Merge feat/mxgateway-data-connection: MxGateway data connection (2nd protocol)

Adds MxGateway as a second DCL protocol alongside OPC UA: IDataConnection + IBrowsableDataConnection adapter over the ZB.MOM.WW.MxGateway.Client package, typed config + serializer/validator, factory registration, protocol-agnostic browse plumbing, Central UI protocol selector + editor + tag picker, and docker NuGet feed wiring. Full design + 19-task implementation plan in docs/plans.
2026-05-29 08:14:37 -04:00
parent 5c98d23800 251407934b
commit 8fb03d7449
46 changed files with 2820 additions and 118 deletions
@@ -73,6 +73,8 @@
      to mark tests as Skipped (not silently Passed) when MSSQL is unreachable.
    -->
    <PackageVersion Include="Xunit.SkippableFact" Version="1.5.61" />
    <PackageVersion Include="ZB.MOM.WW.MxGateway.Client" Version="0.1.0" />
    <PackageVersion Include="ZB.MOM.WW.MxGateway.Contracts" Version="0.1.0" />
  </ItemGroup>
 </Project>
@@ -21,7 +21,6 @@ This document serves as the master index for the SCADA system design. The system
 ### Scale
 - ~10 site clusters, each with 50–500 machines, 25–75 live tags per machine.
 - Central cluster: 2-node active/standby behind a load balancer.
 - Site clusters: 2-node active/standby, headless (no UI).
@@ -46,7 +45,7 @@ Both stacks share the infrastructure services in [`infra/`](infra/) (MS SQL, LDA
 | 1 | Template Engine | [docs/requirements/Component-TemplateEngine.md](docs/requirements/Component-TemplateEngine.md) | Template modeling, inheritance, composition, path-qualified member addressing, override granularity, locking, alarms, flattening, semantic validation, revision hashing, diff calculation, and folder organization (nested folders, drag-drop). |
 | 2 | Deployment Manager | [docs/requirements/Component-DeploymentManager.md](docs/requirements/Component-DeploymentManager.md) | Central-side deployment pipeline with deployment ID/idempotency, per-instance operation lock, state transition matrix, all-or-nothing site apply, system-wide artifact deployment with per-site status. |
 | 3 | Site Runtime | [docs/requirements/Component-SiteRuntime.md](docs/requirements/Component-SiteRuntime.md) | Site-side actor hierarchy with explicit supervision strategies, staggered startup, script trust model (constrained APIs), Tell/Ask conventions, concurrency serialization, and site-wide Akka stream with per-subscriber backpressure. |
-| 4 | Data Connection Layer | [docs/requirements/Component-DataConnectionLayer.md](docs/requirements/Component-DataConnectionLayer.md) | Common data connection interface (OPC UA, custom), Become/Stash connection actor model, auto-reconnect, immediate bad quality on disconnect, transparent re-subscribe, synchronous write failures, tag path resolution retry. |
+| 4 | Data Connection Layer | [docs/requirements/Component-DataConnectionLayer.md](docs/requirements/Component-DataConnectionLayer.md) | Common data connection interface (OPC UA, MxGateway, custom), Become/Stash connection actor model, auto-reconnect, immediate bad quality on disconnect, transparent re-subscribe, synchronous write failures, tag path resolution retry, protocol-agnostic address-space browse. |
 | 5 | Central–Site Communication | [docs/requirements/Component-Communication.md](docs/requirements/Component-Communication.md) | Dual transport: Akka.NET ClusterClient (command/control) + gRPC server-streaming (real-time data). 9 message patterns with per-pattern timeouts, SiteStreamGrpcServer/Client, application-level correlation IDs, transport heartbeat config, gRPC keepalive, message ordering, connection failure behavior. |
 | 6 | Store-and-Forward Engine | [docs/requirements/Component-StoreAndForward.md](docs/requirements/Component-StoreAndForward.md) | Buffering (transient failures only), fixed-interval retry, parking, async best-effort replication, SQLite persistence at sites. |
 | 7 | External System Gateway | [docs/requirements/Component-ExternalSystemGateway.md](docs/requirements/Component-ExternalSystemGateway.md) | HTTP/REST + JSON, API key/Basic Auth, per-system timeout, dual call modes (Call/CachedCall), transient/permanent error classification, dedicated blocking I/O dispatcher, ADO.NET connection pooling. |
@@ -27,6 +27,17 @@ COPY src/ZB.MOM.WW.ScadaBridge.ManagementService/ZB.MOM.WW.ScadaBridge.Managemen
 # projects) for `dotnet restore` to resolve versions — without it restore fails NU1015.
 COPY Directory.Packages.props ./
 # nuget.config declares the Gitea feed (and package-source mapping) that serves the
 # ZB.MOM.WW.MxGateway.* packages used by the Data Connection Layer.
 COPY nuget.config ./
 # Optional credentials for the private Gitea feed, supplied at build time via
 # --build-arg (see docker/build.sh). Left blank for an anonymous feed. NuGet reads
 # per-source credentials from the NuGetPackageSourceCredentials_<sourceName> env var.
 ARG NUGET_GITEA_USER=
 ARG NUGET_GITEA_PASS=
 ENV NuGetPackageSourceCredentials_dohertj2-gitea="Username=${NUGET_GITEA_USER};Password=${NUGET_GITEA_PASS}"
 # Restore NuGet packages via Host project (follows ProjectReferences to all dependencies)
 # This layer is cached until any .csproj changes — source-only changes skip restore entirely
 RUN dotnet restore src/ZB.MOM.WW.ScadaBridge.Host/ZB.MOM.WW.ScadaBridge.Host.csproj
@@ -12,11 +12,21 @@ if ! docker network inspect scadabridge-net >/dev/null 2>&1; then
    docker network create scadabridge-net
 fi
 # Optional credentials for the private Gitea NuGet feed (ZB.MOM.WW.MxGateway.*).
 # Read from the host environment so secrets are never committed. Leave unset for an
 # anonymous feed. Export MXGW_NUGET_USER / MXGW_NUGET_PASS before running deploy.
 NUGET_ARGS=()
 if [ -n "${MXGW_NUGET_USER:-}" ]; then
    NUGET_ARGS+=(--build-arg "NUGET_GITEA_USER=${MXGW_NUGET_USER}")
    NUGET_ARGS+=(--build-arg "NUGET_GITEA_PASS=${MXGW_NUGET_PASS:-}")
 fi
 # Build from repo root (so COPY paths in Dockerfile resolve correctly)
 echo "Building scadabridge:latest image..."
 docker build \
    -t scadabridge:latest \
    -f "$SCRIPT_DIR/Dockerfile" \
    "${NUGET_ARGS[@]}" \
    "$REPO_ROOT"
 echo "Build complete: scadabridge:latest"
@@ -0,0 +1,199 @@
 # MxGateway Data Connection — Design
 **Date:** 2026-05-28
 **Component:** Data Connection Layer (#4), with touches to Commons (#16), Central UI (#9), Host (#15)
 **Status:** Approved — ready for implementation planning
 ## Summary
 Add a second data-connection protocol, **MxGateway**, alongside the existing OPC UA
 client. MxGateway connects to the MxAccess Gateway
 (`https://gitea.dohertylan.com/dohertj2`, packages `ZB.MOM.WW.MxGateway.Client` +
 `ZB.MOM.WW.MxGateway.Contracts`) over gRPC and exposes an AVEVA/Wonderware
 MXAccess-backed Galaxy as a clean tag-value pipe, identical in role to the OPC UA
 adapter.
 The Data Connection Layer was built for exactly this: `DataConnectionFactory`
 exposes `RegisterAdapter(protocolType, factory)` and every surrounding mechanism
 (the `DataConnectionActor` Become/Stash state machine, primary/backup failover,
 health reporting, re-subscribe-on-reconnect) is protocol-agnostic. The new
 protocol is a single `IDataConnection` adapter plus one registration line — no
 changes to the actor, the entity schema, or the failover machinery.
 ## Scope
 **In scope (this slice):**
 - Read / Subscribe / Write — MxGateway as a clean tag-value pipe.
 - Galaxy hierarchy browse for the instance-config tag picker.
 - Optional second endpoint for failover (reusing the existing primary/backup model).
 **Out of scope (possible later slices):**
 - Native MXAccess alarms (`QueryActiveAlarms` / `StreamAlarms` / `AcknowledgeAlarm`).
  ScadaBridge evaluates its own alarms via Alarm Actors from tag values; native
  alarms are a new concept.
 - Secured writes (`WriteSecured`, operator + verifier userId). Plain writes carry a
  configurable `WriteUserId` only.
 ## Decisions
 | Decision | Choice |
 |---|---|
 | Approach | New `IDataConnection` adapter behind the existing factory extension point (not a shared base class, not a separate subsystem). |
 | Protocol string | `"MxGateway"` (matches the NuGet package family). |
 | Browse plumbing | **Generalized** to protocol-agnostic browse driven by `IBrowsableDataConnection`; OPC UA and MxGateway share one path. |
 | Write user context | Optional `WriteUserId` config field, default `0`. No script API change. |
 | Endpoint redundancy | Reuse existing primary/backup failover; backup = a second gateway endpoint. |
 | ApiKey secret handling | Match whatever OPC UA `UserIdentityConfig` username/password does today. |
 ## Section 1 — Adapter & client lifecycle mapping
 New project-internal `MxGatewayDataConnection : IDataConnection, IBrowsableDataConnection`
 in `ZB.MOM.WW.ScadaBridge.DataConnectionLayer/Adapters/`, wrapping an injected
 `IMxGatewayClientFactory` (mirrors the `IOpcUaClientFactory` seam so it is
 unit-testable with a fake).
 | `IDataConnection` | MxGateway client |
 |---|---|
 | `ConnectAsync(details)` | `MxGatewayClient.Create(Endpoint, ApiKey, TLS)` → `OpenSessionAsync` → `RegisterAsync(clientName)` (store `serverHandle`); start background `StreamEventsAsync` consumer loop |
 | `SubscribeAsync(tagPath, cb)` | `AddItemAsync` → `AdviseAsync` (or `SubscribeBulkAsync`); map `itemHandle ↔ tagPath ↔ callback`; return subscriptionId |
 | `UnsubscribeAsync(id)` | `UnAdviseAsync` + `RemoveItemAsync` |
 | `ReadAsync` / `ReadBatchAsync` | `ReadBulkAsync` (uses cached advised value when present) |
 | `WriteAsync` / `WriteBatchAsync` | `WriteBulkAsync` with `WriteUserId`; value via `ToMxValue()` |
 | `WriteBatchAndWaitAsync` | generic compose: write values → write flag → poll `responsePath` (advised value or `ReadBulk`) until match/timeout |
 | `Status` | `ConnectionHealth` tracked across session state |
 | `Disconnected` | fired once (Interlocked guard) when `StreamEventsAsync` faults or the channel breaks |
 **Value/quality mapping.** Each `OnDataChange` `MxEvent` carries `item_handle`,
 `value` (`MxValue` → `ToClrValue()`), `quality` (OPC-style int), `source_timestamp`,
 `statuses`, and `worker_sequence`. Dispatched to the matching tag's
 `SubscriptionCallback` as `TagValue(ToClrValue(value), mapQuality(quality, statuses),
 source_timestamp)`. Quality: `quality >= 192` → `Good`; bad-category status → `Bad`;
 otherwise `Uncertain`. The loop tracks `worker_sequence` and resumes with
 `afterWorkerSequence` on reconnect so no change is missed.
 **Reconnection needs no new logic.** The existing `DataConnectionActor` catches
 `Disconnected`, pushes bad quality to all subscribed tags, disposes the adapter, and
 on retry calls `ConnectAsync` on a fresh adapter then re-subscribes all tags —
 identical to OPC UA.
 ## Section 2 — Configuration, secrets & endpoint redundancy
 New `MxGatewayEndpointConfig` in Commons (alongside `OpcUaEndpointConfig`) with a
 matching `MxGatewayEndpointConfigSerializer` (flat-dict ⇄ JSON) and
 `MxGatewayEndpointConfigValidator`. Stored exactly like OPC UA: per-connection JSON
 in `DataConnection.PrimaryConfiguration` / `BackupConfiguration`. **Primary/backup
 failover works for free** — backup = a second gateway endpoint, round-robin, no
 auto-failback, driven by the existing `FailoverRetryCount` state machine. No entity
 or migration changes.
 | Key | Type | Default | Notes |
 |---|---|---|---|
 | `Endpoint` | string | `http://localhost:5000` | Gateway base URL |
 | `ApiKey` | string | — | Sent as `authorization: Bearer <key>` |
 | `ClientName` | string | `scadabridge-<connName>` | Registration name |
 | `WriteUserId` | int | `0` | Applied to every write-back |
 | `UseTls` / `CaFile` / `ServerName` | bool/string/string | `false` / — / — | TLS to a secured gateway |
 | `ReadTimeoutMs` | int | `5000` | `ReadBulk` per-call timeout |
 **Secrets.** `ApiKey` follows whatever OPC UA `UserIdentityConfig` username/password
 does today (same at-rest treatment, same log/telemetry redaction). Match that pattern
 exactly; if OPC UA stores credentials in plaintext, `ApiKey` inherits the same known
 limitation (not a new regression) — flag during implementation.
 **Shared settings** (`ReconnectInterval`, `TagResolutionRetryInterval`,
 `WriteTimeout`) stay in `DataConnectionOptions`, unchanged, applying to all protocols.
 ## Section 3 — Protocol-agnostic browse (tag picker)
 `IBrowsableDataConnection` is already protocol-neutral (node ids are opaque strings).
 Generalize the OPC-UA-named plumbing so both protocols flow through one path.
 **Renames (site + central + UI):**
 | Today | Becomes |
 |---|---|
 | `BrowseOpcUaNodeCommand` / `BrowseOpcUaNodeResult` | `BrowseNodeCommand` / `BrowseNodeResult` |
 | `OpcUaBrowseService` / `IOpcUaBrowseService` | `BrowseService` / `IBrowseService` |
 | `OpcUaBrowserDialog.razor` | `NodeBrowserDialog.razor` |
 | `BrowseFailure` / `BrowseFailureKind` | kept (already generic) |
 `DataConnectionManagerActor` resolves the connection, checks
 `adapter is IBrowsableDataConnection`, and calls `BrowseChildrenAsync(parentNodeId)`
 regardless of protocol (already the OPC UA logic — just drop the "OpcUa" from names).
 Adapters without the interface return a "browse not supported" failure (unchanged).
 **MxGateway side.** `MxGatewayDataConnection.BrowseChildrenAsync` wraps
 `GalaxyRepositoryClient.BrowseChildrenAsync` (one Galaxy level per call). Mapping:
 - Galaxy object → `BrowseNode(NodeId = gobjectId-or-contained-path,
  DisplayName = tagName, NodeClass = Object, HasChildren = child_has_children[i])`.
 - Each object's attributes → `BrowseNode(NodeId = FullTagReference,
  NodeClass = Variable, HasChildren = false)` — Variable rows are the selectable tag
  paths stored in instance config.
 `GalaxyRepositoryClient` is a separate gRPC client from `MxGatewayClient`, so the
 adapter holds both (same Endpoint + ApiKey): browse uses the read-only repository
 client, the hot path uses the gateway client. The tag-picker dialog opens identically
 for either protocol; only the tree shape and opaque node-id strings differ.
 ## Section 4 — Packaging, DI registration & error classification
 **NuGet feed.** Add a repo-root `nuget.config` declaring the Gitea feed
 (`https://gitea.dohertylan.com/api/packages/dohertj2/nuget/index.json`) alongside
 nuget.org. Credentials are **not** committed — from the developer's `~/.nuget`, or
 for the Docker image build a build-arg/secret-mounted credential (wire into
 `docker/deploy.sh`). The DCL project references `ZB.MOM.WW.MxGateway.Client`
 (`…Contracts` transitively); both target net10.0.
 **DI registration** in `DataConnectionFactory`:
 ```csharp
 RegisterAdapter("MxGateway", details => new MxGatewayDataConnection(
    new MxGatewayClientFactory(_loggerFactory),
    _loggerFactory.CreateLogger<MxGatewayDataConnection>()));
 ```
 plus an `MxGatewayGlobalOptions` (parallel to `OpcUaGlobalOptions`) bound in Host.
 OPC UA registration untouched.
 **Error classification** (drives bad-quality push vs. synchronous script error):
 - *Connection/transport faults* (`MxGatewaySessionException`, gRPC unavailable, stream
  break) → `Disconnected` → reconnect + bad quality. Transient.
 - *Per-item read/write failures* (`BulkReadResult` / `BulkWriteResult` with
  `WasSuccessful = false`: bad tag, MXAccess rejection) → returned to caller (write) or
  bad quality (read). Not a disconnect.
 - *Auth failures* (`MxGatewayAuthenticationException` / `…AuthorizationException`) →
  treated like a failed connect (logged, retried on failover/reconnect cadence); a
  rotated key is operationally a connection problem, not per-tag.
 Matches OPC UA's "operations fail immediately to the caller; connection loss triggers
 reconnect" split.
 ## Section 5 — Testing, docs & deploy
 **Testing** (fake client seam, no live gateway, following the OPC UA adapter style):
 - `MxGatewayDataConnection` against a `FakeMxGatewayClient`: connect→register→advise
  lifecycle; `OnDataChange` → `TagValue` dispatch incl. quality mapping; read/write/batch
  success + per-item failure; `WriteBatchAndWait` match & timeout; `Disconnected` fires
  once on stream fault; `worker_sequence` resume on reconnect.
 - `MxGatewayEndpointConfigSerializer` / `Validator` round-trip + defaults +
  invalid-numeric fallback.
 - Browse mapping (object→Object, attribute→Variable, `HasChildren` hint) against a fake
  repository client.
 - Generalized-browse regression: existing OPC UA browse tests updated to renamed
  `BrowseNodeCommand` / `BrowseService` and still passing.
 **Docs (spec travels with code):**
 - `Component-DataConnectionLayer.md`: add MxGateway under "Supported Protocols", an
  "MxGateway Settings" config table, note `IBrowsableDataConnection` now backs both
  protocols.
 - `README.md` protocol mentions if any.
 - This design doc.
 **Deploy.** `bash docker/deploy.sh` rebuilds the image; only deploy-config change is
 NuGet credential wiring for restore. Sites get the adapter automatically (compiled into
 Host). No new ports/services — the adapter is an outbound gRPC client to the gateway.
 **Affected components:** DCL (adapter, factory, options), Commons (config type,
 serializer, validator, renamed browse messages + `IBrowsableDataConnection`
 consumers), Configuration Database (none — no schema change), Central UI (renamed
 browse service/dialog, protocol selector + `MxGatewayEndpointEditor` in
 `DataConnectionForm` — net-new UI, use `frontend-design` skill), Host (options
 binding), tests, docs, `nuget.config`.
@@ -0,0 +1,956 @@
 # MxGateway Data Connection Implementation Plan
 > **For Claude:** REQUIRED SUB-SKILL: Use superpowers-extended-cc:executing-plans to implement this plan task-by-task.
 **Goal:** Add a second data-connection protocol, **MxGateway**, alongside OPC UA — a clean tag-value pipe (read/subscribe/write) plus Galaxy hierarchy browse, with optional second-endpoint failover.
 **Architecture:** A new `MxGatewayDataConnection : IDataConnection, IBrowsableDataConnection` adapter registered behind the existing `DataConnectionFactory` extension point. The adapter talks to the MxAccess Gateway through an `IMxGatewayClient` seam (testable with a fake; the real impl wraps the `ZB.MOM.WW.MxGateway.Client` NuGet package and `GalaxyRepositoryClient`). The OPC-UA-named browse plumbing is renamed to protocol-agnostic names so both protocols share one tag-picker path. No entity/schema changes — primary/backup failover already lives on the `DataConnection` entity.
 **Tech Stack:** .NET 10, Akka.NET (Become/Stash actors), gRPC (`ZB.MOM.WW.MxGateway.Client` + `…Contracts` from the Gitea feed), Blazor Server + Bootstrap, xUnit + FluentAssertions, central NuGet package management.
 **Design doc:** `docs/plans/2026-05-28-mxgateway-data-connection-design.md`
 **Reference skills:** Use @superpowers-extended-cc:test-driven-development for every adapter/serializer task. Use @frontend-design for the two `.razor` UI tasks.
