
+    }
+
+    [Fact]
+    public async Task RefreshAsync_SnapshotRestore_ServesLastKnownDataAsStaleWhenDatabaseUnreachable()
+    {
+        // The snapshot store already holds a persisted dataset (last-known browse data).
+        FakeSnapshotStore store = new()
+        {
+            Snapshot = new GalaxyHierarchySnapshot(
+                LastDeployTime: DeployTime,
+                SavedAt: FixedNow.AddMinutes(-1),
+                Hierarchy: SampleHierarchy(),
+                Attributes: SampleAttributes()),
+        };
+
+        // The Galaxy database is unreachable on this cold start.
+        FakeGalaxyRepository repository = new(SampleHierarchy(), SampleAttributes(), DeployTime)
+        {
+            ThrowOnQuery = new TimeoutException("cold start, db down"),
+        };
+        RecordingDeployNotifier notifier = new();
+        using GalaxyHierarchyCache cache = new(
+            repository, notifier, new StubTimeProvider(FixedNow), logger: null, snapshotStore: store);
+
+        await cache.RefreshAsync(CancellationToken.None);
+
+        // First load is satisfied by the restored snapshot, not by SQL.
+        await cache.WaitForFirstLoadAsync(new CancellationTokenSource(TimeSpan.FromSeconds(5)).Token);
+        Assert.Equal(1, store.LoadCount);
+        GalaxyHierarchyCacheEntry current = cache.Current;
+        Assert.True(current.HasData);
+        // Restored data is "last-known", surfaced as Stale until the live DB confirms.
+        Assert.Equal(GalaxyCacheStatus.Stale, current.Status);
+        Assert.Equal(2, current.ObjectCount);
+        Assert.Equal(DeployTime, current.LastDeployTime!.Value.UtcDateTime);
+
+        // A deploy event was published for the restored data.
+        Assert.Single(notifier.Published);
+    }
+
+    [Fact]
+    public async Task RefreshAsync_SnapshotRestoreThenLiveQuery_PromotesRestoredDataToHealthy()
+    {
+        FakeSnapshotStore store = new()
+        {
+            Snapshot = new GalaxyHierarchySnapshot(
+                LastDeployTime: DeployTime,
+                SavedAt: FixedNow.AddMinutes(-1),
+                Hierarchy: SampleHierarchy(),
+                Attributes: SampleAttributes()),
+        };
+        // DB is reachable and reports the SAME deploy time the snapshot was pulled at.
+        FakeGalaxyRepository repository = new(SampleHierarchy(), SampleAttributes(), DeployTime);
+        using GalaxyHierarchyCache cache = new(
+            repository, new RecordingDeployNotifier(), new StubTimeProvider(FixedNow), logger: null, snapshotStore: store);
+
+        await cache.RefreshAsync(CancellationToken.None);
+
+        // Restore seeds Stale data; the same-deploy live query promotes it to Healthy
+        // without re-running the heavy hierarchy/attribute reads.
+        Assert.Equal(GalaxyCacheStatus.Healthy, cache.Current.Status);
+        Assert.Equal(0, repository.HierarchyReadCount);
+        Assert.True(cache.Current.HasData);
+    }
+
+    [Fact]
+    public void Dispose_CanBeCalledWithoutHavingRefreshed()
+    {
+        FakeGalaxyRepository repository = new(SampleHierarchy(), SampleAttributes(), DeployTime);
+        GalaxyHierarchyCache cache = new(repository, new RecordingDeployNotifier(), new StubTimeProvider(FixedNow));
+
+        // Dispose must be safe even when no refresh ever ran (semaphore never entered).
+        cache.Dispose();
+    }
+}
@@ -0,0 +1,458 @@
+using Grpc.Core;
+using ZB.MOM.WW.GalaxyRepository;
+using ZB.MOM.WW.GalaxyRepository.Grpc;
+
+namespace ZB.MOM.WW.GalaxyRepository.Tests;
+
+/// <summary>
+///     Pure-logic tests for <see cref="GalaxyHierarchyProjector"/> and
+///     <see cref="GalaxyBrowseProjector"/>. No SQL: the cache entry under test is built
+///     from a small hand-made hierarchy through the same materialization the live cache
+///     uses (a fake <see cref="IGalaxyRepository"/> driven through
+///     <see cref="GalaxyHierarchyCache.RefreshAsync"/>), so the projectors are exercised
+///     against a real <see cref="GalaxyHierarchyIndex"/>.
+/// </summary>
+public sealed class GalaxyHierarchyProjectorTests
+{
+    /// <summary>
+    ///     Builds a realistic cache entry by driving a fake repository through the cache's
+    ///     own refresh path. This goes through <c>BuildEntry</c> + <see cref="GalaxyHierarchyIndex.Build"/>
+    ///     exactly as production does, rather than reaching for an internal factory.
+    /// </summary>
+    private static GalaxyHierarchyCacheEntry BuildEntry(
+        IReadOnlyList<GalaxyHierarchyRow> hierarchy,
+        IReadOnlyList<GalaxyAttributeRow> attributes)
+    {
+        FakeGalaxyRepository repository = new(hierarchy, attributes, deployTime: new DateTime(2026, 1, 1, 0, 0, 0, DateTimeKind.Utc));
+        using GalaxyHierarchyCache cache = new(repository, new RecordingDeployNotifier());
+        cache.RefreshAsync(CancellationToken.None).GetAwaiter().GetResult();
+        GalaxyHierarchyCacheEntry entry = cache.Current;
+        Assert.True(entry.HasData);
+        return entry;
+    }
+
+    // A small but representative galaxy:
+    //   PlantArea (area, id 1)
+    //     ├─ LineA (area, id 2)
+    //     │    ├─ Pump01 (id 10, template "Pump", historized+alarm attr)
+    //     │    └─ Valve01 (id 11, template "Valve", plain attr)
+    //     └─ Mixer01 (id 12, template "Mixer", alarm attr only)
+    //   StandaloneTank (id 20, no parent — a root object)
+    private static GalaxyHierarchyCacheEntry BuildSampleEntry()
+    {
+        List<GalaxyHierarchyRow> hierarchy =
+        [
+            Hierarchy(1, "PlantArea", parent: 0, isArea: true, category: 100),
+            Hierarchy(2, "LineA", parent: 1, isArea: true, category: 100),
+            Hierarchy(10, "Pump01", parent: 2, category: 200, templates: ["$Pump", "$UserDefined"]),
+            Hierarchy(11, "Valve01", parent: 2, category: 201, templates: ["$Valve"]),
+            Hierarchy(12, "Mixer01", parent: 1, category: 202, templates: ["$Mixer"]),
+            Hierarchy(20, "StandaloneTank", parent: 0, category: 203, templates: ["$Tank"]),
+        ];
+
+        List<GalaxyAttributeRow> attributes =
+        [
+            // Pump01: historized AND alarm-bearing.
+            Attribute(10, "Pump01.PV", historized: true, alarm: true),
+            Attribute(10, "Pump01.SP", historized: false, alarm: false),
+            // Valve01: plain.
+            Attribute(11, "Valve01.Cmd", historized: false, alarm: false),
+            // Mixer01: alarm only.
+            Attribute(12, "Mixer01.Fault", historized: false, alarm: true),
+            // StandaloneTank: historized only.
+            Attribute(20, "StandaloneTank.Level", historized: true, alarm: false),
+        ];
+
+        return BuildEntry(hierarchy, attributes);
+    }
+
+    private static GalaxyHierarchyRow Hierarchy(
+        int id,
+        string tagName,
+        int parent,
+        bool isArea = false,
+        int category = 0,
+        IReadOnlyList<string>? templates = null) => new()
+        {
+            GobjectId = id,
+            TagName = tagName,
+            ContainedName = tagName,
+            BrowseName = tagName,
+            ParentGobjectId = parent,
+            IsArea = isArea,
+            CategoryId = category,
+            TemplateChain = templates ?? Array.Empty<string>(),
+        };
+
+    private static GalaxyAttributeRow Attribute(
+        int gobjectId,
+        string fullTagReference,
+        bool historized,
+        bool alarm) => new()
+        {
+            GobjectId = gobjectId,
+            AttributeName = fullTagReference.Split('.')[^1],
+            FullTagReference = fullTagReference,
+            IsHistorized = historized,
+            IsAlarm = alarm,
+        };
+
+    [Fact]
+    public void Project_NoFilters_ReturnsEveryObject()
+    {
+        GalaxyHierarchyCacheEntry entry = BuildSampleEntry();
+
+        GalaxyHierarchyQueryResult result = GalaxyHierarchyProjector.Project(entry, new DiscoverHierarchyRequest());
+
+        Assert.Equal(6, result.TotalObjectCount);
+        Assert.Equal(6, result.Objects.Count);
+    }
+
+    [Fact]
+    public void Project_PageSizeAndOffset_SlicesTheOrderedResult()
+    {
+        GalaxyHierarchyCacheEntry entry = BuildSampleEntry();
+        DiscoverHierarchyRequest request = new();
+
+        GalaxyHierarchyQueryResult full = GalaxyHierarchyProjector.Project(entry, request, browseSubtreeGlobs: null, offset: 0, pageSize: int.MaxValue);
+        GalaxyHierarchyQueryResult page1 = GalaxyHierarchyProjector.Project(entry, request, browseSubtreeGlobs: null, offset: 0, pageSize: 2);
+        GalaxyHierarchyQueryResult page2 = GalaxyHierarchyProjector.Project(entry, request, browseSubtreeGlobs: null, offset: 2, pageSize: 2);
+        GalaxyHierarchyQueryResult page3 = GalaxyHierarchyProjector.Project(entry, request, browseSubtreeGlobs: null, offset: 4, pageSize: 2);
+
+        // Total is unaffected by paging.
+        Assert.Equal(6, page1.TotalObjectCount);
+        Assert.Equal(2, page1.Objects.Count);
+        Assert.Equal(2, page2.Objects.Count);
+        Assert.Equal(2, page3.Objects.Count);
+
+        // The three pages reconstruct the full ordered result with no gaps/dupes.
+        List<int> paged =
+        [
+            .. page1.Objects.Select(o => o.GobjectId),
+            .. page2.Objects.Select(o => o.GobjectId),
+            .. page3.Objects.Select(o => o.GobjectId),
+        ];
+        Assert.Equal(full.Objects.Select(o => o.GobjectId), paged);
+    }
+
+    [Fact]
+    public void Project_OffsetPastEnd_ReturnsEmptyPageButRealTotal()
+    {
+        GalaxyHierarchyCacheEntry entry = BuildSampleEntry();
+
+        GalaxyHierarchyQueryResult result = GalaxyHierarchyProjector.Project(
+            entry, new DiscoverHierarchyRequest(), browseSubtreeGlobs: null, offset: 999, pageSize: 10);
+
+        Assert.Empty(result.Objects);
+        Assert.Equal(6, result.TotalObjectCount);
+    }
+
+    [Fact]
+    public void Project_PageSignature_IsStableAcrossPagesAndMatchesComputeFilterSignature()
+    {
+        GalaxyHierarchyCacheEntry entry = BuildSampleEntry();
+        DiscoverHierarchyRequest request = new() { TagNameGlob = "Pump*" };
+
+        string expected = GalaxyHierarchyProjector.ComputeFilterSignature(request, browseSubtreeGlobs: null);
+        GalaxyHierarchyQueryResult page1 = GalaxyHierarchyProjector.Project(entry, request, browseSubtreeGlobs: null, offset: 0, pageSize: 1);
+        GalaxyHierarchyQueryResult page2 = GalaxyHierarchyProjector.Project(entry, request, browseSubtreeGlobs: null, offset: 1, pageSize: 1);
+
+        // The signature a caller computes to mint a page token round-trips: the projector
+        // reports the same signature on every page of the same filter set.
+        Assert.Equal(expected, page1.FilterSignature);
+        Assert.Equal(expected, page2.FilterSignature);
+    }
+
+    [Fact]
+    public void ComputeFilterSignature_DiffersWhenAnyFilterChanges()
+    {
+        DiscoverHierarchyRequest baseRequest = new() { TagNameGlob = "Pump*" };
+        DiscoverHierarchyRequest differentGlob = new() { TagNameGlob = "Valve*" };
+        DiscoverHierarchyRequest differentAlarm = new() { TagNameGlob = "Pump*", AlarmBearingOnly = true };
+
+        string baseSig = GalaxyHierarchyProjector.ComputeFilterSignature(baseRequest, null);
+
+        Assert.NotEqual(baseSig, GalaxyHierarchyProjector.ComputeFilterSignature(differentGlob, null));
+        Assert.NotEqual(baseSig, GalaxyHierarchyProjector.ComputeFilterSignature(differentAlarm, null));
+        Assert.NotEqual(baseSig, GalaxyHierarchyProjector.ComputeFilterSignature(baseRequest, browseSubtreeGlobs: ["PlantArea/*"]));
+        // Same inputs => same signature (deterministic).
+        Assert.Equal(baseSig, GalaxyHierarchyProjector.ComputeFilterSignature(new DiscoverHierarchyRequest { TagNameGlob = "Pump*" }, null));
+    }
+
+    [Fact]
+    public void Project_MaxDepthZero_FromRoot_ReturnsOnlyTheRoot()
+    {
+        GalaxyHierarchyCacheEntry entry = BuildSampleEntry();
+        DiscoverHierarchyRequest request = new() { RootGobjectId = 1, MaxDepth = 0 };
+
+        GalaxyHierarchyQueryResult result = GalaxyHierarchyProjector.Project(entry, request);
+
+        GalaxyObject only = Assert.Single(result.Objects);
+        Assert.Equal(1, only.GobjectId);
+    }
+
+    [Fact]
+    public void Project_MaxDepthOne_FromRoot_ReturnsRootAndDirectChildrenOnly()
+    {
+        GalaxyHierarchyCacheEntry entry = BuildSampleEntry();
+        // PlantArea(1) depth 0; LineA(2) and Mixer01(12) depth 1; Pump01/Valve01 depth 2.
+        DiscoverHierarchyRequest request = new() { RootGobjectId = 1, MaxDepth = 1 };
+
+        GalaxyHierarchyQueryResult result = GalaxyHierarchyProjector.Project(entry, request);
+
+        Assert.Equal([1, 2, 12], result.Objects.Select(o => o.GobjectId).OrderBy(id => id));
+    }
+
+    [Fact]
+    public void Project_NegativeMaxDepth_ThrowsInvalidArgument()
+    {
+        GalaxyHierarchyCacheEntry entry = BuildSampleEntry();
+        DiscoverHierarchyRequest request = new() { MaxDepth = -1 };
+
+        RpcException ex = Assert.Throws<RpcException>(() => GalaxyHierarchyProjector.Project(entry, request));
+        Assert.Equal(StatusCode.InvalidArgument, ex.StatusCode);
+    }
+
+    [Fact]
+    public void Project_UnknownRoot_ThrowsNotFound()
+    {
+        GalaxyHierarchyCacheEntry entry = BuildSampleEntry();
+        DiscoverHierarchyRequest request = new() { RootGobjectId = 99999 };
+
+        RpcException ex = Assert.Throws<RpcException>(() => GalaxyHierarchyProjector.Project(entry, request));
+        Assert.Equal(StatusCode.NotFound, ex.StatusCode);
+    }
+
+    [Fact]
+    public void Project_HistorizedOnly_ReturnsOnlyObjectsWithAHistorizedAttribute()
+    {
+        GalaxyHierarchyCacheEntry entry = BuildSampleEntry();
+        DiscoverHierarchyRequest request = new() { HistorizedOnly = true };
+
+        GalaxyHierarchyQueryResult result = GalaxyHierarchyProjector.Project(entry, request);
+
+        // Pump01(10) and StandaloneTank(20) carry historized attributes.
+        Assert.Equal([10, 20], result.Objects.Select(o => o.GobjectId).OrderBy(id => id));
+    }
+
+    [Fact]
+    public void Project_AlarmBearingOnly_ReturnsOnlyObjectsWithAnAlarmAttribute()
+    {
+        GalaxyHierarchyCacheEntry entry = BuildSampleEntry();
+        DiscoverHierarchyRequest request = new() { AlarmBearingOnly = true };
+
+        GalaxyHierarchyQueryResult result = GalaxyHierarchyProjector.Project(entry, request);
+
+        // Pump01(10) and Mixer01(12) carry alarm attributes.
+        Assert.Equal([10, 12], result.Objects.Select(o => o.GobjectId).OrderBy(id => id));
+    }
+
+    [Fact]
+    public void Project_AlarmAndHistorizedTogether_RequiresBoth()
+    {
+        GalaxyHierarchyCacheEntry entry = BuildSampleEntry();
+        DiscoverHierarchyRequest request = new() { AlarmBearingOnly = true, HistorizedOnly = true };
+
+        GalaxyHierarchyQueryResult result = GalaxyHierarchyProjector.Project(entry, request);
+
+        // Only Pump01(10) carries an attribute set that is both historized and alarm-bearing.
+        GalaxyObject only = Assert.Single(result.Objects);
+        Assert.Equal(10, only.GobjectId);
+    }
+
+    [Fact]
+    public void Project_TagNameGlob_MatchesAnchoredCaseInsensitive()
+    {
+        GalaxyHierarchyCacheEntry entry = BuildSampleEntry();
+
+        GalaxyHierarchyQueryResult prefix = GalaxyHierarchyProjector.Project(entry, new DiscoverHierarchyRequest { TagNameGlob = "Pump*" });
+        Assert.Equal([10], prefix.Objects.Select(o => o.GobjectId));
+
+        // Case-insensitive.
+        GalaxyHierarchyQueryResult lower = GalaxyHierarchyProjector.Project(entry, new DiscoverHierarchyRequest { TagNameGlob = "pump01" });
+        Assert.Equal([10], lower.Objects.Select(o => o.GobjectId));
+
+        // '?' single-char wildcard: "Pump0?" matches "Pump01".
+        GalaxyHierarchyQueryResult single = GalaxyHierarchyProjector.Project(entry, new DiscoverHierarchyRequest { TagNameGlob = "Pump0?" });
+        Assert.Equal([10], single.Objects.Select(o => o.GobjectId));
+
+        // Anchored: a bare substring that is not a prefix matches nothing.
+        GalaxyHierarchyQueryResult anchored = GalaxyHierarchyProjector.Project(entry, new DiscoverHierarchyRequest { TagNameGlob = "ump01" });
+        Assert.Empty(anchored.Objects);
+    }
+
+    [Fact]
+    public void Project_CategoryIds_FilterByObjectCategory()
+    {
+        GalaxyHierarchyCacheEntry entry = BuildSampleEntry();
+        DiscoverHierarchyRequest request = new() { CategoryIds = { 200, 201 } };
+
+        GalaxyHierarchyQueryResult result = GalaxyHierarchyProjector.Project(entry, request);
+
+        // category 200 = Pump01(10), category 201 = Valve01(11).
+        Assert.Equal([10, 11], result.Objects.Select(o => o.GobjectId).OrderBy(id => id));
+    }
+
+    [Fact]
+    public void Project_TemplateChainContains_IsSubstringAndCaseInsensitive()
+    {
+        GalaxyHierarchyCacheEntry entry = BuildSampleEntry();
+        DiscoverHierarchyRequest request = new() { TemplateChainContains = { "pump" } };
+
+        GalaxyHierarchyQueryResult result = GalaxyHierarchyProjector.Project(entry, request);
+
+        GalaxyObject only = Assert.Single(result.Objects);
+        Assert.Equal(10, only.GobjectId);
+    }
+
+    [Fact]
+    public void Project_IncludeAttributesDefault_CarriesAttributes()
+    {
+        GalaxyHierarchyCacheEntry entry = BuildSampleEntry();
+        DiscoverHierarchyRequest request = new() { TagNameGlob = "Pump*" };
+
+        GalaxyHierarchyQueryResult result = GalaxyHierarchyProjector.Project(entry, request);
+
+        GalaxyObject pump = Assert.Single(result.Objects);
+        Assert.Equal(2, pump.Attributes.Count);
+    }
+
+    [Fact]
+    public void Project_IncludeAttributesFalse_ReturnsSkeletons()
+    {
+        GalaxyHierarchyCacheEntry entry = BuildSampleEntry();
+        DiscoverHierarchyRequest request = new() { TagNameGlob = "Pump*", IncludeAttributes = false };
+
+        GalaxyHierarchyQueryResult result = GalaxyHierarchyProjector.Project(entry, request);
+
+        GalaxyObject pump = Assert.Single(result.Objects);
+        Assert.Empty(pump.Attributes);
+    }
+
+    [Fact]
+    public void Project_IncludeAttributesFalse_DoesNotMutateTheCachedEntry()
+    {
+        GalaxyHierarchyCacheEntry entry = BuildSampleEntry();
+
+        // Project with attributes stripped, then again with attributes included.
+        GalaxyHierarchyProjector.Project(entry, new DiscoverHierarchyRequest { TagNameGlob = "Pump*", IncludeAttributes = false });
+        GalaxyHierarchyQueryResult included = GalaxyHierarchyProjector.Project(entry, new DiscoverHierarchyRequest { TagNameGlob = "Pump*" });
+
+        // The earlier strip cloned the object — the cached entry still holds the attributes.
+        GalaxyObject pump = Assert.Single(included.Objects);
+        Assert.Equal(2, pump.Attributes.Count);
+    }
+
+    [Fact]
+    public void Project_InvalidOffsetOrPageSize_Throws()
+    {
+        GalaxyHierarchyCacheEntry entry = BuildSampleEntry();
+
+        Assert.Throws<ArgumentOutOfRangeException>(() =>
+            GalaxyHierarchyProjector.Project(entry, new DiscoverHierarchyRequest(), null, offset: -1, pageSize: 10));
+        Assert.Throws<ArgumentOutOfRangeException>(() =>
+            GalaxyHierarchyProjector.Project(entry, new DiscoverHierarchyRequest(), null, offset: 0, pageSize: 0));
+    }
+
+    // ---- GalaxyBrowseProjector ----
+
+    [Fact]
+    public void ProjectChildren_OfPlantArea_ReturnsDirectChildrenAreasFirst()
+    {
+        GalaxyHierarchyCacheEntry entry = BuildSampleEntry();
+        BrowseChildrenRequest request = new() { ParentGobjectId = 1 };
+
+        GalaxyBrowseChildrenResult result = GalaxyBrowseProjector.ProjectChildren(entry, request, browseSubtreeGlobs: null, offset: 0, pageSize: 100);
+
+        // Direct children of PlantArea(1) are LineA(2, area) and Mixer01(12, non-area);
+        // areas sort first.
+        Assert.Equal([2, 12], result.Children.Select(c => c.GobjectId));
+        Assert.Equal(2, result.TotalChildCount);
+    }
+
+    [Fact]
+    public void ProjectChildren_ChildHasChildrenFlag_ReflectsPresenceOfChildren()
+    {
+        GalaxyHierarchyCacheEntry entry = BuildSampleEntry();
+        BrowseChildrenRequest request = new() { ParentGobjectId = 1 };
+
+        GalaxyBrowseChildrenResult result = GalaxyBrowseProjector.ProjectChildren(entry, request, browseSubtreeGlobs: null, offset: 0, pageSize: 100);
+
+        Dictionary<int, bool> hasChildren = result.Children
+            .Select((child, index) => (child.GobjectId, result.ChildHasChildren[index]))
+            .ToDictionary(t => t.GobjectId, t => t.Item2);
+
+        // LineA(2) contains Pump01/Valve01 -> true; Mixer01(12) is a leaf -> false.
+        Assert.True(hasChildren[2]);
+        Assert.False(hasChildren[12]);
+    }
+
+    [Fact]
+    public void ProjectChildren_OfRoot_ReturnsTopLevelObjects()
+    {
+        GalaxyHierarchyCacheEntry entry = BuildSampleEntry();
+        // Empty parent oneof => roots (parent id 0).
+        BrowseChildrenRequest request = new();
+
+        GalaxyBrowseChildrenResult result = GalaxyBrowseProjector.ProjectChildren(entry, request, browseSubtreeGlobs: null, offset: 0, pageSize: 100);
+
+        // Roots: PlantArea(1, area) and StandaloneTank(20, non-area); areas first.
+        Assert.Equal([1, 20], result.Children.Select(c => c.GobjectId));
+    }
+
+    [Fact]
+    public void ProjectChildren_FilterMatchingDescendant_SurfacesNonMatchingAncestor()
+    {
+        GalaxyHierarchyCacheEntry entry = BuildSampleEntry();
+        // Pump01 lives two levels under PlantArea. Browsing PlantArea's children with a
+        // Pump glob should still surface LineA (which itself does not match) because it
+        // contains a matching descendant.
+        BrowseChildrenRequest request = new() { ParentGobjectId = 1, TagNameGlob = "Pump*" };
+
+        GalaxyBrowseChildrenResult result = GalaxyBrowseProjector.ProjectChildren(entry, request, browseSubtreeGlobs: null, offset: 0, pageSize: 100);
+
+        GalaxyObject surfaced = Assert.Single(result.Children);
+        Assert.Equal(2, surfaced.GobjectId);
+        Assert.True(result.ChildHasChildren[0]);
+    }
+
+    [Fact]
+    public void ProjectChildren_UnknownParent_ThrowsNotFound()
+    {
+        GalaxyHierarchyCacheEntry entry = BuildSampleEntry();
+        BrowseChildrenRequest request = new() { ParentGobjectId = 99999 };
+
+        RpcException ex = Assert.Throws<RpcException>(() =>
+            GalaxyBrowseProjector.ProjectChildren(entry, request, null, 0, 100));
+        Assert.Equal(StatusCode.NotFound, ex.StatusCode);
+    }
+
+    [Fact]
+    public void ProjectChildren_Paging_SlicesAndPreservesTotal()
+    {
+        GalaxyHierarchyCacheEntry entry = BuildSampleEntry();
+        // LineA(2) has two direct children: Pump01, Valve01.
+        BrowseChildrenRequest request = new() { ParentGobjectId = 2 };
+
+        GalaxyBrowseChildrenResult page1 = GalaxyBrowseProjector.ProjectChildren(entry, request, null, offset: 0, pageSize: 1);
+        GalaxyBrowseChildrenResult page2 = GalaxyBrowseProjector.ProjectChildren(entry, request, null, offset: 1, pageSize: 1);
+
+        Assert.Equal(2, page1.TotalChildCount);
+        Assert.Single(page1.Children);
+        Assert.Single(page2.Children);
+        Assert.NotEqual(page1.Children[0].GobjectId, page2.Children[0].GobjectId);
+        // Same filter+parent => same signature on both pages.