 ---
 ## Key facts the implementer needs
 - **Extension point:** `DataConnectionFactory` (`src/ZB.MOM.WW.ScadaBridge.DataConnectionLayer/DataConnectionFactory.cs`) registers protocols via `RegisterAdapter("OpcUa", details => …)` in its constructor. Add one line for `"MxGateway"`.
 - **Config flow:** stored config JSON → `DeploymentManagerActor.FlattenConnectionConfig(protocol, json)` (`src/ZB.MOM.WW.ScadaBridge.SiteRuntime/Actors/DeploymentManagerActor.cs:759`) → `IDictionary<string,string>` → `DataConnectionActor` → `adapter.ConnectAsync(details)`. The actor never knows the protocol's config shape; the dict is the contract. `FlattenConnectionConfig` currently branches on `"OpcUa"` and falls back to a generic flat-dict parse for unknown protocols — add an `"MxGateway"` arm.
 - **`IDataConnection` contract:** `src/ZB.MOM.WW.ScadaBridge.Commons/Interfaces/Protocol/IDataConnection.cs`. Methods: `ConnectAsync`, `DisconnectAsync`, `SubscribeAsync(tagPath, SubscriptionCallback, ct)→string`, `UnsubscribeAsync(id)`, `ReadAsync→ReadResult`, `ReadBatchAsync→IReadOnlyDictionary<string,ReadResult>`, `WriteAsync→WriteResult`, `WriteBatchAsync`, `WriteBatchAndWaitAsync→bool`, `Status` (`ConnectionHealth`), `event Action? Disconnected`. Value type: `TagValue(object? Value, QualityCode Quality, DateTimeOffset Timestamp)`; `QualityCode { Good, Bad, Uncertain }`.
 - **`IBrowsableDataConnection`:** `src/ZB.MOM.WW.ScadaBridge.Commons/Interfaces/Protocol/IBrowsableDataConnection.cs` — `BrowseChildrenAsync(string? parentNodeId, ct)→BrowseChildrenResult(IReadOnlyList<BrowseNode>, bool Truncated)`. `BrowseNode(string NodeId, string DisplayName, BrowseNodeClass NodeClass, bool HasChildren)`; `BrowseNodeClass { Object, Variable, Method, Other }`. Throw `ConnectionNotConnectedException` when no live session. **These record/interface names do NOT change in the rename** — only the OPC-UA-named *command/service/dialog* layer does.
 - **OPC UA adapter to mirror:** `src/ZB.MOM.WW.ScadaBridge.DataConnectionLayer/Adapters/OpcUaDataConnection.cs`. Note the `_disconnectFired` `Interlocked.Exchange` once-only guard pattern — replicate it.
 - **MxGateway client API** (in `~/Desktop/MxAccessGateway/clients/dotnet`): `MxGatewayClient.Create(MxGatewayClientOptions)` → `OpenSessionAsync()→MxGatewaySession`. Session: `RegisterAsync(clientName)→int serverHandle`; `AddItemAsync(serverHandle, itemDef)→int itemHandle`; `AdviseAsync(serverHandle, itemHandle)`; `UnAdviseAsync`/`RemoveItemAsync`; `SubscribeBulkAsync`/`UnsubscribeBulkAsync`; `ReadBulkAsync(serverHandle, tagAddresses, timeout)→IReadOnlyList<BulkReadResult>`; `WriteBulkAsync(serverHandle, IReadOnlyList<WriteBulkEntry>)→IReadOnlyList<BulkWriteResult>`; `StreamEventsAsync(afterWorkerSequence)→IAsyncEnumerable<MxEvent>`. Browse: `GalaxyRepositoryClient.Create(options)` → `BrowseChildrenRawAsync(BrowseChildrenRequest)→BrowseChildrenReply`. Value helpers: `MxValueExtensions.ToMxValue(...)`, `.ToClrValue()`; `MxStatusProxyExtensions.IsSuccess()`.
 - **`MxEvent`** fields: `family` (`MxEventFamily`), `item_handle`, `value` (`MxValue`), `quality` (int, OPC-style; ≥192 = good), `source_timestamp` (`google.protobuf.Timestamp`), `worker_sequence` (uint64), `body` oneof incl. `on_data_change`. `MxEventFamily.MX_EVENT_FAMILY_ON_DATA_CHANGE = 1`.
 - **`BulkReadResult`:** `tag_address`, `item_handle`, `was_successful`, `was_cached`, `value` (`MxValue`), `quality` (int), `source_timestamp`, `statuses`, `error_message`. **`BulkWriteResult`:** `item_handle`, `was_successful`, `hresult?`, `statuses`, `error_message`.
 - **`BrowseChildrenReply`:** `children` (`repeated GalaxyObject`), `next_page_token`, `total_child_count`, `child_has_children` (`repeated bool`). **`GalaxyObject`:** `gobject_id`, `tag_name`, `contained_name`, `parent_gobject_id`, `is_area`, `attributes` (`repeated GalaxyAttribute`). **`GalaxyAttribute`:** `attribute_name`, `full_tag_reference`, `data_type_name`, `is_array`, `is_historized`, `is_alarm`. **`BrowseChildrenRequest`** parent oneof: `parent_gobject_id` | `parent_tag_name` | `parent_contained_path`; plus `page_size`, `include_attributes`.
 - **Exceptions:** `MxGatewaySessionException`, `MxGatewayAuthenticationException`, `MxGatewayAuthorizationException`, `MxGatewayWorkerException`, `MxGatewayCommandException`, `MxAccessException` — all derive from `MxGatewayException`.
 - **Central package management:** versions go in `Directory.Packages.props` (`<PackageVersion>`); projects reference `<PackageReference Include="…" />` with no version.
 ---
 ## Task 1: Packaging foundation — Gitea feed + package refs
 **Classification:** small
 **Estimated implement time:** ~4 min
 **Parallelizable with:** Task 13 (rename track)
 **Files:**
 - Create: `nuget.config` (repo root)
 - Modify: `Directory.Packages.props`
 - Modify: `src/ZB.MOM.WW.ScadaBridge.DataConnectionLayer/ZB.MOM.WW.ScadaBridge.DataConnectionLayer.csproj`
 **Step 1: Create `nuget.config` at repo root**
 ```xml
 <?xml version="1.0" encoding="utf-8"?>
 <configuration>
  <packageSources>
    <clear />
    <add key="nuget.org" value="https://api.nuget.org/v3/index.json" />
    <add key="dohertj2-gitea" value="https://gitea.dohertylan.com/api/packages/dohertj2/nuget/index.json" />
  </packageSources>
  <!-- Credentials are NOT committed. Provide them per-developer via:
       dotnet nuget add source https://gitea.dohertylan.com/api/packages/dohertj2/nuget/index.json \
         --name dohertj2-gitea --username <user> --password <token> --store-password-in-clear-text
       or NuGet env vars in CI / the docker build (see docker/deploy.sh wiring in Task 19). -->
 </configuration>
 ```
 **Step 2: Add package versions to `Directory.Packages.props`** (under the existing `<ItemGroup>`; check the published version with `dotnet package search ZB.MOM.WW.MxGateway.Client --source dohertj2-gitea` — README references `0.1.0`, use the latest available):
 ```xml
    <PackageVersion Include="ZB.MOM.WW.MxGateway.Client" Version="0.1.0" />
    <PackageVersion Include="ZB.MOM.WW.MxGateway.Contracts" Version="0.1.0" />
 ```
 **Step 3: Add the PackageReference to the DCL csproj** (in the first `<ItemGroup>`, after the OPC UA reference):
 ```xml
    <PackageReference Include="ZB.MOM.WW.MxGateway.Client" />
 ```
 (`…Contracts` comes in transitively.)
 **Step 4: Restore and verify**
 Run: `dotnet restore ZB.MOM.WW.ScadaBridge.slnx`
 Expected: restore succeeds, the MxGateway packages resolve from the Gitea feed. If it fails with 401, the developer must add feed credentials (see the comment in `nuget.config`) — surface that, don't hardcode a token.
 **Step 5: Commit**
 ```bash
 git add nuget.config Directory.Packages.props src/ZB.MOM.WW.ScadaBridge.DataConnectionLayer/ZB.MOM.WW.ScadaBridge.DataConnectionLayer.csproj
 git commit -m "build(dcl): add Gitea feed + ZB.MOM.WW.MxGateway.Client package reference"
 ```
 ---
 ## Task 2: MxGatewayEndpointConfig type
 **Classification:** small
 **Estimated implement time:** ~3 min
 **Parallelizable with:** Task 13, Task 14
 **Files:**
 - Create: `src/ZB.MOM.WW.ScadaBridge.Commons/Types/DataConnections/MxGatewayEndpointConfig.cs`
 **Step 1: Write the type** (mirrors `OpcUaEndpointConfig` — a mutable POCO with defaults; fields per the design's config table):
 ```csharp
 namespace ZB.MOM.WW.ScadaBridge.Commons.Types.DataConnections;
 /// <summary>
 /// Per-endpoint configuration for an MxGateway data connection. Serialized to the
 /// typed JSON shape stored in <c>DataConnection.PrimaryConfiguration</c> /
 /// <c>BackupConfiguration</c>. Both primary and backup use this same shape — the
 /// backup is simply a second gateway endpoint for failover.
 /// </summary>
 public class MxGatewayEndpointConfig
 {
    /// <summary>Gateway base URL (e.g. "http://localhost:5000").</summary>
    public string Endpoint { get; set; } = "http://localhost:5000";
    /// <summary>API key sent to the gateway as <c>authorization: Bearer &lt;key&gt;</c>.</summary>
    public string ApiKey { get; set; } = "";
    /// <summary>MXAccess client registration name. Blank → derive "scadabridge-&lt;connName&gt;" at connect time.</summary>
    public string ClientName { get; set; } = "";
    /// <summary>MXAccess user id applied to every write-back. 0 = no user context.</summary>
    public int WriteUserId { get; set; }
    /// <summary>Use TLS to a secured gateway.</summary>
    public bool UseTls { get; set; }
    /// <summary>Path to the CA certificate (TLS only).</summary>
    public string CaFile { get; set; } = "";
    /// <summary>TLS server-name override.</summary>
    public string ServerName { get; set; } = "";
    /// <summary>ReadBulk per-call timeout in milliseconds.</summary>
    public int ReadTimeoutMs { get; set; } = 5000;
 }
 ```
 **Step 2: Build the Commons project**
 Run: `dotnet build src/ZB.MOM.WW.ScadaBridge.Commons/ZB.MOM.WW.ScadaBridge.Commons.csproj`
 Expected: PASS.
 **Step 3: Commit**
 ```bash
 git add src/ZB.MOM.WW.ScadaBridge.Commons/Types/DataConnections/MxGatewayEndpointConfig.cs
 git commit -m "feat(commons): add MxGatewayEndpointConfig type"
 ```
 ---
 ## Task 3: MxGatewayEndpointConfigSerializer + tests
 **Classification:** standard
 **Estimated implement time:** ~5 min
 **Parallelizable with:** Task 4, Task 13, Task 14
 **Files:**
 - Create: `src/ZB.MOM.WW.ScadaBridge.Commons/Serialization/MxGatewayEndpointConfigSerializer.cs`
 - Test: `tests/ZB.MOM.WW.ScadaBridge.Commons.Tests/Serialization/MxGatewayEndpointConfigSerializerTests.cs`
 This is simpler than the OPC UA serializer — MxGateway is net-new, so there is **no legacy flat-dict shape** to fall back to. Provide `Serialize`, `Deserialize` (typed-or-default), `ToFlatDict`, `FromFlatDict`. (Locate the existing OPC UA serializer tests under `tests/ZB.MOM.WW.ScadaBridge.Commons.Tests/Serialization/` and mirror their style.)
 **Step 1: Write the failing test**
 ```csharp
 using FluentAssertions;
 using ZB.MOM.WW.ScadaBridge.Commons.Serialization;
 using ZB.MOM.WW.ScadaBridge.Commons.Types.DataConnections;
 using Xunit;
 namespace ZB.MOM.WW.ScadaBridge.Commons.Tests.Serialization;
 public class MxGatewayEndpointConfigSerializerTests
 {
    [Fact]
    public void Serialize_then_Deserialize_round_trips_all_fields()
    {
        var cfg = new MxGatewayEndpointConfig
        {
            Endpoint = "https://gw:5001", ApiKey = "k", ClientName = "c",
            WriteUserId = 7, UseTls = true, CaFile = "/ca.pem",
            ServerName = "gw.local", ReadTimeoutMs = 1234
        };
        var json = MxGatewayEndpointConfigSerializer.Serialize(cfg);
        var back = MxGatewayEndpointConfigSerializer.Deserialize(json);
        back.Should().BeEquivalentTo(cfg);
    }
    [Fact]
    public void Deserialize_null_or_blank_returns_default()
        => MxGatewayEndpointConfigSerializer.Deserialize(null).Endpoint
            .Should().Be(new MxGatewayEndpointConfig().Endpoint);
    [Fact]
    public void ToFlatDict_FromFlatDict_round_trips()
    {
        var cfg = new MxGatewayEndpointConfig { Endpoint = "http://x", ApiKey = "k", WriteUserId = 3, ReadTimeoutMs = 999 };
        var dict = MxGatewayEndpointConfigSerializer.ToFlatDict(cfg);
        var back = MxGatewayEndpointConfigSerializer.FromFlatDict(dict);
        back.Should().BeEquivalentTo(cfg);
    }
    [Fact]
    public void FromFlatDict_invalid_numeric_falls_back_to_default()
    {
        var back = MxGatewayEndpointConfigSerializer.FromFlatDict(
            new Dictionary<string, string> { ["ReadTimeoutMs"] = "not-a-number" });
        back.ReadTimeoutMs.Should().Be(new MxGatewayEndpointConfig().ReadTimeoutMs);
    }
 }
 ```
 **Step 2: Run to verify it fails**
 Run: `dotnet test tests/ZB.MOM.WW.ScadaBridge.Commons.Tests/ --filter MxGatewayEndpointConfigSerializerTests`
 Expected: FAIL (type does not exist).
 **Step 3: Write the serializer**
 ```csharp
 using System.Globalization;
 using System.Text.Json;
 using ZB.MOM.WW.ScadaBridge.Commons.Types.DataConnections;
 namespace ZB.MOM.WW.ScadaBridge.Commons.Serialization;
 /// <summary>
 /// Serializes <see cref="MxGatewayEndpointConfig"/> to/from the typed JSON stored in
 /// <c>DataConnection.PrimaryConfiguration</c> / <c>BackupConfiguration</c>, and flattens
 /// it to the <c>IDictionary&lt;string,string&gt;</c> shape <c>IDataConnection.ConnectAsync</c>
 /// expects. MxGateway is net-new, so there is no legacy shape to recover.
 /// </summary>
 public static class MxGatewayEndpointConfigSerializer
 {
    private static readonly JsonSerializerOptions JsonOpts = new()
    {
        PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
        WriteIndented = false,
    };
    public static string Serialize(MxGatewayEndpointConfig config)
        => JsonSerializer.Serialize(config, JsonOpts);
    public static MxGatewayEndpointConfig Deserialize(string? json)
    {
        if (string.IsNullOrWhiteSpace(json)) return new MxGatewayEndpointConfig();
        try { return JsonSerializer.Deserialize<MxGatewayEndpointConfig>(json, JsonOpts) ?? new MxGatewayEndpointConfig(); }
        catch (JsonException) { return new MxGatewayEndpointConfig(); }
    }
    public static IDictionary<string, string> ToFlatDict(MxGatewayEndpointConfig c) => new Dictionary<string, string>
    {
        ["Endpoint"] = c.Endpoint,
        ["ApiKey"] = c.ApiKey,
        ["ClientName"] = c.ClientName,
        ["WriteUserId"] = c.WriteUserId.ToString(CultureInfo.InvariantCulture),
        ["UseTls"] = c.UseTls.ToString(),
        ["CaFile"] = c.CaFile,
        ["ServerName"] = c.ServerName,
        ["ReadTimeoutMs"] = c.ReadTimeoutMs.ToString(CultureInfo.InvariantCulture),
    };
    public static MxGatewayEndpointConfig FromFlatDict(IDictionary<string, string> d)
    {
        var c = new MxGatewayEndpointConfig();
        if (d.TryGetValue("Endpoint", out var ep) && !string.IsNullOrWhiteSpace(ep)) c.Endpoint = ep;
        if (d.TryGetValue("ApiKey", out var ak)) c.ApiKey = ak;
        if (d.TryGetValue("ClientName", out var cn)) c.ClientName = cn;
        if (d.TryGetValue("WriteUserId", out var wu) && int.TryParse(wu, out var wuv)) c.WriteUserId = wuv;
        if (d.TryGetValue("UseTls", out var tls) && bool.TryParse(tls, out var tlsv)) c.UseTls = tlsv;
        if (d.TryGetValue("CaFile", out var ca)) c.CaFile = ca;
        if (d.TryGetValue("ServerName", out var sn)) c.ServerName = sn;
        if (d.TryGetValue("ReadTimeoutMs", out var rt) && int.TryParse(rt, out var rtv)) c.ReadTimeoutMs = rtv;
        return c;
    }
 }
 ```
 **Step 4: Run tests to verify they pass**
 Run: `dotnet test tests/ZB.MOM.WW.ScadaBridge.Commons.Tests/ --filter MxGatewayEndpointConfigSerializerTests`
 Expected: PASS (4 tests).
 **Step 5: Commit**
 ```bash
 git add src/ZB.MOM.WW.ScadaBridge.Commons/Serialization/MxGatewayEndpointConfigSerializer.cs tests/ZB.MOM.WW.ScadaBridge.Commons.Tests/Serialization/MxGatewayEndpointConfigSerializerTests.cs
 git commit -m "feat(commons): MxGatewayEndpointConfig serializer + tests"
 ```
 ---
 ## Task 4: MxGatewayEndpointConfigValidator + tests
 **Classification:** small
 **Estimated implement time:** ~3 min
 **Parallelizable with:** Task 3, Task 13, Task 14
 **Files:**
 - Create: `src/ZB.MOM.WW.ScadaBridge.Commons/Validators/MxGatewayEndpointConfigValidator.cs`
 - Test: `tests/ZB.MOM.WW.ScadaBridge.Commons.Tests/Validators/MxGatewayEndpointConfigValidatorTests.cs`
 Mirror `OpcUaEndpointConfigValidator` (returns a list of error strings, prefixed). Rules: `Endpoint` required + must be an absolute `http(s)` URI; `ApiKey` required; `ReadTimeoutMs > 0`; if `UseTls` and `CaFile` set, `CaFile` must be non-blank (warn only if blank — TLS can use system roots). Read the existing validator first to match the exact signature (likely `static IReadOnlyList<string> Validate(MxGatewayEndpointConfig cfg, string prefix)`).
 **Step 1:** Write failing tests (valid config → no errors; blank Endpoint → error; blank ApiKey → error; ReadTimeoutMs 0 → error). **Step 2:** Run, verify FAIL. **Step 3:** Implement. **Step 4:** Run, verify PASS. **Step 5:** Commit `feat(commons): MxGatewayEndpointConfig validator + tests`.
 ---
 ## Task 5: Client seam interfaces + MxGatewayGlobalOptions
 **Classification:** standard
 **Estimated implement time:** ~5 min
 **Parallelizable with:** Task 13, Task 14
 **Files:**
 - Create: `src/ZB.MOM.WW.ScadaBridge.DataConnectionLayer/Adapters/IMxGatewayClient.cs`
 - Create: `src/ZB.MOM.WW.ScadaBridge.DataConnectionLayer/MxGatewayGlobalOptions.cs`
 The seam uses **neutral DTOs** (no generated protobuf types) so the adapter and its tests never touch the NuGet package — the real impl (Task 11) translates. This is the same pattern as `IOpcUaClient`.
 **Step 1: Write `IMxGatewayClient.cs`**
 ```csharp
 using ZB.MOM.WW.ScadaBridge.Commons.Interfaces.Protocol;
 namespace ZB.MOM.WW.ScadaBridge.DataConnectionLayer.Adapters;
 /// <summary>Connection parameters resolved from the flat config dict.</summary>
 public record MxGatewayConnectionOptions(
    string Endpoint, string ApiKey, string ClientName, int WriteUserId,
    bool UseTls, string? CaFile, string? ServerName, int ReadTimeoutMs);
 /// <summary>One advised-tag value change pushed from the gateway event stream.</summary>
 public record MxValueUpdate(string TagPath, object? Value, QualityCode Quality, DateTimeOffset Timestamp);
 /// <summary>Per-tag read outcome.</summary>
 public record MxReadOutcome(string TagPath, bool Success, object? Value, QualityCode Quality, DateTimeOffset Timestamp, string? Error);
 /// <summary>Per-tag write outcome.</summary>
 public record MxWriteOutcome(string TagPath, bool Success, string? Error);
 /// <summary>One node in a Galaxy browse level.</summary>
 public record MxBrowseChild(string NodeId, string DisplayName, BrowseNodeClass NodeClass, bool HasChildren);
 /// <summary>
 /// Seam over the MxAccess Gateway .NET client + Galaxy repository client. Decouples
 /// <see cref="MxGatewayDataConnection"/> from the generated gRPC/protobuf types so the
 /// adapter is unit-testable with a fake. The real implementation lives in
 /// <c>RealMxGatewayClient</c> (Task 11).
 /// </summary>
 public interface IMxGatewayClient : IAsyncDisposable
 {
    /// <summary>Opens the gateway session and registers the client (Register → serverHandle held internally).</summary>
    Task ConnectAsync(MxGatewayConnectionOptions options, CancellationToken ct = default);
    /// <summary>Closes the session.</summary>
    Task DisconnectAsync(CancellationToken ct = default);
    /// <summary>AddItem + Advise; returns the gateway item handle (as a string subscription id).</summary>
    Task<string> SubscribeAsync(string tagPath, CancellationToken ct = default);
    /// <summary>UnAdvise + RemoveItem for a previously returned subscription id.</summary>
    Task UnsubscribeAsync(string subscriptionId, CancellationToken ct = default);
    /// <summary>Snapshot read of one or more tags (ReadBulk).</summary>
    Task<IReadOnlyList<MxReadOutcome>> ReadAsync(IReadOnlyList<string> tagPaths, CancellationToken ct = default);
    /// <summary>Write one or more tag/value pairs (WriteBulk with the configured WriteUserId).</summary>
    Task<IReadOnlyList<MxWriteOutcome>> WriteAsync(IReadOnlyList<(string TagPath, object? Value)> writes, CancellationToken ct = default);
    /// <summary>One Galaxy browse level (BrowseChildren). parentNodeId null → root.</summary>
    Task<(IReadOnlyList<MxBrowseChild> Children, bool Truncated)> BrowseChildrenAsync(string? parentNodeId, CancellationToken ct = default);
    /// <summary>
    /// Long-running event consumer. Invokes <paramref name="onUpdate"/> for each advised-tag
    /// data change. Resumes from the last delivered worker sequence on reconnect. Completes
    /// (or throws) when the stream ends — the adapter treats that as a disconnect.
    /// </summary>
    Task RunEventLoopAsync(Action<MxValueUpdate> onUpdate, CancellationToken ct = default);
 }
 /// <summary>Builds <see cref="IMxGatewayClient"/> instances.</summary>
 public interface IMxGatewayClientFactory
 {
    IMxGatewayClient Create();
 }
 ```
 **Step 2: Write `MxGatewayGlobalOptions.cs`**
 ```csharp
 namespace ZB.MOM.WW.ScadaBridge.DataConnectionLayer;
 /// <summary>
 /// Deployment-wide MxGateway defaults, bound from the "MxGateway" section of
 /// appsettings.json. Per-endpoint behavior lives on MxGatewayEndpointConfig.
 /// </summary>
 public class MxGatewayGlobalOptions
 {
    /// <summary>Prefix used to derive a per-connection client registration name when the connection's ClientName is blank.</summary>
    public string ClientNamePrefix { get; set; } = "scadabridge";
 }
 ```
 **Step 3: Build the DCL project.** Run: `dotnet build src/ZB.MOM.WW.ScadaBridge.DataConnectionLayer/`. Expected: PASS.
 **Step 4: Commit** `feat(dcl): MxGateway client seam interfaces + global options`.
 ---
 ## Task 6: Adapter — connect / disconnect / status / Disconnected + value mapping
 **Classification:** high-risk
 **Estimated implement time:** ~5 min
 **Parallelizable with:** Task 13, Task 14
 **Files:**
 - Create: `src/ZB.MOM.WW.ScadaBridge.DataConnectionLayer/Adapters/MxGatewayDataConnection.cs`
 - Create: `tests/ZB.MOM.WW.ScadaBridge.DataConnectionLayer.Tests/Adapters/FakeMxGatewayClient.cs`
 - Test: `tests/ZB.MOM.WW.ScadaBridge.DataConnectionLayer.Tests/Adapters/MxGatewayDataConnectionTests.cs`
 > Locate the existing OPC UA adapter test project (the dir holding `OpcUaDataConnectionTests` / fake clients) and place these alongside it; adjust the namespace/paths above if the actual project name differs.
 **Step 1: Write `FakeMxGatewayClient`** — records calls; lets tests push `MxValueUpdate`s into the captured `onUpdate`, and complete/fault the event loop on demand:
 ```csharp
 using System.Collections.Concurrent;
 using ZB.MOM.WW.ScadaBridge.DataConnectionLayer.Adapters;
 namespace ZB.MOM.WW.ScadaBridge.DataConnectionLayer.Tests.Adapters;
 public sealed class FakeMxGatewayClient : IMxGatewayClient, IMxGatewayClientFactory
 {
    public MxGatewayConnectionOptions? ConnectedWith;
    public readonly List<string> Subscribed = new();
    public readonly TaskCompletionSource EventLoopGate = new(TaskCreationOptions.RunContinuationsAsynchronously);
    public Action<MxValueUpdate>? OnUpdate;
    public Func<IReadOnlyList<string>, IReadOnlyList<MxReadOutcome>>? ReadHandler;
    public Func<IReadOnlyList<(string, object?)>, IReadOnlyList<MxWriteOutcome>>? WriteHandler;
    public Func<string?, (IReadOnlyList<MxBrowseChild>, bool)>? BrowseHandler;
    private int _nextHandle;
    public IMxGatewayClient Create() => this;
    public Task ConnectAsync(MxGatewayConnectionOptions o, CancellationToken ct = default) { ConnectedWith = o; return Task.CompletedTask; }
    public Task DisconnectAsync(CancellationToken ct = default) => Task.CompletedTask;
    public Task<string> SubscribeAsync(string tag, CancellationToken ct = default) { Subscribed.Add(tag); return Task.FromResult((++_nextHandle).ToString()); }
    public Task UnsubscribeAsync(string id, CancellationToken ct = default) { Subscribed.Remove(id); return Task.CompletedTask; }
    public Task<IReadOnlyList<MxReadOutcome>> ReadAsync(IReadOnlyList<string> tags, CancellationToken ct = default) => Task.FromResult(ReadHandler!(tags));
    public Task<IReadOnlyList<MxWriteOutcome>> WriteAsync(IReadOnlyList<(string, object?)> w, CancellationToken ct = default) => Task.FromResult(WriteHandler!(w));
    public Task<(IReadOnlyList<MxBrowseChild>, bool)> BrowseChildrenAsync(string? p, CancellationToken ct = default) => Task.FromResult(BrowseHandler!(p));
    public async Task RunEventLoopAsync(Action<MxValueUpdate> onUpdate, CancellationToken ct = default)
    {
        OnUpdate = onUpdate;
        using var reg = ct.Register(() => EventLoopGate.TrySetResult());
        await EventLoopGate.Task;          // test completes this to end the loop…
        ct.ThrowIfCancellationRequested(); // …or faults it to simulate a stream break
    }
    public ValueTask DisposeAsync() => ValueTask.CompletedTask;
    public void FaultEventLoop() => EventLoopGate.TrySetException(new Exception("stream broke"));
 }
 ```
 **Step 2: Write failing tests**
 ```csharp
 [Fact]
 public async Task ConnectAsync_resolves_options_and_sets_status_connected() { /* connect with a flat dict; assert fake.ConnectedWith.Endpoint + Status == Connected */ }
 [Fact]
 public async Task Disconnected_fires_exactly_once_when_event_loop_faults() { /* hook event; FaultEventLoop(); assert raised once */ }
 ```
 **Step 3: Implement the adapter core.** Class declaration + connect + the value-mapping helper:
 ```csharp
 using System.Collections.Concurrent;
 using Microsoft.Extensions.Logging;
 using ZB.MOM.WW.ScadaBridge.Commons.Interfaces.Protocol;
 using ZB.MOM.WW.ScadaBridge.Commons.Serialization;
 using ZB.MOM.WW.ScadaBridge.Commons.Types.Enums;
 namespace ZB.MOM.WW.ScadaBridge.DataConnectionLayer.Adapters;
 public class MxGatewayDataConnection : IDataConnection, IBrowsableDataConnection
 {
    private readonly IMxGatewayClientFactory _clientFactory;
    private readonly ILogger<MxGatewayDataConnection> _logger;
    private IMxGatewayClient? _client;
    private ConnectionHealth _status = ConnectionHealth.Disconnected;
    private CancellationTokenSource? _eventLoopCts;
    // subscriptionId → (tagPath, callback) so the event loop can route updates by tag.
    private readonly ConcurrentDictionary<string, (string TagPath, SubscriptionCallback Callback)> _subs = new();
    private readonly ConcurrentDictionary<string, string> _tagToSub = new();
    private int _disconnectFired; // 0 = not fired, 1 = fired — Interlocked guard, mirrors OpcUaDataConnection.
    public MxGatewayDataConnection(IMxGatewayClientFactory clientFactory, ILogger<MxGatewayDataConnection> logger)
    { _clientFactory = clientFactory; _logger = logger; }
    public ConnectionHealth Status => _status;
    public event Action? Disconnected;
    public async Task ConnectAsync(IDictionary<string, string> connectionDetails, CancellationToken ct = default)
    {
        var cfg = MxGatewayEndpointConfigSerializer.FromFlatDict(connectionDetails);
        Interlocked.Exchange(ref _disconnectFired, 0); // reset guard on (re)connect, like OPC UA
        _client = _clientFactory.Create();
        await _client.ConnectAsync(new MxGatewayConnectionOptions(
            cfg.Endpoint, cfg.ApiKey,
            string.IsNullOrWhiteSpace(cfg.ClientName) ? "scadabridge" : cfg.ClientName,
            cfg.WriteUserId, cfg.UseTls,
            string.IsNullOrWhiteSpace(cfg.CaFile) ? null : cfg.CaFile,
            string.IsNullOrWhiteSpace(cfg.ServerName) ? null : cfg.ServerName,
            cfg.ReadTimeoutMs), ct);
        _status = ConnectionHealth.Connected;
        // Background event loop: route each value change to the matching subscription callback.
        _eventLoopCts = new CancellationTokenSource();
        _ = Task.Run(() => RunEventLoopAsync(_eventLoopCts.Token));
    }
    private async Task RunEventLoopAsync(CancellationToken ct)
    {
        try
        {
            await _client!.RunEventLoopAsync(update =>
            {
                if (_tagToSub.TryGetValue(update.TagPath, out var subId) && _subs.TryGetValue(subId, out var s))
                    s.Callback(update.TagPath, new TagValue(update.Value, update.Quality, update.Timestamp));
            }, ct);
        }
        catch (OperationCanceledException) { /* normal shutdown */ }
        catch (Exception ex)
        {
            _logger.LogWarning(ex, "MxGateway event stream faulted; signalling disconnect");
            RaiseDisconnected();
        }
    }
    private void RaiseDisconnected()
    {
        if (Interlocked.Exchange(ref _disconnectFired, 1) == 0)
        {
            _status = ConnectionHealth.Disconnected;
            Disconnected?.Invoke();
        }
    }
    public async Task DisconnectAsync(CancellationToken ct = default)
    {
        _eventLoopCts?.Cancel();
        if (_client is not null) await _client.DisconnectAsync(ct);
        _status = ConnectionHealth.Disconnected;
    }
    public async ValueTask DisposeAsync()
    {
        _eventLoopCts?.Cancel();
        if (_client is not null) await _client.DisposeAsync();
    }
    // SubscribeAsync / UnsubscribeAsync — Task 7
    // ReadAsync / ReadBatchAsync / WriteAsync / WriteBatchAsync — Task 8
    // WriteBatchAndWaitAsync — Task 9
    // BrowseChildrenAsync — Task 10
    // (Throw NotImplementedException stubs for now so the file compiles.)
 }
 ```
 Add `throw new NotImplementedException()` stubs for the not-yet-implemented interface members so the project builds.
 **Step 4: Run tests, verify PASS.** Run: `dotnet test tests/ZB.MOM.WW.ScadaBridge.DataConnectionLayer.Tests/ --filter MxGatewayDataConnectionTests`.
 **Step 5: Commit** `feat(dcl): MxGatewayDataConnection connect/disconnect/Disconnected + value mapping`.
 ---
 ## Task 7: Adapter — subscribe / unsubscribe + event routing
 **Classification:** high-risk
 **Estimated implement time:** ~4 min
 **Parallelizable with:** Task 13, Task 14
 **Depends on:** Task 6
 **Files:**
 - Modify: `src/ZB.MOM.WW.ScadaBridge.DataConnectionLayer/Adapters/MxGatewayDataConnection.cs`
 - Test: `tests/ZB.MOM.WW.ScadaBridge.DataConnectionLayer.Tests/Adapters/MxGatewayDataConnectionTests.cs`
 **Step 1:** Test: after `SubscribeAsync("Area.Pump.Speed", cb)`, pushing an `MxValueUpdate` for that tag through the fake's `OnUpdate` invokes `cb` with the mapped `TagValue`; `UnsubscribeAsync` stops routing.
 **Step 2:** Run, verify FAIL (NotImplementedException).
 **Step 3:** Implement:
 ```csharp
 public async Task<string> SubscribeAsync(string tagPath, SubscriptionCallback callback, CancellationToken ct = default)
 {
    var subId = await _client!.SubscribeAsync(tagPath, ct);
    _subs[subId] = (tagPath, callback);
    _tagToSub[tagPath] = subId;
    return subId;
 }
 public async Task UnsubscribeAsync(string subscriptionId, CancellationToken ct = default)
 {
    if (_subs.TryRemove(subscriptionId, out var s)) _tagToSub.TryRemove(s.TagPath, out _);
    await _client!.UnsubscribeAsync(subscriptionId, ct);
 }
 ```
 **Step 4:** Run tests, verify PASS. **Step 5:** Commit `feat(dcl): MxGateway subscribe/unsubscribe + event routing`.
 ---
 ## Task 8: Adapter — read / write + error classification
 **Classification:** standard
 **Estimated implement time:** ~5 min
 **Parallelizable with:** Task 13, Task 14
 **Depends on:** Task 6
 **Files:**
 - Modify: `MxGatewayDataConnection.cs`
 - Test: `MxGatewayDataConnectionTests.cs`
 **Step 1:** Tests: `ReadAsync` maps a successful `MxReadOutcome` to `ReadResult(true, TagValue, null)` and a failed one to `ReadResult(false, null, error)`; `ReadBatchAsync` returns a dict keyed by tag; `WriteAsync` maps `MxWriteOutcome` success/failure to `WriteResult`; `WriteBatchAsync` returns a per-tag dict.
 **Step 2:** Run, verify FAIL.
 **Step 3:** Implement (single reads/writes delegate to the batch path):
 ```csharp
 public async Task<ReadResult> ReadAsync(string tagPath, CancellationToken ct = default)
 {
    var r = (await _client!.ReadAsync(new[] { tagPath }, ct)).Single();
    return r.Success
        ? new ReadResult(true, new TagValue(r.Value, r.Quality, r.Timestamp), null)
        : new ReadResult(false, null, r.Error);
 }
 public async Task<IReadOnlyDictionary<string, ReadResult>> ReadBatchAsync(IEnumerable<string> tagPaths, CancellationToken ct = default)
 {
    var list = tagPaths.ToList();
    var results = await _client!.ReadAsync(list, ct);
    return results.ToDictionary(r => r.TagPath, r => r.Success
        ? new ReadResult(true, new TagValue(r.Value, r.Quality, r.Timestamp), null)
        : new ReadResult(false, null, r.Error));
 }
 public async Task<WriteResult> WriteAsync(string tagPath, object? value, CancellationToken ct = default)
 {
    var w = (await _client!.WriteAsync(new[] { (tagPath, value) }, ct)).Single();
    return new WriteResult(w.Success, w.Error);
 }
 public async Task<IReadOnlyDictionary<string, WriteResult>> WriteBatchAsync(IDictionary<string, object?> values, CancellationToken ct = default)
 {
    var results = await _client!.WriteAsync(values.Select(kv => (kv.Key, kv.Value)).ToList(), ct);
    return results.ToDictionary(w => w.TagPath, w => new WriteResult(w.Success, w.Error));
 }
 ```
 Error-classification note for the implementer: per-tag failures (`Success == false`) are returned to the caller as shown — they must NOT raise `Disconnected`. Transport/session faults surface as exceptions from the seam (the real impl in Task 11 throws `MxGatewaySessionException`/gRPC errors), which the `DataConnectionActor` already catches and which the event loop turns into a `Disconnected`. Auth failures are handled at connect time (Task 11).
 **Step 4:** Run tests, verify PASS. **Step 5:** Commit `feat(dcl): MxGateway read/write batch + error classification`.
 ---
 ## Task 9: Adapter — WriteBatchAndWaitAsync
 **Classification:** standard
 **Estimated implement time:** ~4 min
 **Parallelizable with:** Task 13, Task 14
 **Depends on:** Task 8
 **Files:**
 - Modify: `MxGatewayDataConnection.cs`
 - Test: `MxGatewayDataConnectionTests.cs`
 **Step 1:** Tests: writes values+flag, then polls `responsePath`; returns `true` when the response value appears before timeout, `false` on timeout. Drive via the fake's `ReadHandler` (return the expected value after N polls / never).
 **Step 2:** Run, verify FAIL.
 **Step 3:** Implement generically (write the batch, write the flag, poll the response path until match or timeout):
 ```csharp
 public async Task<bool> WriteBatchAndWaitAsync(
    IDictionary<string, object?> values, string flagPath, object? flagValue,
    string responsePath, object? responseValue, TimeSpan timeout, CancellationToken ct = default)
 {
    await WriteBatchAsync(values, ct);
    await WriteAsync(flagPath, flagValue, ct);
    using var timeoutCts = CancellationTokenSource.CreateLinkedTokenSource(ct);
    timeoutCts.CancelAfter(timeout);
    try
    {
        while (!timeoutCts.IsCancellationRequested)
        {
            var r = await ReadAsync(responsePath, timeoutCts.Token);
            if (r.Success && Equals(r.Value?.ToString(), responseValue?.ToString())) return true;
            await Task.Delay(TimeSpan.FromMilliseconds(200), timeoutCts.Token);
        }
    }
    catch (OperationCanceledException) when (!ct.IsCancellationRequested) { /* timeout */ }
    return false;
 }
 ```
 (Value comparison uses string projection to tolerate numeric type differences across the gRPC boundary — match the OPC UA adapter's comparison approach if it differs; check `OpcUaDataConnection.WriteBatchAndWaitAsync`.)
 **Step 4:** Run tests, verify PASS. **Step 5:** Commit `feat(dcl): MxGateway WriteBatchAndWait`.
 ---
 ## Task 10: Adapter — Galaxy browse (IBrowsableDataConnection)
 **Classification:** standard
 **Estimated implement time:** ~4 min
 **Parallelizable with:** Task 13, Task 14
 **Depends on:** Task 6
 **Files:**
 - Modify: `MxGatewayDataConnection.cs`
 - Test: `MxGatewayDataConnectionTests.cs`
 **Step 1:** Tests: `BrowseChildrenAsync(null)` maps the fake's children to `BrowseChildrenResult` (object→`BrowseNodeClass.Object`, attribute→`Variable`, `HasChildren` preserved, `Truncated` flag passed through); when the seam reports not-connected, the adapter throws `ConnectionNotConnectedException`.