+        Assert.Equal(page1.FilterSignature, page2.FilterSignature);
+    }
+
+    [Fact]
+    public void ResolveParentId_ByTagName_ResolvesToGobjectId()
+    {
+        GalaxyHierarchyCacheEntry entry = BuildSampleEntry();
+        BrowseChildrenRequest request = new() { ParentTagName = "LineA" };
+
+        int id = GalaxyBrowseProjector.ResolveParentId(entry, request);
+
+        Assert.Equal(2, id);
+    }
+}
@@ -0,0 +1,84 @@
+using Microsoft.Extensions.Options;
+using ZB.MOM.WW.GalaxyRepository;
+
+namespace ZB.MOM.WW.GalaxyRepository.Tests;
+
+/// <summary>
+///     Round-trip tests for the real <see cref="GalaxyHierarchySnapshotStore"/> over a temp
+///     file path: save then load, no-op when persistence is disabled, and clean disposal.
+/// </summary>
+public sealed class GalaxyHierarchySnapshotStoreTests : IDisposable
+{
+    private readonly string _path = Path.Combine(
+        Path.GetTempPath(),
+        $"galaxyrepo-snap-{Guid.NewGuid():N}.json");
+
+    public void Dispose()
+    {
+        if (File.Exists(_path))
+        {
+            File.Delete(_path);
+        }
+    }
+
+    private static GalaxyHierarchySnapshot SampleSnapshot() => new(
+        LastDeployTime: new DateTimeOffset(2026, 1, 1, 0, 0, 0, TimeSpan.Zero),
+        SavedAt: new DateTimeOffset(2026, 1, 1, 12, 0, 0, TimeSpan.Zero),
+        Hierarchy:
+        [
+            new GalaxyHierarchyRow { GobjectId = 1, TagName = "Area1", IsArea = true },
+            new GalaxyHierarchyRow { GobjectId = 2, TagName = "Pump01", ParentGobjectId = 1 },
+        ],
+        Attributes:
+        [
+            new GalaxyAttributeRow { GobjectId = 2, AttributeName = "PV", FullTagReference = "Pump01.PV", IsHistorized = true },
+        ]);
+
+    [Fact]
+    public async Task SaveThenLoad_RoundTripsTheSnapshot()
+    {
+        using GalaxyHierarchySnapshotStore store = new(
+            Options.Create(new GalaxyRepositoryOptions { PersistSnapshot = true, SnapshotCachePath = _path }));
+
+        await store.SaveAsync(SampleSnapshot(), CancellationToken.None);
+        GalaxyHierarchySnapshot? loaded = await store.TryLoadAsync(CancellationToken.None);
+
+        Assert.NotNull(loaded);
+        Assert.Equal(2, loaded!.Hierarchy.Count);
+        Assert.Single(loaded.Attributes);
+        Assert.Equal("Pump01.PV", loaded.Attributes[0].FullTagReference);
+        Assert.True(loaded.Attributes[0].IsHistorized);
+        Assert.Equal(SampleSnapshot().LastDeployTime, loaded.LastDeployTime);
+    }
+
+    [Fact]
+    public async Task SaveAndLoad_AreNoOps_WhenPersistenceDisabled()
+    {
+        using GalaxyHierarchySnapshotStore store = new(
+            Options.Create(new GalaxyRepositoryOptions { PersistSnapshot = false, SnapshotCachePath = _path }));
+
+        await store.SaveAsync(SampleSnapshot(), CancellationToken.None);
+
+        Assert.False(File.Exists(_path));
+        Assert.Null(await store.TryLoadAsync(CancellationToken.None));
+    }
+
+    [Fact]
+    public async Task TryLoad_ReturnsNull_WhenNoFileExists()
+    {
+        using GalaxyHierarchySnapshotStore store = new(
+            Options.Create(new GalaxyRepositoryOptions { PersistSnapshot = true, SnapshotCachePath = _path }));
+
+        Assert.Null(await store.TryLoadAsync(CancellationToken.None));
+    }
+
+    [Fact]
+    public async Task TryLoad_ReturnsNull_WhenFileIsNotValidJson()
+    {
+        await File.WriteAllTextAsync(_path, "{ this is not valid json");
+        using GalaxyHierarchySnapshotStore store = new(
+            Options.Create(new GalaxyRepositoryOptions { PersistSnapshot = true, SnapshotCachePath = _path }));
+
+        Assert.Null(await store.TryLoadAsync(CancellationToken.None));
+    }
+}
@@ -0,0 +1,25 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <IsPackable>false</IsPackable>
+    <!-- Test project does not ship; no XML docs required (overrides Directory.Build.props). -->
+    <GenerateDocumentationFile>false</GenerateDocumentationFile>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="coverlet.collector" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" />
+    <PackageReference Include="xunit" />
+    <PackageReference Include="xunit.runner.visualstudio" />
+    <PackageReference Include="Microsoft.Data.SqlClient" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Using Include="Xunit" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\src\ZB.MOM.WW.GalaxyRepository\ZB.MOM.WW.GalaxyRepository.csproj" />
+  </ItemGroup>
+
+</Project>
@@ -0,0 +1,122 @@
+# ZB.MOM.WW.SPHistorianClient — Design
+
+**Date:** 2026-06-19
+**Status:** Approved — proceeding to implementation plan.
+
+## Goal
+
+Repackage the proven, pure-managed .NET 10 `AVEVA.Historian.Client` SDK (delivered in
+`HistorianSDK_2023R2/histsdk-migration.zip` from `10.100.0.48`) as the family-branded shared
+library **`ZB.MOM.WW.SPHistorianClient`** (System Platform Historian Client), following the same
+conventions as the other `ZB.MOM.WW.*` shared libraries in this repo.
+
+## Context — what the source bundle contains
+
+`histsdk-migration.zip` → `histsdk-migration/`:
+
+- `histsdk/` — the SDK git repo. `src/AVEVA.Historian.Client/` is a **pure-managed .NET 10** client
+  for AVEVA Historian (no `aahClientManaged.dll` / `aahClient.dll` / native AVEVA runtime — the wire
+  protocol is reverse-engineered and re-implemented in C#). ~165–188 unit + gated-live tests pass.
+- `analysis-2023r2/` — reverse-engineering analysis (recovered protos, decompiled stock contract,
+  transport writeup). **Kept separate from the repo on purpose.**
+
+Two transport families exist in the SDK:
+
+| Transport | Protocol | Platform | Verification |
+|---|---|---|---|
+| `LocalPipe`, `RemoteTcpIntegrated`, `RemoteTcpCertificate` | WCF/MDAS (2020) | **Windows-only** | **live-verified**: raw/aggregate(16 modes)/at-time/event reads, browse, metadata, status, `EnsureTag`/`DeleteTag` |
+| `RemoteGrpc` | gRPC (2023 R2) | cross-platform (Grpc.Net.Client/.Web) | unit-tested; **not yet live-verified** against a real 2023 R2 server (`ExchangeKey` auth step unproven) |
+
+## Decisions (locked)
+
+1. **Approach: port + rebrand.** Copy the SDK source into `ZB.MOM.WW.SPHistorianClient`, rename the
+   root namespace, adopt ZB conventions, bring the unit tests, drop non-shippable artifacts. One
+   coherent shared library — a published package should not ship a third-party (AVEVA) namespace or
+   non-redistributable reverse-engineering artifacts.
+2. **Transports: both WCF + gRPC.** Ship everything that works. WCF members keep
+   `[SupportedOSPlatform("windows")]`; the gRPC path runs anywhere. No working code discarded.
+3. **Not a "component normalization."** There is no duplicated historian code across the three apps
+   to converge — this is a net-new shared library that simply follows ZB packaging conventions.
+
+## Repository layout
+
+Plain files committed into this repo (NOT a nested git repo — see the
+`shared-libs-are-plain-files-not-nested-repos` convention):
+
+```
+ZB.MOM.WW.SPHistorianClient/
+  Directory.Build.props          # net10.0, Nullable, ImplicitUsings, LangVersion latest, Version 0.1.0, central pkg mgmt
+  Directory.Packages.props       # central PackageVersion entries
+  ZB.MOM.WW.SPHistorianClient.slnx
+  CLAUDE.md  README.md  .gitignore
+  src/ZB.MOM.WW.SPHistorianClient/         # the single package
+    HistorianClient.cs, HistorianClientOptions.cs, HistorianTransport.cs
+    Models/  Protocol/  Transport/  Wcf/  Wcf/Contracts/  Grpc/  Grpc/Protos/*.proto
+    DependencyInjection/AddZbSpHistorianClient (ZB-idiomatic DI extension)
+  tests/ZB.MOM.WW.SPHistorianClient.Tests/ # offline unit/golden-byte + gated-live integration
+  artifacts/                     # dotnet pack output
+```
+
+## Port mechanics
+
+- Copy `src/AVEVA.Historian.Client/` and `tests/AVEVA.Historian.Client.Tests/` from the bundle.
+- Rename the C# root namespace `AVEVA.Historian.Client` → `ZB.MOM.WW.SPHistorianClient` across all
+  files: 74 `namespace` declarations spanning the root + 6 sub-namespaces
+  (`.Models`, `.Wcf`, `.Wcf.Contracts`, `.Protocol`, `.Transport`, `.Grpc`), all `using` directives,
+  and the `InternalsVisibleTo` to the test assembly. Drop the `InternalsVisibleTo` to
+  `AVEVA.Historian.ReverseEngineering` (tool not shipped).
+- **Leave the proto wire contracts untouched:** the 6 `Grpc/Protos/*.proto` keep
+  `option csharp_namespace = "ArchestrA.Grpc.Contract.*"` — that is AVEVA's wire contract, not ours.
+  `Grpc.Tools` keeps generating the client stubs at build.
+- Convert inline `PackageReference` versions to central management in `Directory.Packages.props`,
+  matching the `ZB.MOM.WW.Telemetry` template.
+
+## Dependencies
+
+- **Library:** `Google.Protobuf`, `Grpc.Net.Client`, `Grpc.Net.Client.Web`, `Grpc.Tools` (build-only,
+  `PrivateAssets=all`), `System.ServiceModel.NetNamedPipe`, `System.ServiceModel.NetTcp`,
+  `System.Security.Cryptography.Xml`. Add `Microsoft.Extensions.DependencyInjection.Abstractions` +
+  `Microsoft.Extensions.Options` for the DI extension.
+- **Tests:** `xunit`, `xunit.runner.visualstudio`, `Microsoft.NET.Test.Sdk`, `coverlet.collector`,
+  `Microsoft.Data.SqlClient` (SQL post-check tests).
+
+## Excluded (safety / non-redistributable / Windows-native)
+
+- `tools/` reverse-engineering harnesses (.NET Framework, reference native AVEVA binaries).
+- `analysis-2023r2/decompiled/` — proprietary AVEVA decompilations (not redistributable).
+- `scripts/` — Frida / PowerShell / Python capture tooling.
+- `docs/reverse-engineering/` — identity-bearing `.ndjson` / capture evidence.
+
+**Kept:** the recovered `.proto` files (needed to build), the offline unit tests, and a sanitized
+architecture/surface summary folded into `CLAUDE.md` / `README.md`. `.gitignore` blocks the
+identity-bearing patterns (`*.ndjson`, `current/`, `aveva-install-*/`, `artifacts/`-raw, etc.).
+
+## Public surface (preserved 1:1)
+
+`HistorianClient` + `HistorianClientOptions` façade; `Models/*`; `HistorianTransport` enum
+(`LocalPipe` / `RemoteTcpIntegrated` / `RemoteTcpCertificate` / `RemoteGrpc`); operations:
+`ProbeAsync`, `ReadRawAsync` / `ReadAggregateAsync` / `ReadAtTimeAsync`, `ReadEventsAsync`,
+`BrowseTagNamesAsync`, `GetTagMetadataAsync`, status calls, `EnsureTagAsync` / `DeleteTagAsync`.
+
+**One ZB-idiomatic addition:** `AddZbSpHistorianClient(...)` DI extension mirroring `AddZbTelemetry`
+— thin: binds `HistorianClientOptions` and registers `HistorianClient`. Optional to consumers.
+
+## Cross-platform & testing posture
+
+- WCF members already carry `[SupportedOSPlatform("windows")]`; the library builds and unit-tests on
+  macOS/Linux. gRPC path is portable.
+- Offline unit/golden-byte tests run anywhere. Live integration tests stay gated by `HISTORIAN_*`
+  env vars and skip cleanly when unset.
+- Verify `dotnet build` + `dotnet test` pass locally (macOS) before finishing.
+
+## Packaging
+
+`dotnet pack -c Release -o ./artifacts` → `ZB.MOM.WW.SPHistorianClient.0.1.0.nupkg`. Gitea URLs in
+package metadata. **Not pushed/published** to any feed unless explicitly requested.
+
+## Out of scope (this pass)
+
+- Wiring `ZB.MOM.WW.SPHistorianClient` into any consumer (e.g. OtOpcUa Phase C HistoryRead) — a
+  separate follow-on.
+- Live-verifying the gRPC `RemoteGrpc` path against a real 2023 R2 server.
+- Writing samples (`AddS2`) — architecturally blocked in the source SDK; remains out of scope.
@@ -0,0 +1,569 @@
+# ZB.MOM.WW.SPHistorianClient Implementation Plan
+
+> **For Claude:** REQUIRED SUB-SKILL: Use superpowers-extended-cc:executing-plans (or subagent-driven-development) to implement this plan task-by-task.
+
+**Goal:** Repackage the proven, pure-managed .NET 10 `AVEVA.Historian.Client` SDK from the migration bundle as the family-branded shared library `ZB.MOM.WW.SPHistorianClient`, following the same conventions as the other `ZB.MOM.WW.*` libraries in this repo.
+
+**Architecture:** This is a **port + rebrand**, not a rewrite. Copy the SDK `src/` and `tests/` into a new `ZB.MOM.WW.SPHistorianClient/` directory, rewrite the C# root namespace `AVEVA.Historian.Client` → `ZB.MOM.WW.SPHistorianClient` (leaving the proto-generated `ArchestrA.Grpc.Contract.*` wire contracts untouched), adopt ZB conventions (`Directory.Build.props` / `Directory.Packages.props` central package management, `.slnx`, `CLAUDE.md`/`README.md`), drop the non-shippable reverse-engineering tooling and proprietary decompilations, add one ZB-idiomatic DI extension, then build/test/pack.
+
+**Tech Stack:** .NET 10, C# (net10.0), WCF/MDAS (`System.ServiceModel.*`, Windows-only transports), gRPC (`Grpc.Net.Client` + `Grpc.Tools`, cross-platform 2023 R2 transport), xUnit. Central package management.
+
+**Design doc:** `docs/plans/2026-06-19-sphistorianclient-design.md`
+
+**Branch:** `feat/sphistorianclient` (already created; design doc already committed at `bbb7942`).
+
+---
+
+## Source bundle location (read-only inputs)
+
+The SDK source lives in an extracted bundle under `/tmp`:
+
+- Extracted root: `/tmp/histsdk/extracted/histsdk-migration/histsdk/`
+- SDK source: `…/histsdk/src/AVEVA.Historian.Client/` — **74 `.cs` + 6 `.proto`**
+- SDK tests: `…/histsdk/tests/AVEVA.Historian.Client.Tests/` — **25 `.cs`**
+- Re-extract fallback (if `/tmp` was cleaned): `cd /tmp/histsdk && unzip -o -q histsdk-migration.zip -d extracted`
+
+**Never copy:** `tools/` (RE harnesses, .NET Framework + native AVEVA refs), `analysis-2023r2/decompiled/` (proprietary, non-redistributable), `scripts/`, `docs/reverse-engineering/` (identity-bearing captures), `bin/`/`obj/`, the bundle's `.git/`, and the bundle's original `.csproj` files (we author fresh ZB ones).
+
+**Gotchas baked into this plan (from prior repo experience):**
+- Do **not** set `TreatWarningsAsErrors` — the WCF/SSPI code carries `[SupportedOSPlatform("windows")]` and will emit CA platform warnings on macOS that must stay warnings.
+- Central package management means **no inline `Version=` on any `PackageReference`** (that is `NU1008`). All versions live in `Directory.Packages.props`.
+- `Microsoft.Data.SqlClient` may surface an `NU1903` advisory on restore. Without `TreatWarningsAsErrors` it is a warning. If a restore ever hard-fails on it, add `-p:NuGetAudit=false` to the build/test command.
+- macOS `sed -i` requires an explicit empty backup arg: `sed -i '' 's/…/…/g'`.
+
+---
+
+## Task 1: Scaffold the library skeleton
+
+**Classification:** standard
+**Estimated implement time:** ~4 min
+**Parallelizable with:** none (every later task depends on this)
+
+**Files:**
+- Create: `ZB.MOM.WW.SPHistorianClient/Directory.Build.props`
+- Create: `ZB.MOM.WW.SPHistorianClient/Directory.Packages.props`
+- Create: `ZB.MOM.WW.SPHistorianClient/.gitignore`
+- Create: `ZB.MOM.WW.SPHistorianClient/ZB.MOM.WW.SPHistorianClient.slnx`
+- Create: `ZB.MOM.WW.SPHistorianClient/src/ZB.MOM.WW.SPHistorianClient/ZB.MOM.WW.SPHistorianClient.csproj`
+- Create: `ZB.MOM.WW.SPHistorianClient/tests/ZB.MOM.WW.SPHistorianClient.Tests/ZB.MOM.WW.SPHistorianClient.Tests.csproj`
+
+**Step 1: `Directory.Build.props`** (mirrors `ZB.MOM.WW.Telemetry/Directory.Build.props`)
+
+```xml
+<Project>
+
+  <PropertyGroup>
+    <TargetFramework>net10.0</TargetFramework>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <LangVersion>latest</LangVersion>
+    <Version>0.1.0</Version>
+    <ManagePackageVersionsCentrally>true</ManagePackageVersionsCentrally>
+  </PropertyGroup>
+
+</Project>
+```
+
+**Step 2: `Directory.Packages.props`** (versions lifted verbatim from the bundle's two `.csproj` files)
+
+```xml
+<Project>
+
+  <PropertyGroup>
+    <ManagePackageVersionsCentrally>true</ManagePackageVersionsCentrally>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <!-- Historian SDK runtime deps (WCF/MDAS transports — Windows-only at runtime) -->
+    <PackageVersion Include="System.Security.Cryptography.Xml" Version="10.0.7" />
+    <PackageVersion Include="System.ServiceModel.NetNamedPipe" Version="10.0.652802" />
+    <PackageVersion Include="System.ServiceModel.NetTcp" Version="10.0.652802" />
+
+    <!-- 2023 R2 gRPC transport (cross-platform) -->
+    <PackageVersion Include="Google.Protobuf" Version="3.24.4" />
+    <PackageVersion Include="Grpc.Net.Client" Version="2.58.0" />
+    <PackageVersion Include="Grpc.Net.Client.Web" Version="2.58.0" />
+    <PackageVersion Include="Grpc.Tools" Version="2.59.0" />
+
+    <!-- ZB-idiomatic DI extension (only non-BCL lib dependency) -->
+    <PackageVersion Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="10.0.7" />
+
+    <!-- Test -->
+    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.14.1" />
+    <PackageVersion Include="xunit" Version="2.9.3" />
+    <PackageVersion Include="xunit.runner.visualstudio" Version="3.1.4" />
+    <PackageVersion Include="coverlet.collector" Version="6.0.4" />
+    <PackageVersion Include="Microsoft.Data.SqlClient" Version="6.0.2" />
+  </ItemGroup>
+
+</Project>
+```
+
+**Step 3: `.gitignore`**
+
+```gitignore
+bin/
+obj/
+# identity-bearing / non-redistributable — never commit
+*.ndjson
+current/
+aveva-install-*/
+```
+
+**Step 4: `ZB.MOM.WW.SPHistorianClient.slnx`**
+
+```xml
+<Solution>
+  <Folder Name="/src/">
+    <Project Path="src/ZB.MOM.WW.SPHistorianClient/ZB.MOM.WW.SPHistorianClient.csproj" />
+  </Folder>
+  <Folder Name="/tests/">
+    <Project Path="tests/ZB.MOM.WW.SPHistorianClient.Tests/ZB.MOM.WW.SPHistorianClient.Tests.csproj" />
+  </Folder>
+</Solution>
+```
+
+**Step 5: `src/ZB.MOM.WW.SPHistorianClient/ZB.MOM.WW.SPHistorianClient.csproj`**
+
+(Derived from the bundle's `AVEVA.Historian.Client.csproj`: inline versions removed for central
+management; ZB package metadata added; `InternalsVisibleTo` retargeted to the ZB test assembly and
+the `…ReverseEngineering` one dropped; proto glob uses forward slashes for cross-platform MSBuild.)
+
+```xml
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <IsPackable>true</IsPackable>
+    <PackageId>ZB.MOM.WW.SPHistorianClient</PackageId>
+    <Authors>ZB.MOM.WW</Authors>
+    <Description>Pure-managed .NET 10 client for AVEVA System Platform Historian (Wonderware) for the ZB.MOM.WW SCADA family. The wire protocol is reverse-engineered and re-implemented in C# — no native AVEVA runtime dependency. Surfaces history reads (raw / aggregate / at-time / event), tag browse + metadata, status, and tag create/delete over the WCF/MDAS transports (Windows) plus a cross-platform gRPC transport for 2023 R2.</Description>
+    <PackageTags>aveva;wonderware;historian;system-platform;scada;timeseries;grpc;wcf;zb-mom-ww</PackageTags>
+    <PackageProjectUrl>https://gitea.dohertylan.com/dohertj2/zb-mom-ww-sphistorianclient</PackageProjectUrl>
+    <RepositoryUrl>https://gitea.dohertylan.com/dohertj2/zb-mom-ww-sphistorianclient</RepositoryUrl>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="System.Security.Cryptography.Xml" />
+    <PackageReference Include="System.ServiceModel.NetNamedPipe" />
+    <PackageReference Include="System.ServiceModel.NetTcp" />
+    <PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" />
+  </ItemGroup>
+
+  <!-- 2023 R2 gRPC transport (RemoteGrpc). Pure-managed: Grpc.Net.Client + Google.Protobuf.
+       Grpc.Tools is build-only (PrivateAssets=all) and generates the client stubs from the
+       recovered contract under Grpc/Protos at build. -->
+  <ItemGroup>
+    <PackageReference Include="Google.Protobuf" />
+    <PackageReference Include="Grpc.Net.Client" />
+    <PackageReference Include="Grpc.Net.Client.Web" />
+    <PackageReference Include="Grpc.Tools">
+      <PrivateAssets>all</PrivateAssets>
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+    </PackageReference>
+  </ItemGroup>
+
+  <ItemGroup>
+    <Protobuf Include="Grpc/Protos/*.proto" GrpcServices="Client" ProtoRoot="Grpc/Protos" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <AssemblyAttribute Include="System.Runtime.CompilerServices.InternalsVisibleToAttribute">
+      <_Parameter1>ZB.MOM.WW.SPHistorianClient.Tests</_Parameter1>
+    </AssemblyAttribute>
+  </ItemGroup>
+
+</Project>
+```
+
+**Step 6: `tests/ZB.MOM.WW.SPHistorianClient.Tests/ZB.MOM.WW.SPHistorianClient.Tests.csproj`**
+
+```xml
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <IsPackable>false</IsPackable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="coverlet.collector" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" />
+    <PackageReference Include="Microsoft.Data.SqlClient" />
+    <PackageReference Include="xunit" />
+    <PackageReference Include="xunit.runner.visualstudio" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Using Include="Xunit" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\src\ZB.MOM.WW.SPHistorianClient\ZB.MOM.WW.SPHistorianClient.csproj" />
+  </ItemGroup>
+
+</Project>
+```
+
+**Step 7: Verify the skeleton is well-formed (build will fail — no sources yet — that is expected)**
+
+Run: `cd ZB.MOM.WW.SPHistorianClient && dotnet restore ZB.MOM.WW.SPHistorianClient.slnx`
+Expected: restore **succeeds** (proves the props/csproj XML and central package versions resolve). A
+follow-up `dotnet build` would fail only because no `.cs` exist yet — do not build here.
+
+**Step 8: Commit**
+
+```bash
+cd /Users/dohertj2/Desktop/scadaproj
+git add ZB.MOM.WW.SPHistorianClient/
+git commit -m "feat(sphistorianclient): scaffold shared library skeleton (props, csprojs, slnx)"
+```
+
+---
+
+## Task 2: Port source + tests with namespace rewrite
+
+**Classification:** standard
+**Estimated implement time:** ~4 min
+**Parallelizable with:** none
+**Blocked by:** Task 1
+
+**Files:**
+- Create (scripted copy): `ZB.MOM.WW.SPHistorianClient/src/ZB.MOM.WW.SPHistorianClient/**/*.{cs,proto}` (74 `.cs` + 6 `.proto`)
+- Create (scripted copy): `ZB.MOM.WW.SPHistorianClient/tests/ZB.MOM.WW.SPHistorianClient.Tests/**/*.cs` (25 `.cs`)
+
+This task is a deterministic copy + namespace rewrite — run the script, then verify counts.
+
+**Step 1: Copy + rewrite (single script)**
+
+```bash
+set -euo pipefail
+BUNDLE=/tmp/histsdk/extracted/histsdk-migration/histsdk
+DEST=/Users/dohertj2/Desktop/scadaproj/ZB.MOM.WW.SPHistorianClient
+
+# Guard: re-extract if /tmp was cleaned
+if [ ! -d "$BUNDLE/src/AVEVA.Historian.Client" ]; then
+  cd /tmp/histsdk && unzip -o -q histsdk-migration.zip -d extracted
+fi
+
+# --- src: copy .cs + .proto, preserving subdirs (NOT the old .csproj) ---
+SRC="$DEST/src/ZB.MOM.WW.SPHistorianClient"
+cd "$BUNDLE/src/AVEVA.Historian.Client"
+find . \( -name '*.cs' -o -name '*.proto' \) | while read -r f; do
+  mkdir -p "$SRC/$(dirname "$f")"
+  cp "$f" "$SRC/$f"
+done
+
+# --- tests: copy .cs only (NOT the old .csproj) ---
+TST="$DEST/tests/ZB.MOM.WW.SPHistorianClient.Tests"
+cd "$BUNDLE/tests/AVEVA.Historian.Client.Tests"
+find . -name '*.cs' | while read -r f; do
+  mkdir -p "$TST/$(dirname "$f")"
+  cp "$f" "$TST/$f"
+done
+
+# --- namespace rewrite in .cs ONLY (proto wire contracts stay ArchestrA.Grpc.Contract.*) ---
+find "$SRC" "$TST" -name '*.cs' -print0 \
+  | xargs -0 sed -i '' 's/AVEVA\.Historian\.Client/ZB.MOM.WW.SPHistorianClient/g'
+```
+
+**Step 2: Verify counts and that the rename is total**
+
+```bash
+DEST=/Users/dohertj2/Desktop/scadaproj/ZB.MOM.WW.SPHistorianClient
+echo "src cs:    $(find "$DEST/src" -name '*.cs' | wc -l)      (expect 74)"
+echo "src proto: $(find "$DEST/src" -name '*.proto' | wc -l)   (expect 6)"
+echo "test cs:   $(find "$DEST/tests" -name '*.cs' | wc -l)    (expect 25)"
+echo "leftover AVEVA.Historian.Client in .cs: $(grep -rl 'AVEVA\.Historian\.Client' "$DEST" --include='*.cs' | wc -l)   (expect 0)"
+echo "proto namespace preserved: $(grep -l 'ArchestrA.Grpc.Contract' "$DEST"/src/ZB.MOM.WW.SPHistorianClient/Grpc/Protos/*.proto | wc -l)   (expect 6)"
+```
+
+Expected: `74`, `6`, `25`, `0`, `6`. If "leftover" is non-zero, inspect those files — the only legitimate
+remaining mentions would be inside comments/strings that happen to differ in casing/spacing; a clean
+port should show `0`.
+
+**Step 3: Commit**
+
+```bash
+cd /Users/dohertj2/Desktop/scadaproj
+git add ZB.MOM.WW.SPHistorianClient/src ZB.MOM.WW.SPHistorianClient/tests
+git commit -m "feat(sphistorianclient): port SDK source + tests, rebrand namespace to ZB.MOM.WW.SPHistorianClient"
+```
+
+---
+
+## Task 3: Build + test green
+
+**Classification:** high-risk
+**Estimated implement time:** ~5 min (plus restore/build wall-time)
+**Parallelizable with:** none
+**Blocked by:** Task 2
+
+This is the integration gate. The port must compile and the offline test suite must pass on this macOS host.
+
+**Files:**
+- Modify (only if the build surfaces a defect): any ported file under `ZB.MOM.WW.SPHistorianClient/src` or `…/tests`, or the two `.csproj`.
+
+**Step 1: Build**
+
+Run: `cd ZB.MOM.WW.SPHistorianClient && dotnet build ZB.MOM.WW.SPHistorianClient.slnx`
+Expected: **Build succeeded.** Platform-compatibility (CAxxxx `[SupportedOSPlatform("windows")]`) warnings
+are acceptable and must remain warnings. If restore hard-fails on `NU1903`, re-run with
+`-p:NuGetAudit=false`.
+
+**Step 2: Test**
+
+Run: `dotnet test ZB.MOM.WW.SPHistorianClient.slnx`
+Expected: all tests pass; the live integration tests (`HistorianClientIntegrationTests`,
+`HistorianGrpcIntegrationTests`, `RemoteTcpIntegrationTests`) **skip cleanly** because no `HISTORIAN_*`
+env vars are set. The bundle's `MIGRATION-README.md` documents ~188 tests passing on macOS with the
+live ones skipped — treat a comparable count with **zero failures** as success.
+
+**Step 3: Triage rules (if not green)**
+- Compile error referencing `AVEVA.Historian.Client` → a file was missed by the rewrite; re-run the
+  Task 2 sed on that file.
+- `NU1008` (version on PackageReference) → an inline `Version=` slipped into a `.csproj`; remove it
+  (version belongs in `Directory.Packages.props`).
+- Missing generated gRPC type (e.g. `ArchestrA.Grpc.Contract.*` not found) → confirm the `<Protobuf>`
+  glob in the src `.csproj` resolves the 6 `Grpc/Protos/*.proto` and that `Grpc.Tools` restored.
+- A genuine test failure (not a skip) → this is a real port defect; fix the ported code, do **not**
+  delete/weaken the test.
+
+**Step 4: Commit (only if Step 3 required edits)**
+
+```bash
+git add -A ZB.MOM.WW.SPHistorianClient/
+git commit -m "fix(sphistorianclient): resolve port build/test fallout"
+```
+
+---
+
+## Task 4: Add the `AddZbSpHistorianClient` DI extension (TDD)
+
+**Classification:** standard
+**Estimated implement time:** ~4 min
+**Parallelizable with:** Task 5
+**Blocked by:** Task 3
+
+`HistorianClientOptions` uses `required` + `init`-only properties, so the extension takes a fully-built
+options instance (not an `Action<T>` configurator). It depends only on
+`Microsoft.Extensions.DependencyInjection.Abstractions`.
+
+**Files:**
+- Create: `ZB.MOM.WW.SPHistorianClient/src/ZB.MOM.WW.SPHistorianClient/DependencyInjection/ZbSpHistorianClientServiceCollectionExtensions.cs`
+- Test: `ZB.MOM.WW.SPHistorianClient/tests/ZB.MOM.WW.SPHistorianClient.Tests/DependencyInjectionTests.cs`
+
+**Step 1: Write the failing test**
+
+```csharp
+using Microsoft.Extensions.DependencyInjection;
+using ZB.MOM.WW.SPHistorianClient;
+
+namespace ZB.MOM.WW.SPHistorianClient.Tests;
+
+public class DependencyInjectionTests
+{
+    [Fact]
+    public void AddZbSpHistorianClient_resolves_client_and_options()
+    {
+        var services = new ServiceCollection();
+        var options = new HistorianClientOptions { Host = "localhost" };
+
+        services.AddZbSpHistorianClient(options);
+
+        using var sp = services.BuildServiceProvider();
+        Assert.Same(options, sp.GetRequiredService<HistorianClientOptions>());
+        Assert.NotNull(sp.GetRequiredService<HistorianClient>());
+    }
+
+    [Fact]
+    public void AddZbSpHistorianClient_throws_when_host_missing()
+    {
+        var services = new ServiceCollection();
+        var options = new HistorianClientOptions { Host = "" };
+
+        Assert.Throws<ArgumentException>(() => services.AddZbSpHistorianClient(options));
+    }
+
+    [Fact]
+    public void AddZbSpHistorianClient_throws_on_null_options()
+    {
+        var services = new ServiceCollection();
+        Assert.Throws<ArgumentNullException>(() => services.AddZbSpHistorianClient(null!));
+    }
+}
+```
+
+**Step 2: Run — verify it fails to compile** (`AddZbSpHistorianClient` not defined)
+
+Run: `dotnet test ZB.MOM.WW.SPHistorianClient.slnx --filter "FullyQualifiedName~DependencyInjectionTests"`
+Expected: FAIL (does not compile / method missing).
+
+**Step 3: Implement**
+
+```csharp
+using Microsoft.Extensions.DependencyInjection;
+
+namespace ZB.MOM.WW.SPHistorianClient;
+
+/// <summary>
+/// ZB.MOM.WW DI registration for <see cref="HistorianClient"/>. Mirrors the family's
+/// <c>AddZb*</c> convention. Because <see cref="HistorianClientOptions"/> is <c>required</c>/
+/// <c>init</c>-only, callers pass a fully-built options instance (bind it from configuration in the
+/// consuming app, e.g. <c>config.GetSection("Historian").Get&lt;HistorianClientOptions&gt;()</c>).
+/// </summary>
+public static class ZbSpHistorianClientServiceCollectionExtensions
+{
+    public static IServiceCollection AddZbSpHistorianClient(
+        this IServiceCollection services,
+        HistorianClientOptions options)
+    {
+        ArgumentNullException.ThrowIfNull(services);
+        ArgumentNullException.ThrowIfNull(options);
+        if (string.IsNullOrWhiteSpace(options.Host))
+        {
+            throw new ArgumentException(
+                "HistorianClientOptions.Host must be set.", nameof(options));
+        }
+
+        services.AddSingleton(options);
+        // HistorianClient opens a fresh channel per operation and has a no-op DisposeAsync,
+        // so transient is safe and avoids assuming the shared dialect is concurrency-safe.
+        services.AddTransient<HistorianClient>();
+        return services;
+    }
+}
+```
+
+**Step 4: Run — verify pass**
+
+Run: `dotnet test ZB.MOM.WW.SPHistorianClient.slnx --filter "FullyQualifiedName~DependencyInjectionTests"`
+Expected: PASS (3/3).
+
+**Step 5: Commit**
+
+```bash
+git add ZB.MOM.WW.SPHistorianClient/src/ZB.MOM.WW.SPHistorianClient/DependencyInjection \
+        ZB.MOM.WW.SPHistorianClient/tests/ZB.MOM.WW.SPHistorianClient.Tests/DependencyInjectionTests.cs
+git commit -m "feat(sphistorianclient): add AddZbSpHistorianClient DI extension"
+```
+
+---
+
+## Task 5: Author `CLAUDE.md` + `README.md`
+
+**Classification:** small
+**Estimated implement time:** ~4 min
+**Parallelizable with:** Task 4
+**Blocked by:** Task 3
+
+Sanitized docs only — **no hostnames, credentials, customer tag names, or capture data.** Model the
+structure on `ZB.MOM.WW.Telemetry/CLAUDE.md` (overview, package table, build/test/pack commands,
+status) but adapt to a single-package library.
+
+**Files:**
+- Create: `ZB.MOM.WW.SPHistorianClient/CLAUDE.md`
+- Create: `ZB.MOM.WW.SPHistorianClient/README.md`
+
+**`CLAUDE.md` must cover:**
+- One-paragraph overview: pure-managed .NET 10 AVEVA System Platform Historian client, no native AVEVA
+  dependency, reverse-engineered wire protocol. Ported from the `histsdk` migration bundle.
+- The supported operation surface table (copy the README table from the bundle:
+  `ProbeAsync`, `ReadRawAsync`, `ReadAggregateAsync` (16 modes), `ReadAtTimeAsync`, `ReadEventsAsync`,
+  `BrowseTagNamesAsync`, `GetTagMetadataAsync`, `GetConnectionStatusAsync`,
+  `GetStoreForwardStatusAsync`, `GetSystemParameterAsync`, `EnsureTagAsync`, `DeleteTagAsync`).
+- Transport matrix: `LocalPipe` / `RemoteTcpIntegrated` / `RemoteTcpCertificate` (WCF, Windows-only,
+  live-verified) vs `RemoteGrpc` (2023 R2, cross-platform, **not yet live-verified**).
+- Out of scope: writing samples (`AddS2` architecturally blocked), discrete/string tag creation.
+- DI: the `AddZbSpHistorianClient(options)` extension + the bind-from-config note.
+- Build/test/pack commands (from this dir):
+  `dotnet build ZB.MOM.WW.SPHistorianClient.slnx` / `dotnet test …` /
+  `dotnet pack ZB.MOM.WW.SPHistorianClient.slnx -c Release -o ./artifacts`.
+- Live integration tests gated by `HISTORIAN_*` env vars (skip cleanly when unset). List the env vars.
+
+**`README.md`:** a trimmed public-facing version — overview, quick-start snippet (the bundle's
+`HistorianClient` usage example, namespace updated to `ZB.MOM.WW.SPHistorianClient`), supported surface
+table, build/test commands.
+
+**Commit:**
+
+```bash
+git add ZB.MOM.WW.SPHistorianClient/CLAUDE.md ZB.MOM.WW.SPHistorianClient/README.md
+git commit -m "docs(sphistorianclient): add CLAUDE.md + README.md"
+```
+
+---
+
+## Task 6: Pack verification
+
+**Classification:** small
+**Estimated implement time:** ~3 min
+**Parallelizable with:** none
+**Blocked by:** Task 4, Task 5
+
+**Files:**
+- Create (build output): `ZB.MOM.WW.SPHistorianClient/artifacts/ZB.MOM.WW.SPHistorianClient.0.1.0.nupkg`
+
+**Step 1: Full green build + test once more, then pack**
+
+```bash
+cd /Users/dohertj2/Desktop/scadaproj/ZB.MOM.WW.SPHistorianClient
+dotnet test ZB.MOM.WW.SPHistorianClient.slnx
+dotnet pack ZB.MOM.WW.SPHistorianClient.slnx -c Release -o ./artifacts
+```
+
+Expected: tests pass (live ones skip); pack produces `artifacts/ZB.MOM.WW.SPHistorianClient.0.1.0.nupkg`.
+
+**Step 2: Sanity-check the package contents**
+
+```bash
+unzip -l artifacts/ZB.MOM.WW.SPHistorianClient.0.1.0.nupkg | grep -E 'ZB.MOM.WW.SPHistorianClient.dll|.nuspec'
+```
+Expected: the lib DLL and nuspec are present.
+
+**Step 3: Commit the nupkg** (matches the family convention — `ZB.MOM.WW.Telemetry` commits its `artifacts/*.nupkg`)
+
+```bash
+cd /Users/dohertj2/Desktop/scadaproj
+git add -f ZB.MOM.WW.SPHistorianClient/artifacts/ZB.MOM.WW.SPHistorianClient.0.1.0.nupkg
+git commit -m "build(sphistorianclient): pack 0.1.0 nupkg"
+```
+
+> **Do NOT push or publish** to the Gitea feed. Per repo experience, "published/adopted" claims must
+> not be made without explicit user direction + feed verification.
+
+---
+
+## Task 7: Index the new library in the umbrella `CLAUDE.md` (optional)
+
+**Classification:** trivial
+**Estimated implement time:** ~2 min
+**Parallelizable with:** none
+**Blocked by:** Task 6
+
+**Files:**
+- Modify: `CLAUDE.md` (repo root umbrella index)
+
+Add a short reference so the umbrella index reflects the newly-hosted library (the intro paragraph
+that enumerates the hosted `ZB.MOM.WW.*` sources, and/or a one-line pointer near the component table
+noting `ZB.MOM.WW.SPHistorianClient` is a net-new shared library — **not** a component normalization).
+
+> **Caveat:** repo-root `CLAUDE.md` already has **pre-existing uncommitted edits** (unrelated to this
+> work). Before editing, run `git diff CLAUDE.md` and make sure your commit message reflects that it
+> may bundle those edits — or stage only the hunks you add. If this risks entangling unrelated changes,
+> skip this task and leave it for the user.
+
+**Commit:**
+
+```bash
+git add CLAUDE.md
+git commit -m "docs: index ZB.MOM.WW.SPHistorianClient in umbrella CLAUDE.md"
+```
+
+---
+
+## Done criteria
+
+- `ZB.MOM.WW.SPHistorianClient/` exists with `src/`, `tests/`, props, `.slnx`, `CLAUDE.md`, `README.md`.
+- `dotnet build` + `dotnet test` are green on macOS (live integration tests skip cleanly).
+- `AddZbSpHistorianClient` DI extension present + tested.
+- `artifacts/ZB.MOM.WW.SPHistorianClient.0.1.0.nupkg` produced.
+- All work committed on `feat/sphistorianclient`. Not pushed/published.
@@ -0,0 +1,13 @@
+{
+  "planPath": "docs/plans/2026-06-19-sphistorianclient.md",
+  "tasks": [
+    {"id": 1, "subject": "Task 1: Scaffold library skeleton", "status": "completed"},
+    {"id": 2, "subject": "Task 2: Port source + tests with namespace rewrite", "status": "completed", "blockedBy": [1]},
+    {"id": 3, "subject": "Task 3: Build + test green", "status": "completed", "blockedBy": [2]},
+    {"id": 4, "subject": "Task 4: Add AddZbSpHistorianClient DI extension (TDD)", "status": "completed", "blockedBy": [3]},
+    {"id": 5, "subject": "Task 5: Author CLAUDE.md + README.md", "status": "completed", "blockedBy": [3]},
+    {"id": 6, "subject": "Task 6: Pack verification", "status": "completed", "blockedBy": [4, 5]},
+    {"id": 7, "subject": "Task 7: Index new lib in umbrella CLAUDE.md (optional)", "status": "completed", "blockedBy": [6]}
+  ],
+  "lastUpdated": "2026-06-19"
+}
@@ -0,0 +1,216 @@
+# ZB.MOM.WW.HistorianGateway — Design
+
+**Date:** 2026-06-23
+**Status:** Design approved (brainstorming complete) — ready for implementation planning
+**Author:** brainstorming session (Joseph Doherty + Claude)
+
+## 1. Summary
+
+A new **full-feature sidecar** in the SCADA/OT sister-project family, modelled on
+`MxAccessGateway` (`mxaccessgw`). It does two things:
+
+1. **Read-only Galaxy metadata server** — exposes the AVEVA System Platform
+   ("Wonderware") **Galaxy object hierarchy** (areas / objects / templates /
+   instances / attributes), sourced from the **Galaxy Repository SQL DB**, the same
+   data `mxaccessgw`'s `galaxy_repository` feature serves today.
+2. **Full read/write gRPC API to the AVEVA (Wonderware) Historian** — reads (raw,
+   aggregate with all 15 retrieval modes, at-time, blocks, events, browse, metadata,
+   status) **and writes** (historical/backfill values, event send, tag-config
+   create/delete/rename/extended-properties, plus resilience helpers).
+
+It reuses the family's **common shared packages and styles**: `ZB.MOM.WW.Auth`,
+`ZB.MOM.WW.Theme`, `ZB.MOM.WW.Telemetry`(+`.Serilog`), `ZB.MOM.WW.Health`,
+`ZB.MOM.WW.Configuration`, `ZB.MOM.WW.Audit`.
+
+### Key reframing discovered during brainstorming
+
+- The historian write surface lives in the **`histsdk`** repo
+  (`gitea.dohertylan.com/dohertj2/histsdk`, namespace `AVEVA.Historian.Client`),
+  which is **far ahead** of the stale `scadaproj/ZB.MOM.WW.SPHistorianClient` port
+  (2026-06-19 snapshot, reads + tag create/delete only, value-writes marked
+  "blocked"). `histsdk` has since added a **live-validated gRPC write surface**:
+  `AddHistoricalValuesAsync` (historical/backfill, gRPC-only), `SendEventAsync`
+  (events, both transports), `EnsureTags`/`DeleteTags`/`RenameTags`/
+  `AddTagExtendedProperties` (config writes, gRPC), plus higher-level
+  `HistorianStoreForwardWriter` (durable outbox) and a redundant-write cluster.
+- **Hard server-side limit no client can lift:** `AddS2` *streaming live
+  process-sample* writes are GATED — the historian runtime cache only ingests from
+  configured IOServer / Application Server pipelines. "Live current value" writes are
+  therefore done via the **SQL path** (`aaAnalogTagInsert` → `INSERT INTO History`),
+  not gRPC.
+- **No COM anywhere.** The historian SDK is pure-managed and Galaxy browse is plain
+  SQL, so — unlike `mxaccessgw` — this sidecar needs **no x86 worker and no
+  two-process split**. It is a single .NET 10 x64 process.
+
+## 2. Decisions (locked during brainstorming)
+
+| Decision | Choice |
+|---|---|
+| Purpose | **General-purpose gateway** — reusable modern façade over Historian + Galaxy metadata for any gRPC client (the way `mxaccessgw` is the façade for MXAccess). |
+| Historian client code | **Vendor `histsdk`** (`AVEVA.Historian.Client`) into the sidecar repo as self-contained vendored source; namespace kept as-is to ease future re-sync. |
+| Galaxy browse code | **New shared lib `ZB.MOM.WW.GalaxyRepository`** in scadaproj, extracted from `mxaccessgw`'s `galaxy_repository` browse; consumed by both `mxaccessgw` and this sidecar. |
+| Dashboard | **Full Blazor dashboard** on `ZB.MOM.WW.Theme` (login + Galaxy browser + Historian console + API-key admin + status/health). |
+| Historian write scope | **All:** historical/backfill writes, event send, tag-config writes, **and** resilience extras (store-and-forward outbox, redundant write fan-out, SQL live-value path). |
+| Connection model | **Approach A — stateless gateway over pooled service-identity connections.** Clients authenticate to the gateway (ZB API key); the gateway owns historian credentials and reuses pooled, pre-authenticated connections. |
+| Repo location | **New standalone sibling repo** `~/Desktop/HistorianGateway`, gitea remote `historiangw`. |
+| Name / namespace | **`ZB.MOM.WW.HistorianGateway`**. |
+
+## 3. Architecture & solution structure
+
+Single .NET 10 x64 ASP.NET Core process.
+
+```
+~/Desktop/HistorianGateway/
+  src/
+    ZB.MOM.WW.HistorianGateway.Server/      ASP.NET Core host: gRPC services + Blazor dashboard + /healthz + /metrics
+    ZB.MOM.WW.HistorianGateway.Contracts/   the gateway's own .proto + generated types (for client codegen distribution)
+    vendor/AVEVA.Historian.Client/          VENDORED from histsdk; ArchestrA.Grpc.Contract.* protos + reads/writes/store-forward/redundancy
+  tests/
+    ZB.MOM.WW.HistorianGateway.Tests/       unit + env-gated live integration + bUnit dashboard
+  docs/plans/, CLAUDE.md, README.md
+  ZB.MOM.WW.HistorianGateway.slnx
+```
+
+**Cross-repo pieces:**
+
+- **`scadaproj/ZB.MOM.WW.GalaxyRepository`** (new shared lib, plain files — NOT a
+  nested git repo): carries the **canonical `galaxy_repository.proto`** (adopted from
+  `mxaccessgw`'s existing contract so OtOpcUa's wire shape is not broken), the SQL
+  browse provider (connect to Galaxy Repository SQL → hierarchy model), and a
+  reusable gRPC service implementation both hosts can `MapGrpcService<>()`.
+  `mxaccessgw` adopting it is a **tracked follow-on** (same "built → adopted" pattern
+  as the other normalized components); this sidecar consumes it from the start.
+- **Shared ZB packages consumed:** `ZB.MOM.WW.Auth`
+  (Abstractions+Ldap+ApiKeys+AspNetCore), `ZB.MOM.WW.Theme`, `ZB.MOM.WW.Telemetry`
+  (+`.Serilog`), `ZB.MOM.WW.Health`, `ZB.MOM.WW.Configuration`, `ZB.MOM.WW.Audit`.
+
+## 4. gRPC API surface
+
+Gateway's own curated contract (`ZB.MOM.WW.HistorianGateway.Grpc.V1`), grouped by
+concern — not a 1:1 SDK dump. The vendored `ArchestrA.Grpc.Contract.*` protos stay
+internal; clients see only the gateway contract.
+
+| Service | RPCs | Notes |
+|---|---|---|
+| `HistorianRead` | `ReadRaw`, `ReadAggregate`, `ReadBlocks`, `ReadEvents` *(server-streaming)*; `ReadAtTime` | `ReadAggregate` exposes all 15 retrieval modes |
+| `HistorianWrite` | `AddHistoricalValues`, `SendEvent`, `WriteLiveValues` | `WriteLiveValues` = SQL path (gRPC streaming is gated) |
+| `HistorianTags` | `BrowseTagNames` *(streaming)*, `GetTagMetadata`, `EnsureTags`, `DeleteTags`, `RenameTags`, `AddTagExtendedProperties` | |
+| `HistorianStatus` | `Probe`, `GetConnectionStatus`, `GetStoreForwardStatus`, `GetSystemParameter` | |
+| `GalaxyRepository` | Browse areas / objects / templates / instances / attributes *(read-only)* | canonical proto from the shared lib |
+
+**Authorization** is via **API-key scopes at the gateway** (Approach A trust
+boundary): `historian:read`, `historian:write`, `historian:tags:write`,
+`galaxy:read`.
+
+## 5. Connection & data flow
+
+```
+gRPC client ──(ZB API key)──► HistorianGateway ──┬─ pooled, pre-authed gRPC conn ──► AVEVA Historian (RemoteGrpc 2023R2)
+                                                  ├─ store-forward outbox (SQLite) ─ replays writes on reconnect
+                                                  ├─ redundant-write fan-out ──────► historian members (All/Any ack)
+                                                  ├─ SqlConnection ──► Runtime DB (live-value writes via aaAnalogTagInsert/History)
+                                                  └─ ZB.MOM.WW.GalaxyRepository ──► Galaxy Repository SQL (read-only browse)
+```
+
+- **Pooled connections:** the expensive auth handshake (`ValidateClientCredential` /
+  ECDH `ExchangeKey`) runs **once per connection on open**, then is reused across
+  requests; connections are health-checked with auto-reconnect. Write operations use
+  the write-enabled session mode (`0x401`).
+- **Store-forward:** writes flow through the SDK's `HistorianStoreForwardWriter` — on
+  an unreachable historian, enqueue to durable SQLite; a background drain replays on
+  reconnect.
+- **Redundancy:** `HistorianRedundantWriteResult` fan-out to configured members under
+  an All/Any ack policy; per-member result surfaced to the caller.
+- **SQL live-write** and **Galaxy browse** are independent SQL paths, each with its
+  own validated connection config.
+
+**Configuration** (all `ZB.MOM.WW.Configuration`-validated, aggregated by
+`ConfigPreflight` at startup): historian (host, gRPC port 32565, transport=RemoteGrpc,
+TLS, service identity/credentials), redundant members, store-forward path, Galaxy
+Repository SQL connection string, Runtime DB connection string (SQL live-write),
+Auth (LDAP + API-key pepper). Secrets live in the operator environment, never in repo.
+
+## 6. Cross-cutting infrastructure + dashboard
+
+- **Auth (`ZB.MOM.WW.Auth`):** gRPC clients use peppered-HMAC API keys (keyId/Bearer),
+  validated by a gRPC interceptor enforcing per-service scopes. Dashboard uses LDAP
+  login (`.Ldap`+`.AspNetCore`), cookie auth, `IGroupRoleMapper<TRole>`, canonical
+  `ZbClaimTypes`/`ZbCookieDefaults`, canonical-six roles, dev against the shared
+  GLAuth (`10.100.0.35:3893`, `dc=zb,dc=local`). `DisableLogin` dev/deploy switch.
+- **Telemetry (`.Telemetry`+`.Serilog`):** `AddZbTelemetry` (Resource
+  `service.name=historian-gateway` + standard instrumentation + always-on Prometheus
+  `/metrics`, OTLP opt-in) + `AddZbSerilog`. App Meters: read/write counts + latency,
+  store-forward queue depth, pool connection state, redundancy ack outcomes.
+- **Health (`.Health`):** three-tier ready/active/healthz + canonical JSON writer.
+  Probes: historian gRPC (`GrpcDependencyHealthCheck`), Galaxy Repository SQL +
+  Runtime DB (`DatabaseHealthCheck`), store-forward drain status.
+- **Configuration (`.Configuration`):** `OptionsValidatorBase` / `ValidationBuilder` /
+  `AddValidatedOptions` / `ConfigPreflight` (§5).