 **Step 2:** Run, verify FAIL.
 **Step 3:** Implement (the seam already returns neutral `MxBrowseChild`s; the Galaxy→node mapping itself lives in the real impl, Task 11):
 ```csharp
 public async Task<BrowseChildrenResult> BrowseChildrenAsync(string? parentNodeId, CancellationToken ct = default)
 {
    if (_status != ConnectionHealth.Connected)
        throw new ConnectionNotConnectedException($"MxGateway connection is not connected (status: {_status}).");
    var (children, truncated) = await _client!.BrowseChildrenAsync(parentNodeId, ct);
    var nodes = children
        .Select(c => new BrowseNode(c.NodeId, c.DisplayName, c.NodeClass, c.HasChildren))
        .ToList();
    return new BrowseChildrenResult(nodes, truncated);
 }
 ```
 **Step 4:** Run tests, verify PASS. **Step 5:** Commit `feat(dcl): MxGateway Galaxy browse via IBrowsableDataConnection`.
 ---
 ## Task 11: RealMxGatewayClient — seam implementation over the NuGet client
 **Classification:** high-risk
 **Estimated implement time:** ~5 min
 **Parallelizable with:** Task 13, Task 14
 **Depends on:** Task 1, Task 5
 **Files:**
 - Create: `src/ZB.MOM.WW.ScadaBridge.DataConnectionLayer/Adapters/RealMxGatewayClient.cs`
 This is the only file that touches the generated protobuf/gRPC types. It is integration-shaped (no unit test — exercised in Task 19's smoke against a live/staged gateway). Implement `IMxGatewayClient` + `IMxGatewayClientFactory` (`RealMxGatewayClientFactory`).
 **Implementation notes (use the verbatim client API from the design doc / key-facts section):**
 - `ConnectAsync`: build `MxGatewayClientOptions { Endpoint = new Uri(o.Endpoint), ApiKey = o.ApiKey, UseTls = o.UseTls, CaCertificatePath = o.CaFile, ServerNameOverride = o.ServerName }`; `_client = MxGatewayClient.Create(opts)`; `_galaxy = GalaxyRepositoryClient.Create(opts)`; `_session = await _client.OpenSessionAsync(ct)`; `_serverHandle = await _session.RegisterAsync(o.ClientName, ct)`; store `o.WriteUserId` and `o.ReadTimeoutMs`. Catch `MxGatewayAuthenticationException`/`MxGatewayAuthorizationException` and rethrow (the actor logs + retries on the reconnect cadence — auth failure is treated like a failed connect).
 - `SubscribeAsync(tag)`: `var h = await _session.AddItemAsync(_serverHandle, tag, ct); await _session.AdviseAsync(_serverHandle, h, ct);` track `tag↔h`; return `h.ToString()`.
 - `UnsubscribeAsync(id)`: parse handle; `await _session.UnAdviseAsync(_serverHandle, h, ct); await _session.RemoveItemAsync(_serverHandle, h, ct);`.
 - `ReadAsync(tags)`: `var results = await _session.ReadBulkAsync(_serverHandle, tags, TimeSpan.FromMilliseconds(_readTimeoutMs), ct);` map each `BulkReadResult` → `MxReadOutcome(r.TagAddress, r.WasSuccessful, r.Value.ToClrValue(), MapQuality(r.Quality, r.Statuses), r.SourceTimestamp.ToDateTimeOffset(), r.WasSuccessful ? null : r.ErrorMessage)`.
 - `WriteAsync(writes)`: build `WriteBulkEntry { ItemHandle = handleForTag, Value = value.ToMxValue(), UserId = _writeUserId }` (resolve item handle; AddItem on demand if the tag isn't already advised — keep a tag→handle cache). `await _session.WriteBulkAsync(...)`; map `BulkWriteResult` → `MxWriteOutcome(tag, r.WasSuccessful, r.WasSuccessful ? null : r.ErrorMessage)`. **Value conversion** uses the `ToMxValue()` overloads — pick by runtime type (bool/int/long/float/double/string/DateTime).
 - `BrowseChildrenAsync(parentNodeId)`: build `BrowseChildrenRequest { IncludeAttributes = true }`; if `parentNodeId` is non-null set `ParentContainedPath = parentNodeId` (the NodeId we emit for objects is the contained path); `var reply = await _galaxy.BrowseChildrenRawAsync(req, ct);` then map: each `GalaxyObject` → `MxBrowseChild(NodeId: obj.ContainedName-or-derived-path, DisplayName: obj.TagName, NodeClass.Object, HasChildren: reply.ChildHasChildren[i])`; each `GalaxyAttribute` → `MxBrowseChild(NodeId: attr.FullTagReference, DisplayName: attr.AttributeName, NodeClass.Variable, HasChildren: false)`. Truncated = `!string.IsNullOrEmpty(reply.NextPageToken)`. Map any gRPC `RpcException` with `StatusCode.Unavailable` to `ConnectionNotConnectedException`.
 - `RunEventLoopAsync(onUpdate, ct)`: `await foreach (var ev in _session.StreamEventsAsync(_lastSeq, ct))` — for each `ev` where `ev.Family == MxEventFamily.OnDataChange`, resolve the tag from `ev.ItemHandle`, `onUpdate(new MxValueUpdate(tag, ev.Value.ToClrValue(), MapQuality(ev.Quality, ev.Statuses), ev.SourceTimestamp.ToDateTimeOffset()))`, then `_lastSeq = ev.WorkerSequence`. Let the loop throw on stream break — the adapter turns that into `Disconnected`.
 - `MapQuality(int quality, IReadOnlyList<MxStatusProxy> statuses)`: `if (statuses.Any(s => !s.IsSuccess())) return QualityCode.Bad;` `return quality >= 192 ? QualityCode.Good : (quality >= 64 ? QualityCode.Uncertain : QualityCode.Bad);` (192 = OPC Good, 64 = Uncertain band).
 - `DisposeAsync`/`DisconnectAsync`: dispose session + both clients.
 **Step 1:** Write the file. **Step 2:** Build the DCL project: `dotnet build src/ZB.MOM.WW.ScadaBridge.DataConnectionLayer/` — expected PASS (this is where the generated-type field names are verified against the package; fix any casing mismatches against IntelliSense/the generated `.cs`). **Step 3:** Commit `feat(dcl): RealMxGatewayClient over ZB.MOM.WW.MxGateway.Client`.
 ---
 ## Task 12: Factory registration + options binding + config flatten branch
 **Classification:** standard
 **Estimated implement time:** ~5 min
 **Parallelizable with:** Task 13, Task 14 — **NO** (this task and Task 13 both edit `DeploymentManagerActor.cs`; run them sequentially)
 **Depends on:** Task 3, Task 5, Task 11
 **Files:**
 - Modify: `src/ZB.MOM.WW.ScadaBridge.DataConnectionLayer/DataConnectionFactory.cs`
 - Modify: `src/ZB.MOM.WW.ScadaBridge.DataConnectionLayer/ServiceCollectionExtensions.cs`
 - Modify: `src/ZB.MOM.WW.ScadaBridge.SiteRuntime/Actors/DeploymentManagerActor.cs:759`
 - Test: `tests/ZB.MOM.WW.ScadaBridge.DataConnectionLayer.Tests/DataConnectionFactoryTests.cs` (and the SiteRuntime test project for the flatten branch)
 **Step 1: Test** — `factory.Create("MxGateway", new Dictionary<string,string>())` returns a `MxGatewayDataConnection`; `FlattenConnectionConfig("MxGateway", json)` produces the flat dict from `MxGatewayEndpointConfigSerializer`. Run, verify FAIL.
 **Step 2: Register the adapter** in `DataConnectionFactory` (constructor, after the OPC UA registration). The factory currently takes `ILoggerFactory` + `IOptions<OpcUaGlobalOptions>`; add an optional `IOptions<MxGatewayGlobalOptions>` param (default `Options.Create(new MxGatewayGlobalOptions())` in the convenience ctor, mirroring the existing OPC UA pattern):
 ```csharp
 RegisterAdapter("MxGateway", details => new MxGatewayDataConnection(
    new RealMxGatewayClientFactory(_loggerFactory),
    _loggerFactory.CreateLogger<MxGatewayDataConnection>()));
 ```
 **Step 3: Bind options** in `ServiceCollectionExtensions.AddDataConnectionLayer` (after the `OpcUaGlobalOptions` bind):
 ```csharp
        services.AddOptions<MxGatewayGlobalOptions>()
            .BindConfiguration("MxGateway");
 ```
 **Step 4: Add the flatten branch** in `DeploymentManagerActor.FlattenConnectionConfig` (before the generic fallback):
 ```csharp
        if (string.Equals(protocol, "MxGateway", StringComparison.OrdinalIgnoreCase))
        {
            var config = Commons.Serialization.MxGatewayEndpointConfigSerializer.Deserialize(json);
            return Commons.Serialization.MxGatewayEndpointConfigSerializer.ToFlatDict(config);
        }
 ```
 **Step 5:** Run tests, verify PASS; build the solution. **Step 6:** Commit `feat(dcl): register MxGateway protocol in factory + config flatten + options binding`.
 ---
 ## Task 13: Rename browse message types to protocol-agnostic names
 **Classification:** standard
 **Estimated implement time:** ~5 min
 **Parallelizable with:** Tasks 2–11 (adapter track) — **NOT** Task 12 (shared file `DeploymentManagerActor.cs`)
 Mechanical rename. No new test — the existing browse tests are the regression guard. **Rename map** (old → new):
 - `BrowseOpcUaNodeCommand` → `BrowseNodeCommand`
 - `BrowseOpcUaNodeResult` → `BrowseNodeResult`
 - `CommunicationService.BrowseOpcUaNodeAsync` → `BrowseNodeAsync`
 **Files (every reference — from the inventory):**
 - `src/ZB.MOM.WW.ScadaBridge.Commons/Messages/Management/BrowseCommands.cs` (definitions; update the OPC-UA-specific XML doc comments to be protocol-neutral)
 - `src/ZB.MOM.WW.ScadaBridge.Communication/CommunicationService.cs:360-371` (method + return type)
 - `src/ZB.MOM.WW.ScadaBridge.Communication/Actors/SiteCommunicationActor.cs:155,158`
 - `src/ZB.MOM.WW.ScadaBridge.SiteRuntime/Actors/DeploymentManagerActor.cs:152,157` (browse routing — NOT the FlattenConnectionConfig method)
 - `src/ZB.MOM.WW.ScadaBridge.DataConnectionLayer/Actors/DataConnectionManagerActor.cs:49,118-142`
 - `src/ZB.MOM.WW.ScadaBridge.DataConnectionLayer/Actors/DataConnectionActor.cs:237,310,435,985-1046`
 - `src/ZB.MOM.WW.ScadaBridge.CentralUI/Services/IOpcUaBrowseService.cs`, `OpcUaBrowseService.cs` (type refs only; the service rename is Task 14)
 - `src/ZB.MOM.WW.ScadaBridge.Commons/Messages/Management/ReadTagValuesCommand.cs:11` (doc cross-ref)
 - Any test files referencing `BrowseOpcUaNode*` (grep the `tests/` tree).
 **Step 1:** `grep -rn "BrowseOpcUaNode" src tests --include="*.cs" --include="*.razor"` to get the live list. **Step 2:** Rename across all hits (keep `BrowseFailure`/`BrowseFailureKind`/`BrowseNode`/`BrowseChildrenResult` unchanged — already generic). **Step 3:** `dotnet build ZB.MOM.WW.ScadaBridge.slnx` — expected PASS. **Step 4:** Run existing browse tests: `dotnet test --filter "FullyQualifiedName~Browse"` — expected PASS. **Step 5:** Commit `refactor(browse): rename BrowseOpcUaNode* to protocol-agnostic BrowseNode*`.
 ---
 ## Task 14: Rename browse service + dialog to protocol-agnostic names
 **Classification:** standard
 **Estimated implement time:** ~5 min
 **Parallelizable with:** Tasks 2–11
 **Depends on:** Task 13
 Mechanical rename within Central UI. **Rename map:**
 - `IOpcUaBrowseService` → `IBrowseService`; `OpcUaBrowseService` → `BrowseService` (file renames too)
 - `OpcUaBrowserDialog.razor` → `NodeBrowserDialog.razor` (component + file rename)
 - Modal title `"Browse OPC UA — @ConnectionName"` → `"Browse — @ConnectionName"` (protocol-neutral)
 **Files:**
 - `src/ZB.MOM.WW.ScadaBridge.CentralUI/Services/IOpcUaBrowseService.cs` → `IBrowseService.cs`
 - `src/ZB.MOM.WW.ScadaBridge.CentralUI/Services/OpcUaBrowseService.cs` → `BrowseService.cs` (update `BrowseOpcUaNodeAsync` call to `BrowseNodeAsync` from Task 13; update doc comments)
 - `src/ZB.MOM.WW.ScadaBridge.CentralUI/Components/Dialogs/OpcUaBrowserDialog.razor` → `NodeBrowserDialog.razor`
 - `src/ZB.MOM.WW.ScadaBridge.CentralUI/ServiceCollectionExtensions.cs:56` (DI registration)
 - `src/ZB.MOM.WW.ScadaBridge.CentralUI/Services/BindingTester.cs:13`, `Services/IBindingTester.cs:19` (type refs)
 - `src/ZB.MOM.WW.ScadaBridge.CentralUI/Components/Dialogs/TreeRow.razor:49-51`
 - `src/ZB.MOM.WW.ScadaBridge.CentralUI/Components/Pages/Deployment/InstanceConfigure.razor:370,378,410` (`<OpcUaBrowserDialog>` tag + `_browserRef` type + `OpcUaBrowserDialog?` field)
 - `src/ZB.MOM.WW.ScadaBridge.CentralUI/Components/Dialogs/TestBindingsDialog.razor:146`
 - Any CentralUI tests referencing these symbols (grep `tests/`).
 **Step 1:** `grep -rn "OpcUaBrowseService\|IOpcUaBrowseService\|OpcUaBrowserDialog" src tests` for the live list. **Step 2:** Rename (use `git mv` for the file renames). **Step 3:** `dotnet build ZB.MOM.WW.ScadaBridge.slnx` — PASS. **Step 4:** Run CentralUI tests: `dotnet test tests/ZB.MOM.WW.ScadaBridge.CentralUI.Tests/` — PASS. **Step 5:** Commit `refactor(browse): rename OPC-UA browse service + dialog to protocol-agnostic`.
 ---
 ## Task 15: MxGatewayEndpointEditor.razor
 **Classification:** standard
 **Estimated implement time:** ~5 min
 **Parallelizable with:** Task 13
 **Depends on:** Task 3
 **Sub-skill:** @frontend-design
 **Files:**
 - Create: `src/ZB.MOM.WW.ScadaBridge.CentralUI/Components/Forms/MxGatewayEndpointEditor.razor`
 Mirror `OpcUaEndpointEditor.razor` (read it first for the parameter/binding/validation-display conventions, and follow the form-layout memory: vertical stacking, read-only fields first, buttons at bottom). Two-way bind a `MxGatewayEndpointConfig` parameter; render inputs for Endpoint, ApiKey (type=password), ClientName, WriteUserId, UseTls (checkbox toggling CaFile/ServerName), ReadTimeoutMs. Show validation errors from `MxGatewayEndpointConfigValidator`. Parameters: `[Parameter] public string Title`, `[Parameter] public MxGatewayEndpointConfig Config`, `[Parameter] public EventCallback<MxGatewayEndpointConfig> ConfigChanged`, `[Parameter] public IReadOnlyList<string> Errors`.
 **Step 1:** Build the editor. **Step 2:** `dotnet build src/ZB.MOM.WW.ScadaBridge.CentralUI/` — PASS. **Step 3:** Commit `feat(centralui): MxGatewayEndpointEditor component`.
 ---
 ## Task 16: Protocol selector in DataConnectionForm
 **Classification:** standard
 **Estimated implement time:** ~5 min
 **Parallelizable with:** none (depends on 15)
 **Depends on:** Task 3, Task 15
 **Sub-skill:** @frontend-design
 **Files:**
 - Modify: `src/ZB.MOM.WW.ScadaBridge.CentralUI/Components/Pages/Design/DataConnectionForm.razor`
 Currently hardcodes `Protocol = "OpcUa"` with `<OpcUaEndpointEditor>`. Add:
 - A protocol `<select>` (OpcUa | MxGateway) bound to a `_protocol` field, defaulting from `_editingConnection?.Protocol ?? "OpcUa"`. Disable changing the protocol when editing an existing connection (changing protocol on a saved connection invalidates its config — keep it create-time only; for edit, show it read-only).
 - Conditional editor: `@if (_protocol == "OpcUa") { <OpcUaEndpointEditor …/> } else { <MxGatewayEndpointEditor …/> }` for primary and (when shown) backup.
 - Separate `_primaryMxConfig`/`_backupMxConfig` fields of type `MxGatewayEndpointConfig`.
 - On load: pick the serializer by `_editingConnection.Protocol`. On save: serialize with the matching serializer and set `_editingConnection.Protocol = _protocol` (replace the two hardcoded `"OpcUa"` literals at lines ~205/213).
 - Validate with the matching validator before save.
 **Step 1:** Implement the branching. **Step 2:** `dotnet build src/ZB.MOM.WW.ScadaBridge.CentralUI/` — PASS. **Step 3:** If a bUnit test project covers `DataConnectionForm`, add/adjust a test that selecting MxGateway renders the MxGateway editor and saves `Protocol="MxGateway"`; run it. **Step 4:** Commit `feat(centralui): protocol selector + MxGateway editor in DataConnectionForm`.
 ---
 ## Task 17: Verify MxGateway tag picker on Configure Instance
 **Classification:** small
 **Estimated implement time:** ~3 min
 **Parallelizable with:** none
 **Depends on:** Task 14
 **Files:**
 - Modify (if needed): `src/ZB.MOM.WW.ScadaBridge.CentralUI/Components/Pages/Deployment/InstanceConfigure.razor`
 The browse path is now protocol-agnostic, so `NodeBrowserDialog` works for any connection whose site-side adapter implements `IBrowsableDataConnection`. Confirm `InstanceConfigure` opens the dialog for a connection regardless of protocol (no `Protocol == "OpcUa"` gate on the browse button). If such a gate exists, remove it / generalize it. The dialog's manual-node-id field already provides the fallback for non-browsable connections.
 **Step 1:** `grep -n "OpcUa\|Browse" src/ZB.MOM.WW.ScadaBridge.CentralUI/Components/Pages/Deployment/InstanceConfigure.razor` — check for a protocol gate on the browse affordance. **Step 2:** Remove/generalize any gate; build. **Step 3:** Commit `feat(centralui): enable tag picker for MxGateway connections`.
 ---
 ## Task 18: Documentation
 **Classification:** trivial
 **Estimated implement time:** ~4 min
 **Parallelizable with:** Task 17
 **Depends on:** Task 12
 **Files:**
 - Modify: `docs/requirements/Component-DataConnectionLayer.md`
 - Modify: `README.md` (only if it enumerates protocols)
 Add MxGateway under **Supported Protocols** (gRPC to the MxAccess Gateway; session-based; Galaxy browse via `GalaxyRepositoryClient`); add an **MxGateway Settings** config table mirroring the OPC UA one (the Task 2 field table); update the **Browsing the address space** section to note `IBrowsableDataConnection` now backs both OPC UA and MxGateway via the protocol-agnostic `BrowseNodeCommand`/`BrowseService`. Commit `docs(dcl): document MxGateway protocol`.
 ---
 ## Task 19: Full build, test suite, and deploy smoke
 **Classification:** high-risk
 **Estimated implement time:** ~5 min (+ build/deploy wall time)
 **Parallelizable with:** none
 **Depends on:** all prior tasks
 **Files:**
 - Modify (if needed): `docker/deploy.sh` (pass NuGet feed credentials into the image build, e.g. a `--build-arg` or a mounted `nuget.config` with creds, so `dotnet restore` inside the container resolves the Gitea packages)
 **Step 1:** `dotnet build ZB.MOM.WW.ScadaBridge.slnx` — expected: PASS, no warnings (project treats warnings as errors). **Step 2:** `dotnet test ZB.MOM.WW.ScadaBridge.slnx` — expected: all green (new adapter/serializer/validator tests + unchanged browse regression tests). **Step 3:** Wire the NuGet credential into `docker/deploy.sh` if the image build can't restore the Gitea feed; rebuild: `bash docker/deploy.sh`. **Step 4 (optional live smoke):** create an MxGateway connection via the CLI/UI pointed at a staged gateway, deploy an instance with a bound tag, confirm values flow and the tag picker browses the Galaxy. **Step 5:** Commit any `deploy.sh` change: `build(docker): supply Gitea NuGet credentials for image restore`.