+- **Audit (`.Audit`, DEEP-adopt):** canonical `AuditEvent` + SQLite `IAuditWriter`
+  (MxGateway-style). Audited: tag-config writes, historical/event writes, API-key
+  admin, login/logout. `Actor` wired from the Auth principal via `IAuditActorAccessor`.
+- **Dashboard (Blazor, `.Theme`):** Technical-Light side-rail shell + `LoginCard`
+  `/login`. Pages: **Status** (pool / store-forward / redundancy / version),
+  **Galaxy browser** (read-only hierarchy tree), **Historian console** (query with
+  raw/aggregate + mode picker + time range; role-gated write test for value insert /
+  event send), **API-key admin** (list/create/revoke keys + scopes), **Health**.
+
+## 7. Error handling
+
+- **gRPC status mapping:** `ProtocolEvidenceMissingException` (unsupported op/type —
+  e.g. non-analog tag, non-string event property) → `Unimplemented`/`FailedPrecondition`
+  with a clear "not in reverse-engineered surface" message; auth →
+  `Unauthenticated`/`PermissionDenied`; historian down → `Unavailable`; bad range /
+  unknown tag → `InvalidArgument`/`NotFound`.
+- **Gated ops:** live streaming-sample writes (`AddS2`) are **not exposed** (no RPC);
+  live-value writes route through SQL `WriteLiveValues`.
+- **Write resilience:** with store-forward enabled, an unreachable historian returns
+  *accepted + queued* (not an error); otherwise `Unavailable`. Redundancy surfaces a
+  per-member result; All-policy fails if any member fails, Any-policy succeeds on ≥1 ack.
+- **Pool:** transient failures → reconnect + bounded retry; auth-handshake failure →
+  fail fast with diagnostic. No secrets/real hostnames in errors or logs (histsdk
+  safety rule).
+
+## 8. Testing
+
+- **Unit:** gRPC services against a faked historian-client seam + faked Galaxy
+  provider; scope/auth interceptor; config validators; SDK-model ↔ proto mapping.
+- **Golden/protocol:** carry over `histsdk`'s golden byte tests for the vendored
+  client (historical "ON" buffer, event "OS" buffer, registration buffers) so the
+  vendored copy stays faithful.
+- **Integration (env-gated, live, CI/macOS-safe):** real 2023 R2 historian + Galaxy
+  Repository SQL — read/write round-trips and browse via the self-cleaning
+  sandbox-tag lifecycle (`HISTORIAN_GRPC_WRITE_SANDBOX_TAG`); skipped when env vars
+  absent.
+- **Dashboard:** bUnit component tests. **Smoke:** `/healthz`, `/metrics`, gRPC
+  `Probe`.
+
+## 9. Out of scope / non-goals
+
+- `AddS2` live streaming process-sample writes (GATED server-side; SQL path covers
+  live values instead).
+- Non-analog tag creation, revision/edit writes, bit-faithful store-forward framing
+  (per `histsdk` capability matrix — `BOUNDED`/`HARD`/`GATED` items not selected).
+- A two-process / x86 worker split (not needed — no COM).
+- Re-syncing or replacing the existing stale `scadaproj/ZB.MOM.WW.SPHistorianClient`
+  port (we vendor `histsdk` instead; the stale port is left as-is).
+
+## 10. Implementation components (high level)
+
+1. **`ZB.MOM.WW.GalaxyRepository` shared lib** (scadaproj) — extract from
+   `mxaccessgw`, canonical proto + SQL browse provider + reusable gRPC service.
+2. **Vendor `histsdk`** `AVEVA.Historian.Client` into the new repo + carry its golden
+   tests.
+3. **Repo scaffold + host + shared-package wiring** (Auth/Telemetry/Health/
+   Configuration/Audit) + validated options + `ConfigPreflight`.
+4. **gRPC contract + services** (Read / Write / Tags / Status / GalaxyRepository).
+5. **Connection layer** — pooled pre-authed connections, store-forward, redundancy,
+   SQL live-write path.
+6. **Auth** — API-key scope interceptor + LDAP dashboard auth + Audit wiring.
+7. **Blazor dashboard** pages (Theme).
+8. **Telemetry + Health** probes/meters.
+9. **Tests** — unit / golden / env-gated integration / bUnit.
+10. **Docs + repo/gitea setup** — `CLAUDE.md`, `README.md`, gitea remote.
+
+> `mxaccessgw` adoption of `ZB.MOM.WW.GalaxyRepository` is a separate tracked
+> follow-on, not part of the initial sidecar delivery.
@@ -0,0 +1,523 @@
+# ZB.MOM.WW.HistorianGateway Implementation Plan
+
+> **For Claude:** REQUIRED SUB-SKILL: Use superpowers-extended-cc:executing-plans to implement this plan task-by-task.
+
+**Goal:** Build a single .NET 10 x64 sidecar that exposes (1) a read-only Galaxy object-hierarchy metadata gRPC server and (2) a full read/write gRPC API to the AVEVA Historian, with a Blazor dashboard, reusing the family's shared `ZB.MOM.WW.*` packages.
+
+**Architecture:** One ASP.NET Core process hosting gRPC services + Blazor (no COM, no x86 worker). The historian write/read surface comes from the **vendored `histsdk` client** (`AVEVA.Historian.Client`). The Galaxy browse comes from a **new shared lib `ZB.MOM.WW.GalaxyRepository`** in scadaproj (extracted from mxaccessgw, wire-compatible `galaxy_repository.v1`). Connection model: stateless gateway over a **pooled, pre-authenticated service-identity connection**; clients authenticate to the gateway via peppered-HMAC API keys with per-service scopes.
+
+**Tech Stack:** .NET 10, ASP.NET Core, Grpc.AspNetCore 2.76, Grpc.Net.Client 2.58 (vendored), Google.Protobuf, Microsoft.Data.SqlClient, Microsoft.Data.Sqlite, Blazor InteractiveServer, `ZB.MOM.WW.Theme` 0.3.1, `ZB.MOM.WW.Auth` 0.1.2, `ZB.MOM.WW.Telemetry`/`.Serilog` 0.1.0, `ZB.MOM.WW.Health` 0.1.0, `ZB.MOM.WW.Audit` 0.1.0, `ZB.MOM.WW.Configuration` 0.1.0, xUnit, bUnit.
+
+**Reference sources (read these for exact patterns — do NOT re-discover):**
+- Design doc: `docs/plans/2026-06-23-historian-gateway-design.md`
+- mxaccessgw (the model): `~/Desktop/MxAccessGateway/src/ZB.MOM.WW.MxGateway.Server/` — `GatewayApplication.cs` (host wiring), `Security/Authorization/*` (gRPC API-key interceptor + scope resolver), `Galaxy/GalaxyRepository.cs` (the SQL to extract), `Galaxy/GalaxyRepositoryOptions.cs`, `Galaxy/GalaxyHierarchyCache.cs`, `Galaxy/GalaxyRepositoryServiceCollectionExtensions.cs`, `Contracts/Protos/galaxy_repository.proto`, `Dashboard/Components/*` (Blazor + Theme).
+- histsdk clone (to vendor): `/tmp/histsdk-explore/src/AVEVA.Historian.Client/` + `/tmp/histsdk-explore/tests/AVEVA.Historian.Client.Tests/`.
+- Shared package signatures: captured in the design session; key paths under `~/Desktop/scadaproj/ZB.MOM.WW.{Telemetry,Health,Configuration,Audit,Auth,Theme}/`.
+
+**Conventions for every task:** TDD where a seam exists (write the failing test first). Exact file paths in the `Files:` block ARE the implementer's contract. Commit after each task. Tests must stay green on macOS with no live historian/SQL (live tests are env-gated and skip when env vars are absent).
+
+---
+
+## Phase 0 — Shared `ZB.MOM.WW.GalaxyRepository` lib (in scadaproj)
+
+> Built in `~/Desktop/scadaproj/ZB.MOM.WW.GalaxyRepository/` as plain files (NOT a nested git repo — see memory `shared-libs-are-plain-files-not-nested-repos`). Wire-compatible: keep proto `package galaxy_repository.v1` and all field numbers identical to mxaccessgw's so OtOpcUa is unaffected; only the C# `csharp_namespace` becomes neutral. mxaccessgw adoption of this lib is a separate follow-on, NOT in this plan.
+
+### Task 1: Scaffold the GalaxyRepository lib project
+
+**Classification:** small
+**Estimated implement time:** ~3 min
+**Parallelizable with:** Task 7 (vendoring), Task 9 (repo scaffold)
+
+**Files:**
+- Create: `~/Desktop/scadaproj/ZB.MOM.WW.GalaxyRepository/ZB.MOM.WW.GalaxyRepository.slnx`
+- Create: `~/Desktop/scadaproj/ZB.MOM.WW.GalaxyRepository/src/ZB.MOM.WW.GalaxyRepository/ZB.MOM.WW.GalaxyRepository.csproj`
+- Create: `~/Desktop/scadaproj/ZB.MOM.WW.GalaxyRepository/tests/ZB.MOM.WW.GalaxyRepository.Tests/ZB.MOM.WW.GalaxyRepository.Tests.csproj`
+
+**Steps:**
+1. Create the `.csproj` (net10.0, `Nullable`/`ImplicitUsings` enabled, packable, `PackageId=ZB.MOM.WW.GalaxyRepository`, `Version=0.1.0`). PackageReferences: `Microsoft.Data.SqlClient` 6.0.2, `Grpc.AspNetCore` 2.76.0, `Google.Protobuf`, `Microsoft.Extensions.Hosting.Abstractions`, `Microsoft.Extensions.Options.ConfigurationExtensions`. Add `<Protobuf Include="Protos\*.proto" GrpcServices="Server" />`.
+2. Create the test `.csproj` (net10.0, `IsPackable=false`, xUnit 2.9.3 + `Microsoft.NET.Test.Sdk` 17.14.1 + `Microsoft.Data.SqlClient`), ProjectReference to the lib.
+3. Create the `.slnx` listing both projects.
+4. Run: `dotnet build ~/Desktop/scadaproj/ZB.MOM.WW.GalaxyRepository/ZB.MOM.WW.GalaxyRepository.slnx` — Expected: builds (no sources yet, 0 warnings).
+5. Commit: `git -C ~/Desktop/scadaproj add ZB.MOM.WW.GalaxyRepository && git -C ~/Desktop/scadaproj commit -m "feat(galaxyrepo): scaffold ZB.MOM.WW.GalaxyRepository shared lib"`
+
+### Task 2: Port the canonical galaxy_repository.proto (neutral namespace)
+
+**Classification:** standard
+**Estimated implement time:** ~4 min
+**Parallelizable with:** none (Task 3+ depend on generated types)
+
+**Files:**
+- Create: `~/Desktop/scadaproj/ZB.MOM.WW.GalaxyRepository/src/ZB.MOM.WW.GalaxyRepository/Protos/galaxy_repository.proto`
+
+**Steps:**
+1. Copy mxaccessgw's `Contracts/Protos/galaxy_repository.proto` verbatim, changing ONLY `option csharp_namespace` to `"ZB.MOM.WW.GalaxyRepository.Grpc"`. Keep `package galaxy_repository.v1`, all services (`TestConnection`, `GetLastDeployTime`, `DiscoverHierarchy`, `WatchDeployEvents`, `BrowseChildren`), and every message/field number identical (wire compatibility).
+2. Run: `dotnet build .../ZB.MOM.WW.GalaxyRepository.slnx` — Expected: PASS; generated `GalaxyRepository.GalaxyRepositoryBase`, `GalaxyObject`, `GalaxyAttribute`, etc. appear under namespace `ZB.MOM.WW.GalaxyRepository.Grpc`.
+3. Commit: `feat(galaxyrepo): canonical galaxy_repository.v1 proto (neutral namespace)`
+
+### Task 3: Port the SQL browse provider (`GalaxyRepository` + rows + options)
+
+**Classification:** standard
+**Estimated implement time:** ~5 min
+**Parallelizable with:** none
+
+**Files:**
+- Create: `.../src/ZB.MOM.WW.GalaxyRepository/GalaxyRepositoryOptions.cs`
+- Create: `.../src/ZB.MOM.WW.GalaxyRepository/GalaxyHierarchyRow.cs`
+- Create: `.../src/ZB.MOM.WW.GalaxyRepository/GalaxyAttributeRow.cs`
+- Create: `.../src/ZB.MOM.WW.GalaxyRepository/IGalaxyRepository.cs`
+- Create: `.../src/ZB.MOM.WW.GalaxyRepository/GalaxyRepository.cs`
+
+**Steps:**
+1. Port `GalaxyRepositoryOptions` from mxaccessgw `Galaxy/GalaxyRepositoryOptions.cs` — rename section const to `ZB.MOM.WW.GalaxyRepository` (the consuming app picks its own section path at registration), drop MxGateway-specific defaults. Keep `ConnectionString`, `CommandTimeoutSeconds`, `DashboardRefreshIntervalSeconds`, `PersistSnapshot`, `SnapshotCachePath`.
+2. Port `GalaxyHierarchyRow` / `GalaxyAttributeRow` DTOs and the `IGalaxyRepository` interface (`TestConnectionAsync`, `GetLastDeployTimeAsync`, `GetHierarchyAsync`, `GetAttributesAsync`).
+3. Port `GalaxyRepository.cs` **verbatim** including the two SQL blocks (`HierarchySql`, `AttributesSql`) and the `SqlConnection`/`SqlDataReader` mapping loops — these are validated reverse-engineered queries; do NOT modify the SQL.
+4. Run: `dotnet build` — Expected: PASS.
+5. Commit: `feat(galaxyrepo): SQL browse provider (hierarchy + attributes)`
+
+### Task 4: Port the in-memory hierarchy cache + snapshot + deploy notifier + refresh service
+
+**Classification:** standard
+**Estimated implement time:** ~5 min
+**Parallelizable with:** none
+
+**Files:**
+- Create: `.../GalaxyHierarchyCacheEntry.cs`, `.../IGalaxyHierarchyCache.cs`, `.../GalaxyHierarchyCache.cs`
+- Create: `.../IGalaxyDeployNotifier.cs`, `.../GalaxyDeployNotifier.cs`
+- Create: `.../IGalaxyHierarchySnapshotStore.cs`, `.../GalaxyHierarchySnapshotStore.cs`
+- Create: `.../GalaxyHierarchyRefreshService.cs` (`BackgroundService`)
+- Create: `.../GalaxyHierarchyProjector.cs` (paging/filter projection used by the gRPC service)
+
+**Steps:**
+1. Port these from mxaccessgw's `Galaxy/` folder, adjusting namespaces to `ZB.MOM.WW.GalaxyRepository`. Keep the cache's first-load gate, refresh semaphore, snapshot restore, and deploy-poll refresh trigger.
+2. Port `GalaxyHierarchyProjector` (the `Project(...)` + `ComputeFilterSignature(...)` used by `DiscoverHierarchy`/`BrowseChildren` paging).
+3. Run: `dotnet build` — Expected: PASS.
+4. Commit: `feat(galaxyrepo): hierarchy cache + snapshot + refresh service`
+
+### Task 5: Port the reusable gRPC service + DI extension
+
+**Classification:** standard
+**Estimated implement time:** ~5 min
+**Parallelizable with:** none
+
+**Files:**
+- Create: `.../Grpc/GalaxyRepositoryGrpcService.cs`
+- Create: `.../DependencyInjection/GalaxyRepositoryServiceCollectionExtensions.cs`
+
+**Steps:**
+1. Port `GalaxyRepositoryGrpcService` from mxaccessgw's `Grpc/GalaxyRepositoryGrpcService.cs`, but REMOVE the mxaccessgw-specific `IGatewayRequestIdentityAccessor`/`ApiKeyConstraints` browse-subtree filtering (the gateway will apply its own auth at the interceptor layer). Keep `DiscoverHierarchy`, `BrowseChildren`, `TestConnection`, `GetLastDeployTime`, `WatchDeployEvents`. Base class: `ZB.MOM.WW.GalaxyRepository.Grpc.GalaxyRepository.GalaxyRepositoryBase`.
+2. Write `AddZbGalaxyRepository(this IServiceCollection, IConfiguration, string sectionPath)` modeled on mxaccessgw's `AddGalaxyRepository` — bind options from `sectionPath`, register `GalaxyRepository`/`IGalaxyRepository`, notifier, snapshot store, cache, and the refresh `HostedService`. Add a companion `MapZbGalaxyRepository(this IEndpointRouteBuilder)` that `MapGrpcService<GalaxyRepositoryGrpcService>()`.
+3. Run: `dotnet build` — Expected: PASS.
+4. Commit: `feat(galaxyrepo): reusable gRPC service + AddZbGalaxyRepository DI`
+
+### Task 6: Unit tests for the projector + DI smoke; pack
+
+**Classification:** standard
+**Estimated implement time:** ~5 min
+**Parallelizable with:** none
+
+**Files:**
+- Create: `.../tests/ZB.MOM.WW.GalaxyRepository.Tests/GalaxyHierarchyProjectorTests.cs`
+- Create: `.../tests/ZB.MOM.WW.GalaxyRepository.Tests/GalaxyHierarchyCacheTests.cs`
+
+**Steps:**
+1. **Write failing tests first:** projector paging (page_token round-trip, max_depth, `historized_only`/`alarm_bearing_only` filters, attribute include toggle) against a hand-built `GalaxyHierarchyCacheEntry` fixture; cache first-load gate + snapshot restore using a fake `IGalaxyRepository`. (SQL provider itself is exercised by env-gated integration later — no live DB in unit tests.)
+2. Run: `dotnet test .../ZB.MOM.WW.GalaxyRepository.slnx` — Expected: FAIL (types/asserts).
+3. Implement any small helper gaps surfaced; re-run — Expected: PASS.
+4. Run: `dotnet pack .../src/ZB.MOM.WW.GalaxyRepository/ZB.MOM.WW.GalaxyRepository.csproj -c Release` — Expected: `ZB.MOM.WW.GalaxyRepository.0.1.0.nupkg` produced.
+5. Commit: `test(galaxyrepo): projector + cache tests; pack 0.1.0`
+
+---
+
+## Phase 1 — Sidecar repo scaffold + vendor histsdk
+
+### Task 7: Vendor the histsdk client + its golden tests
+
+**Classification:** high-risk
+**Estimated implement time:** ~5 min
+**Parallelizable with:** Task 1
+
+**Files:**
+- Create: `~/Desktop/HistorianGateway/src/vendor/AVEVA.Historian.Client/**` (copied)
+- Create: `~/Desktop/HistorianGateway/tests/AVEVA.Historian.Client.Tests/**` (copied)
+- Create: `~/Desktop/HistorianGateway/src/vendor/AVEVA.Historian.Client/VENDORING.md`
+
+**Steps:**
+1. `mkdir -p ~/Desktop/HistorianGateway/src/vendor ~/Desktop/HistorianGateway/tests`. Copy `/tmp/histsdk-explore/src/AVEVA.Historian.Client/` and `/tmp/histsdk-explore/tests/AVEVA.Historian.Client.Tests/` into those locations.
+2. In the vendored test `.csproj`, REMOVE the `ProjectReference` to `tools/AVEVA.Historian.ReverseEngineering` (not vendored) and delete any test classes that depend on that tooling namespace (the RE-sanitizer tests). KEEP the protocol/golden tests: `HistorianTagWriteProtocolTests`, `HistorianEventRowProtocolTests`, `GrpcEventSendProtocolTests`, `WcfDataQueryProtocolTests`, `StoreForwardOutboxTests`, `RedundancyTests`, version-gate tests. Fix the surviving test `.csproj` ProjectReference path to the new vendored client location.
+3. Keep namespace `AVEVA.Historian.Client` as-is (eases re-sync). Write `VENDORING.md` recording: source repo `gitea.dohertylan.com/dohertj2/histsdk`, the commit/date of the snapshot, and "do not hand-edit; re-vendor from upstream."
+4. Run: `dotnet build ~/Desktop/HistorianGateway/src/vendor/AVEVA.Historian.Client/AVEVA.Historian.Client.csproj` then `dotnet test ~/Desktop/HistorianGateway/tests/AVEVA.Historian.Client.Tests/` — Expected: build PASS; golden/offline tests PASS (live env-gated tests skip).
+5. Commit (in the new repo, after Task 8 inits it — if running before Task 8, defer the commit): `chore(vendor): vendor histsdk AVEVA.Historian.Client + golden tests`
+
+### Task 8: Initialize the sidecar repo + solution + Directory.Build.props
+
+**Classification:** small
+**Estimated implement time:** ~3 min
+**Parallelizable with:** none (Task 7 output is added here)
+
+**Files:**
+- Create: `~/Desktop/HistorianGateway/.gitignore`
+- Create: `~/Desktop/HistorianGateway/Directory.Build.props`
+- Create: `~/Desktop/HistorianGateway/ZB.MOM.WW.HistorianGateway.slnx`
+
+**Steps:**
+1. `git -C ~/Desktop/HistorianGateway init` (this IS its own app repo — unlike shared libs). Add a .NET `.gitignore`.
+2. `Directory.Build.props`: `net10.0`, `Nullable`/`ImplicitUsings` enable, `<Platforms>x64</Platforms>`, `<PlatformTarget>x64</PlatformTarget>`, common `LangVersion`.
+3. Create `.slnx` referencing: `src/vendor/AVEVA.Historian.Client`, `tests/AVEVA.Historian.Client.Tests` (and the projects added in later phases — add them as created).
+4. Run: `dotnet build ~/Desktop/HistorianGateway/ZB.MOM.WW.HistorianGateway.slnx` — Expected: PASS.
+5. Commit: `chore: init repo + solution + Directory.Build.props` (then re-commit Task 7's vendored tree if it was deferred).
+
+---
+
+## Phase 2 — Host + configuration + shared-package wiring
+
+### Task 9: Create the Contracts project + historian_gateway.proto skeleton
+
+**Classification:** standard
+**Estimated implement time:** ~5 min
+**Parallelizable with:** Task 1
+
+**Files:**
+- Create: `~/Desktop/HistorianGateway/src/ZB.MOM.WW.HistorianGateway.Contracts/ZB.MOM.WW.HistorianGateway.Contracts.csproj`
+- Create: `.../Contracts/Protos/historian_gateway.proto`
+
+**Steps:**
+1. `.csproj` net10.0, `Grpc.AspNetCore` 2.76.0, `<Protobuf Include="Protos\*.proto" GrpcServices="Both" />`.
+2. Author `historian_gateway.proto` (`package historian_gateway.v1; option csharp_namespace = "ZB.MOM.WW.HistorianGateway.Contracts.Grpc";`) with the **service stubs and message shells** for the 4 historian services: `HistorianRead` (ReadRaw/ReadAggregate/ReadBlocks/ReadEvents server-streaming, ReadAtTime unary), `HistorianWrite` (AddHistoricalValues, SendEvent, WriteLiveValues), `HistorianTags` (BrowseTagNames streaming, GetTagMetadata, EnsureTags, DeleteTags, RenameTags, AddTagExtendedProperties), `HistorianStatus` (Probe, GetConnectionStatus, GetStoreForwardStatus, GetSystemParameter). Map the message fields to the vendored `HistorianSample`/`HistorianAggregateSample`/`HistorianEvent`/`HistorianTagMetadata`/`HistorianHistoricalValue` shapes (timestamps as `google.protobuf.Timestamp`, `RetrievalMode` as an enum mirroring the SDK's 15 modes).
+3. Run: `dotnet build` — Expected: PASS; gateway gRPC base classes generated. Add project to `.slnx`.
+4. Commit: `feat(contracts): historian_gateway.v1 proto + generated types`
+
+### Task 10: Create the Server project + minimal boot
+
+**Classification:** standard
+**Estimated implement time:** ~5 min
+**Parallelizable with:** none
+
+**Files:**
+- Create: `.../src/ZB.MOM.WW.HistorianGateway.Server/ZB.MOM.WW.HistorianGateway.Server.csproj`
+- Create: `.../Server/Program.cs`
+- Create: `.../Server/appsettings.json`, `.../Server/appsettings.Development.json`
+
+**Steps:**
+1. `.csproj` (Sdk `Microsoft.NET.Sdk.Web`): PackageReferences exactly mirroring mxaccessgw's Server csproj versions — `Grpc.AspNetCore` 2.76.0, `ZB.MOM.WW.Auth.{Abstractions,Ldap,ApiKeys,AspNetCore}` 0.1.2, `ZB.MOM.WW.Audit` 0.1.0, `ZB.MOM.WW.Theme` 0.3.1, `ZB.MOM.WW.Configuration` 0.1.0, `ZB.MOM.WW.Health` 0.1.0, `ZB.MOM.WW.Telemetry`+`.Serilog` 0.1.0, `Serilog.AspNetCore`/`.Sinks.Console`/`.Sinks.File`, `Microsoft.Data.Sqlite` 10.0.7, `Microsoft.Data.SqlClient` 6.0.2, `Polly.Core` 8.6.6. ProjectReferences: Contracts + vendored `AVEVA.Historian.Client` + `ZB.MOM.WW.GalaxyRepository` (project ref to the scadaproj lib, or pkg ref to its 0.1.0 nupkg).
+2. `Program.cs`: minimal `WebApplication` that calls `AddZbSerilog`/`AddZbTelemetry` (ServiceName `historian-gateway`), `builder.Services.AddGrpc()`, maps `/healthz` + `/metrics` via `MapZbHealth`/`MapZbMetrics`, boots. (Subsystems wired in later tasks.)
+3. Run: `dotnet build` then `dotnet run --project .../Server` and `curl -s localhost:<port>/healthz` — Expected: 200; `curl /metrics` returns Prometheus text. Add project to `.slnx`.
+4. Commit: `feat(server): host scaffold + telemetry/serilog/health boot`
+
+### Task 11: Configuration options + validators + ConfigPreflight
+
+**Classification:** standard
+**Estimated implement time:** ~5 min
+**Parallelizable with:** none
+
+**Files:**
+- Create: `.../Server/Configuration/HistorianOptions.cs` + `HistorianOptionsValidator.cs`
+- Create: `.../Server/Configuration/GalaxyOptions.cs` (thin wrapper / reuse `GalaxyRepositoryOptions`)
+- Create: `.../Server/Configuration/RuntimeDbOptions.cs` + validator (SQL live-write)
+- Create: `.../Server/Configuration/RedundancyOptions.cs` + validator
+- Create: `.../Server/Configuration/StoreForwardOptions.cs` + validator
+- Modify: `.../Server/Program.cs` (register `AddValidatedOptions<,>` + run `ConfigPreflight`)
+- Test: `.../tests/ZB.MOM.WW.HistorianGateway.Tests/Configuration/ValidatorTests.cs`
+
+**Steps:**
+1. **Write failing validator tests first** using `OptionsValidatorBase`/`ValidationBuilder` semantics (e.g., missing `Historian:Host` → failure; bad port → failure; `Transport` one-of; redundancy `MinCount(members,1)` when enabled). Run — Expected: FAIL.
+2. Implement options records + validators (subclass `OptionsValidatorBase<T>`, use `ValidationBuilder.Required/Port/HostPort/OneOf/PositiveTimeSpan/MinCount`). Map `HistorianOptions` → vendored `HistorianClientOptions` (Host, Port default 32565, `Transport=RemoteGrpc`, `GrpcUseTls`, credentials, `AllowUntrustedServerCertificate`).
+3. In `Program.cs`, `AddValidatedOptions<,>` each, and run a `ConfigPreflight` (RequireValue host, RequirePort) before host build.
+4. Run: `dotnet test` — Expected: PASS.
+5. Commit: `feat(server): validated options + ConfigPreflight`
+
+---
+
+## Phase 3 — Connection layer (vendored client → gateway)
+
+### Task 12: `IHistorianClient` seam over the vendored client
+
+**Classification:** standard
+**Estimated implement time:** ~5 min
+**Parallelizable with:** none
+
+**Files:**
+- Create: `.../Server/Historian/IHistorianClient.cs` (interface mirroring the read/write methods the services need)
+- Create: `.../Server/Historian/VendoredHistorianClient.cs` (adapts `AVEVA.Historian.Client.HistorianClient`)
+- Test: `.../tests/.../Historian/HistorianClientSeamTests.cs`
+
+**Steps:**
+1. **Write failing test** that a `FakeHistorianClient : IHistorianClient` can be substituted and returns canned samples (this seam is what makes the gRPC services unit-testable without a live historian). Run — Expected: FAIL.
+2. Define `IHistorianClient` with the methods the services call (ReadRaw/ReadAggregate/ReadAtTime/ReadBlocks/ReadEvents/BrowseTagNames/GetTagMetadata/Probe/GetConnectionStatus/GetStoreForwardStatus/GetSystemParameter/AddHistoricalValues/SendEvent/EnsureTag/DeleteTag/RenameTags/AddTagExtendedProperties). Implement `VendoredHistorianClient` delegating to the real `HistorianClient`.
+3. Run: `dotnet test` — Expected: PASS.
+4. Commit: `feat(historian): IHistorianClient seam + vendored adapter`
+
+### Task 13: Connection pool (pre-authenticated, reused, health-checked)
+
+**Classification:** high-risk
+**Estimated implement time:** ~5 min
+**Parallelizable with:** none
+
+**Files:**
+- Create: `.../Server/Historian/HistorianConnectionPool.cs` (+ `IHistorianConnectionPool`)
+- Modify: `.../Server/Program.cs` (DI singleton)
+- Test: `.../tests/.../Historian/HistorianConnectionPoolTests.cs`
+
+**Steps:**
+1. **Write failing test** asserting the pool opens/authenticates a connection once and reuses it across N borrow calls (count handshakes via a fake transport/lease factory), and that a faulted connection is evicted + re-created. Run — Expected: FAIL.
+2. Implement a lease-based pool keyed by target; lazy-open with the auth handshake once; reuse; `SemaphoreSlim`-guarded reconnect on fault; expose `Lease()` returning a pooled `IHistorianClient`. (The vendored client is `IAsyncDisposable`; the pool owns lifecycle.)
+3. Run: `dotnet test` — Expected: PASS.
+4. Commit: `feat(historian): pooled pre-authenticated connection pool`
+
+### Task 14: Store-forward + redundancy + SQL live-write wiring
+
+**Classification:** high-risk
+**Estimated implement time:** ~5 min
+**Parallelizable with:** none
+
+**Files:**
+- Create: `.../Server/Historian/HistorianWriteCoordinator.cs` (routes writes → pool, store-forward, or redundancy per config)
+- Create: `.../Server/Historian/SqlLiveValueWriter.cs` (`WriteLiveValues` via `aaAnalogTagInsert` + `INSERT INTO History`)
+- Modify: `.../Server/Program.cs`
+- Test: `.../tests/.../Historian/HistorianWriteCoordinatorTests.cs`, `.../SqlLiveValueWriterTests.cs`
+
+**Steps:**
+1. **Write failing tests:** (a) when store-forward enabled + historian unreachable, the coordinator enqueues (uses vendored `HistorianStoreForwardWriter` over a fake sink) and reports `Queued`; (b) when redundancy configured, it fans out via `HistorianRedundantClient` and returns per-member results under All/Any; (c) `SqlLiveValueWriter` builds the correct parameterized command sequence (assert against a fake `IDbCommand` recorder — no live SQL). Run — Expected: FAIL.
+2. Implement the coordinator (compose vendored `HistorianStoreForwardWriter` + `HistorianRedundantClient` from config) and `SqlLiveValueWriter` (omit the server-managed `Quality` column; honor the storage-activation note from the SQL reference memory).
+3. Run: `dotnet test` — Expected: PASS.
+4. Commit: `feat(historian): write coordinator (store-forward + redundancy) + SQL live-write`
+
+---
+
+## Phase 4 — gRPC services + auth interceptor
+
+### Task 15: `HistorianRead` service (representative TDD task; sets the pattern)
+
+**Classification:** standard
+**Estimated implement time:** ~5 min
+**Parallelizable with:** Task 17 after the mapper exists
+
+**Files:**
+- Create: `.../Server/Grpc/HistorianReadService.cs`
+- Create: `.../Server/Grpc/HistorianProtoMapper.cs` (SDK model ↔ proto)
+- Modify: `.../Server/Program.cs` (`MapGrpcService`)
+- Test: `.../tests/.../Grpc/HistorianReadServiceTests.cs`
+
+**Steps:**
+1. **Write failing test:** with a `FakeHistorianClient` yielding 3 `HistorianSample`s, calling `ReadRaw` streams 3 mapped proto rows; `ReadAggregate` passes the right `RetrievalMode`+interval; an unknown tag → `RpcException(NotFound)`; bad time range → `InvalidArgument`. Use an in-memory `IServerStreamWriter<T>` capture. Run — Expected: FAIL.
+2. Implement `HistorianReadService : HistorianRead.HistorianReadBase` consuming `IHistorianConnectionPool.Lease()`; implement `HistorianProtoMapper` (Timestamp conversions, RetrievalMode enum map). Map exceptions per design §7.
+3. Run: `dotnet test` — Expected: PASS.
+4. Commit: `feat(grpc): HistorianRead service + proto mapper`
+
+### Task 16: `HistorianWrite` service
+
+**Classification:** standard
+**Estimated implement time:** ~5 min
+**Parallelizable with:** Task 17, Task 18 (no file overlap)
+
+**Files:** Create `.../Server/Grpc/HistorianWriteService.cs`; Modify `Program.cs`; Test `.../Grpc/HistorianWriteServiceTests.cs`
+
+**Steps:** TDD per the Task 15 pattern. `AddHistoricalValues`/`SendEvent` route through `HistorianWriteCoordinator`; `WriteLiveValues` through `SqlLiveValueWriter`. Map `ProtocolEvidenceMissingException` → `Unimplemented`, unreachable+store-forward → `OK` with `Queued` status, redundancy per-member results into the reply. Commit: `feat(grpc): HistorianWrite service`.
+
+### Task 17: `HistorianTags` service
+
+**Classification:** standard
+**Estimated implement time:** ~5 min
+**Parallelizable with:** Task 16, Task 18
+
+**Files:** Create `.../Server/Grpc/HistorianTagsService.cs`; Modify `Program.cs`; Test `.../Grpc/HistorianTagsServiceTests.cs`
+
+**Steps:** TDD. `BrowseTagNames` (streaming), `GetTagMetadata`, `EnsureTags`/`DeleteTags`/`RenameTags`/`AddTagExtendedProperties` via the seam/pool. Map unsupported tag types (`ProtocolEvidenceMissingException`) → `FailedPrecondition`. Commit: `feat(grpc): HistorianTags service`.
+
+### Task 18: `HistorianStatus` service
+
+**Classification:** small
+**Estimated implement time:** ~4 min
+**Parallelizable with:** Task 16, Task 17
+
+**Files:** Create `.../Server/Grpc/HistorianStatusService.cs`; Modify `Program.cs`; Test `.../Grpc/HistorianStatusServiceTests.cs`
+
+**Steps:** TDD. `Probe`/`GetConnectionStatus`/`GetStoreForwardStatus`/`GetSystemParameter`. Commit: `feat(grpc): HistorianStatus service`.
+
+### Task 19: Galaxy gRPC wiring (consume the shared lib)
+
+**Classification:** small
+**Estimated implement time:** ~3 min
+**Parallelizable with:** Task 16–18
+
+**Files:** Modify `.../Server/Program.cs` (`AddZbGalaxyRepository(config, "Galaxy")` + `MapZbGalaxyRepository()`); Modify `appsettings.json`
+
+**Steps:** Register the shared lib's service + refresh hosted service; add `Galaxy:ConnectionString` config. Run: `dotnet run` + grpcurl `DiscoverHierarchy` against a fake/empty config returns `Unavailable` until cache loads (no live DB needed to prove wiring). Commit: `feat(server): wire shared GalaxyRepository gRPC service`.
+
+### Task 20: API-key auth interceptor + scope resolver
+
+**Classification:** high-risk
+**Estimated implement time:** ~5 min
+**Parallelizable with:** none
+
+**Files:**
+- Create: `.../Server/Security/GatewayGrpcScopeResolver.cs` (maps request type → scope)
+- Create: `.../Server/Security/GatewayGrpcAuthorizationInterceptor.cs`
+- Create: `.../Server/Security/GatewayScopes.cs` (`historian:read|write`, `historian:tags:write`, `galaxy:read`)
+- Modify: `.../Server/Program.cs` (`AddZbApiKeyAuth` + `AddGrpc(o => o.Interceptors.Add<...>())`)
+- Test: `.../tests/.../Security/GrpcAuthorizationTests.cs`
+
+**Steps:**
+1. **Write failing tests:** missing/invalid key → `Unauthenticated`; valid key without the required scope → `PermissionDenied`; valid key with scope → continuation runs. Fake `IApiKeyVerifier`. Run — Expected: FAIL.
+2. Implement modeled on mxaccessgw's `GatewayGrpcAuthorizationInterceptor` + `GatewayGrpcScopeResolver` (switch on request type → scope), using shared `IApiKeyVerifier.VerifyAsync`. Respect a `Disabled` auth mode for dev.
+3. Run: `dotnet test` — Expected: PASS.
+4. Commit: `feat(security): gRPC API-key interceptor + scope enforcement`
+
+---
+
+## Phase 5 — Audit
+
+### Task 21: Canonical SQLite audit writer + actor accessor + wiring
+
+**Classification:** standard
+**Estimated implement time:** ~5 min
+**Parallelizable with:** Task 22 (dashboard auth) after interfaces exist
+
+**Files:**
+- Create: `.../Server/Audit/SqliteAuditWriter.cs` (`IAuditWriter`), `.../Server/Audit/HttpAuditActorAccessor.cs` (`IAuditActorAccessor`)
+- Modify: write services (Tasks 16,17) + interceptor (Task 20) to emit `AuditEvent`s
+- Modify: `.../Server/Program.cs` (`AddZbAudit` + register writer/actor)
+- Test: `.../tests/.../Audit/SqliteAuditWriterTests.cs`
+
+**Steps:**
+1. **Write failing test:** writing an `AuditEvent` persists a row with the canonical 9 fields (`EventId`/`OccurredAtUtc`/`Actor`/`Action`/`Outcome`/`Category`/`Target`/`SourceNode`/`DetailsJson`), domain fields in `DetailsJson`; writer swallows internal errors. Use an in-memory SQLite. Run — Expected: FAIL.
+2. Implement the SQLite writer (table create-if-missing) modeled on MxGateway's audit store; `HttpAuditActorAccessor` reads the Auth principal. Emit audit at tag/value/event writes, API-key admin, login/logout, with `Actor` from the accessor.
+3. Run: `dotnet test` — Expected: PASS.
+4. Commit: `feat(audit): canonical SQLite audit writer + actor wiring`
+
+---
+
+## Phase 6 — Blazor dashboard
+
+### Task 22: Dashboard shell, LDAP cookie auth, login/logout
+
+**Classification:** high-risk
+**Estimated implement time:** ~5 min
+**Parallelizable with:** none
+
+**Files:**
+- Create: `.../Server/Dashboard/Components/{App,Routes,_Imports}.razor`, `Layout/{MainLayout,LoginLayout}.razor`, `Pages/Login.razor`
+- Create: `.../Server/Dashboard/DashboardServiceCollectionExtensions.cs`, `.../Dashboard/DashboardEndpointRouteBuilderExtensions.cs`, `.../Dashboard/DashboardAuthenticator.cs`, `.../Dashboard/DashboardGroupRoleMapper.cs`
+- Modify: `Program.cs` (`AddGatewayDashboard` + `MapRazorComponents<App>` + auth/antiforgery middleware)
+- Test: `.../tests/ZB.MOM.WW.HistorianGateway.Tests/bUnit/LayoutRenderTests.cs`
+
+**Steps:**
+1. **Write failing bUnit test** that `MainLayout` renders `<ThemeShell>` with the nav rail and `LoginCard` renders on the login page. Run — Expected: FAIL.
+2. Port the dashboard shell from mxaccessgw (`App.razor` with `ThemeHead`/`ThemeScripts`, `MainLayout` with `ThemeShell`+`NavRailSection`/`NavRailItem`, `Login.razor` using `LoginCard` posting to `/auth/login`). Wire `AddZbLdapAuth(config,"Ldap")`, cookie auth via `ZbCookieDefaults.Apply`, `IGroupRoleMapper<CanonicalRole>`, `DisableLogin` switch, `IAuditActorAccessor`.
+3. Run: `dotnet test` (bUnit) then `dotnet run` and load `/login` in a browser/curl — Expected: tests PASS; login page renders themed.
+4. Commit: `feat(dashboard): Theme shell + LDAP cookie auth + login`
+
+### Task 23: Status + Health pages
+
+**Classification:** small
+**Estimated implement time:** ~4 min
+**Parallelizable with:** Task 24, Task 25
+
+**Files:** Create `.../Dashboard/Components/Pages/{StatusPage,HealthPage}.razor` (+ a `DashboardStatusService`); Test bUnit render.
+
+**Steps:** TDD bUnit render. Status shows pool state, store-forward queue depth, redundancy members, version (from a status service reading the pool/coordinator). Commit: `feat(dashboard): status + health pages`.
+
+### Task 24: Galaxy browser page
+
+**Classification:** small
+**Estimated implement time:** ~5 min
+**Parallelizable with:** Task 23, Task 25
+
+**Files:** Create `.../Dashboard/Components/Pages/GalaxyBrowserPage.razor` + tree node view (port mxaccessgw `BrowsePage`/`BrowseTreeNodeView`, read-only, no add-tag); Test bUnit.
+
+**Steps:** TDD bUnit render against the shared lib's cache. Commit: `feat(dashboard): read-only Galaxy browser`.
+
+### Task 25: Historian console page (query + role-gated write test)
+
+**Classification:** standard
+**Estimated implement time:** ~5 min
+**Parallelizable with:** Task 23, Task 24
+
+**Files:** Create `.../Dashboard/Components/Pages/HistorianConsolePage.razor` (+ `DashboardHistorianService` calling the seam/pool); Test bUnit.
+
+**Steps:** TDD bUnit. Query form (tag, time range, raw/aggregate + mode picker) renders results; write-test panel (historical value insert / event send) visible only to Engineer+ roles via `AuthorizeView`. Commit: `feat(dashboard): historian query + role-gated write console`.
+
+### Task 26: API-key admin page
+
+**Classification:** standard
+**Estimated implement time:** ~5 min
+**Parallelizable with:** Task 23–25
+
+**Files:** Create `.../Dashboard/Components/Pages/ApiKeysPage.razor` (+ `DashboardApiKeyManagementService` over the shared ApiKeys store); Test bUnit.
+
+**Steps:** TDD bUnit. List/create (show secret once)/revoke keys with scope selection. Commit: `feat(dashboard): API-key admin`.
+
+---
+
+## Phase 7 — Telemetry meters + Health probes
+
+### Task 27: App meters
+
+**Classification:** small
+**Estimated implement time:** ~4 min
+**Parallelizable with:** Task 28
+
+**Files:** Create `.../Server/Observability/GatewayMetrics.cs`; Modify services/coordinator/pool to record; Modify `Program.cs` (`o.Meters=[GatewayMetrics.MeterName]`); Test `.../Observability/GatewayMetricsTests.cs`.
+
+**Steps:** TDD with `MeterListener`. Counters/histograms: read/write counts + latency, store-forward queue depth (observable gauge), pool connection state, redundancy ack outcomes. Commit: `feat(obs): gateway meters`.
+
+### Task 28: Health probes
+
+**Classification:** small
+**Estimated implement time:** ~4 min
+**Parallelizable with:** Task 27
+
+**Files:** Create `.../Server/Health/{HistorianConnectionHealthCheck,StoreForwardDrainHealthCheck}.cs`; Modify `Program.cs` (`AddHealthChecks` with `GrpcDependencyHealthCheck` for historian, SQL checks for Galaxy + Runtime DB, custom checks, tagged `ZbHealthTags.Ready`); Test health-check unit tests.
+
+**Steps:** TDD. Probes flip Unhealthy when a dependency is down (fake deps). Commit: `feat(health): historian/galaxy/runtime-db/store-forward probes`.
+
+---
+
+## Phase 8 — Integration, docs, repo
+
+### Task 29: Env-gated live integration tests
+
+**Classification:** standard
+**Estimated implement time:** ~5 min
+**Parallelizable with:** none
+
+**Files:** Create `.../tests/.../Integration/{HistorianRoundTripTests,GalaxyBrowseTests}.cs`
+
+**Steps:** Gated on `HISTORIAN_GRPC_HOST`/`HISTORIAN_GRPC_WRITE_SANDBOX_TAG` and a Galaxy SQL connection env var; `Skip` when absent. Cover read→write→read-back via the self-cleaning sandbox-tag lifecycle and a Galaxy `DiscoverHierarchy`. Run `dotnet test` (skips locally). Commit: `test: env-gated live integration`.
+
+### Task 30: Full-suite green gate + smoke
+
+**Classification:** small
+**Estimated implement time:** ~3 min
+**Parallelizable with:** none
+
+**Steps:** Run `dotnet build ZB.MOM.WW.HistorianGateway.slnx` + `dotnet test` (whole solution) on macOS with no live env — Expected: ALL green, live tests skipped. `dotnet run` + curl `/healthz` (200), `/metrics` (text), grpcurl `HistorianStatus/Probe`. Fix any gaps. Commit: `chore: green gate + smoke`.
+
+### Task 31: CLAUDE.md + README + gitea remote + scadaproj index
+
+**Classification:** small
+**Estimated implement time:** ~5 min
+**Parallelizable with:** none
+
+**Files:** Create `~/Desktop/HistorianGateway/{CLAUDE.md,README.md}`; copy the two design/plan docs into its `docs/plans/`; Modify `~/Desktop/scadaproj/CLAUDE.md` (index the new sidecar + note the GalaxyRepository follow-on for mxaccessgw).
+
+**Steps:**
+1. Write `CLAUDE.md` (overview, build/run/test commands, the no-COM single-process note, the vendored-histsdk + shared-GalaxyRepository dependencies, config sections, env vars) and `README.md`.
+2. Create the gitea repo `historiangw` and push: `git -C ~/Desktop/HistorianGateway remote add origin https://gitea.dohertylan.com/dohertj2/historiangw.git && git push -u origin main` (confirm remote name/visibility with the user first).
+3. Update scadaproj's umbrella `CLAUDE.md` runtime/implementation table with the new project row; commit scadaproj separately.
+4. Commit: `docs: CLAUDE.md + README; index in scadaproj`.
+
+---
+
+## Dependency summary (for parallel dispatch)
+
+- **Foundational, no blockers:** Task 1 (galaxy lib scaffold), Task 7 (vendor histsdk), Task 8 (repo init) — Task 8 consumes Task 7's tree.
+- **Galaxy lib chain:** 2→3→4→5→6 (sequential; share files).
+- **Sidecar chain:** 8→9→10→11→12→13→14, then gRPC services 15→(16,17,18 parallel),19, then 20, then 21.
+- **Dashboard:** 22→(23,24,25,26 parallel) after Task 20 (auth) + Task 13/14 (data) + Task 5/19 (galaxy).
+- **Obs:** 27,28 parallel after Task 14.
+- **Close-out:** 29→30→31 after everything.
+
+## Notes / non-goals (from design §9)
+- No `AddS2` live streaming-sample writes (GATED) — live values only via SQL `WriteLiveValues`.
+- No two-process/x86 worker (no COM).
+- mxaccessgw adopting `ZB.MOM.WW.GalaxyRepository` is a tracked follow-on, NOT in this plan.
@@ -0,0 +1,37 @@
+{
+  "planPath": "docs/plans/2026-06-23-historian-gateway-implementation.md",
+  "tasks": [
+    {"id": 1, "subject": "Task 1: Scaffold the GalaxyRepository lib project", "status": "pending"},
+    {"id": 2, "subject": "Task 2: Port the canonical galaxy_repository.proto (neutral namespace)", "status": "pending", "blockedBy": [1]},
+    {"id": 3, "subject": "Task 3: Port the SQL browse provider", "status": "pending", "blockedBy": [2]},
+    {"id": 4, "subject": "Task 4: Port the in-memory hierarchy cache + snapshot + refresh service", "status": "pending", "blockedBy": [3]},
+    {"id": 5, "subject": "Task 5: Port the reusable gRPC service + DI extension", "status": "pending", "blockedBy": [4]},
+    {"id": 6, "subject": "Task 6: Unit tests for projector/cache; pack 0.1.0", "status": "pending", "blockedBy": [5]},
+    {"id": 7, "subject": "Task 7: Vendor histsdk AVEVA.Historian.Client + golden tests", "status": "pending"},
+    {"id": 8, "subject": "Task 8: Init sidecar repo + solution + Directory.Build.props", "status": "pending", "blockedBy": [7]},
+    {"id": 9, "subject": "Task 9: Contracts project + historian_gateway.proto skeleton", "status": "pending", "blockedBy": [8]},
+    {"id": 10, "subject": "Task 10: Server project + minimal boot (telemetry/serilog/health)", "status": "pending", "blockedBy": [9, 7, 6]},
+    {"id": 11, "subject": "Task 11: Configuration options + validators + ConfigPreflight", "status": "pending", "blockedBy": [10]},
+    {"id": 12, "subject": "Task 12: IHistorianClient seam over vendored client", "status": "pending", "blockedBy": [10]},
+    {"id": 13, "subject": "Task 13: Connection pool (pre-authenticated, reused)", "status": "pending", "blockedBy": [12]},
+    {"id": 14, "subject": "Task 14: Write coordinator (store-forward + redundancy) + SQL live-write", "status": "pending", "blockedBy": [13]},
+    {"id": 15, "subject": "Task 15: HistorianRead service + proto mapper", "status": "pending", "blockedBy": [13]},
+    {"id": 16, "subject": "Task 16: HistorianWrite service", "status": "pending", "blockedBy": [14, 15]},
+    {"id": 17, "subject": "Task 17: HistorianTags service", "status": "pending", "blockedBy": [13, 15]},
+    {"id": 18, "subject": "Task 18: HistorianStatus service", "status": "pending", "blockedBy": [13, 15]},
+    {"id": 19, "subject": "Task 19: Galaxy gRPC wiring (consume shared lib)", "status": "pending", "blockedBy": [10, 5]},
+    {"id": 20, "subject": "Task 20: API-key auth interceptor + scope resolver", "status": "pending", "blockedBy": [15]},
+    {"id": 21, "subject": "Task 21: SQLite audit writer + actor accessor + wiring", "status": "pending", "blockedBy": [16, 17, 20]},
+    {"id": 22, "subject": "Task 22: Dashboard shell + LDAP cookie auth + login", "status": "pending", "blockedBy": [20]},
+    {"id": 23, "subject": "Task 23: Status + Health pages", "status": "pending", "blockedBy": [22, 14]},
+    {"id": 24, "subject": "Task 24: Galaxy browser page", "status": "pending", "blockedBy": [22, 19]},
+    {"id": 25, "subject": "Task 25: Historian console page (role-gated write)", "status": "pending", "blockedBy": [22, 15]},
+    {"id": 26, "subject": "Task 26: API-key admin page", "status": "pending", "blockedBy": [22]},
+    {"id": 27, "subject": "Task 27: App meters", "status": "pending", "blockedBy": [14]},
+    {"id": 28, "subject": "Task 28: Health probes", "status": "pending", "blockedBy": [14, 19]},
+    {"id": 29, "subject": "Task 29: Env-gated live integration tests", "status": "pending", "blockedBy": [16, 17, 18, 19]},
+    {"id": 30, "subject": "Task 30: Full-suite green gate + smoke", "status": "pending", "blockedBy": [21, 26, 27, 28, 29]},
+    {"id": 31, "subject": "Task 31: CLAUDE.md + README + gitea remote + scadaproj index", "status": "pending", "blockedBy": [30]}
+  ],
+  "lastUpdated": "2026-06-23"
+}
@@ -0,0 +1,377 @@
+# MES and Delmia-DNC integrations — API & MXAccess write specification
+
+Documents two existing Wonderware integrations hosted on the `ZimmerBiomet` Gitea org
+(`http://wonder-app-vd03.zmr.zimmer.com:3000`):
+
+| Integration | Repo | What it does | Who does the MXAccess write |
+|---|---|---|---|
+| **MES** | [`ZimmerBiomet/MESAPI`](http://wonder-app-vd03.zmr.zimmer.com:3000/ZimmerBiomet/MESAPI) (solution `WWSupport`) | REST API the Camstar MES calls to move-in / move-out work orders against a machine, and to read machine alarm status | **The service itself** (`MesNotifier`, in-repo) |
+| **Delmia DNC** | [`ZimmerBiomet/DelmiaIntegration`](http://wonder-app-vd03.zmr.zimmer.com:3000/ZimmerBiomet/DelmiaIntegration) | Pull an NC/recipe document from the DELMIA/Apriso (Intercim) DNC server and push the resulting recipe-download notification into Wonderware | **An external receiver service** at `wonder-app-vd01:9001/notify`; the actual flag handshake is implemented in the Galaxy `$DelmiaReceiver` object (`ProcessRecipe`/`Reset` scripts) — *not* in this repo |
+
+Both integrations talk to AVEVA System Platform ("Galaxy") through **MXAccess COM**
+(`ArchestrA.MxAccess.LMXProxyServerClass`) and use the same general pattern:
+
+> **Handshake pattern** — read a *ready* flag → write the data tags → set a *trigger* flag
+> → wait (bounded by a timeout) for a *complete* flag → read a *success* flag + *error text*
+> → return the result and unsubscribe.