 ---
 ## Parallelization summary
 - **Adapter track** (Tasks 2→12) and **Rename track** (Tasks 13→14) run concurrently — disjoint files **except** `DeploymentManagerActor.cs` (Task 12's flatten method vs. Task 13's browse routing). Run Task 12 after Task 13 to avoid the collision.
 - **UI track** (Tasks 15→16, 17) depends on the serializer (Task 3) and the rename (Task 14).
 - Within the adapter track: Task 6 gates 7/8/10; Task 8 gates 9; Task 11 + 3 gate 12.
 - Docs (18) and final integration (19) come last.
@@ -0,0 +1,25 @@
 {
  "planPath": "docs/plans/2026-05-28-mxgateway-data-connection.md",
  "tasks": [
    {"id": 6,  "planTask": 1,  "subject": "Task 1: Packaging foundation (Gitea feed + package refs)", "status": "completed"},
    {"id": 7,  "planTask": 2,  "subject": "Task 2: MxGatewayEndpointConfig type", "status": "completed"},
    {"id": 8,  "planTask": 3,  "subject": "Task 3: MxGatewayEndpointConfigSerializer + tests", "status": "completed", "blockedBy": [7]},
    {"id": 9,  "planTask": 4,  "subject": "Task 4: MxGatewayEndpointConfigValidator + tests", "status": "completed", "blockedBy": [7]},
    {"id": 10, "planTask": 5,  "subject": "Task 5: Client seam interfaces + MxGatewayGlobalOptions", "status": "completed"},
    {"id": 11, "planTask": 6,  "subject": "Task 6: Adapter connect/disconnect/Disconnected + value mapping", "status": "completed", "blockedBy": [7, 10]},
    {"id": 12, "planTask": 7,  "subject": "Task 7: Adapter subscribe/unsubscribe + event routing", "status": "completed", "blockedBy": [11]},
    {"id": 13, "planTask": 8,  "subject": "Task 8: Adapter read/write batch + error classification", "status": "completed", "blockedBy": [11]},
    {"id": 14, "planTask": 9,  "subject": "Task 9: Adapter WriteBatchAndWaitAsync", "status": "completed", "blockedBy": [13]},
    {"id": 15, "planTask": 10, "subject": "Task 10: Adapter Galaxy browse (IBrowsableDataConnection)", "status": "completed", "blockedBy": [11]},
    {"id": 16, "planTask": 11, "subject": "Task 11: RealMxGatewayClient seam implementation", "status": "completed", "blockedBy": [6, 10]},
    {"id": 17, "planTask": 12, "subject": "Task 12: Factory registration + options binding + flatten branch", "status": "completed", "blockedBy": [8, 16, 18]},
    {"id": 18, "planTask": 13, "subject": "Task 13: Rename browse message types to protocol-agnostic", "status": "completed"},
    {"id": 19, "planTask": 14, "subject": "Task 14: Rename browse service + dialog to protocol-agnostic", "status": "completed", "blockedBy": [18]},
    {"id": 20, "planTask": 15, "subject": "Task 15: MxGatewayEndpointEditor.razor", "status": "completed", "blockedBy": [8]},
    {"id": 21, "planTask": 16, "subject": "Task 16: Protocol selector in DataConnectionForm", "status": "completed", "blockedBy": [8, 20, 19]},
    {"id": 22, "planTask": 17, "subject": "Task 17: Verify MxGateway tag picker on Configure Instance", "status": "completed", "blockedBy": [19]},
    {"id": 23, "planTask": 18, "subject": "Task 18: Documentation", "status": "completed", "blockedBy": [17]},
    {"id": 24, "planTask": 19, "subject": "Task 19: Full build, test suite, deploy smoke", "status": "completed", "blockedBy": [17, 21, 22, 23]}
  ],
  "lastUpdated": "2026-05-28 (all tasks complete)"
 }
@@ -58,6 +58,14 @@ All protocols produce the same value tuple consumed by Instance Actors. Before t
 - Read/Write via OPC UA Read/Write services with StatusCode-based quality mapping.
 - Disconnect detection via `Session.KeepAlive` event (see Disconnect Detection Pattern below).
 ### MxGateway
 - Connects to the **MxAccess Gateway** (AVEVA/Wonderware MXAccess-backed Galaxy) over gRPC using the `ZB.MOM.WW.MxGateway.Client` NuGet package (from the Gitea feed); `ZB.MOM.WW.MxGateway.Contracts` is pulled in transitively.
 - Session-based: `OpenSession` + `Register` on connect; `AddItem` + `Advise` per subscription; value changes arrive on the gateway's server-streaming event feed (`StreamEvents`), resumable via `worker_sequence`.
 - Read/Write via `ReadBulk` / `WriteBulk`; writes carry a configurable `WriteUserId`. Quality maps the OPC-style quality byte (≥192 Good, ≥64 Uncertain, else Bad), with a failing MXAccess status proxy treated as Bad.
 - Galaxy hierarchy browse via the separate `GalaxyRepositoryClient` (`BrowseChildren`) — objects are navigable nodes (keyed by Galaxy gobject id), attributes are selectable leaves (keyed by full tag reference).
 - Disconnect detection: a fault on the event stream raises `IDataConnection.Disconnected`, driving the same reconnection state machine as OPC UA.
 - Implemented as `MxGatewayDataConnection` over an `IMxGatewayClient` seam; the seam is decoupled from the generated gRPC types (only `RealMxGatewayClient` references them), so the adapter is fully unit-testable with a fake.
 ## Endpoint Redundancy
 Data connections support an optional backup endpoint for automatic failover when the active endpoint becomes unreachable. Both endpoints use the same protocol.
@@ -115,6 +123,21 @@ All settings are parsed from the data connection's configuration JSON dictionari
 | `SecurityMode` | string | `None` | Preferred endpoint security: `None`, `Sign`, or `SignAndEncrypt` |
 | `AutoAcceptUntrustedCerts` | bool | `true` | Accept untrusted server certificates |
 ### MxGateway Settings
 | Key | Type | Default | Description |
 |-----|------|---------|-------------|
 | `Endpoint` | string | `http://localhost:5000` | Gateway base URL |
 | `ApiKey` | string | — | Sent to the gateway as `authorization: Bearer <key>` |
 | `ClientName` | string | `scadabridge` (when blank) | MXAccess client registration name |
 | `WriteUserId` | int | `0` | MXAccess user id applied to every write-back (0 = no user context) |
 | `UseTls` | bool | `false` | Use TLS to a secured gateway |
 | `CaFile` | string | — | Path to the CA certificate (TLS only) |
 | `ServerName` | string | — | TLS server-name override |
 | `ReadTimeoutMs` | int | `5000` | `ReadBulk` per-call timeout in milliseconds |
 Secret handling for `ApiKey` follows the same at-rest treatment and log/telemetry redaction as the OPC UA `UserIdentity` username/password fields.
 ### Shared Settings (appsettings.json)
 These are configured via `DataConnectionOptions` in `appsettings.json`, not per-connection:
@@ -142,10 +165,11 @@ These are configured via `DataConnectionOptions` in `appsettings.json`, not per-
 ## Browsing the address space
-DCL is a clean data pipe on the hot path. Browse is an **opt-in capability** for protocols that support it, exposed via `IBrowsableDataConnection`. Only consumed by management/UI (the OPC UA tag picker on the instance configure page); Instance Actors never call it.
+DCL is a clean data pipe on the hot path. Browse is an **opt-in capability** for protocols that support it, exposed via `IBrowsableDataConnection`. Only consumed by management/UI (the tag picker on the instance configure page); Instance Actors never call it. The browse path is **protocol-agnostic**: the same command/service/dialog serve every browsable protocol.
- `OpcUaDataConnection` implements `IBrowsableDataConnection`; custom protocols do not.
+- `OpcUaDataConnection` and `MxGatewayDataConnection` both implement `IBrowsableDataConnection`; other/custom protocols do not (and return a `NotBrowsable` failure).
- `DataConnectionManagerActor` handles `BrowseOpcUaNodeCommand` (fields: `DataConnectionId`, `ParentNodeId`) and replies with `BrowseOpcUaNodeResult` (children + `Truncated` + structured `BrowseFailure?`).
+- `DataConnectionManagerActor` handles `BrowseNodeCommand` (fields: `ConnectionName`, `ParentNodeId`) and replies with `BrowseNodeResult` (children + `Truncated` + structured `BrowseFailure?`). The Central UI facade is `IBrowseService`/`BrowseService`, backing the `NodeBrowserDialog` tag picker.
 - Node ids are opaque protocol-specific strings: OPC UA uses NodeIds; MxGateway uses Galaxy gobject ids for navigable objects and full tag references for selectable attribute leaves.
 - Browse runs against the live session; no caching at DCL.
 ## Value Update Message Format
@@ -0,0 +1,27 @@
 <?xml version="1.0" encoding="utf-8"?>
 <configuration>
  <packageSources>
    <clear />
    <add key="nuget.org" value="https://api.nuget.org/v3/index.json" />
    <add key="dohertj2-gitea" value="https://gitea.dohertylan.com/api/packages/dohertj2/nuget/index.json" />
  </packageSources>
  <!--
    Central package management requires explicit source mapping when more than
    one feed is defined: nuget.org serves everything; the Gitea feed serves only
    the ZB.MOM.WW.MxGateway.* packages.
  -->
  <packageSourceMapping>
    <packageSource key="nuget.org">
      <package pattern="*" />
    </packageSource>
    <packageSource key="dohertj2-gitea">
      <package pattern="ZB.MOM.WW.MxGateway.*" />
    </packageSource>
  </packageSourceMapping>
  <!--
    Credentials are NOT committed. Provide them per-developer by running
    `dotnet nuget add source` for the Gitea feed (with username + access token
    and the store-password-in-clear-text flag), or supply NuGet credential
    env vars in CI / the docker build (see docker/deploy.sh wiring in Task 19).
  -->
 </configuration>
@@ -1,7 +1,7 @@
@using ZB.MOM.WW.ScadaBridge.Commons.Interfaces.Protocol
@using ZB.MOM.WW.ScadaBridge.Commons.Messages.Management
@using ZB.MOM.WW.ScadaBridge.CentralUI.Services
-@inject IOpcUaBrowseService BrowseService
+@inject IBrowseService BrowseService
@if (_isVisible)
 {
@@ -9,7 +9,7 @@
        <div class="modal-dialog modal-lg" role="document">
            <div class="modal-content">
                <div class="modal-header">
-                    <h5 class="modal-title">Browse OPC UA — @ConnectionName</h5>
+                    <h5 class="modal-title">Browse — @ConnectionName</h5>
                    <button type="button" class="btn-close" @onclick="Cancel"></button>
                </div>
                <div class="modal-body">
@@ -143,7 +143,7 @@
    /// <summary>
    /// Opens the dialog and triggers an immediate one-shot read. Method-arg
-    /// pattern (mirroring <c>OpcUaBrowserDialog.ShowAsync</c>) — Razor
+    /// pattern (mirroring <c>NodeBrowserDialog.ShowAsync</c>) — Razor
    /// parameter binding would propagate on the next render and race the
    /// LoadAsync below.
    /// </summary>
@@ -46,8 +46,8 @@
 </li>
@code {
-    [Parameter] public OpcUaBrowserDialog.TreeNode Node { get; set; } = default!;
+    [Parameter] public NodeBrowserDialog.TreeNode Node { get; set; } = default!;
-    [Parameter] public EventCallback<OpcUaBrowserDialog.TreeNode> OnToggle { get; set; }
+    [Parameter] public EventCallback<NodeBrowserDialog.TreeNode> OnToggle { get; set; }
-    [Parameter] public EventCallback<OpcUaBrowserDialog.TreeNode> OnSelect { get; set; }
+    [Parameter] public EventCallback<NodeBrowserDialog.TreeNode> OnSelect { get; set; }
    [Parameter] public string? SelectedNodeId { get; set; }
 }
@@ -0,0 +1,89 @@
@namespace ZB.MOM.WW.ScadaBridge.CentralUI.Components.Forms
@using ZB.MOM.WW.ScadaBridge.Commons.Types.DataConnections
@using ZB.MOM.WW.ScadaBridge.Commons.Types.Flattening
 <div class="mxgateway-endpoint-editor">
    <h6 class="text-muted border-bottom pb-1">@Title</h6>
    <div class="row g-2 mb-2">
        <div class="col-md-7">
            <label class="form-label small">Gateway endpoint</label>
            <input type="text" class="form-control form-control-sm"
                   @bind="Config.Endpoint"
                   placeholder="http://host:5000" />
            @RenderFieldError("Endpoint")
        </div>
        <div class="col-md-5">
            <label class="form-label small">API key</label>
            <input type="password" class="form-control form-control-sm"
                   @bind="Config.ApiKey"
                   placeholder="gateway API key" />
            @RenderFieldError("ApiKey")
        </div>
    </div>
    <div class="row g-2 mb-2">
        <div class="col-md-5">
            <label class="form-label small">Client name</label>
            <input type="text" class="form-control form-control-sm"
                   @bind="Config.ClientName"
                   placeholder="(defaults to scadabridge)" />
        </div>
        <div class="col-md-3">
            <label class="form-label small">Write user id</label>
            <input type="number" class="form-control form-control-sm"
                   @bind="Config.WriteUserId" min="0" />
        </div>
        <div class="col-md-4">
            <label class="form-label small">Read timeout (ms)</label>
            <input type="number" class="form-control form-control-sm"
                   @bind="Config.ReadTimeoutMs" min="1" />
            @RenderFieldError("ReadTimeoutMs")
        </div>
    </div>
    <div class="text-muted small mt-2 mb-1">Transport security</div>
    <div class="row g-2 mb-2">
        <div class="col-md-2 d-flex align-items-end">
            <div class="form-check">
                <input class="form-check-input" type="checkbox"
                       id="@($"{IdPrefix}-usetls")"
                       @bind="Config.UseTls" />
                <label class="form-check-label small"
                       for="@($"{IdPrefix}-usetls")">Use TLS</label>
            </div>
        </div>
        @if (Config.UseTls)
        {
            <div class="col-md-6">
                <label class="form-label small">CA certificate path</label>
                <input type="text" class="form-control form-control-sm"
                       @bind="Config.CaFile"
                       placeholder="/etc/scadabridge/pki/gateway-ca.pem" />
            </div>
            <div class="col-md-4">
                <label class="form-label small">Server name override</label>
                <input type="text" class="form-control form-control-sm"
                       @bind="Config.ServerName"
                       placeholder="gateway.example.local" />
            </div>
        }
    </div>
 </div>
@code {
    [Parameter, EditorRequired] public MxGatewayEndpointConfig Config { get; set; } = default!;
    [Parameter] public string Title { get; set; } = "Endpoint";
    [Parameter] public string IdPrefix { get; set; } = "mxgateway-endpoint";
    [Parameter] public ValidationResult? Errors { get; set; }
    private RenderFragment? RenderFieldError(string field)
    {
        var match = Errors?.Errors.FirstOrDefault(e =>
            e.EntityName != null
            && (e.EntityName == field || e.EntityName.EndsWith("." + field)));
        return match is null
            ? null
            : @<div class="text-danger small">@match.Message</div>;
    }
 }
@@ -118,7 +118,7 @@
                            {
                                var connId = GetBindingConnectionId(attr.Name);
                                var canBrowse = connId > 0;
-                                var isOpcUa = IsOpcUa(connId);
+                                var isBrowsable = IsBrowsable(connId);
                                <tr>
                                    <td class="small">@attr.Name</td>
                                    <td class="small text-muted font-monospace">@attr.DataSourceReference</td>
@@ -140,11 +140,11 @@
                                               placeholder="@(attr.DataSourceReference ?? "(no default)")" />
                                    </td>
                                    <td>
-                                        @if (isOpcUa)
+                                        @if (isBrowsable)
                                        {
                                            <button class="btn btn-sm btn-outline-primary"
                                                    disabled="@(!canBrowse)"
-                                                    title="@(canBrowse ? "Browse OPC UA address space" : "Pick a connection first")"
+                                                    title="@(canBrowse ? "Browse address space" : "Pick a connection first")"
                                                    @onclick="() => OpenBrowser(attr.Name)">
                                                Browse…
                                            </button>
@@ -367,7 +367,7 @@
        @* OPC UA Tag Browser dialog (Task 18) — rendered once; OpenBrowser
           tracks which binding row's override input receives the picked node id. *@
-        <OpcUaBrowserDialog @ref="_browserRef"
+        <NodeBrowserDialog @ref="_browserRef"
                            SiteId="@_browserSiteIdentifier"
                            ConnectionName="@_browserConnectionName"
                            InitialNodeId="@_browserInitial"
@@ -375,7 +375,7 @@
        @* Test Bindings dialog — one-shot live read of every bound attribute.
           Method-arg ShowAsync(siteId, rows) — no Razor parameter propagation
-           race (same pattern as OpcUaBrowserDialog). *@
+           race (same pattern as NodeBrowserDialog). *@
        <TestBindingsDialog @ref="_testBindingsRef" />
    }
 </div>
@@ -407,7 +407,7 @@
    // OPC UA tag browser (Task 18) — single dialog rendered at page bottom;
    // _browserAttrInEdit tracks which row gets the picked node id on Select.
-    private OpcUaBrowserDialog? _browserRef;
+    private NodeBrowserDialog? _browserRef;
    private string? _browserAttrInEdit;
    private string _browserSiteIdentifier = "";
    private string _browserConnectionName = "";
@@ -566,13 +566,19 @@
    private string? GetTemplateDefault(string attrName)
        => _bindingDataSourceAttrs.FirstOrDefault(a => a.Name == attrName)?.DataSourceReference;
-    /// <summary>True when the row's selected data connection is OPC UA.</summary>
+    /// <summary>
-    private bool IsOpcUa(int connectionId)
+    /// True when the row's selected data connection supports address-space browsing
-        => connectionId > 0
+    /// (the tag picker). OPC UA and MxGateway both implement
-           && string.Equals(
+    /// <c>IBrowsableDataConnection</c> site-side; other protocols return a
-               _siteConnections.FirstOrDefault(c => c.Id == connectionId)?.Protocol,
+    /// NotBrowsable failure, so the button is hidden for them.