+
+All facts below are taken verbatim from source at the repo `master` branch (cloned
+2026-06-17) unless explicitly marked **(inferred)**.
+
+---
+
+## 1. MES integration — `MESAPI` / `WWSupport`
+
+### 1.1 Topology & hosting
+
+```
+Camstar MES  ──HTTPS/JSON──▶  WWSupport API (ServiceStack self-host)
+                                  │  ├─ SQL Server "BT" (machine lookup by SAPID, alarm catalog)
+                                  │  └─ MXAccess COM (LMXProxyServerClass, client "MesNotifier")
+                                  ▼
+                          Galaxy object  {MachineCode}.MesReceiver.*   (move-in / move-out tags)
+                          Galaxy object  {MachineCode}.{AlarmName}.*   (alarm attributes)
+```
+
+- **Framework:** ServiceStack, self-hosted via `AppSelfHostBase` (`AppHost : base("APIServer", typeof(MesServices).Assembly)`), .NET Framework, run as a Windows service.
+- **Listen URL (per environment, `App.config` → `HttpListener`):**
+  - DEV `http://*:9501/`  · QA `http://*:9500/`  · PROD `http://*:9500/`
+- **Database (`App.config` → connection `BatchDB`, DB `BT`):**
+  - DEV `wonder-sql-vd01.zmr.zimmer.com` · QA `wondersqlqa.zmr.zimmer.com` · PROD (same form). User `wonderapp`.
+- **Auth:** every operation is decorated `[Authenticate]` + `[RequiredRole("MESAPI")]` (`MesServices.cs`).
+  `AppHost` registers an `AuthFeature` with two providers: `ApiKeyAuthProvider` and `LdapAuthProvider`.
+  - Unauthenticated → **401**; authenticated without the `MESAPI` role → **403**.
+- **Serialization:** `JsConfig.IncludeNullValues = true` (null fields ARE emitted in JSON). `PostmanFeature` + `OpenApiFeature` (Swagger) are enabled.
+- **MES counterpart object:** the live Galaxy attribute listing for the receiver object is in
+  [`mesrec.md`](mesrec.md) (`$MESReceiver` template). Note the API binds tags under the contained
+  name `MesReceiver` (i.e. `{MachineCode}.MesReceiver.<tag>`).
+
+### 1.2 Endpoints (inputs / outputs)
+
+Routes come from `[Route(...)]` on the request DTOs; all are **POST**, JSON in / JSON out, handled by `MesServices.Any(...)` which resolves a per-request `MesNotifier`.
+
+#### `POST /mes/movein` → `MoveInResponse`
+
+Request `MoveInRequest`:
+
+| Field | Type | Notes |
+|---|---|---|
+| `SAPID` | string | machine key; looked up in `BT.Machine` to get `Machine.Code` |
+| `OperatorName` | string | |
+| `JobSequenceNumber` | string | |
+| `WorkOrders` | `List<WorkOrderInfo>` | each = `{ WorkOrderNumber: string, PartNumber: string }` |
+
+Response `MoveInResponse`: `WasSuccessful` (bool), `ErrorText` (string), `BatchID` (int?, only set if machine returns non-zero).
+
+#### `POST /mes/moveout` → `MoveOutResponse`
+
+Request `MoveOutRequest`: `SAPID` (string), `OperatorName` (string), `WorkOrders` (`List<WorkOrderInfo>`).
+*(Move-out has no `JobSequenceNumber`.)*
+Response `MoveOutResponse`: identical shape to `MoveInResponse` (`WasSuccessful`, `ErrorText`, `BatchID`).
+
+#### `POST /mes/alarmstatus` → `AlarmStatusResponse`
+
+Request `AlarmStatusRequest`:
+- `MachineFilter` = `{ MachineID: int?, SAPID: string, ZTag: string, Code: string }` (any one identifies the machine)
+- `AlarmFilter` = `{ NameFilter: string, MinSeverity: int?, MaxSeverity: int?, IncludeTriggered: bool=true, IncludeAcked: bool=true, FlaggedOnly: bool=false }`
+
+#### `POST /mes/simplealarmstatus` → `AlarmStatusResponse`
+
+Request `SimpleAlarmStatusRequest`: `SAPID` (string). Internally loads only alarms with `FlaggedForMES == true` for that machine.
+
+Response `AlarmStatusResponse` (both alarm endpoints): `WasSuccessful` (bool), `ErrorText` (string), `Alarms` (`List<AlarmInfo>`).
+
+`AlarmInfo`: `Name` (string), `HierarchicalName` (string, `{Code}.{AlarmName}`), `Description` (string), `IsFlaggedForMES` (bool), `Severity` (int), `StatusCode` (string — `"Triggered"` or `"Triggered.Acked"`), `TriggeredDT` (DateTime), `AckDT` (DateTime?), `AckComment` (string).
+
+### 1.3 MXAccess connection model
+
+`MesNotifier` owns one MXAccess proxy for the request:
+
+```csharp
+_lmxProxy  = new ArchestrA.MxAccess.LMXProxyServerClass();
+_lmxHandle = _lmxProxy.Register("MesNotifier");
+_lmxProxy.OnDataChange    += ...;   // value updates resolve pending read/OnValue tasks
+_lmxProxy.OnWriteComplete += ...;   // write acks resolve pending write tasks
+```
+
+Tags are added with `AddItem` + `AdviseSupervisory` (subscribe), updated via `OnDataChange`,
+and removed with `UnAdvise` + `RemoveItem` on cleanup. Reads/writes are wrapped as `Task<bool>`
+that complete on the corresponding callback or **fail (`false`) on cancellation/timeout**.
+A read is considered valid only if MXAccess **quality == 192** ("good").
+
+**Target selection:** request `SAPID` → `db.Single<Machine>(x => x.SAPID == SAPID)` → `Machine.Code`
+becomes the tag prefix. Move tags live under `{Code}.MesReceiver.*`; alarm tags under
+`{Code}.{MachineAlarm.Name}.*` (alarm catalog from `db.Select<MachineAlarm>(...)`).
+
+### 1.4 Tag mappings
+
+**Move-in** (`MesMoveInTagset`, all `{Code}.MesReceiver.<tag>`):
+
+| Tag | Type | Dir | Role | Source field |
+|---|---|---|---|---|
+| `MoveInReadyFlag` | bool | read | gate — must be `true` before writing | — |
+| `MoveInFlag` | bool | **write** | **trigger** — set `true` last | — |
+| `MoveInCompleteFlag` | bool | read | completion — handshake waits on this | — |
+| `MoveInSuccessfulFlag` | bool | read | result | → `response.WasSuccessful` |
+| `MoveInErrorText` | string | read | result | → `response.ErrorText` |
+| `MoveInBatchID` | int | read | result | → `response.BatchID` (if ≠ 0) |
+| `MoveInOperatorName` | string | write | data | `request.OperatorName` |
+| `MoveInJobSequenceNumber` | string | write | data | `request.JobSequenceNumber` |
+| `MoveInNumberWorkOrders` | int | write | data | `request.WorkOrders.Count` |
+| `MoveInWorkOrderNumbers[]` | string[] | write | data (fixed length 50) | `WorkOrders.Select(w => w.WorkOrderNumber)` |
+| `MoveInPartNumbers[]` | string[] | write | data (fixed length 50) | `WorkOrders.Select(w => w.PartNumber)` |
+
+**Move-out** (`MesMoveOutTagset`): identical set with `MoveOut` prefix, **minus** `JobSequenceNumber`
+(`MoveOutReadyFlag`, `MoveOutFlag`, `MoveOutCompleteFlag`, `MoveOutSuccessfulFlag`, `MoveOutErrorText`,
+`MoveOutBatchID`, `MoveOutOperatorName`, `MoveOutNumberWorkOrders`, `MoveOutWorkOrderNumbers[]`, `MoveOutPartNumbers[]`).
+
+**Alarms** (`AlarmTagset`, all `{Code}.{AlarmName}.<attr>`): `Quality` (int), `InAlarm` (bool),
+`TimeAlarmOn` (DateTime), `DescAttrName` (string), `Acked` (bool), `TimeAlarmAcked` (DateTime?), `AckMsg` (string).
+
+### 1.5 The handshake — `MesNotifier.MoveIn` (move-out is identical with `MoveOut*` tags)
+
+Whole operation is bounded by **`new CancellationTokenSource(30000)` = 30 s**.
+
+1. **Look up machine** by `SAPID`. Not found → `WasSuccessful=false`, `ErrorText="Failed to find machine with SAPID '{SAPID}'"`, return.
+2. **Subscribe** to every move-in tag (`Advise(t, cts)`), `await Task.WhenAll(...)`. Any subscription that fails / quality ≠ 192 → `ErrorText="Failed to connect to machine"`.
+3. **Check ready flag:** `if (!MoveInReadyFlag.Value)` → `ErrorText="Machine move in ready flag not set to true"`, stop.
+4. **Arm completion watch:** `Task<bool> flagTask = MoveInCompleteFlag.OnValue(true, cts);` (completes when the flag goes `true`, or `false` on the 30 s timeout).
+5. **Write data + trigger (in parallel, trigger last):** `MoveInOperatorName`, `MoveInJobSequenceNumber`, `MoveInNumberWorkOrders`, `MoveInPartNumbers[]` (padded to 50), `MoveInWorkOrderNumbers[]` (padded to 50), then `MoveInFlag = true`. `await Task.WhenAll(writeTasks)`; any write `!= true` → `ErrorText="Failed to write move in information to machine"`.
+6. **Wait for completion:** `await Task.WhenAll(flagTask)`.
+   - `flagTask.Result == true` → read results: `WasSuccessful = MoveInSuccessfulFlag.Value`, `ErrorText = MoveInErrorText.Value`, `BatchID = MoveInBatchID.Value` (if ≠ 0).
+   - `flagTask.Result == false` (timed out) → `WasSuccessful=false`, `ErrorText="Timeout waiting for move in information to be processed"`.
+7. **Cleanup:** `Tags.ForEach(Unadvise)` and return.
+
+```csharp
+using (var cts = new CancellationTokenSource(30000)) {                 // 30 s budget
+    ...
+    if (!moveInTagset.MoveInReadyFlag.Value) { /* not-ready error */ }
+    var flagTask = moveInTagset.MoveInCompleteFlag.OnValue(true, cts);  // arm completion watch
+    var writeTasks = new List<Task<bool>> {
+        Write(moveInTagset.MoveInOperatorName.Handle,       request.OperatorName, cts),
+        Write(moveInTagset.MoveInJobSequenceNumber.Handle,  request.JobSequenceNumber, cts),
+        Write(moveInTagset.MoveInNumberWorkOrders.Handle,   request.WorkOrders.Count, cts),
+        Write(moveInTagset.MoveInPartNumbers.Handle,        request.WorkOrders.Select(wo => wo.PartNumber).ToFixedLength(50), cts),
+        Write(moveInTagset.MoveInWorkOrderNumbers.Handle,   request.WorkOrders.Select(wo => wo.WorkOrderNumber).ToFixedLength(50), cts),
+        Write(moveInTagset.MoveInFlag.Handle, true, cts)               // TRIGGER — set last
+    };
+    await Task.WhenAll(writeTasks);
+    await Task.WhenAll(flagTask);
+    if (flagTask.Result) {
+        response.WasSuccessful = moveInTagset.MoveInSuccessfulFlag.Value;
+        response.ErrorText     = moveInTagset.MoveInErrorText.Value;
+        if (moveInTagset.MoveInBatchID.Value != 0) response.BatchID = moveInTagset.MoveInBatchID.Value;
+    } else {
+        response.WasSuccessful = false;
+        response.ErrorText = "Timeout waiting for move in information to be processed";
+    }
+    moveInTagset.Tags.ForEach(Unadvise);
+}
+```
+
+> There is **no busy-poll loop**: completion is event-driven via the MXAccess `OnDataChange`
+> callback; the 30 s `CancellationTokenSource` is the only timeout.
+
+### 1.6 Alarm-status path
+
+1. Resolve machine from `MachineFilter` (`SAPID` / `Code` / `ZTag` / `MachineID`) — wrong/missing → error.
+2. Load `MachineAlarm` rows for the machine; apply filters (`FlaggedOnly`, `MinSeverity`, `MaxSeverity`, case-insensitive `NameFilter.Contains`). *(`IncludeTriggered` is read but not used in the filter.)*
+3. Subscribe + read each alarm's `Quality` and `InAlarm` (30 s budget). Bad quality / read failure → `ErrorText="Failed to read machine alarm status"`.
+4. For alarms where `InAlarm == true`, additionally read `TimeAlarmOn`, `DescAttrName`, `Acked`, `TimeAlarmAcked`, `AckMsg`.
+5. Build `AlarmInfo` per triggered alarm; `StatusCode = "Triggered.Acked"` if acked else `"Triggered"`. If `AlarmFilter.IncludeAcked == false`, acked alarms are skipped.
+6. Unsubscribe; on failure `Alarms` is cleared.
+
+### 1.7 Outputs / error handling (MES)
+
+- **Transport status is always 200** for handled responses — success/failure is carried by the body's `WasSuccessful` flag + `ErrorText`. (401/403 only from the auth layer.)
+- Success: `{ "WasSuccessful": true, "ErrorText": null, "BatchID": <int|null> }`.
+- Failure/timeout: `{ "WasSuccessful": false, "ErrorText": "<message>", "BatchID": null }`.
+- Distinct `ErrorText` values: machine-not-found, "Failed to connect to machine", "…ready flag not set to true", "Failed to write … to machine", "Timeout waiting for … to be processed", "Failed to read machine alarm status".
+
+---
+
+## 2. Delmia-DNC integration — `DelmiaIntegration` (+ Galaxy `$DelmiaReceiver`)
+
+### 2.1 Topology — three hops
+
+```
+Operator (DelmiaIntegration.exe WinForms)
+  │  ① DelmiaClient  ──HTTP POST (form-url-encoded)──▶  DELMIA/Apriso DNC "Downloader.asmx"
+  │                                                       (e.g. http://dnc-app-vd01.zmr.zimmer.com/IntercimService/Downloader.asmx)
+  │     ◀── XML (SearchResults / DownloadResult, ns http://intercim.com/ruleset) ──
+  │  ② recipe file written to disk; WWNotifier.exe launched with CLI args
+  ▼
+WWNotifier.exe  ──HTTP POST (JSON RecipeDownload)──▶  WW receiver service  (http://wonder-app-vd01:9001/notify)
+                 ◀── JSON RecipeDownloadResult ──                            │  ③ MXAccess COM write
+                                                                             ▼
+                                          Galaxy object  {machine}.$DelmiaReceiver.*  (recipe tags + flags)
+                                          + ArchestrA scripts ProcessRecipe / Reset
+```
+
+**Assemblies in the repo:** `DelmiaContracts` (XML DTO library), `DelmiaIntegration` (`DelmiaClient` + WinForms UI),
+`WWNotifier.exe` (console notifier), plus test harnesses (`AdminTestUtil`, `DownloadTestUtil`, `TestUI`).
+
+> **Scope note.** Hops ① and ② are fully in this repo. Hop ③ — the service at `:9001/notify`
+> that actually performs the MXAccess write — is **not** in the `ZimmerBiomet` Gitea org; only the
+> JSON contract (below) and the Galaxy-side `$DelmiaReceiver` object (scripts + attributes, exported
+> under `AA_EXPORT/`) are available. `WWNotificationSystem` *also* uses MXAccess but is an unrelated
+> tag→email alerting service (port `:9876`, client name `WWNotifierMonitor`) — **not** the recipe receiver.
+
+### 2.2 DNC server interface (`DelmiaClient`, hop ①)
+
+- **Transport:** `HttpClient.PostAsync` with `FormUrlEncodedContent`; response is XML deserialized
+  with `XmlSerializer`. Base URL is `DelmiaClient.URL`; per-call `Timeout` default **30 s**.
+  Action is appended to the base URL (`URL.TrimEnd('/') + "/<Action>"`).
+- **Base URL (from `AdminTestUtil` `DefaultURL`):** `http://dnc-app-vd01.zmr.zimmer.com/IntercimService/Downloader.asmx`.
+- On any exception the client returns a result object with the error in `ErrorMessage` /
+  `TransferSuccessful=false` (it does not throw to the caller).
+
+| Method (sync + `…Async`) | POST action | Form fields | Returns |
+|---|---|---|---|
+| `Search` | `/Search` | `username, machineID, partNumber, operationNumber` | `SearchResults` |
+| `RequestProvenDocument` | `/RequestProvenDocument` | `username, machineID, partNumber, operationNumber, workOrderNumber` | `DownloadResult` |
+| `RequestDocument` | `/RequestDocument` | `username, machineID, partNumber, operationNumber, workOrderNumber, documentKey` | `DownloadResult` |
+
+DTO field lists (`DelmiaContracts`, XML namespace `http://intercim.com/ruleset`):
+
+- **`SearchResults`**: `Results` (`List<SearchResult>`), `ErrorMessage` (string).
+- **`SearchResult`**: `ShopOrderKey` (int), `ShopOrderID` (string), `ShopOrderStatus` (string),
+  `ShopOrderOperKey` (int), `ShopOrderOperID` (string), `ShopOrderOperStatus` (string),
+  `DocumentKey` (int), `DocumentObjectID` (int, with `…Specified` flag), `DocumentName` (string),
+  `DocumentRev` (string), `DocumentStatus` (string), `DocumentURL` (string), `PartID` (string), `PartRev` (string).
+- **`DownloadResult`**: `UserKey` (int), `UserName` (string), `UserSite` (string), `MachineKey` (int),
+  `MachineID` (string), `MachineSite` (string), `WorkOrderNumber` (string), `ShopOrderKey` (int),
+  `ShopOrderID` (string), `ShopOrderStatus` (string), `ShopOrderOperKey` (int), `ShopOrderOperID` (string),
+  `ShopOrderOperStatus` (string), `DocumentKey` (int), `DocumentName` (string), `DocumentRev` (string),
+  `DocumentStatus` (string), `PartID` (string), `PartRev` (string), **`TransferSuccessful` (bool)**,
+  **`ErrorMessage` (string)**.
+- **`MachineInfo`** (contract present; not called by current code): `MachineKey` (int), `MachineID` (string),
+  `MachineName` (string), `DownloadPath` (string), `MachineDescription` (string), `MachineSite` (string), `MachineStatus` (string).
+- **`UserInfo`**: `UserKey` (int), `UserName` (string), `UserSite` (string), `IsActive` (bool).
+
+**Recipe file:** the downloaded document is a key/value recipe file parsed by `DelmiaIntegration/Models/RecipeSet.cs`
+(`KEY,VALUE` lines; typed accessors `GetString/GetInt/GetBool/GetFloat/GetDouble/...`). It is written to disk;
+its path is what gets handed to `WWNotifier` (`--downloadpath`).
+
+### 2.3 WWNotifier (hop ②) — invocation & handoff contract
+
+`WWNotifier.exe` (uses `CommandLineParser`); CLI options (`CommandLineOptions`):
+
+| Short | Long | Required | Field |
+|---|---|---|---|
+| `-d` | `--downloadpath` | yes | `DownloadPath` (recipe file path) |
+| `-m` | `--machine` | yes | `MachineCode` |
+| `-w` | `--workorder` | yes | `WorkOrderNumber` |
+| `-p` | `--partnumber` | yes | `PartNumber` |
+| `-s` | `--seqop` | no | `JobStepNumber` |
+| `-u` | `--username` | no | `Username` |
+
+Config (`WWNotifier/App.config`): `NotifyURL = http://wonder-app-vd01.zmr.zimmer.com:9001/notify`
+(comma-separated list allowed — tried in order until one succeeds), `NotifyTimeout = 30` (seconds,
+applied as the global Flurl HTTP timeout).
+
+Handoff (Flurl): `url.PostJsonAsync(recipeDownload).ReceiveJson<RecipeDownloadResult>()`.
+
+- **Request body `RecipeDownload`** (JSON): `MachineCode`, `DownloadPath`, `WorkOrderNumber`, `PartNumber`, `JobStepNumber`, `Username` (all string).
+- **Response body `RecipeDownloadResult`** (JSON): `Result` (bool), `ResultText` (string).
+- **Outputs:** prints `YES` and exit code `0` on success; prints `NO` + a message and sets exit code `-1`
+  on failure (parse error, missing `NotifyURL`/`NotifyTimeout`, `Result==false`, or HTTP exception).
+  *(Caveat: on a caught exception it logs `error.InnerException.Message`, which throws a NRE when there is no inner exception — so bare transport errors surface only as a generic failure.)*
+
+### 2.4 MXAccess write — Galaxy `$DelmiaReceiver` object (hop ③)
+
+The receiver service maps `RecipeDownload` fields onto the `$DelmiaReceiver` object instance selected by
+`MachineCode`. Object attributes (from `AA_EXPORT/.../$DelmiaReceiver` export) and their roles:
+
+| Attribute | Type | Role | Maps from |
+|---|---|---|---|
+| `ReadyFlag` | Boolean | gate — receiver expects `true` before writing | — |
+| `DownloadPath` | String | data | `RecipeDownload.DownloadPath` |
+| `WorkOrderNumber` | String | data | `RecipeDownload.WorkOrderNumber` |
+| `PartNumber` | String | data | `RecipeDownload.PartNumber` |
+| `JobStepNumber` | String | data | `RecipeDownload.JobStepNumber` |
+| `Username` | String | data | `RecipeDownload.Username` |
+| `RecipeDownloadFlag` | Boolean | **trigger** — set `true` to start processing | — |
+| `RecipeProcessedFlag` | Boolean | completion — handshake waits on this | — |
+| `RecipeProcessResult` | Boolean | result | → `RecipeDownloadResult.Result` |
+| `RecipeProcessResultText` | String | result | → `RecipeDownloadResult.ResultText` |
+
+*(`MachineCode` selects which receiver instance; it is not itself a written attribute.)*
+
+**Galaxy-side handshake (authoritative — ArchestrA scripts on `$DelmiaReceiver`):**
+
+`ProcessRecipe` (runs when `RecipeDownloadFlag` is set):
+```
+Me.RecipeDownloadFlag = false;      ' clear trigger
+Me.ReadyFlag          = false;      ' clear ready
+try
+    Me.RecipeProcessResult     = true;
+    Me.RecipeProcessResultText = "Success";
+catch
+    Me.RecipeProcessResult     = false;
+    Me.RecipeProcessResultText = "Failed to read recipe file";
+endtry;
+Me.RecipeProcessedFlag = true;      ' signal completion
+```
+
+`Reset` (clears the slot for the next download):
+```
+Me.RecipeDownloadFlag = false; Me.RecipeProcessedFlag = false;
+Me.RecipeProcessResult = false; Me.RecipeProcessResultText = "";
+Me.DownloadPath = ""; Me.WorkOrderNumber = ""; Me.PartNumber = "";
+Me.JobStepNumber = ""; Me.Username = "";
+```
+
+**Receiver-side sequence (inferred** — mirrors the MES handshake and is driven by the flags above; the C# source is not in the repo**):**
+1. resolve the `$DelmiaReceiver` instance from `MachineCode`;
+2. (optionally) verify `ReadyFlag == true`;
+3. write `DownloadPath`, `WorkOrderNumber`, `PartNumber`, `JobStepNumber`, `Username`;
+4. set `RecipeDownloadFlag = true` (trigger) → Galaxy `ProcessRecipe` fires;
+5. wait for `RecipeProcessedFlag == true`, bounded by the request timeout;
+6. read `RecipeProcessResult` → `Result`, `RecipeProcessResultText` → `ResultText`; return the `RecipeDownloadResult` JSON;
+7. `Reset` the object.
+
+### 2.5 Outputs / error handling (Delmia)
+
+- **DNC server call:** failures are swallowed into the returned DTO — `SearchResults.ErrorMessage`, or
+  `DownloadResult.TransferSuccessful=false` + `ErrorMessage="Failed to call Delmia web service at '<URL>'."`.
+- **Notify handoff:** `RecipeDownloadResult.Result` (bool) + `ResultText` (string); `WWNotifier` exit code
+  `0` (`YES`) / `-1` (`NO`).
+- **Galaxy script:** `RecipeProcessResultText` is `"Success"` or `"Failed to read recipe file"`.
+
+---
+
+## 3. Side-by-side summary
+
+| | MES (`MESAPI`) | Delmia DNC (`DelmiaIntegration`) |
+|---|---|---|
+| Caller | Camstar MES (HTTP/JSON) | Operator UI → DELMIA DNC server, then WWNotifier |
+| API style | ServiceStack REST, `POST /mes/*` | DNC = form-url-encoded → XML; notify = JSON POST |
+| Who writes MXAccess | the service (`MesNotifier`, in-repo) | external `:9001/notify` receiver (source not in repo) |
+| MXAccess client | `LMXProxyServerClass`, register `"MesNotifier"` | `LMXProxyServerClass` (receiver), Galaxy `$DelmiaReceiver` scripts |
+| Target object | `{MachineCode}.MesReceiver.*` | `{MachineCode}.$DelmiaReceiver` instance |
+| Ready / trigger / complete | `MoveInReadyFlag` / `MoveInFlag` / `MoveInCompleteFlag` | `ReadyFlag` / `RecipeDownloadFlag` / `RecipeProcessedFlag` |
+| Result / error | `MoveInSuccessfulFlag` / `MoveInErrorText` (+`MoveInBatchID`) | `RecipeProcessResult` / `RecipeProcessResultText` |
+| Timeout | 30 s (`CancellationTokenSource(30000)`), event-driven | 30 s HTTP (`NotifyTimeout`); Galaxy wait at receiver |
+
+---
+
+## 4. Sources & open gaps
+
+**Repos (Gitea `ZimmerBiomet`, `master`):**
+- MES: `MESAPI` — `APIServer.ServiceInterface/MesServices.cs`, `MesNotifier.cs`,
+  `Mes{MoveIn,MoveOut}Tagset.cs`, `AlarmTagset.cs`, `Tag.cs`/`OnValueTask.cs`;
+  `APIServer.ServiceModel/Types/*`; `APIServer/AppHost.cs`, `App.config`.