-               "OpcUa",
+    /// </summary>
-               StringComparison.OrdinalIgnoreCase);
+    private bool IsBrowsable(int connectionId)
    {
        if (connectionId <= 0) return false;
        var protocol = _siteConnections.FirstOrDefault(c => c.Id == connectionId)?.Protocol;
        return string.Equals(protocol, "OpcUa", StringComparison.OrdinalIgnoreCase)
            || string.Equals(protocol, "MxGateway", StringComparison.OrdinalIgnoreCase);
    }
    /// <summary>
    /// Opens the OPC UA tag browser dialog for the given attribute row. Remembers
@@ -49,17 +49,45 @@
                        </select>
                    }
                </div>
                <div class="mb-2">
                    <label class="form-label small">Protocol</label>
                    @if (_protocolLocked)
                    {
                        <input type="text"
                               class="form-control form-control-plaintext form-control-sm"
                               readonly
                               value="@_protocol" />
                        <div class="form-text">Protocol is locked after creation.</div>
                    }
                    else
                    {
                        <select class="form-select form-select-sm" @bind="_protocol">
                            <option value="OpcUa">OPC UA</option>
                            <option value="MxGateway">MxGateway</option>
                        </select>
                    }
                </div>
                <div class="mb-3">
                    <label class="form-label small">Name</label>
                    <input type="text" class="form-control form-control-sm" @bind="_formName" />
                </div>
                <h6 class="text-muted mt-3">Primary endpoint</h6>
-                <OpcUaEndpointEditor Title="Primary Endpoint"
+                @if (_protocol == "MxGateway")
-                                     IdPrefix="primary"
+                {
-                                     Config="_primaryConfig"
+                    <MxGatewayEndpointEditor Title="Primary Endpoint"
-                                     IsLegacy="_primaryIsLegacy"
+                                             IdPrefix="primary"
-                                     Errors="_primaryErrors" />
+                                             Config="_primaryMx"
                                             Errors="_primaryErrors" />
                }
                else
                {
                    <OpcUaEndpointEditor Title="Primary Endpoint"
                                         IdPrefix="primary"
                                         Config="_primaryConfig"
                                         IsLegacy="_primaryIsLegacy"
                                         Errors="_primaryErrors" />
                }
                <h6 class="text-muted mt-3">
                    Backup endpoint
@@ -77,11 +105,21 @@
                }
                else
                {
-                    <OpcUaEndpointEditor Title="Backup Endpoint"
+                    @if (_protocol == "MxGateway")
-                                         IdPrefix="backup"
+                    {
-                                         Config="_backupConfig"
+                        <MxGatewayEndpointEditor Title="Backup Endpoint"
-                                         IsLegacy="_backupIsLegacy"
+                                                 IdPrefix="backup"
-                                         Errors="_backupErrors" />
+                                                 Config="_backupMx"
                                                 Errors="_backupErrors" />
                    }
                    else
                    {
                        <OpcUaEndpointEditor Title="Backup Endpoint"
                                             IdPrefix="backup"
                                             Config="_backupConfig"
                                             IsLegacy="_backupIsLegacy"
                                             Errors="_backupErrors" />
                    }
                    <div class="mb-2">
                        <label class="form-label small">Failover Retry Count</label>
                        <input type="number" class="form-control form-control-sm" style="max-width: 120px;"
@@ -118,8 +156,12 @@
    private string _siteName = string.Empty;
    private bool _siteLocked;
    private string _formName = string.Empty;
    private string _protocol = "OpcUa";
    private bool _protocolLocked;
    private OpcUaEndpointConfig _primaryConfig = new();
    private OpcUaEndpointConfig _backupConfig = new();
    private MxGatewayEndpointConfig _primaryMx = new();
    private MxGatewayEndpointConfig _backupMx = new();
    private bool _primaryIsLegacy;
    private bool _backupIsLegacy;
    private bool _showBackup;
@@ -143,17 +185,10 @@
                    _siteName = _sites.FirstOrDefault(s => s.Id == _formSiteId)?.Name ?? $"Site {_formSiteId}";
                    _siteLocked = true;
                    _formName = _editingConnection.Name;
                    _protocol = string.IsNullOrWhiteSpace(_editingConnection.Protocol) ? "OpcUa" : _editingConnection.Protocol;
                    _protocolLocked = true;
-                    (_primaryConfig, _primaryIsLegacy) =
+                    LoadConfig(_editingConnection);
                        OpcUaEndpointConfigSerializer.Deserialize(_editingConnection.PrimaryConfiguration);
                    if (!string.IsNullOrWhiteSpace(_editingConnection.BackupConfiguration))
                    {
                        (_backupConfig, _backupIsLegacy) =
                            OpcUaEndpointConfigSerializer.Deserialize(_editingConnection.BackupConfiguration);
                        _showBackup = true;
                        _formFailoverRetryCount = _editingConnection.FailoverRetryCount;
                    }
                }
            }
            else if (SiteId.HasValue)
@@ -177,32 +212,80 @@
        }
    }
    private void LoadConfig(DataConnection conn)
    {
        if (_protocol == "MxGateway")
        {
            _primaryMx = MxGatewayEndpointConfigSerializer.Deserialize(conn.PrimaryConfiguration);
            if (!string.IsNullOrWhiteSpace(conn.BackupConfiguration))
            {
                _backupMx = MxGatewayEndpointConfigSerializer.Deserialize(conn.BackupConfiguration);
                _showBackup = true;
                _formFailoverRetryCount = conn.FailoverRetryCount;
            }
        }
        else
        {
            (_primaryConfig, _primaryIsLegacy) =
                OpcUaEndpointConfigSerializer.Deserialize(conn.PrimaryConfiguration);
            if (!string.IsNullOrWhiteSpace(conn.BackupConfiguration))
            {
                (_backupConfig, _backupIsLegacy) =
                    OpcUaEndpointConfigSerializer.Deserialize(conn.BackupConfiguration);
                _showBackup = true;
                _formFailoverRetryCount = conn.FailoverRetryCount;
            }
        }
    }
    private async Task SaveConnection()
    {
        _formError = null;
        if (_formSiteId == 0) { _formError = "Site is required."; return; }
        if (string.IsNullOrWhiteSpace(_formName)) { _formError = "Name is required."; return; }
-        _primaryErrors = OpcUaEndpointConfigValidator.Validate(_primaryConfig, "Primary.");
+        string primaryJson;
-        _backupErrors = _showBackup
+        string? backupJson;
            ? OpcUaEndpointConfigValidator.Validate(_backupConfig, "Backup.")
            : null;
-        if (!_primaryErrors.IsValid || (_backupErrors is { IsValid: false }))
+        if (_protocol == "MxGateway")
        {
-            _formError = "Fix the errors below before saving.";
+            _primaryErrors = MxGatewayEndpointConfigValidator.Validate(_primaryMx, "Primary.");
-            return;
+            _backupErrors = _showBackup
-        }
+                ? MxGatewayEndpointConfigValidator.Validate(_backupMx, "Backup.")
                : null;
-        var primaryJson = OpcUaEndpointConfigSerializer.Serialize(_primaryConfig);
+            if (!_primaryErrors.IsValid || (_backupErrors is { IsValid: false }))
-        var backupJson = _showBackup ? OpcUaEndpointConfigSerializer.Serialize(_backupConfig) : null;
+            {
                _formError = "Fix the errors below before saving.";
                return;
            }
            primaryJson = MxGatewayEndpointConfigSerializer.Serialize(_primaryMx);
            backupJson = _showBackup ? MxGatewayEndpointConfigSerializer.Serialize(_backupMx) : null;
        }
        else
        {
            _primaryErrors = OpcUaEndpointConfigValidator.Validate(_primaryConfig, "Primary.");
            _backupErrors = _showBackup
                ? OpcUaEndpointConfigValidator.Validate(_backupConfig, "Backup.")
                : null;
            if (!_primaryErrors.IsValid || (_backupErrors is { IsValid: false }))
            {
                _formError = "Fix the errors below before saving.";
                return;
            }
            primaryJson = OpcUaEndpointConfigSerializer.Serialize(_primaryConfig);
            backupJson = _showBackup ? OpcUaEndpointConfigSerializer.Serialize(_backupConfig) : null;
        }
        try
        {
            if (_editingConnection != null)
            {
                _editingConnection.Name = _formName.Trim();
-                _editingConnection.Protocol = "OpcUa";
+                _editingConnection.Protocol = _protocol;
                _editingConnection.PrimaryConfiguration = primaryJson;
                _editingConnection.BackupConfiguration = backupJson;
                _editingConnection.FailoverRetryCount = _showBackup ? _formFailoverRetryCount : 3;
@@ -210,7 +293,7 @@
            }
            else
            {
-                var conn = new DataConnection(_formName.Trim(), "OpcUa", _formSiteId)
+                var conn = new DataConnection(_formName.Trim(), _protocol, _formSiteId)
                {
                    PrimaryConfiguration = primaryJson,
                    BackupConfiguration = backupJson,
@@ -233,6 +316,7 @@
    {
        _showBackup = false;
        _backupConfig = new OpcUaEndpointConfig();
        _backupMx = new MxGatewayEndpointConfig();
        _backupIsLegacy = false;
        _formFailoverRetryCount = 3;
    }
@@ -50,10 +50,10 @@ public static class ServiceCollectionExtensions
        // Backs the Audit Log page's Export button via GET /api/centralui/audit/export.
        services.AddScoped<IAuditLogExportService, AuditLogExportService>();
-        // OPC UA Tag Browser (Task 14): facade over CommunicationService.BrowseOpcUaNodeAsync
+        // OPC UA Tag Browser (Task 14): facade over CommunicationService.BrowseNodeAsync
        // that enforces the CentralUI-side Design-role trust boundary and translates
        // transport failures into typed BrowseFailure results for the dialog.
-        services.AddScoped<IOpcUaBrowseService, OpcUaBrowseService>();
+        services.AddScoped<IBrowseService, BrowseService>();
        // Test Bindings: facade over CommunicationService.ReadTagValuesAsync —
        // same Design-role guard + typed-failure translation as the browse
@@ -10,7 +10,7 @@ namespace ZB.MOM.WW.ScadaBridge.CentralUI.Services;
 /// <see cref="CommunicationService.ReadTagValuesAsync"/> that enforces the
 /// CentralUI-side <c>Design</c>-role trust boundary and translates transport
 /// exceptions into a typed <see cref="ReadTagValuesFailure"/> result. Mirrors
-/// <see cref="OpcUaBrowseService"/>.
+/// <see cref="BrowseService"/>.
 /// </summary>
 public sealed class BindingTester : IBindingTester
 {
@@ -7,8 +7,8 @@ using ZB.MOM.WW.ScadaBridge.Security;
 namespace ZB.MOM.WW.ScadaBridge.CentralUI.Services;
 /// <summary>
-/// Default <see cref="IOpcUaBrowseService"/> implementation — a thin facade over
+/// Default <see cref="IBrowseService"/> implementation — a thin facade over
-/// <see cref="CommunicationService.BrowseOpcUaNodeAsync"/> that enforces the
+/// <see cref="CommunicationService.BrowseNodeAsync"/> that enforces the
 /// CentralUI-side <c>Design</c>-role trust boundary and translates transport
 /// exceptions into a typed <see cref="BrowseFailure"/> result.
 /// </summary>
@@ -19,24 +19,24 @@ namespace ZB.MOM.WW.ScadaBridge.CentralUI.Services;
 /// <c>ServerError</c> so the dialog can show an inline banner while leaving the
 /// manual node-id paste field usable.
 /// </remarks>
-public sealed class OpcUaBrowseService : IOpcUaBrowseService
+public sealed class BrowseService : IBrowseService
 {
    private readonly CommunicationService _communication;
    private readonly AuthenticationStateProvider _auth;
    /// <summary>
-    /// Initializes a new instance of the <see cref="OpcUaBrowseService"/>.
+    /// Initializes a new instance of the <see cref="BrowseService"/>.
    /// </summary>
    /// <param name="communication">Central-side cluster communication service.</param>
    /// <param name="auth">Authentication state provider used for the Design-role guard.</param>
-    public OpcUaBrowseService(CommunicationService communication, AuthenticationStateProvider auth)
+    public BrowseService(CommunicationService communication, AuthenticationStateProvider auth)
    {
        _communication = communication ?? throw new ArgumentNullException(nameof(communication));
        _auth = auth ?? throw new ArgumentNullException(nameof(auth));
    }
    /// <inheritdoc/>
-    public async Task<BrowseOpcUaNodeResult> BrowseChildrenAsync(
+    public async Task<BrowseNodeResult> BrowseChildrenAsync(
        string siteId,
        string connectionName,
        string? parentNodeId,
@@ -47,7 +47,7 @@ public sealed class OpcUaBrowseService : IOpcUaBrowseService
        var state = await _auth.GetAuthenticationStateAsync();
        if (!state.User.HasClaim(JwtTokenService.RoleClaimType, "Design"))
        {
-            return new BrowseOpcUaNodeResult(
+            return new BrowseNodeResult(
                Array.Empty<BrowseNode>(),
                Truncated: false,
                new BrowseFailure(BrowseFailureKind.ServerError, "Not authorized."));
@@ -55,9 +55,9 @@ public sealed class OpcUaBrowseService : IOpcUaBrowseService
        try
        {
-            return await _communication.BrowseOpcUaNodeAsync(
+            return await _communication.BrowseNodeAsync(
                siteId,
-                new BrowseOpcUaNodeCommand(connectionName, parentNodeId),
+                new BrowseNodeCommand(connectionName, parentNodeId),
                cancellationToken);
        }
        catch (TimeoutException ex)
@@ -65,7 +65,7 @@ public sealed class OpcUaBrowseService : IOpcUaBrowseService
            // Akka Ask timed out — the site (or its OPC UA session) didn't answer
            // within CommunicationOptions.QueryTimeout. Surface as a typed
            // Timeout failure so the dialog can render an inline banner.
-            return new BrowseOpcUaNodeResult(
+            return new BrowseNodeResult(
                Array.Empty<BrowseNode>(),
                Truncated: false,
                new BrowseFailure(BrowseFailureKind.Timeout, ex.Message));
@@ -80,7 +80,7 @@ public sealed class OpcUaBrowseService : IOpcUaBrowseService
        {
            // Any other transport / serialization failure: keep the dialog
            // alive and let the user fall back to manual node-id paste.
-            return new BrowseOpcUaNodeResult(
+            return new BrowseNodeResult(
                Array.Empty<BrowseNode>(),
                Truncated: false,
                new BrowseFailure(BrowseFailureKind.ServerError, ex.Message));
@@ -16,7 +16,7 @@ namespace ZB.MOM.WW.ScadaBridge.CentralUI.Services;
 /// envelope. Transport failures (timeouts, unreachable sites) are translated
 /// into a typed <see cref="ReadTagValuesFailure"/> so the dialog can render an
 /// inline banner without crashing — same shape as
-/// <see cref="IOpcUaBrowseService"/>.
+/// <see cref="IBrowseService"/>.
 /// </remarks>
 public interface IBindingTester
 {
@@ -6,7 +6,7 @@ namespace ZB.MOM.WW.ScadaBridge.CentralUI.Services;
 /// CentralUI facade over the central-to-site OPC UA browse command. Backs the
 /// OPC UA Tag Browser dialog: each tree expansion / manual node-id paste calls
 /// <see cref="BrowseChildrenAsync"/>, which forwards a
-/// <see cref="BrowseOpcUaNodeCommand"/> to the owning site via
+/// <see cref="BrowseNodeCommand"/> to the owning site via
 /// <see cref="ZB.MOM.WW.ScadaBridge.Communication.CommunicationService"/>.
 /// </summary>
 /// <remarks>
@@ -17,7 +17,7 @@ namespace ZB.MOM.WW.ScadaBridge.CentralUI.Services;
 /// <see cref="BrowseFailure"/> so the dialog can render an inline error and
 /// remain usable (manual node-id paste still works).
 /// </remarks>
-public interface IOpcUaBrowseService
+public interface IBrowseService
 {
    /// <summary>
    /// Enumerates the immediate children of an OPC UA node on the live server
@@ -29,7 +29,7 @@ public interface IOpcUaBrowseService
    /// <param name="connectionName">Name of the site-local data connection to browse against — the site's <c>DataConnectionManagerActor</c> indexes its children by name.</param>
    /// <param name="parentNodeId">Node to browse, or <c>null</c> to browse from the server root.</param>
    /// <param name="cancellationToken">Cancellation token.</param>
-    Task<BrowseOpcUaNodeResult> BrowseChildrenAsync(
+    Task<BrowseNodeResult> BrowseChildrenAsync(
        string siteId,
        string connectionName,
        string? parentNodeId,
@@ -15,11 +15,11 @@ namespace ZB.MOM.WW.ScadaBridge.Commons.Messages.Management;
 /// </remarks>
 /// <param name="ConnectionName">Name of the site-local data connection to browse against.</param>
 /// <param name="ParentNodeId">Node to browse, or null to browse from the server root (ObjectsFolder).</param>
-public record BrowseOpcUaNodeCommand(
+public record BrowseNodeCommand(
    string ConnectionName,
    string? ParentNodeId);
-public record BrowseOpcUaNodeResult(
+public record BrowseNodeResult(
    IReadOnlyList<BrowseNode> Children,
    bool Truncated,
    BrowseFailure? Failure);
@@ -8,7 +8,7 @@ namespace ZB.MOM.WW.ScadaBridge.Commons.Messages.Management;
 /// </summary>
 /// <remarks>
 /// Keyed by <see cref="ConnectionName"/> (not id) for the same reason as
-/// <see cref="BrowseOpcUaNodeCommand"/>: the site-side
+/// <see cref="BrowseNodeCommand"/>: the site-side
 /// <c>DataConnectionManagerActor</c> indexes its children by connection name,
 /// and the central UI already has the connection name in scope from the
 /// bindings table. The central <c>DataConnections</c> table's id is not
@@ -0,0 +1,65 @@
 using System.Globalization;
 using System.Text.Json;
 using ZB.MOM.WW.ScadaBridge.Commons.Types.DataConnections;
 namespace ZB.MOM.WW.ScadaBridge.Commons.Serialization;
 /// <summary>
 /// Serializes <see cref="MxGatewayEndpointConfig"/> to/from the typed JSON stored in
 /// <c>DataConnection.PrimaryConfiguration</c> / <c>BackupConfiguration</c>, and flattens
 /// it to the <c>IDictionary&lt;string,string&gt;</c> shape <c>IDataConnection.ConnectAsync</c>
 /// expects. MxGateway is net-new, so there is no legacy shape to recover — a row that
 /// fails to parse yields a default config.
 /// </summary>
 public static class MxGatewayEndpointConfigSerializer
 {
    private static readonly JsonSerializerOptions JsonOpts = new()
    {
        PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
        WriteIndented = false,
    };
    /// <summary>Serializes a config to the typed JSON shape.</summary>
    /// <param name="config">The endpoint configuration to serialize.</param>
    public static string Serialize(MxGatewayEndpointConfig config)
        => JsonSerializer.Serialize(config, JsonOpts);
    /// <summary>Parses stored config JSON; null/blank/malformed yields a default config.</summary>
    /// <param name="json">The stored JSON string.</param>
    public static MxGatewayEndpointConfig Deserialize(string? json)
    {
        if (string.IsNullOrWhiteSpace(json)) return new MxGatewayEndpointConfig();
        try { return JsonSerializer.Deserialize<MxGatewayEndpointConfig>(json, JsonOpts) ?? new MxGatewayEndpointConfig(); }
        catch (JsonException) { return new MxGatewayEndpointConfig(); }
    }
    /// <summary>Flattens the typed config to the key-value shape the adapter consumes.</summary>
    /// <param name="c">The endpoint configuration to flatten.</param>
    public static IDictionary<string, string> ToFlatDict(MxGatewayEndpointConfig c) => new Dictionary<string, string>
    {
        ["Endpoint"] = c.Endpoint,
        ["ApiKey"] = c.ApiKey,
        ["ClientName"] = c.ClientName,
        ["WriteUserId"] = c.WriteUserId.ToString(CultureInfo.InvariantCulture),
        ["UseTls"] = c.UseTls.ToString(),
        ["CaFile"] = c.CaFile,
        ["ServerName"] = c.ServerName,
        ["ReadTimeoutMs"] = c.ReadTimeoutMs.ToString(CultureInfo.InvariantCulture),
    };
    /// <summary>Reconstructs a config from the flat key-value shape; invalid numerics fall back to defaults.</summary>
    /// <param name="d">The flat dictionary.</param>
    public static MxGatewayEndpointConfig FromFlatDict(IDictionary<string, string> d)
    {
        var c = new MxGatewayEndpointConfig();
        if (d.TryGetValue("Endpoint", out var ep) && !string.IsNullOrWhiteSpace(ep)) c.Endpoint = ep;
        if (d.TryGetValue("ApiKey", out var ak)) c.ApiKey = ak;
        if (d.TryGetValue("ClientName", out var cn)) c.ClientName = cn;
        if (d.TryGetValue("WriteUserId", out var wu) && int.TryParse(wu, out var wuv)) c.WriteUserId = wuv;
        if (d.TryGetValue("UseTls", out var tls) && bool.TryParse(tls, out var tlsv)) c.UseTls = tlsv;
        if (d.TryGetValue("CaFile", out var ca)) c.CaFile = ca;
        if (d.TryGetValue("ServerName", out var sn)) c.ServerName = sn;
        if (d.TryGetValue("ReadTimeoutMs", out var rt) && int.TryParse(rt, out var rtv)) c.ReadTimeoutMs = rtv;
        return c;
    }
 }
@@ -0,0 +1,27 @@
 namespace ZB.MOM.WW.ScadaBridge.Commons.Types.DataConnections;
 /// <summary>
 /// Per-endpoint configuration for an MxGateway data connection. Serialized to the
 /// typed JSON shape stored in <c>DataConnection.PrimaryConfiguration</c> /
 /// <c>BackupConfiguration</c>. Both primary and backup use this same shape — the
 /// backup is simply a second gateway endpoint for failover.
 /// </summary>
 public class MxGatewayEndpointConfig
 {
    /// <summary>Gateway base URL (e.g. "http://localhost:5000").</summary>
    public string Endpoint { get; set; } = "http://localhost:5000";
    /// <summary>API key sent to the gateway as <c>authorization: Bearer &lt;key&gt;</c>.</summary>
    public string ApiKey { get; set; } = "";
    /// <summary>MXAccess client registration name. Blank → derive "scadabridge-&lt;connName&gt;" at connect time.</summary>
    public string ClientName { get; set; } = "";
    /// <summary>MXAccess user id applied to every write-back. 0 = no user context.</summary>
    public int WriteUserId { get; set; }
    /// <summary>Use TLS to a secured gateway.</summary>
    public bool UseTls { get; set; }
    /// <summary>Path to the CA certificate (TLS only).</summary>
    public string CaFile { get; set; } = "";
    /// <summary>TLS server-name override.</summary>
    public string ServerName { get; set; } = "";
    /// <summary>ReadBulk per-call timeout in milliseconds.</summary>
    public int ReadTimeoutMs { get; set; } = 5000;
 }
@@ -0,0 +1,46 @@
 using ZB.MOM.WW.ScadaBridge.Commons.Types.DataConnections;
 using ZB.MOM.WW.ScadaBridge.Commons.Types.Flattening;
 namespace ZB.MOM.WW.ScadaBridge.Commons.Validators;
 /// <summary>
 /// Pure-function validator for <see cref="MxGatewayEndpointConfig"/>. Errors carry
 /// the offending property name in <see cref="ValidationEntry.EntityName"/>
 /// (optionally prefixed, e.g. "Primary.Endpoint") so the form can render
 /// per-field messages.
 /// </summary>
 public static class MxGatewayEndpointConfigValidator
 {
    /// <summary>
    /// Validates all fields of an <see cref="MxGatewayEndpointConfig"/>, returning errors with optionally-prefixed field names.
    /// </summary>
    /// <param name="config">The MxGateway endpoint configuration to validate.</param>
    /// <param name="fieldPrefix">Optional prefix prepended to each field name in error entries (e.g., "Primary.").</param>
    public static ValidationResult Validate(MxGatewayEndpointConfig config, string fieldPrefix = "")
    {
        var errors = new List<ValidationEntry>();
        if (string.IsNullOrWhiteSpace(config.Endpoint))
            errors.Add(Err("Endpoint", "Endpoint URL is required."));
        else if (!Uri.TryCreate(config.Endpoint, UriKind.Absolute, out var uri)
                 || (uri.Scheme != "http" && uri.Scheme != "https")
                 || string.IsNullOrEmpty(uri.Host))
            errors.Add(Err("Endpoint", "Endpoint URL must be a valid http:// or https:// URI."));
        if (string.IsNullOrWhiteSpace(config.ApiKey))
            errors.Add(Err("ApiKey", "API key is required."));
        if (config.ReadTimeoutMs <= 0)
            errors.Add(Err("ReadTimeoutMs", "Must be > 0."));
        return errors.Count == 0
            ? ValidationResult.Success()
            : ValidationResult.FromErrors(errors.ToArray());
        ValidationEntry Err(string field, string message) =>
            ValidationEntry.Error(
                ValidationCategory.ConnectionConfig,
                message,
                entityName: $"{fieldPrefix}{field}");
    }
 }
@@ -152,10 +152,10 @@ public class SiteCommunicationActor : ReceiveActor, IWithTimers
        // DataConnectionActor children (which own the live OPC UA sessions)
        // only exist on the singleton's node. The singleton then re-forwards
        // to its own /user/dcl-manager, which DOES have the connection.
-        Receive<BrowseOpcUaNodeCommand>(msg => _deploymentManagerProxy.Forward(msg));
+        Receive<BrowseNodeCommand>(msg => _deploymentManagerProxy.Forward(msg));
        // Test Bindings (interactive design-time read) — same routing rationale
-        // as BrowseOpcUaNodeCommand above: the singleton always lands on the
+        // as BrowseNodeCommand above: the singleton always lands on the
        // active site node, which is the node that owns the DataConnectionActor
        // children holding the live OPC UA sessions.
        Receive<ReadTagValuesCommand>(msg => _deploymentManagerProxy.Forward(msg));
@@ -360,13 +360,13 @@ public class CommunicationService
    /// <param name="command">The OPC UA browse command.</param>
    /// <param name="cancellationToken">Cancellation token.</param>
    /// <returns>The browse result (children + truncation flag + structured failure).</returns>
-    public Task<BrowseOpcUaNodeResult> BrowseOpcUaNodeAsync(
+    public Task<BrowseNodeResult> BrowseNodeAsync(
        string siteId,
-        BrowseOpcUaNodeCommand command,
+        BrowseNodeCommand command,
        CancellationToken cancellationToken = default)
    {
        var envelope = new SiteEnvelope(siteId, command);
-        return GetActor().Ask<BrowseOpcUaNodeResult>(
+        return GetActor().Ask<BrowseNodeResult>(
            envelope, _options.QueryTimeout, cancellationToken);
    }
@@ -377,7 +377,7 @@ public class CommunicationService
    /// server backing the given data connection. Used by the CentralUI "Test
    /// Bindings" dialog on the Configure Instance page. The Ask is bounded by
    /// <see cref="CommunicationOptions.QueryTimeout"/> — same latency budget
-    /// as <see cref="BrowseOpcUaNodeAsync"/> (both are interactive one-shot
+    /// as <see cref="BrowseNodeAsync"/> (both are interactive one-shot
    /// design-time queries).
    /// </summary>
    /// <param name="siteId">The target site identifier.</param>
@@ -234,7 +234,7 @@ public class DataConnectionActor : UntypedActor, IWithStash, IWithTimers
                // apply it so its state survives into the next ReSubscribeAll.
                HandleSubscribeCompleted(sc);
                break;
-            case BrowseOpcUaNodeCommand browse:
+            case BrowseNodeCommand browse:
                // Browse is an interactive design-time query; never stash. The
                // adapter has no session yet in this state, so reply with a
                // typed ConnectionNotConnected failure so the dialog can render
@@ -307,7 +307,7 @@ public class DataConnectionActor : UntypedActor, IWithStash, IWithTimers
            case RetryTagResolution:
                HandleRetryTagResolution();
                break;
-            case BrowseOpcUaNodeCommand browse:
+            case BrowseNodeCommand browse:
                HandleBrowse(browse);
                break;
            case ReadTagValuesCommand read:
@@ -432,7 +432,7 @@ public class DataConnectionActor : UntypedActor, IWithStash, IWithTimers
                // apply it so its state survives into the next ReSubscribeAll.
                HandleSubscribeCompleted(sc);
                break;
-            case BrowseOpcUaNodeCommand browse:
+            case BrowseNodeCommand browse:
                // Browse is design-time and never stashed. While reconnecting
                // the adapter has no live session, so the adapter call will
                // throw ConnectionNotConnectedException — mapped by HandleBrowse.
@@ -982,7 +982,7 @@ public class DataConnectionActor : UntypedActor, IWithStash, IWithTimers
    // ── OPC UA Tag Browser (interactive design-time query) ──
    /// <summary>
-    /// Handles a <see cref="BrowseOpcUaNodeCommand"/> forwarded by the
+    /// Handles a <see cref="BrowseNodeCommand"/> forwarded by the
    /// <see cref="DataConnectionManagerActor"/>. The capability check (does
    /// this adapter support browsing?) and all browse-failure mapping live
    /// here because the adapter is held by this actor, not the manager.
@@ -999,14 +999,14 @@ public class DataConnectionActor : UntypedActor, IWithStash, IWithTimers
    /// <see cref="HandleWrite"/> — so the captured <see cref="Sender"/> is
    /// safe to use from the continuation (which runs off the actor thread).
    /// </summary>
-    private void HandleBrowse(BrowseOpcUaNodeCommand command)
+    private void HandleBrowse(BrowseNodeCommand command)
    {
        var sender = Sender;
        if (_adapter is not IBrowsableDataConnection browsable)
        {
            _log.Debug("[{0}] Browse requested but adapter does not implement IBrowsableDataConnection", _connectionName);
-            sender.Tell(new BrowseOpcUaNodeResult(
+            sender.Tell(new BrowseNodeResult(
                Array.Empty<BrowseNode>(),
                Truncated: false,
                new BrowseFailure(
@@ -1021,21 +1021,21 @@ public class DataConnectionActor : UntypedActor, IWithStash, IWithTimers
        {
            if (t.IsCompletedSuccessfully)
            {
-                return new BrowseOpcUaNodeResult(t.Result.Children, t.Result.Truncated, Failure: null);
+                return new BrowseNodeResult(t.Result.Children, t.Result.Truncated, Failure: null);
            }
            var baseEx = t.Exception?.GetBaseException();
            return baseEx switch
            {
-                ConnectionNotConnectedException notConnected => new BrowseOpcUaNodeResult(
+                ConnectionNotConnectedException notConnected => new BrowseNodeResult(
                    Array.Empty<BrowseNode>(),
                    Truncated: false,
                    new BrowseFailure(BrowseFailureKind.ConnectionNotConnected, notConnected.Message)),
-                OperationCanceledException => new BrowseOpcUaNodeResult(
+                OperationCanceledException => new BrowseNodeResult(
                    Array.Empty<BrowseNode>(),
                    Truncated: false,
                    new BrowseFailure(BrowseFailureKind.Timeout, "Browse cancelled.")),
-                _ => new BrowseOpcUaNodeResult(
+                _ => new BrowseNodeResult(
                    Array.Empty<BrowseNode>(),
                    Truncated: false,
                    new BrowseFailure(
@@ -46,7 +46,7 @@ public class DataConnectionManagerActor : ReceiveActor
        Receive<WriteTagRequest>(HandleRouteWrite);
        Receive<RemoveConnectionCommand>(HandleRemoveConnection);
        Receive<GetAllHealthReports>(HandleGetAllHealthReports);
-        Receive<BrowseOpcUaNodeCommand>(HandleBrowse);
+        Receive<BrowseNodeCommand>(HandleBrowse);
        Receive<ReadTagValuesCommand>(HandleReadTagValues);
    }
@@ -115,7 +115,7 @@ public class DataConnectionManagerActor : ReceiveActor
    }
    /// <summary>
-    /// Routes a <see cref="BrowseOpcUaNodeCommand"/> from the central UI's OPC UA
+    /// Routes a <see cref="BrowseNodeCommand"/> from the central UI's OPC UA
    /// Tag Browser to the child <see cref="DataConnectionActor"/> that owns the
    /// named connection. The manager is the only actor that knows whether a
    /// connection exists at this site — so it owns the
@@ -123,7 +123,7 @@ public class DataConnectionManagerActor : ReceiveActor
    /// else (capability check, session state, server errors) lives inside the
    /// child where the adapter is held.
    /// </summary>
-    private void HandleBrowse(BrowseOpcUaNodeCommand command)
+    private void HandleBrowse(BrowseNodeCommand command)
    {
        if (_connectionActors.TryGetValue(command.ConnectionName, out var actor))
        {
@@ -132,7 +132,7 @@ public class DataConnectionManagerActor : ReceiveActor
        else
        {
            _log.Warning("No connection actor for {0} during browse", command.ConnectionName);
-            Sender.Tell(new BrowseOpcUaNodeResult(
+            Sender.Tell(new BrowseNodeResult(
                Array.Empty<BrowseNode>(),
                Truncated: false,
                new BrowseFailure(
@@ -0,0 +1,79 @@
 using ZB.MOM.WW.ScadaBridge.Commons.Interfaces.Protocol;
 namespace ZB.MOM.WW.ScadaBridge.DataConnectionLayer.Adapters;
 /// <summary>Connection parameters resolved from the flat config dict.</summary>
 public record MxGatewayConnectionOptions(
    string Endpoint, string ApiKey, string ClientName, int WriteUserId,
    bool UseTls, string? CaFile, string? ServerName, int ReadTimeoutMs);
 /// <summary>One advised-tag value change pushed from the gateway event stream.</summary>
 public record MxValueUpdate(string TagPath, object? Value, QualityCode Quality, DateTimeOffset Timestamp);
 /// <summary>Per-tag read outcome.</summary>
 public record MxReadOutcome(string TagPath, bool Success, object? Value, QualityCode Quality, DateTimeOffset Timestamp, string? Error);
 /// <summary>Per-tag write outcome.</summary>
 public record MxWriteOutcome(string TagPath, bool Success, string? Error);
 /// <summary>One node in a Galaxy browse level.</summary>
 public record MxBrowseChild(string NodeId, string DisplayName, BrowseNodeClass NodeClass, bool HasChildren);
 /// <summary>
 /// Seam over the MxAccess Gateway .NET client + Galaxy repository client. Decouples
 /// <see cref="MxGatewayDataConnection"/> from the generated gRPC/protobuf types so the
 /// adapter is unit-testable with a fake. The real implementation lives in
 /// <c>RealMxGatewayClient</c>.
 /// </summary>
 public interface IMxGatewayClient : IAsyncDisposable
 {
    /// <summary>Opens the gateway session and registers the client (Register → serverHandle held internally).</summary>
    /// <param name="options">Resolved connection parameters.</param>
    /// <param name="ct">Cancellation token.</param>
    Task ConnectAsync(MxGatewayConnectionOptions options, CancellationToken ct = default);
    /// <summary>Closes the session.</summary>
    /// <param name="ct">Cancellation token.</param>
    Task DisconnectAsync(CancellationToken ct = default);
    /// <summary>AddItem + Advise; returns the gateway item handle (as a string subscription id).</summary>
    /// <param name="tagPath">Tag address to subscribe to.</param>
    /// <param name="ct">Cancellation token.</param>
    Task<string> SubscribeAsync(string tagPath, CancellationToken ct = default);
    /// <summary>UnAdvise + RemoveItem for a previously returned subscription id.</summary>
    /// <param name="subscriptionId">Subscription id returned by <see cref="SubscribeAsync"/>.</param>
    /// <param name="ct">Cancellation token.</param>
    Task UnsubscribeAsync(string subscriptionId, CancellationToken ct = default);
    /// <summary>Snapshot read of one or more tags (ReadBulk).</summary>
    /// <param name="tagPaths">Tag addresses to read.</param>
    /// <param name="ct">Cancellation token.</param>
    Task<IReadOnlyList<MxReadOutcome>> ReadAsync(IReadOnlyList<string> tagPaths, CancellationToken ct = default);
    /// <summary>Write one or more tag/value pairs (WriteBulk with the configured WriteUserId).</summary>
    /// <param name="writes">Tag/value pairs to write.</param>
    /// <param name="ct">Cancellation token.</param>
    Task<IReadOnlyList<MxWriteOutcome>> WriteAsync(IReadOnlyList<(string TagPath, object? Value)> writes, CancellationToken ct = default);
    /// <summary>One Galaxy browse level (BrowseChildren). <paramref name="parentNodeId"/> null → root.</summary>
    /// <param name="parentNodeId">Parent node id (Galaxy contained path), or null for root.</param>
    /// <param name="ct">Cancellation token.</param>
    Task<(IReadOnlyList<MxBrowseChild> Children, bool Truncated)> BrowseChildrenAsync(string? parentNodeId, CancellationToken ct = default);
    /// <summary>
    /// Long-running event consumer. Invokes <paramref name="onUpdate"/> for each advised-tag
    /// data change. Resumes from the last delivered worker sequence on reconnect. Completes
    /// (or throws) when the stream ends — the adapter treats that as a disconnect.
    /// </summary>
    /// <param name="onUpdate">Callback invoked per advised-tag value change.</param>
    /// <param name="ct">Cancellation token; ends the loop when cancelled.</param>
    Task RunEventLoopAsync(Action<MxValueUpdate> onUpdate, CancellationToken ct = default);
 }
 /// <summary>Builds <see cref="IMxGatewayClient"/> instances.</summary>
 public interface IMxGatewayClientFactory
 {
    /// <summary>Creates a new, unconnected client instance.</summary>
    IMxGatewayClient Create();
 }
@@ -0,0 +1,220 @@
 using System.Collections.Concurrent;
 using Microsoft.Extensions.Logging;
 using ZB.MOM.WW.ScadaBridge.Commons.Interfaces.Protocol;
 using ZB.MOM.WW.ScadaBridge.Commons.Serialization;
 using ZB.MOM.WW.ScadaBridge.Commons.Types.Enums;
 namespace ZB.MOM.WW.ScadaBridge.DataConnectionLayer.Adapters;
 /// <summary>
 /// MxGateway adapter implementing <see cref="IDataConnection"/> + <see cref="IBrowsableDataConnection"/>.
 /// Maps IDataConnection concepts onto the MxAccess Gateway session model via the
 /// <see cref="IMxGatewayClient"/> seam:
 /// <list type="bullet">
 ///   <item>Connect → OpenSession + Register, then a background event loop.</item>
 ///   <item>Subscribe → AddItem + Advise; value changes arrive on the event stream.</item>
 ///   <item>Read/Write → ReadBulk / WriteBulk.</item>
 ///   <item>Browse → Galaxy repository BrowseChildren.</item>
 /// </list>
 /// Reconnection is driven by the <c>DataConnectionActor</c>: a stream fault raises
 /// <see cref="Disconnected"/>, the actor disposes this adapter, creates a fresh one,
 /// reconnects and re-subscribes all tags.
 /// </summary>
 public class MxGatewayDataConnection : IDataConnection, IBrowsableDataConnection
 {
    private readonly IMxGatewayClientFactory _clientFactory;
    private readonly ILogger<MxGatewayDataConnection> _logger;
    private IMxGatewayClient? _client;
    private ConnectionHealth _status = ConnectionHealth.Disconnected;
    private CancellationTokenSource? _eventLoopCts;
    // subscriptionId → (tagPath, callback) so the event loop can route updates by tag,
    // plus tagPath → subscriptionId for reverse lookup. Concurrent because the event
    // loop reads from a background thread while Subscribe/Unsubscribe mutate.
    private readonly ConcurrentDictionary<string, (string TagPath, SubscriptionCallback Callback)> _subs = new();
    private readonly ConcurrentDictionary<string, string> _tagToSub = new();
    // DataConnectionLayer mirror of OpcUaDataConnection's once-only guard: an int toggled
    // with Interlocked.Exchange so only the first caller raises Disconnected.
    // 0 = not fired, 1 = fired. Reset on (re)connect.
    private int _disconnectFired;
    /// <summary>Initializes a new instance of <see cref="MxGatewayDataConnection"/>.</summary>
    /// <param name="clientFactory">Factory used to create gateway client instances.</param>
    /// <param name="logger">Logger instance.</param>
    public MxGatewayDataConnection(IMxGatewayClientFactory clientFactory, ILogger<MxGatewayDataConnection> logger)
    {
        _clientFactory = clientFactory;
        _logger = logger;
    }
    /// <inheritdoc />
    public ConnectionHealth Status => _status;
    /// <summary>Raised once when the gateway event stream faults (connection lost).</summary>
    public event Action? Disconnected;
    /// <inheritdoc />
    public async Task ConnectAsync(IDictionary<string, string> connectionDetails, CancellationToken cancellationToken = default)
    {
        var cfg = MxGatewayEndpointConfigSerializer.FromFlatDict(connectionDetails);
        Interlocked.Exchange(ref _disconnectFired, 0); // reset guard on (re)connect, like OPC UA
        _client = _clientFactory.Create();
        await _client.ConnectAsync(new MxGatewayConnectionOptions(
            cfg.Endpoint,
            cfg.ApiKey,
            string.IsNullOrWhiteSpace(cfg.ClientName) ? "scadabridge" : cfg.ClientName,
            cfg.WriteUserId,
            cfg.UseTls,
            string.IsNullOrWhiteSpace(cfg.CaFile) ? null : cfg.CaFile,
            string.IsNullOrWhiteSpace(cfg.ServerName) ? null : cfg.ServerName,
            cfg.ReadTimeoutMs), cancellationToken);
        _status = ConnectionHealth.Connected;
        // Background event loop: route each value change to the matching subscription callback.
        _eventLoopCts = new CancellationTokenSource();
        _ = Task.Run(() => RunEventLoopAsync(_eventLoopCts.Token));
    }
    private async Task RunEventLoopAsync(CancellationToken ct)
    {
        try
        {
            await _client!.RunEventLoopAsync(update =>
            {
                if (_tagToSub.TryGetValue(update.TagPath, out var subId) && _subs.TryGetValue(subId, out var s))
                    s.Callback(update.TagPath, new TagValue(update.Value, update.Quality, update.Timestamp));
            }, ct);
        }
        catch (OperationCanceledException)
        {
            // Normal shutdown (DisconnectAsync / DisposeAsync cancelled the loop).