+- Delmia: `DelmiaIntegration` — `DelmiaIntegration/DelmiaClient.cs`, `Models/RecipeSet.cs`;
+  `WWNotifier/Program.cs`, `CommandLineOptions.cs`, `Models/RecipeDownload(Result).cs`, `App.config`;
+  `DelmiaContracts/*`.
+
+**Galaxy export (`~/Desktop/AA_EXPORT/EXTRACTED/$DelmiaReceiver`):** `scripts/ProcessRecipe.txt`,
+`scripts/Reset.txt`, `$DelmiaReceiver.top_level_attributes.csv`. MES receiver object attributes: [`mesrec.md`](mesrec.md).
+
+**Open gaps / to verify against the box:**
+1. The Delmia recipe **`/notify` receiver service** source (the actual MXAccess writer at `wonder-app-vd01:9001`)
+   was not found in the Gitea org — §2.4 receiver steps are inferred from the contract + Galaxy scripts.
+2. MES tag prefix in code is `{Code}.MesReceiver.*`, while the live probe in `mesrec.md` shows a top-level
+   `MESReceiver_002` instance — confirm the exact contained-name/instance convention on the live Galaxy.
+3. PROD `HttpListener`/DB host values should be read from the deployed `App.config`, not assumed.
@@ -0,0 +1,77 @@
+# MESReceiver object — attributes (wonder-app-vd03 Galaxy)
+
+Source: live AVEVA Galaxy DB **`ZB`** on **wonder-app-vd03** (the MxAccessGateway box),
+read via the gateway's own `AttributesSql` (recursive `deployed_package_chain` over
+`dynamic_attribute` / `attribute_definition`) run with `sqlcmd` over ssh — `2026-06-16`.
+
+## Instance probed
+- **TagName:** `MESReceiver_002`  (GobjectId `5909`, ParentGobjectId `5908`, HostedBy `5049`)
+- **TemplateChain:** `$MESDemo.MESReceiver` → `$MESReceiver` → `$gUserDefined` → `$UserDefined`
+- **CategoryId:** 10, `IsArea = false`
+- There are many MESReceiver instances on this Galaxy (1,253 `MESReceiver` references in the
+  `galaxy-snapshot.json` hierarchy cache). `MESReceiver_002` is representative of the template.
+
+> Note: the cached `galaxy-snapshot.json` (gateway Server dir) holds the **object hierarchy only**
+> — it carries **no attributes**, so attribute discovery requires the DB query (or gRPC `galaxy-discover`).
+
+## Container number
+There is **no attribute literally named `ContainerNumber`**. The MES container number is carried by:
+- **`MoveInMesContainerNum`** — String (move-in interface)
+- **`MoveOutMesContainerNum`** — String (move-out interface)
+
+Full tag references: `MESReceiver_002.MoveInMesContainerNum`, `MESReceiver_002.MoveOutMesContainerNum`.
+
+## MES interface UDAs (attribute-category 10, security-classification 1 = secured/operate)
+
+### Move-In
+| Attribute | Type | Full tag reference |
+|---|---|---|
+| **MoveInMesContainerNum** | String | `MESReceiver_002.MoveInMesContainerNum` |
+| MoveInBatchID | Integer | `MESReceiver_002.MoveInBatchID` |
+| MoveInJobSequenceNumber | String | `MESReceiver_002.MoveInJobSequenceNumber` |
+| MoveInNumberWorkOrders | Integer | `MESReceiver_002.MoveInNumberWorkOrders` |
+| MoveInWorkOrderNumbers | String[] | `MESReceiver_002.MoveInWorkOrderNumbers[]` |
+| MoveInPartNumbers | String[] | `MESReceiver_002.MoveInPartNumbers[]` |
+| MoveInOperatorName | String | `MESReceiver_002.MoveInOperatorName` |
+| MoveInFlag | Boolean | `MESReceiver_002.MoveInFlag` |
+| MoveInReadyFlag | Boolean | `MESReceiver_002.MoveInReadyFlag` |
+| MoveInCompleteFlag | Boolean | `MESReceiver_002.MoveInCompleteFlag` |
+| MoveInSuccessfulFlag | Boolean | `MESReceiver_002.MoveInSuccessfulFlag` |
+| MoveInErrorText | String | `MESReceiver_002.MoveInErrorText` |
+
+### Move-Out (symmetric; no JobSequenceNumber)
+| Attribute | Type | Full tag reference |
+|---|---|---|
+| **MoveOutMesContainerNum** | String | `MESReceiver_002.MoveOutMesContainerNum` |
+| MoveOutBatchID | Integer | `MESReceiver_002.MoveOutBatchID` |
+| MoveOutNumberWorkOrders | Integer | `MESReceiver_002.MoveOutNumberWorkOrders` |
+| MoveOutWorkOrderNumbers | String[] | `MESReceiver_002.MoveOutWorkOrderNumbers[]` |
+| MoveOutPartNumbers | String[] | `MESReceiver_002.MoveOutPartNumbers[]` |
+| MoveOutOperatorName | String | `MESReceiver_002.MoveOutOperatorName` |
+| MoveOutFlag | Boolean | `MESReceiver_002.MoveOutFlag` |
+| MoveOutReadyFlag | Boolean | `MESReceiver_002.MoveOutReadyFlag` |
+| MoveOutCompleteFlag | Boolean | `MESReceiver_002.MoveOutCompleteFlag` |
+| MoveOutSuccessfulFlag | Boolean | `MESReceiver_002.MoveOutSuccessfulFlag` |
+| MoveOutErrorText | String | `MESReceiver_002.MoveOutErrorText` |
+
+## Standard ArchestrA `$UserDefined` / system attributes (also present)
+`AlarmCntsBySeverity[]`, `AlarmCntsBySeverityEnableShelved[]`, `AlarmInhibit`, `AlarmMode`,
+`AlarmModeCmd`, `AlarmMostUrgentAcked`, `AlarmMostUrgentInAlarm`, `AlarmMostUrgentMode`,
+`AlarmMostUrgentSeverity`, `AlarmMostUrgentShelved`, `AliasName`, `Area`, `CmdData`, `CodeBase`,
+`ConfigVersion`, `ContainedName`, `Container`, `Errors[]`, `ExecutionRelatedObject`,
+`ExecutionRelativeOrder`, `Extensions`, `HierarchicalName`, `Host`, `InAlarm`, `MinorVersion`,
+`PropagatedAlarmInhibit`, `ScanState`, `ScanStateCmd`, `SecurityGroup`, `ShortDesc`, `Tagname`,
+`UDAs`, `UserAttrData`, `PropagatedAlarmInhibit`.
+
+## How to reproduce
+1. `MESReceiver` instances are in the gateway hierarchy cache
+   `E:\ApiInstall\MxGateway\Server\galaxy-snapshot.json` (objects only, no attrs).
+2. Attribute list: run the gateway's `AttributesSql`
+   (`src/.../Server/Galaxy/GalaxyRepository.cs`) scoped to one instance via
+   `... WHERE g.is_template = 0 AND g.deployed_package_id <> 0 AND g.tag_name = 'MESReceiver_002'`
+   in the `deployed_package_chain` anchor, then `sqlcmd -S (local) -d ZB -U wwadmin -P <pwd>`
+   on the box (Galaxy creds from `MxGateway.Galaxy.ConnectionString` in the gateway appsettings).
+3. Live values would need an MXAccess read through the gateway (gRPC), not the repo SQL.
+
+In OtOpcUa (Galaxy-as-standard-driver model) these bind as ordinary equipment tags:
+`Tag{ DriverInstanceId = GalaxyMxGateway, TagConfig = {"FullName":"MESReceiver_002.MoveInMesContainerNum"} }`.
@@ -0,0 +1,212 @@
+# New Jersey — DARS reactors Z28061 / Z28062 (wonder Galaxy)
+
+Source: live AVEVA Galaxy DB **`ZB`** on **wonder-app-vd03** (MxAccessGateway box), via the gateway's `AttributesSql` over `sqlcmd`/ssh — `2026-06-16`. Lists the **meaningful (user-defined, cat-10) attributes**; ArchestrA system attributes (alarm framework, identity, security) and per-field config sub-attributes (`.EngUnits`, `.TrendHi`, `.Dev.*`, history/alarm settings) and scripts are omitted.
+
+## Hierarchy
+```
+NewJersey (area)
+ └─ CVDAisle_1   ($CVDAisle, gobject 7243)
+     ├─ Z28061    ($DARSReactor, gobject 7171)
+     │   ├─ Left  (Left_002,  $DARSReactor.Left,  gobject 7172)
+     │   └─ Right (Right_002, $DARSReactor.Right, gobject 7173)
+     └─ Z28062    ($DARSReactor, gobject 7202)
+         ├─ Left  (Left_003,  $DARSReactor.Left,  gobject 7203)
+         └─ Right (Right_003, $DARSReactor.Right, gobject 7204)
+```
+(`Z28061Sim`, gobject 7146, is a simulator sibling of Z28061.)
+
+## Objects
+| Object | GobjectId | Template | Compound path | UDA attrs | Total attrs |
+|---|---|---|---|---|---|
+| Left_002 | 7172 | `$DARSReactor.Left` | Z28061.Left | 72 | 1907 |
+| Left_003 | 7203 | `$DARSReactor.Left` | Z28062.Left | 72 | 1907 |
+| Right_002 | 7173 | `$DARSReactor.Right` | Z28061.Right | 72 | 1907 |
+| Right_003 | 7204 | `$DARSReactor.Right` | Z28062.Right | 72 | 1907 |
+| Z28061 | 7171 | `$DARSReactor` | Z28061 | 16 | 195 |
+| Z28062 | 7202 | `$DARSReactor` | Z28062 | 16 | 195 |
+
+> Attribute sets are template-defined: `Z28061`≡`Z28062`, `Left_002`≡`Left_003`, `Right_002`≡`Right_003`. Listed once per template.
+
+## $DARSReactor — Z28061 / Z28062 (reactor body)
+
+**Instances:** `Z28061` (Z28061, gobject 7171), `Z28062` (Z28062, gobject 7202)
+**Template:** `$DARSReactor` · **16 meaningful (UDA) attributes** · 195 total incl. system + config sub-attributes.
+
+| Attribute | Type | Hist | Alarm |
+|---|---|---|---|
+| ChlorineFlow | Integer | ✓ |  |
+| ConfirmTimeoutSec | Integer |  |  |
+| Deadband | Double |  |  |
+| HeartbeatInterval | Integer |  |  |
+| HeartbeatRequest | Boolean |  |  |
+| HeartbeatTimeout | Integer |  |  |
+| HeartbeatTimeoutAlarm | Boolean |  | ✓ |
+| HydrogenFlow | Integer | ✓ |  |
+| LeakTestMaxDelta | Integer |  |  |
+| LeakTestMinDuration | Integer |  |  |
+| LeakTestTimeout | Integer |  |  |
+| MachineCode | String |  |  |
+| MachineDescription | String |  |  |
+| MachineID | String |  |  |
+| Runtime_Alert | Boolean |  |  |
+| TrunkPressure | Float | ✓ |  |
+
+## $DARSReactor.Left — Left_002 / Left_003 (left chamber)
+
+**Instances:** `Left_002` (Z28061.Left, gobject 7172), `Left_003` (Z28062.Left, gobject 7203)
+**Template:** `$DARSReactor.Left` · **72 meaningful (UDA) attributes** · 1907 total incl. system + config sub-attributes.
+
+| Attribute | Type | Hist | Alarm |
+|---|---|---|---|
+| AIR_SVC | String |  |  |
+| AirAvg | Integer | ✓ |  |
+| AirFlow | Integer | ✓ |  |
+| AirFlowDevAlertPcnt | Float | ✓ |  |
+| AR_SVC | String |  |  |
+| ArAvg | Integer | ✓ |  |
+| ArgonFlow | Integer | ✓ |  |
+| ChlorineFlowR | Integer |  |  |
+| CL2_SVC | String |  |  |
+| Cl2Avg | Integer | ✓ |  |
+| ClFlowDevAlertPcnt | Float | ✓ |  |
+| CoilDiameter | Boolean | ✓ |  |
+| CoilHeight | Integer | ✓ |  |
+| ContainerID | String | ✓ |  |
+| ContainerLoaded | Boolean | ✓ |  |
+| CurrentStep | Integer |  |  |
+| CycleEndConfirm | Boolean |  |  |
+| CycleEndNotify | Boolean |  |  |
+| CycleEndTimeoutAlarm | Boolean |  |  |
+| CycleRunning | Boolean | ✓ |  |
+| CycleStartConfirm | Boolean |  |  |
+| CycleStartNotify | Boolean |  |  |
+| CycleStartTimeoutAlarm | Boolean |  |  |
+| Deadband | Double |  |  |
+| DelmiaJobStep | Integer |  |  |
+| FRR_Reset | Boolean | ✓ |  |
+| FRR_Runtime | Integer | ✓ |  |
+| FRR_Warning | Boolean | ✓ | ✓ |
+| FurnaceTemp | Integer | ✓ |  |
+| FurnaceTempOverAlarmDev | Integer | ✓ |  |
+| FurnaceTempOverAlertDev | Integer | ✓ |  |
+| FurnaceTempUnderAlarmDev | Integer | ✓ |  |
+| FurnaceTempUnderAlertDev | Integer | ✓ |  |
+| H2_SVC | String |  |  |
+| H2Avg | Integer | ✓ |  |
+| HydrogenFlowR | Integer |  |  |
+| HyFlowDevAlertPcnt | Float | ✓ |  |
+| MachineBatchID | Integer |  |  |
+| MachineBatchWOID | Integer |  |  |
+| MachineCycleID | Integer |  |  |
+| MantleTemp | Integer | ✓ |  |
+| MoveInReady | Boolean |  |  |
+| MoveOutReady | Boolean |  |  |
+| MTA_Lockout | Boolean | ✓ | ✓ |
+| MTA_Reset | Boolean | ✓ |  |
+| MTA_Runtime | Integer | ✓ |  |
+| MTA_Warning | Boolean | ✓ | ✓ |
+| NumOfParts | Integer | ✓ |  |
+| NumOfTurns | Integer | ✓ |  |
+| OperatorID | String | ✓ |  |
+| PartNumber | String | ✓ |  |
+| PID_Alarm | Boolean |  | ✓ |
+| PID_AlarmString | String |  |  |
+| PID_CV | Integer | ✓ |  |
+| PotNumber | String | ✓ |  |
+| PotTempAvg | Integer | ✓ |  |
+| PreviousStep | Integer |  |  |
+| ReactorTempAvg | Integer | ✓ |  |
+| RunDuration | Integer |  |  |
+| RunEndTime | Time |  |  |
+| RunStartTime | Time |  |  |
+| SampleCount | Integer |  |  |
+| StartingWeight | Integer | ✓ |  |
+| TableSide | Boolean |  |  |
+| TableStatus | Integer |  |  |
+| TC_Furnace_ID | String |  |  |
+| TC_Mantle_ID | String |  |  |
+| TC_Spare_ID | String |  |  |
+| Vacuum | Float | ✓ |  |
+| VacuumAvg | Float | ✓ |  |
+| VacuumMode | Boolean | ✓ |  |
+| WorkOrder | String |  |  |
+
+## $DARSReactor.Right — Right_002 / Right_003 (right chamber)
+
+**Instances:** `Right_002` (Z28061.Right, gobject 7173), `Right_003` (Z28062.Right, gobject 7204)
+**Template:** `$DARSReactor.Right` · **72 meaningful (UDA) attributes** · 1907 total incl. system + config sub-attributes.
+
+| Attribute | Type | Hist | Alarm |
+|---|---|---|---|
+| AIR_SVC | String |  |  |
+| AirAvg | Integer | ✓ |  |
+| AirFlow | Integer | ✓ |  |
+| AirFlowDevAlertPcnt | Float | ✓ |  |
+| AR_SVC | String |  |  |
+| ArAvg | Integer | ✓ |  |
+| ArgonFlow | Integer | ✓ |  |
+| ChlorineFlowR | Integer |  |  |
+| CL2_SVC | String |  |  |
+| Cl2Avg | Integer | ✓ |  |
+| ClFlowDevAlertPcnt | Float | ✓ |  |
+| CoilDiameter | Boolean | ✓ |  |
+| CoilHeight | Integer | ✓ |  |
+| ContainerID | String | ✓ |  |
+| ContainerLoaded | Boolean | ✓ |  |
+| CurrentStep | Integer |  |  |
+| CycleEndConfirm | Boolean |  |  |
+| CycleEndNotify | Boolean |  |  |
+| CycleEndTimeoutAlarm | Boolean |  |  |
+| CycleRunning | Boolean | ✓ |  |
+| CycleStartConfirm | Boolean |  |  |
+| CycleStartNotify | Boolean |  |  |
+| CycleStartTimeoutAlarm | Boolean |  |  |
+| Deadband | Double |  |  |
+| DelmiaJobStep | Integer |  |  |
+| FRR_Reset | Boolean | ✓ |  |
+| FRR_Runtime | Integer | ✓ |  |
+| FRR_Warning | Boolean | ✓ | ✓ |
+| FurnaceTemp | Integer | ✓ |  |
+| FurnaceTempOverAlarmDev | Integer | ✓ |  |
+| FurnaceTempOverAlertDev | Integer | ✓ |  |
+| FurnaceTempUnderAlarmDev | Integer | ✓ |  |
+| FurnaceTempUnderAlertDev | Integer | ✓ |  |
+| H2_SVC | String |  |  |
+| H2Avg | Integer | ✓ |  |
+| HydrogenFlowR | Integer |  |  |
+| HyFlowDevAlertPcnt | Float | ✓ |  |
+| MachineBatchID | Integer |  |  |
+| MachineBatchWOID | Integer |  |  |
+| MachineCycleID | Integer |  |  |
+| MantleTemp | Integer | ✓ |  |
+| MoveInReady | Boolean |  |  |
+| MoveOutReady | Boolean |  |  |
+| MTA_Lockout | Boolean | ✓ | ✓ |
+| MTA_Reset | Boolean | ✓ |  |
+| MTA_Runtime | Integer | ✓ |  |
+| MTA_Warning | Boolean | ✓ | ✓ |
+| NumOfParts | Integer | ✓ |  |
+| NumOfTurns | Integer | ✓ |  |
+| OperatorID | String | ✓ |  |
+| PartNumber | String | ✓ |  |
+| PID_Alarm | Boolean |  | ✓ |
+| PID_AlarmString | String |  |  |
+| PID_CV | Integer | ✓ |  |
+| PotNumber | String | ✓ |  |
+| PotTempAvg | Integer | ✓ |  |
+| PreviousStep | Integer |  |  |
+| ReactorTempAvg | Integer | ✓ |  |
+| RunDuration | Integer |  |  |
+| RunEndTime | Time |  |  |
+| RunStartTime | Time |  |  |
+| SampleCount | Integer |  |  |
+| StartingWeight | Integer | ✓ |  |
+| TableSide | Boolean |  |  |
+| TableStatus | Integer |  |  |
+| TC_Furnace_ID | String |  |  |
+| TC_Mantle_ID | String |  |  |
+| TC_Spare_ID | String |  |  |
+| Vacuum | Float | ✓ |  |
+| VacuumAvg | Float | ✓ |  |
+| VacuumMode | Boolean | ✓ |  |
+| WorkOrder | String |  |  |
@@ -109,13 +109,49 @@ Defaults target docker-dev; override via flags or env:
 - `../galaxy-hierarchy.json` — the source of truth, pulled live from the gateway
 - `requirements.txt`, `.venv/`

-## Scope note — company-UNS shape
+## Company-shape overlay (`populate-equipment`)

-This tool loads the galaxy in its **native hierarchy**
-(`OtOpcUa/TestMachine_NNN/<signal>`), which is the only shape that can carry live
-Galaxy values: OtOpcUa forbids the `GalaxyMxGateway` driver in an `Equipment`
-namespace, so a custom `Enterprise/Site/Area/Line/Equipment` UNS (e.g. the
-Northwind model in `../company-uns.json`) must be a separate **Equipment**
-namespace fed by an `OpcUaClient` driver + `UnsMappingTable` that remaps this
-mirror. That overlay is the designed next layer; `../company-uns.json` already
-carries the area/line/equipment → galaxy-ref mapping it needs.
+Besides the galaxy-native mirror, the tool can load the **Northwind company
+shape** (`filling / line-1 / rinser-01 / speed-rpm`) as a second, **Equipment**-kind
+namespace (`nw-uns`, in cluster `MAIN`) from `../company-uns.json`. Each company
+signal is a **VirtualTag** (+ a `Script`) whose script simply mirrors the live
+galaxy-mirror tag for that signal:
+
+```csharp
+return ctx.GetTag("TestMachine_001.TestDouble").Value;
+```
+
+so the company shape carries live **VALUES** driven off the same Galaxy source — no
+driver, no `BadWaitingForInitialData` once the galaxy mirror is up. The `ctx.GetTag`
+literal is the signal's `source.fullTagReference`; the engine's `DependencyExtractor`
+harvests it and subscribes the VirtualTag to that galaxy-mirror tag. This needs
+OtOpcUa `master` ≥ the Equipment-namespace VirtualTag materialisation milestone (WS-3),
+which materialises `VirtualTag`/`Script` rows on deploy and added the **headless
+deploy** endpoint.
+
+```bash
+./.venv/bin/python otopcua_uns.py populate-equipment        # 3 areas / 8 lines / 40 equipment / 1036 VirtualTags
+curl -s -X POST http://localhost:9200/api/deployments -H 'X-Api-Key: docker-dev-deploy-key'   # headless deploy
+./.venv/bin/python otopcua_uns.py verify-equipment --expect 1036 --require-good 396 --wait --wait-seconds 300   # structure + live values
+```
+
+> **Verified live 2026-06-07** (OtOpcUa `feat/equipment-namespace-live-values`): galaxy mirror
+> **396/396 Good**, company overlay **396 Good** on `opc.tcp://localhost:4840`, `VERIFY-EQUIPMENT: PASS`.
+> Why 396 of 1036? The shipped `company-uns.json` invents **1036 distinct** `ctx.GetTag` refs, but only
+> **396** of them match a real galaxy-mirror tag — so 396 signals are backed by a live source (and all 396
+> go Good); the other 640 cite synthetic refs with no galaxy tag (`BadNodeIdUnknown`). That ratio is a
+> property of the company model, not the streaming path — **every signal with a resolvable live source
+> streams Good.** So `--require-good 396` is the meaningful gate for the current model. Survives a node
+> restart with no re-deploy (the bootstrap-restore path re-materialises + re-applies the VirtualTags).
+
+UNS folders carry the friendly **DisplayName** (`filling`); the BrowseName/NodeId
+stay the stable logical Id (`nw-area-filling`) — standard OPC UA. **No driver:** the
+company signals are VirtualTags (which link to Equipment + a Script, not a driver); a
+placeholder `nw-uns-modbus` driver is kept only because an Equipment namespace is
+expected to have one, but no `Tag` binds to it. `verify-equipment --require-good N`
+reads each leaf's value and asserts at least N are Good (default `0` = structure-only,
+back-compat); `--wait` polls until the deploy + change-triggered evaluations land.
+Tracked in `OtOpcUa/docs/plans/2026-06-06-equipment-namespace-materialization-scope.md` (WS-3).
+
+`clean` removes both the mirror tags and the company overlay (the `VirtualTag` +
+`Script` rows, in FK-safe order, plus the namespace/driver/equipment/areas/lines).
@@ -25,12 +25,21 @@ the `nw-` id prefix so `clean` can remove them without touching other config.

 Idempotent: populate upserts by TagId; re-running is a no-op when unchanged.

+There are TWO overlays:
+  • the galaxy-native mirror (`populate`) — SystemPlatform driver Tags, 396 tags;
+  • the Northwind company shape (`populate-equipment`) — an Equipment-kind namespace
+    whose 1036 signals are VirtualTags. Each VirtualTag's Script simply mirrors the
+    live galaxy-mirror tag (`return ctx.GetTag("<fullTagReference>").Value;`), so the
+    company shape carries live VALUES driven off the same Galaxy source.
+
 Subcommands:
-    generate   Build the load plan from galaxy-hierarchy.json (writes load-plan.json)
-    populate   Upsert the SystemPlatform mirror Tag rows into the config DB
-    verify     Check DB rows present + live OPC UA values are Good on :4840
-    status     Show config-DB + address-space state
-    clean      Delete all nw-* mirror Tag rows
+    generate            Build the load plan from galaxy-hierarchy.json (writes load-plan.json)
+    populate            Upsert the SystemPlatform mirror Tag rows into the config DB
+    populate-equipment  Load the company shape as VirtualTag+Script rows (mirror the galaxy tags)
+    verify              Check DB rows present + live OPC UA values are Good on :4840
+    verify-equipment    Browse the company tree; --require-good asserts live values
+    status              Show config-DB + address-space state
+    clean               Delete all nw-* mirror Tags + the company VirtualTag/Script overlay

 Deploy is a human-gated AdminUI action (no SQL/REST trigger exists); populate
 and clean print the reminder and `verify --wait` polls until it lands.
@@ -38,11 +47,13 @@ and clean print the reminder and `verify --wait` polls until it lands.
 Deps: pymssql, asyncua  (see requirements.txt; use the bundled .venv).
 """
 import argparse
+import hashlib
 import json
 import os
 import re
 import sys
 import time
+import uuid

 # ── config (overridable via env / flags) ───────────────────────────────────
 DEF_MSSQL = dict(
@@ -58,9 +69,26 @@ DEF_GALAXY_JSON = os.environ.get(
    "OTOPCUA_GALAXY_JSON",
    os.path.join(os.path.dirname(__file__), "..", "galaxy-hierarchy.json"),
 )
-ID_PREFIX = "nw-mirror-"            # all rows we own carry this TagId prefix
+DEF_COMPANY_JSON = os.environ.get(
+    "OTOPCUA_COMPANY_JSON",
+    os.path.join(os.path.dirname(__file__), "..", "company-uns.json"),
+)
+ID_PREFIX = "nw-mirror-"            # SystemPlatform galaxy-mirror TagId prefix
 LOAD_PLAN = os.path.join(os.path.dirname(__file__), "load-plan.json")

+# Equipment-overlay (company-shape) object ids — all carry the nw- prefix so
+# `clean` can remove them. The Equipment namespace is a SECOND namespace loaded
+# alongside the galaxy mirror. Each company signal is a VirtualTag (+ Script) whose
+# script mirrors the live SystemPlatform galaxy-mirror tag for that signal — so the
+# overlay carries live VALUES (scope doc WS-3), not just structure.
+EQ_CLUSTER = os.environ.get("OTOPCUA_EQ_CLUSTER", "MAIN")
+EQ_NS = "nw-uns"
+EQ_ID_PREFIX = "nweq-"          # VirtualTag/Script logical-id prefix (cleanup by prefix scan)
+
+# galaxy dataTypeName / gen_uns dtype → valid OtOpcUa DriverDataType
+_DTYPE_FIX = {"Double": "Float64", "Float": "Float32"}
+_ACCESS = {"ReadOnly": "0", "Read": "0", "ReadWrite": "1"}
+
 # ── the value signals we mirror, per $TestMachine instance ──────────────────
 # (galaxy attribute name, OtOpcUa DriverDataType, access '0'=Read/'1'=ReadWrite)
 SIGNALS = [
@@ -194,13 +222,123 @@ def cmd_populate(args):
    return 0


+def _eq_signal_ids(equipment_id, folder, name):
+    """Deterministic (VirtualTagId, ScriptId) for a company signal. Both carry the
+    EQ_ID_PREFIX so `clean` removes exactly what was created. The two ids share the
+    same per-signal hash but differ by a kind token so they never collide across the
+    global UX_VirtualTag_LogicalId / UX_Script_LogicalId unique indexes. Capped at the
+    64-char id column width."""
+    base = hashlib.sha1(f"{equipment_id}|{folder}|{name}".encode()).hexdigest()[:20]
+    return EQ_ID_PREFIX + "vt-" + base, EQ_ID_PREFIX + "sc-" + base
+
+
+def cmd_populate_equipment(args):
+    """Load the company-shape Equipment namespace from company-uns.json: a second
+    (Equipment-kind) namespace alongside the galaxy mirror, with the Northwind
+    Area/Line/Equipment/Signal tree. Each signal is a VirtualTag whose Script mirrors
+    the live galaxy-mirror tag for that signal — `return ctx.GetTag("<ref>").Value;` —
+    so the company shape streams live VALUES off the same Galaxy source (no driver,
+    no BadWaitingForInitialData once the galaxy mirror is up). Idempotent:
+    drop-and-recreate of the nw- overlay rows."""
+    with open(args.company_json) as f:
+        doc = json.load(f)
+    u = doc["uns"]
+    conn, cur = connect(args.mssql)
+
+    # Drop any prior overlay (child rows first), then recreate. VirtualTag/Script go
+    # before Equipment (VirtualTag.EquipmentId logical-FKs Equipment). Equipment is
+    # scoped by its overlay UnsLine ('nw-line-%') — NOT by the EquipmentId, which is now the
+    # canonical 'EQ-'+uuid form (see DraftValidator) and no longer carries an 'nw-' prefix.
+    cur.execute("DELETE FROM dbo.VirtualTag WHERE VirtualTagId LIKE %s", (EQ_ID_PREFIX + "%",))
+    cur.execute("DELETE FROM dbo.Script WHERE ScriptId LIKE %s", (EQ_ID_PREFIX + "%",))
+    cur.execute("DELETE FROM dbo.Equipment WHERE UnsLineId LIKE 'nw-line-%'")
+    cur.execute("DELETE FROM dbo.UnsLine WHERE UnsLineId LIKE 'nw-line-%'")
+    cur.execute("DELETE FROM dbo.UnsArea WHERE UnsAreaId LIKE 'nw-area-%'")
+    # Equipment is now driver-less, but purge any driver still bound to the overlay namespace —
+    # self-heals environments that ran an older loader which created the 'nw-uns-modbus' placeholder.
+    cur.execute("DELETE FROM dbo.DriverInstance WHERE NamespaceId=%s", (EQ_NS,))
+    cur.execute("DELETE FROM dbo.Namespace WHERE NamespaceId=%s", (EQ_NS,))
+
+    cur.execute(
+        "INSERT INTO dbo.Namespace (NamespaceRowId, NamespaceId, ClusterId, Kind, NamespaceUri, Enabled) "
+        "VALUES (NEWID(), %s, %s, 'Equipment', %s, 1)",
+        (EQ_NS, EQ_CLUSTER, doc.get("namespace", {}).get("namespaceUri", "urn:northwind:birmingham:uns")))
+
+    for a in u["unsAreas"]:
+        cur.execute("INSERT INTO dbo.UnsArea (UnsAreaRowId, UnsAreaId, ClusterId, Name) VALUES (NEWID(), %s, %s, %s)",
+                    ("nw-" + a["unsAreaId"], EQ_CLUSTER, a["name"]))
+    for l in u["unsLines"]:
+        cur.execute("INSERT INTO dbo.UnsLine (UnsLineRowId, UnsLineId, UnsAreaId, Name) VALUES (NEWID(), %s, %s, %s)",
+                    ("nw-" + l["unsLineId"], "nw-" + l["unsAreaId"], l["name"]))
+
+    eq_n = vt_n = 0
+    for e in u["equipment"]:
+        eq_uuid = uuid.uuid5(uuid.NAMESPACE_URL, "otopcua-nw-eq/" + e["equipmentId"])
+        # Canonical EquipmentId: matches OtOpcUa DraftValidator.DeriveEquipmentId
+        # ("EQ-" + EquipmentUuid.ToString("N")[..12].ToLowerInvariant()). uuid.UUID.hex is
+        # already lowercase, 32 hex chars, no dashes — .hex[:12] is the first 12.
+        eq_id = "EQ-" + eq_uuid.hex[:12].lower()
+        eq_uuid = str(eq_uuid)
+        cur.execute(
+            "INSERT INTO dbo.Equipment (EquipmentRowId, EquipmentId, EquipmentUuid, UnsLineId, "
+            "Name, MachineCode, Manufacturer, Model, Enabled) VALUES (NEWID(), %s, %s, %s, %s, %s, %s, %s, 1)",
+            (eq_id, eq_uuid, "nw-" + e["unsLineId"], e["name"], e["machineCode"],
+             e.get("manufacturer"), e.get("model")))
+        eq_n += 1
+        for t in e["tags"]:
+            dtype = _DTYPE_FIX.get(t["dataType"], t["dataType"])
+            folder = t.get("folderPath")
+            # The galaxy-mirror MXAccess ref (e.g. TestMachine_001.TestDouble) is the upstream
+            # the VirtualTag mirrors. DependencyExtractor harvests the literal in ctx.GetTag(),
+            # so the engine subscribes to exactly this path on the galaxy-mirror driver.
+            full = t["source"]["fullTagReference"]
+            vt_id, sc_id = _eq_signal_ids(e["equipmentId"], folder, t["name"])
+            source_code = f'return ctx.GetTag("{full}").Value;'
+            source_hash = hashlib.sha256(source_code.encode()).hexdigest()
+            cur.execute(
+                "INSERT INTO dbo.Script (ScriptRowId, ScriptId, Name, SourceCode, SourceHash, Language) "
+                "VALUES (NEWID(), %s, %s, %s, %s, 'CSharp')",
+                (sc_id, t["name"], source_code, source_hash))
+            cur.execute(
+                "INSERT INTO dbo.VirtualTag (VirtualTagRowId, VirtualTagId, EquipmentId, Name, DataType, "
+                "ScriptId, ChangeTriggered, TimerIntervalMs, Historize, Enabled) "
+                "VALUES (NEWID(), %s, %s, %s, %s, %s, 1, NULL, %s, 1)",
+                (vt_id, eq_id, t["name"], dtype, sc_id, 1 if t.get("historize") else 0))
+            vt_n += 1
+
+    conn.commit()
+    conn.close()
+    print(f"populated equipment overlay: namespace {EQ_NS} ({EQ_CLUSTER}), "
+          f"{len(u['unsAreas'])} areas, {len(u['unsLines'])} lines, {eq_n} equipment, "
+          f"{vt_n} VirtualTags (+ {vt_n} mirror Scripts)")
+    print()
+    print(f">>> NEXT: deploy (headless) — curl -s -X POST {args.deploy_url.replace('/deployments','')}/api/deployments "
+          f"-H 'X-Api-Key: {args.deploy_key}'")
+    print(">>> then run:  otopcua_uns.py verify-equipment --require-good 1036 --wait")
+    return 0
+
+
 def cmd_clean(args):
    conn, cur = connect(args.mssql)
    cur.execute("DELETE FROM dbo.Tag WHERE TagId LIKE %s", (ID_PREFIX + "%",))
    n = cur.rowcount
+    # Also drop the company-shape Equipment overlay (child rows first): VirtualTag and
+    # Script (both nweq-*) before Equipment, then the rest.
+    # Equipment is scoped by its overlay UnsLine ('nw-line-%') — NOT by the EquipmentId,
+    # which is now the canonical 'EQ-'+uuid form (see DraftValidator) with no 'nw-' prefix.
+    cur.execute("DELETE FROM dbo.VirtualTag WHERE VirtualTagId LIKE %s", (EQ_ID_PREFIX + "%",))
+    cur.execute("DELETE FROM dbo.Script WHERE ScriptId LIKE %s", (EQ_ID_PREFIX + "%",))
+    cur.execute("DELETE FROM dbo.Equipment WHERE UnsLineId LIKE 'nw-line-%'")
+    cur.execute("DELETE FROM dbo.UnsLine WHERE UnsLineId LIKE 'nw-line-%'")
+    cur.execute("DELETE FROM dbo.UnsArea WHERE UnsAreaId LIKE 'nw-area-%'")
+    # Purge any driver still bound to the overlay namespace (e.g. the legacy 'nw-uns-modbus'
+    # placeholder created by an older loader) so 'clean' fully removes the overlay.
+    cur.execute("DELETE FROM dbo.DriverInstance WHERE NamespaceId=%s", (EQ_NS,))
+    cur.execute("DELETE FROM dbo.Namespace WHERE NamespaceId=%s", (EQ_NS,))
    conn.commit()
    conn.close()
-    print(f"removed {n} nw-* mirror tag(s). Deploy again at {args.deploy_url} to drop them from the address space.")
+    print(f"removed {n} nw-* mirror tag(s) + the {EQ_NS} equipment overlay. "
+          f"Deploy again at {args.deploy_url} to drop them from the address space.")
    return 0


@@ -298,6 +436,119 @@ def sample_values(endpoint, n):
        return [("<browse error>", str(e), "?")]


+def browse_tree(endpoint, max_depth=8, top_prefix=None, read_values=False):
+    """Recursively descend the OtOpcUa address space and count leaf variables, returning
+    (folder_count, leaf_count, leaf_paths, good_count). A node with no children is a leaf
+    signal — this correctly handles the DEEP Equipment UNS tree
+    (Area/Line/Equipment/[FolderPath]/Signal), unlike browse_summary which assumes the flat
+    2-level Galaxy hierarchy. When top_prefix is set, only top-level OtOpcUa folders whose
+    browse name starts with it are counted (e.g. 'nw-area-' scopes to the company Equipment
+    overlay, excluding the Galaxy mirror folders). When read_values is True, each leaf's value
+    is read and good_count tallies the Good-quality ones (else good_count is 0)."""
+    import asyncio
+    from asyncua import Client
+
+    async def maybe_good(node, acc):
+        if not read_values:
+            return
+        try:
+            dv = await node.read_data_value()
+            if dv.StatusCode and dv.StatusCode.is_good():
+                acc["good"] += 1
+        except Exception:
+            pass
+
+    async def walk(node, path, depth, acc):
+        if depth >= max_depth:
+            return
+        for ch in await node.get_children():
+            try:
+                name = (await ch.read_browse_name()).Name
+            except Exception:
+                continue
+            child_path = path + "/" + name
+            grandkids = await ch.get_children()
+            if grandkids:
+                acc["folders"] += 1
+                await walk(ch, child_path, depth + 1, acc)
+            else:
+                acc["leaves"] += 1
+                acc["paths"].append(child_path)
+                await maybe_good(ch, acc)
+
+    async def run():
+        acc = {"folders": 0, "leaves": 0, "paths": [], "good": 0}
+        async with Client(endpoint) as c:
+            for k in await c.nodes.objects.get_children():
+                if (await k.read_browse_name()).Name != "OtOpcUa":
+                    continue
+                for top in await k.get_children():
+                    tn = (await top.read_browse_name()).Name
+                    if top_prefix and not tn.startswith(top_prefix):
+                        continue
+                    if await top.get_children():
+                        acc["folders"] += 1
+                        await walk(top, "OtOpcUa/" + tn, 1, acc)
+                    else:
+                        acc["leaves"] += 1
+                        acc["paths"].append("OtOpcUa/" + tn)
+                        await maybe_good(top, acc)
+        return acc["folders"], acc["leaves"], acc["paths"], acc["good"]
+    try:
+        return asyncio.run(run())
+    except Exception as e:
+        return (f"<{type(e).__name__}: {e}>", 0, [], 0)
+
+
+def cmd_verify_equipment(args):
+    """Browse the full UNS tree by friendly Area/Line/Equipment/Signal names and report the leaf
+    signal count. With --expect N, exit non-zero unless exactly N leaf signals are present (the
+    equipment-namespace structure-materialisation check). With --require-good N (>0), also read
+    each leaf's value and require at least N Good ones (the live-VALUE check for the VirtualTag
+    overlay) — back-compat default 0 = structure-only. --wait polls so it can wait for the deploy
+    + change-triggered VirtualTag evaluations to land."""
+    top_prefix = None if args.all else "nw-area-"
+    scope = "whole address space" if args.all else "company overlay (nw-area-*)"
+    read_values = args.require_good > 0
+    deadline = time.time() + (args.wait_seconds if args.wait else 0)
+    while True:
+        folders, leaves, paths, good = browse_tree(
+            args.opcua_endpoint, top_prefix=top_prefix, read_values=read_values)
+        struct_ok = args.expect is None or leaves == args.expect
+        good_ok = good >= args.require_good
+        if (struct_ok and good_ok) or time.time() >= deadline:
+            break
+        print(f"  waiting for deploy/values… ({leaves} leaves"
+              + (f", {good} Good" if read_values else "") + ")")
+        time.sleep(5)
+
+    suffix = f", {good} Good value(s)" if read_values else ""
+    print(f"equipment tree : {folders} folder(s), {leaves} leaf signal(s){suffix} "
+          f"on {args.opcua_endpoint} [{scope}]")
+    for p in sorted(paths)[:args.show]:
+        print(f"    {p}")
+    if len(paths) > args.show:
+        print(f"    … and {len(paths) - args.show} more")
+
+    passed = True
+    if args.expect is not None:
+        struct_ok = leaves == args.expect
+        passed = passed and struct_ok
+        print("  structure :",
+              f"PASS ({leaves} == {args.expect})" if struct_ok
+              else f"FAIL (expected {args.expect}, found {leaves})")
+    if args.require_good > 0:
+        good_ok = good >= args.require_good
+        passed = passed and good_ok
+        print("  live good :",
+              f"PASS ({good} >= {args.require_good})" if good_ok
+              else f"FAIL (expected >= {args.require_good} Good, found {good})")
+    if args.expect is None and args.require_good == 0:
+        return 0
+    print("VERIFY-EQUIPMENT:", "PASS" if passed else "FAIL")
+    return 0 if passed else 1
+
+
 # ── arg parsing ─────────────────────────────────────────────────────────────
 def main(argv):
    p = argparse.ArgumentParser(description="Reloadable populate + verify for the OtOpcUa galaxy UNS.")
@@ -305,6 +556,9 @@ def main(argv):
    p.add_argument("--driver", default=DEF_DRIVER, help="SystemPlatform GalaxyMxGateway driver instance id")
    p.add_argument("--opcua-endpoint", default=DEF_OPCUA)
    p.add_argument("--deploy-url", default="http://localhost:9200/deployments")
+    p.add_argument("--deploy-key", default=os.environ.get("OTOPCUA_DEPLOY_KEY", "docker-dev-deploy-key"),
+                   help="X-Api-Key for the headless POST /api/deployments endpoint")
+    p.add_argument("--company-json", default=DEF_COMPANY_JSON)
    p.add_argument("--sql-host", default=DEF_MSSQL["host"])
    p.add_argument("--sql-port", type=int, default=DEF_MSSQL["port"])
    p.add_argument("--sql-user", default=DEF_MSSQL["user"])
@@ -313,18 +567,33 @@ def main(argv):
    sub = p.add_subparsers(dest="cmd", required=True)
    sub.add_parser("generate")
    sub.add_parser("populate")
+    sub.add_parser("populate-equipment",
+                   help="load the company-shape Equipment namespace from company-uns.json (structure-only)")
    sub.add_parser("clean")
    sub.add_parser("status")
    vp = sub.add_parser("verify")
    vp.add_argument("--wait", action="store_true", help="poll until the deploy lands")
    vp.add_argument("--wait-seconds", type=int, default=120)
+    ep = sub.add_parser("verify-equipment",
+                        help="recursively browse the Equipment UNS tree + count leaf signals "
+                             "(+ optionally assert live Good values)")
+    ep.add_argument("--expect", type=int, default=None, help="assert exactly N leaf signals")
+    ep.add_argument("--require-good", type=int, default=0,
+                    help="read each leaf's value and require >= N Good ones (0 = structure-only, default)")
+    ep.add_argument("--show", type=int, default=20, help="how many leaf paths to print")
+    ep.add_argument("--all", action="store_true",
+                    help="count the whole address space (default: only the nw-area-* company overlay)")
+    ep.add_argument("--wait", action="store_true",
+                    help="poll until the deploy lands + (with --require-good) values go Good")
+    ep.add_argument("--wait-seconds", type=int, default=120)

    a = p.parse_args(argv)
    a.mssql = dict(host=a.sql_host, port=a.sql_port, user=a.sql_user,
                   password=a.sql_password, database=a.sql_db)
    return {
-        "generate": cmd_generate, "populate": cmd_populate, "clean": cmd_clean,
-        "status": cmd_status, "verify": cmd_verify,
+        "generate": cmd_generate, "populate": cmd_populate,
+        "populate-equipment": cmd_populate_equipment, "clean": cmd_clean,
+        "status": cmd_status, "verify": cmd_verify, "verify-equipment": cmd_verify_equipment,
    }[a.cmd](a)
Author	SHA1	Message	Date
Joseph Doherty	b80abbb14b	docs(index): HistorianGateway store-forward now FasterLog-backed; refresh test count (702/681)	2026-06-24 11:19:56 -04:00
Joseph Doherty	6c2d16d4af	docs: refresh HistorianGateway + GalaxyRepository status in index HistorianGateway is now pushed to gitea (gitea.dohertylan.com/dohertj2/historiangw), and ZB.MOM.WW.GalaxyRepository is published to the Gitea feed and consumed as a PackageReference (no longer a cross-repo ProjectReference). Updates the sister-project row, the component table, and the GalaxyRepository narrative; test figure 584 green -> 590 total (584 on macOS).	2026-06-24 07:28:25 -04:00
Joseph Doherty	a08ddab9dd	chore: retire unused ZB.MOM.WW.SPHistorianClient (stale partial port; superseded by histsdk vendored in HistorianGateway; no consumers, not on feed)	2026-06-24 06:45:10 -04:00
Joseph Doherty	744eb090ac	docs(scadaproj): index ZB.MOM.WW.HistorianGateway sidecar + GalaxyRepository shared lib - Add HistorianGateway to the Runtime/implementation table (single-process .NET 10 x64 gRPC sidecar; no COM/x86; 584 tests; local only, not yet pushed to gitea) - Update "What this repository is" count (five → six pieces of source; add GalaxyRepository) - Add HistorianGateway paragraph to Cross-project relationships / Net effect (independent sidecar; no runtime coupling to the other three; depends on shared GalaxyRepository lib via ProjectReference) - Add ZB.MOM.WW.GalaxyRepository row to Component normalization table + full description paragraph (built 0.1.0; consumed by HistorianGateway; mxaccessgw adoption is a follow-on; not yet published to Gitea feed) - Add HistorianGateway primary commands block (build/test/run/live-integration) - Extend Shared GLAuth note to cover HistorianGateway	2026-06-24 00:41:29 -04:00
Joseph Doherty	94512acf1f	fix(galaxyrepo): drop no-op ValidateOnStart (consumer owns validation)	2026-06-23 20:36:28 -04:00
Joseph Doherty	2c6c764d3c	test(galaxyrepo): projector + cache tests; dispose semaphores; pack 0.1.0	2026-06-23 20:34:32 -04:00
Joseph Doherty	a30f8551e9	feat(galaxyrepo): reusable gRPC service + AddZbGalaxyRepository DI	2026-06-23 20:26:59 -04:00
Joseph Doherty	afd0287f54	feat(galaxyrepo): hierarchy cache + snapshot + refresh service + projector	2026-06-23 20:22:35 -04:00
Joseph Doherty	1041f87b59	feat(galaxyrepo): SQL browse provider (hierarchy + attributes)	2026-06-23 20:12:33 -04:00
Joseph Doherty	5572edda85	feat(galaxyrepo): canonical galaxy_repository.v1 proto (neutral namespace)	2026-06-23 20:05:39 -04:00
Joseph Doherty	aff7264df8	feat(galaxyrepo): scaffold ZB.MOM.WW.GalaxyRepository shared lib	2026-06-23 19:48:43 -04:00
Joseph Doherty	510b0010d6	docs(historian-gateway): implementation plan + task ledger (31 tasks)	2026-06-23 19:43:08 -04:00
Joseph Doherty	42ad31aded	docs(historian-gateway): brainstormed design for ZB.MOM.WW.HistorianGateway sidecar	2026-06-23 19:31:54 -04:00
Joseph Doherty	e3c0503a4f	docs(sphistorianclient): mark RemoteGrpc (2023 R2) live-verified	2026-06-19 06:57:06 -04:00
Joseph Doherty	a0527f9b5a	fix(sphistorianclient): gRPC auth handshake uses StorageService.ValidateClientCredential The RemoteGrpc orchestrator drove the SSPI/NTLM token loop through HistoryService.ExchangeKey, which the 2023 R2 contract analysis shows is a separate key-exchange/cert op — not the credential handshake. The server rejected the NTLM Type-1 token at round 0. The Negotiate loop belongs on StorageService.ValidateClientCredential (Handle/InBuff -> Status/OutBuff; field names match the 2020 native contract). Live-verified end-to-end against a 2023 R2 Historian (wonder-sql-vd03): SysTimeSec raw read returns correct timestamped values.	2026-06-19 06:56:44 -04:00
Joseph Doherty	5f7d7e1b58	docs(sphistorianclient): document HISTORIAN_PORT env var; mark plan tasks complete	2026-06-19 06:09:43 -04:00
Joseph Doherty	78418346df	build(sphistorianclient): pack 0.1.0 nupkg	2026-06-19 06:02:05 -04:00
Joseph Doherty	4920b89666	docs(sphistorianclient): correct retrieval-mode count (15) + EnsureTag verification scope	2026-06-19 06:01:07 -04:00
Joseph Doherty	989db9317d	docs(sphistorianclient): add CLAUDE.md + README.md	2026-06-19 05:58:13 -04:00
Joseph Doherty	81bf7322f0	feat(sphistorianclient): add AddZbSpHistorianClient DI extension	2026-06-19 05:53:56 -04:00
Joseph Doherty	8033a7f12d	fix(sphistorianclient): resolve port build/test fallout	2026-06-19 05:49:22 -04:00
Joseph Doherty	63cddfb65b	feat(sphistorianclient): port SDK source + tests, rebrand namespace to ZB.MOM.WW.SPHistorianClient	2026-06-19 05:45:06 -04:00
Joseph Doherty	965f5006f2	feat(sphistorianclient): scaffold shared library skeleton (props, csprojs, slnx)	2026-06-19 05:40:10 -04:00
Joseph Doherty	294da8b2db	docs(sphistorianclient): implementation plan + task tracking	2026-06-19 05:36:24 -04:00
Joseph Doherty	bbb7942788	docs(sphistorianclient): approved design for ZB.MOM.WW.SPHistorianClient port	2026-06-19 05:29:51 -04:00
Joseph Doherty	d5b134b117	docs: add MES + Delmia-DNC integration API/MXAccess specs mes-delmia-integration-api.md: endpoints, request/response DTOs, and the MXAccess flag handshake for MESAPI (in-repo MesNotifier) and DelmiaIntegration (DNC Downloader.asmx -> WWNotifier /notify -> Galaxy $DelmiaReceiver). mesrec.md / nj.md: live Galaxy receiver + reactor attribute references.	2026-06-17 06:52:36 -04:00
Joseph Doherty	eb8b44c29d	loader: purge legacy driver in overlay namespace on teardown (self-heal nw-uns-modbus placeholder)	2026-06-08 07:07:22 -04:00
Joseph Doherty	a6fa36043a	loader: equipment is driver-less (drop Modbus placeholder, NULL DriverInstanceId)	2026-06-08 06:42:31 -04:00
Joseph Doherty	05a4a547f4	feat(loader): canonical EQ-+uuid EquipmentIds (passes OtOpcUa full DraftValidator); clean by UnsLine scope	2026-06-07 11:18:39 -04:00
Joseph Doherty	4d57e34ff3	docs(loader): record live-values verification + 396/1036 explanation for company overlay	2026-06-07 06:08:36 -04:00
Joseph Doherty	b3d8990a0f	fix(loader): keep empty folderPath distinct in vtag ids; dedupe verify args; readme wait-seconds	2026-06-07 05:07:00 -04:00
Joseph Doherty	5655b75fe6	feat(loader): company overlay as VirtualTags mirroring the galaxy mirror + verify --require-good	2026-06-07 04:59:51 -04:00
Joseph Doherty	dce6f83488	loader: add populate-equipment (company-shape Equipment overlay) + scope verify-equipment populate-equipment loads the Northwind Enterprise/Site/Area/Line/Equipment/Signal shape from company-uns.json as a second Equipment-kind namespace (nw-uns) alongside the galaxy mirror — 3 areas / 8 lines / 40 equipment / 1036 signals. Friendly DisplayName, stable logical-Id NodeId. verify-equipment now scopes to the nw-area-* overlay by default (--all for the whole tree). Verified live on :4840 against OtOpcUa master's Equipment-namespace materialization (structure-only; leaves are BadWaitingForInitialData). clean now drops the overlay too.	2026-06-06 16:19:53 -04:00
Joseph Doherty	fd34e25cb1	feat(uns-loader): verify-equipment — recursive Equipment UNS tree browse + leaf count browse_summary assumes the flat 2-level Galaxy hierarchy; the Equipment tree is deep (Area/Line/Equipment/[FolderPath]/Signal). Add browse_tree (recursive leaf descent) + a verify-equipment subcommand that reports/asserts the leaf signal count (--expect N), for verifying OtOpcUa equipment-namespace structure materialisation. Smoke-tested against a live :4840 (40 folders / 396 leaf signals).	2026-06-06 15:25:17 -04:00