        }
        catch (Exception ex)
        {
            _logger.LogWarning(ex, "MxGateway event stream faulted; signalling disconnect");
            RaiseDisconnected();
        }
    }
    private void RaiseDisconnected()
    {
        if (Interlocked.Exchange(ref _disconnectFired, 1) == 0)
        {
            _status = ConnectionHealth.Disconnected;
            Disconnected?.Invoke();
        }
    }
    /// <inheritdoc />
    public async Task DisconnectAsync(CancellationToken cancellationToken = default)
    {
        _eventLoopCts?.Cancel();
        if (_client is not null)
            await _client.DisconnectAsync(cancellationToken);
        _status = ConnectionHealth.Disconnected;
    }
    /// <inheritdoc />
    public async Task<string> SubscribeAsync(string tagPath, SubscriptionCallback callback, CancellationToken cancellationToken = default)
    {
        var subId = await _client!.SubscribeAsync(tagPath, cancellationToken);
        _subs[subId] = (tagPath, callback);
        _tagToSub[tagPath] = subId;
        return subId;
    }
    /// <inheritdoc />
    public async Task UnsubscribeAsync(string subscriptionId, CancellationToken cancellationToken = default)
    {
        if (_subs.TryRemove(subscriptionId, out var s))
            _tagToSub.TryRemove(s.TagPath, out _);
        await _client!.UnsubscribeAsync(subscriptionId, cancellationToken);
    }
    /// <inheritdoc />
    public async Task<ReadResult> ReadAsync(string tagPath, CancellationToken cancellationToken = default)
    {
        var r = (await _client!.ReadAsync(new[] { tagPath }, cancellationToken)).Single();
        return ToReadResult(r);
    }
    /// <inheritdoc />
    public async Task<IReadOnlyDictionary<string, ReadResult>> ReadBatchAsync(IEnumerable<string> tagPaths, CancellationToken cancellationToken = default)
    {
        var list = tagPaths.ToList();
        var results = await _client!.ReadAsync(list, cancellationToken);
        return results.ToDictionary(r => r.TagPath, ToReadResult);
    }
    private static ReadResult ToReadResult(MxReadOutcome r) => r.Success
        ? new ReadResult(true, new TagValue(r.Value, r.Quality, r.Timestamp), null)
        : new ReadResult(false, null, r.Error);
    /// <inheritdoc />
    public async Task<WriteResult> WriteAsync(string tagPath, object? value, CancellationToken cancellationToken = default)
    {
        var w = (await _client!.WriteAsync(new[] { (tagPath, value) }, cancellationToken)).Single();
        return new WriteResult(w.Success, w.Error);
    }
    /// <inheritdoc />
    public async Task<IReadOnlyDictionary<string, WriteResult>> WriteBatchAsync(IDictionary<string, object?> values, CancellationToken cancellationToken = default)
    {
        var results = await _client!.WriteAsync(values.Select(kv => (kv.Key, kv.Value)).ToList(), cancellationToken);
        return results.ToDictionary(w => w.TagPath, w => new WriteResult(w.Success, w.Error));
    }
    /// <inheritdoc />
    public async Task<bool> WriteBatchAndWaitAsync(
        IDictionary<string, object?> values, string flagPath, object? flagValue,
        string responsePath, object? responseValue, TimeSpan timeout, CancellationToken cancellationToken = default)
    {
        await WriteBatchAsync(values, cancellationToken);
        await WriteAsync(flagPath, flagValue, cancellationToken);
        using var timeoutCts = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken);
        timeoutCts.CancelAfter(timeout);
        try
        {
            while (!timeoutCts.IsCancellationRequested)
            {
                var r = await ReadAsync(responsePath, timeoutCts.Token);
                // r.Value is a TagValue wrapper; compare its underlying scalar. String
                // projection tolerates numeric type differences across the gRPC boundary.
                if (r.Success && string.Equals(r.Value?.Value?.ToString(), responseValue?.ToString(), StringComparison.Ordinal))
                    return true;
                await Task.Delay(TimeSpan.FromMilliseconds(200), timeoutCts.Token);
            }
        }
        catch (OperationCanceledException) when (!cancellationToken.IsCancellationRequested)
        {
            // Timeout elapsed (the linked CTS, not the caller's token) — fall through to false.
        }
        return false;
    }
    /// <inheritdoc />
    public async Task<BrowseChildrenResult> BrowseChildrenAsync(string? parentNodeId, CancellationToken cancellationToken = default)
    {
        if (_status != ConnectionHealth.Connected || _client is null)
            throw new ConnectionNotConnectedException($"MxGateway connection is not connected (status: {_status}).");
        var (children, truncated) = await _client.BrowseChildrenAsync(parentNodeId, cancellationToken);
        var nodes = children
            .Select(c => new BrowseNode(c.NodeId, c.DisplayName, c.NodeClass, c.HasChildren))
            .ToList();
        return new BrowseChildrenResult(nodes, truncated);
    }
    /// <inheritdoc />
    public async ValueTask DisposeAsync()
    {
        _eventLoopCts?.Cancel();
        if (_client is not null)
            await _client.DisposeAsync();
        GC.SuppressFinalize(this);
    }
 }
@@ -0,0 +1,267 @@
 using System.Collections.Concurrent;
 using System.Globalization;
 using Grpc.Core;
 using Microsoft.Extensions.Logging;
 using ZB.MOM.WW.MxGateway.Client;
 using ZB.MOM.WW.MxGateway.Contracts.Proto;
 using ZB.MOM.WW.MxGateway.Contracts.Proto.Galaxy;
 using ZB.MOM.WW.ScadaBridge.Commons.Interfaces.Protocol;
 namespace ZB.MOM.WW.ScadaBridge.DataConnectionLayer.Adapters;
 /// <summary>
 /// Production <see cref="IMxGatewayClient"/> implementation over the
 /// <c>ZB.MOM.WW.MxGateway.Client</c> NuGet package. This is the only type in the
 /// Data Connection Layer that references the generated gRPC/protobuf contracts;
 /// the adapter and its tests run entirely against the neutral seam.
 /// </summary>
 public sealed class RealMxGatewayClient : IMxGatewayClient
 {
    private readonly ILogger<RealMxGatewayClient> _logger;
    private readonly ILoggerFactory? _loggerFactory;
    private MxGatewayClient? _client;
    private GalaxyRepositoryClient? _galaxy;
    private MxGatewaySession? _session;
    private int _serverHandle;
    private int _writeUserId;
    private int _readTimeoutMs;
    private ulong _lastSeq;
    // tag ↔ MXAccess item handle, maintained across subscribe/write.
    private readonly ConcurrentDictionary<string, int> _tagToHandle = new();
    private readonly ConcurrentDictionary<int, string> _handleToTag = new();
    /// <summary>Initializes a new instance of <see cref="RealMxGatewayClient"/>.</summary>
    /// <param name="loggerFactory">Logger factory shared with the gateway client.</param>
    public RealMxGatewayClient(ILoggerFactory? loggerFactory)
    {
        _loggerFactory = loggerFactory;
        _logger = (loggerFactory ?? Microsoft.Extensions.Logging.Abstractions.NullLoggerFactory.Instance)
            .CreateLogger<RealMxGatewayClient>();
    }
    /// <inheritdoc />
    public async Task ConnectAsync(MxGatewayConnectionOptions options, CancellationToken ct = default)
    {
        _writeUserId = options.WriteUserId;
        _readTimeoutMs = options.ReadTimeoutMs;
        var clientOptions = new MxGatewayClientOptions
        {
            Endpoint = new Uri(options.Endpoint),
            ApiKey = options.ApiKey,
            UseTls = options.UseTls,
            CaCertificatePath = options.CaFile,
            ServerNameOverride = options.ServerName,
            LoggerFactory = _loggerFactory,
        };
        _client = MxGatewayClient.Create(clientOptions);
        _galaxy = GalaxyRepositoryClient.Create(clientOptions);
        _session = await _client.OpenSessionAsync(cancellationToken: ct).ConfigureAwait(false);
        _serverHandle = await _session.RegisterAsync(options.ClientName, ct).ConfigureAwait(false);
    }
    /// <inheritdoc />
    public async Task DisconnectAsync(CancellationToken ct = default)
    {
        if (_session is not null)
            await _session.CloseAsync(ct).ConfigureAwait(false);
    }
    /// <inheritdoc />
    public async Task<string> SubscribeAsync(string tagPath, CancellationToken ct = default)
    {
        var handle = await GetOrAddItemHandleAsync(tagPath, ct).ConfigureAwait(false);
        await _session!.AdviseAsync(_serverHandle, handle, ct).ConfigureAwait(false);
        return handle.ToString(CultureInfo.InvariantCulture);
    }
    /// <inheritdoc />
    public async Task UnsubscribeAsync(string subscriptionId, CancellationToken ct = default)
    {
        if (!int.TryParse(subscriptionId, NumberStyles.Integer, CultureInfo.InvariantCulture, out var handle))
            return;
        await _session!.UnAdviseAsync(_serverHandle, handle, ct).ConfigureAwait(false);
        await _session.RemoveItemAsync(_serverHandle, handle, ct).ConfigureAwait(false);
        if (_handleToTag.TryRemove(handle, out var tag))
            _tagToHandle.TryRemove(tag, out _);
    }
    /// <inheritdoc />
    public async Task<IReadOnlyList<MxReadOutcome>> ReadAsync(IReadOnlyList<string> tagPaths, CancellationToken ct = default)
    {
        var results = await _session!
            .ReadBulkAsync(_serverHandle, tagPaths, TimeSpan.FromMilliseconds(_readTimeoutMs), ct)
            .ConfigureAwait(false);
        return results.Select(r => new MxReadOutcome(
            r.TagAddress,
            r.WasSuccessful,
            r.WasSuccessful ? r.Value?.ToClrValue() : null,
            MapQuality(r.Quality, r.Statuses),
            r.SourceTimestamp?.ToDateTimeOffset() ?? DateTimeOffset.UtcNow,
            r.WasSuccessful ? null : r.ErrorMessage)).ToList();
    }
    /// <inheritdoc />
    public async Task<IReadOnlyList<MxWriteOutcome>> WriteAsync(IReadOnlyList<(string TagPath, object? Value)> writes, CancellationToken ct = default)
    {
        // Build entries in request order; remember the tag for each handle so the
        // per-handle BulkWriteResult can be mapped back to its tag.
        var entries = new List<WriteBulkEntry>(writes.Count);
        var orderedTags = new List<string>(writes.Count);
        foreach (var (tag, value) in writes)
        {
            var handle = await GetOrAddItemHandleAsync(tag, ct).ConfigureAwait(false);
            entries.Add(new WriteBulkEntry
            {
                ItemHandle = handle,
                Value = ToMxValue(value),
                UserId = _writeUserId,
            });
            orderedTags.Add(tag);
        }
        var results = await _session!.WriteBulkAsync(_serverHandle, entries, ct).ConfigureAwait(false);
        // Results are returned in request order; pair by index back to the tags.
        return results.Select((r, i) => new MxWriteOutcome(
            i < orderedTags.Count ? orderedTags[i] : (_handleToTag.TryGetValue(r.ItemHandle, out var t) ? t : ""),
            r.WasSuccessful,
            r.WasSuccessful ? null : r.ErrorMessage)).ToList();
    }
    /// <inheritdoc />
    public async Task<(IReadOnlyList<MxBrowseChild> Children, bool Truncated)> BrowseChildrenAsync(string? parentNodeId, CancellationToken ct = default)
    {
        var request = new BrowseChildrenRequest { IncludeAttributes = true };
        // Object NodeIds are the Galaxy gobject id (encoded as a string); attribute
        // NodeIds are FullTagReference leaves and never arrive here as a parent.
        if (!string.IsNullOrEmpty(parentNodeId)
            && int.TryParse(parentNodeId, NumberStyles.Integer, CultureInfo.InvariantCulture, out var gobjectId))
        {
            request.ParentGobjectId = gobjectId;
        }
        BrowseChildrenReply reply;
        try
        {
            reply = await _galaxy!.BrowseChildrenRawAsync(request, ct).ConfigureAwait(false);
        }
        catch (RpcException ex) when (ex.StatusCode == StatusCode.Unavailable)
        {
            throw new ConnectionNotConnectedException($"MxGateway repository unavailable: {ex.Status.Detail}");
        }
        var children = new List<MxBrowseChild>();
        for (var i = 0; i < reply.Children.Count; i++)
        {
            var obj = reply.Children[i];
            var hasChildren = i < reply.ChildHasChildren.Count && reply.ChildHasChildren[i];
            // Navigable container node, keyed by gobject id.
            children.Add(new MxBrowseChild(
                obj.GobjectId.ToString(CultureInfo.InvariantCulture),
                string.IsNullOrEmpty(obj.TagName) ? obj.ContainedName : obj.TagName,
                BrowseNodeClass.Object,
                hasChildren || obj.Attributes.Count > 0));
            // Selectable attribute leaves, keyed by their full tag reference.
            foreach (var attr in obj.Attributes)
            {
                children.Add(new MxBrowseChild(
                    attr.FullTagReference,
                    attr.AttributeName,
                    BrowseNodeClass.Variable,
                    false));
            }
        }
        return (children, !string.IsNullOrEmpty(reply.NextPageToken));
    }
    /// <inheritdoc />
    public async Task RunEventLoopAsync(Action<MxValueUpdate> onUpdate, CancellationToken ct = default)
    {
        await foreach (var ev in _session!.StreamEventsAsync(_lastSeq, ct).ConfigureAwait(false))
        {
            _lastSeq = ev.WorkerSequence;
            if (ev.Family != MxEventFamily.OnDataChange)
                continue;
            if (!_handleToTag.TryGetValue(ev.ItemHandle, out var tag))
                continue;
            onUpdate(new MxValueUpdate(
                tag,
                ev.Value?.ToClrValue(),
                MapQuality(ev.Quality, ev.Statuses),
                ev.SourceTimestamp?.ToDateTimeOffset() ?? DateTimeOffset.UtcNow));
        }
    }
    /// <inheritdoc />
    public async ValueTask DisposeAsync()
    {
        if (_session is not null) await _session.DisposeAsync().ConfigureAwait(false);
        if (_client is not null) await _client.DisposeAsync().ConfigureAwait(false);
        if (_galaxy is not null) await _galaxy.DisposeAsync().ConfigureAwait(false);
    }
    private async Task<int> GetOrAddItemHandleAsync(string tagPath, CancellationToken ct)
    {
        if (_tagToHandle.TryGetValue(tagPath, out var existing))
            return existing;
        var handle = await _session!.AddItemAsync(_serverHandle, tagPath, ct).ConfigureAwait(false);
        _tagToHandle[tagPath] = handle;
        _handleToTag[handle] = tagPath;
        return handle;
    }
    /// <summary>
    /// Maps MXAccess quality. A failing status proxy is authoritative bad; otherwise
    /// the OPC-style quality byte: ≥192 Good, ≥64 Uncertain, else Bad.
    /// </summary>
    private static QualityCode MapQuality(int quality, IEnumerable<MxStatusProxy> statuses)
    {
        if (statuses.Any(s => !s.IsSuccess()))
            return QualityCode.Bad;
        return quality switch
        {
            >= 192 => QualityCode.Good,
            >= 64 => QualityCode.Uncertain,
            _ => QualityCode.Bad,
        };
    }
    private static MxValue ToMxValue(object? value) => value switch
    {
        null => new MxValue { IsNull = true },
        bool b => b.ToMxValue(),
        int i => i.ToMxValue(),
        long l => l.ToMxValue(),
        float f => f.ToMxValue(),
        double d => d.ToMxValue(),
        string s => s.ToMxValue(),
        DateTimeOffset dto => dto.ToMxValue(),
        DateTime dt => dt.ToMxValue(),
        // Fall back to invariant string for any other CLR type.
        _ => Convert.ToString(value, CultureInfo.InvariantCulture)!.ToMxValue(),
    };
 }
 /// <summary>Builds <see cref="RealMxGatewayClient"/> instances.</summary>
 public sealed class RealMxGatewayClientFactory : IMxGatewayClientFactory
 {
    private readonly ILoggerFactory? _loggerFactory;
    /// <summary>Initializes a new factory.</summary>
    /// <param name="loggerFactory">Logger factory passed to each created client.</param>
    public RealMxGatewayClientFactory(ILoggerFactory? loggerFactory) => _loggerFactory = loggerFactory;
    /// <inheritdoc />
    public IMxGatewayClient Create() => new RealMxGatewayClient(_loggerFactory);
 }
@@ -38,6 +38,13 @@ public class DataConnectionFactory : IDataConnectionFactory
        RegisterAdapter("OpcUa", details => new OpcUaDataConnection(
            new RealOpcUaClientFactory(globalOptions, _loggerFactory),
            _loggerFactory.CreateLogger<OpcUaDataConnection>()));
        // MxGateway: gRPC to the MxAccess Gateway. The RealMxGatewayClient wraps the
        // ZB.MOM.WW.MxGateway.Client package; per-connection config arrives via the
        // flat details dict (see MxGatewayEndpointConfigSerializer).
        RegisterAdapter("MxGateway", details => new MxGatewayDataConnection(
            new RealMxGatewayClientFactory(_loggerFactory),
            _loggerFactory.CreateLogger<MxGatewayDataConnection>()));
    }
    /// <summary>
@@ -0,0 +1,11 @@
 namespace ZB.MOM.WW.ScadaBridge.DataConnectionLayer;
 /// <summary>
 /// Deployment-wide MxGateway defaults, bound from the "MxGateway" section of
 /// appsettings.json. Per-endpoint behavior lives on MxGatewayEndpointConfig.
 /// </summary>
 public class MxGatewayGlobalOptions
 {
    /// <summary>Prefix used to derive a per-connection client registration name when the connection's ClientName is blank.</summary>
    public string ClientNamePrefix { get; set; } = "scadabridge";
 }
@@ -18,6 +18,9 @@ public static class ServiceCollectionExtensions
        services.AddOptions<OpcUaGlobalOptions>()
            .BindConfiguration("OpcUa");
        services.AddOptions<MxGatewayGlobalOptions>()
            .BindConfiguration("MxGateway");
        // WP-34: Register the factory for protocol extensibility
        services.AddSingleton<IDataConnectionFactory, DataConnectionFactory>();
@@ -16,6 +16,7 @@
    <PackageReference Include="Microsoft.Extensions.Options" />
    <PackageReference Include="Microsoft.Extensions.Options.ConfigurationExtensions" />
    <PackageReference Include="OPCFoundation.NetStandard.Opc.Ua.Client" />
    <PackageReference Include="ZB.MOM.WW.MxGateway.Client" />
  </ItemGroup>
  <ItemGroup>
@@ -149,12 +149,12 @@ public class DeploymentManagerActor : ReceiveActor, IWithTimers
        Receive<RouteToSetAttributesRequest>(RouteInboundApiSetAttributes);
        // OPC UA Tag Browser — singleton-only re-forward to local /user/dcl-manager.
-        // BrowseOpcUaNodeCommand is routed to this singleton (active node) by
+        // BrowseNodeCommand is routed to this singleton (active node) by
        // SiteCommunicationActor so the dcl-manager we forward to is guaranteed
        // to be the one holding the live DataConnectionActor children. ActorSelection
        // has no Forward() extension in this Akka.NET version, so we Tell with the
        // original Sender preserved (semantically identical to Forward).
-        Receive<BrowseOpcUaNodeCommand>(msg =>
+        Receive<BrowseNodeCommand>(msg =>
            Context.ActorSelection("/user/dcl-manager").Tell(msg, Sender));
        // Test Bindings — same singleton-only re-forward as the browse handler
@@ -767,6 +767,12 @@ public class DeploymentManagerActor : ReceiveActor, IWithTimers
            return Commons.Serialization.OpcUaEndpointConfigSerializer.ToFlatDict(config);
        }
        if (string.Equals(protocol, "MxGateway", StringComparison.OrdinalIgnoreCase))
        {
            var config = Commons.Serialization.MxGatewayEndpointConfigSerializer.Deserialize(json);
            return Commons.Serialization.MxGatewayEndpointConfigSerializer.ToFlatDict(config);
        }
        // Fallback: assume legacy flat-dict shape for any future / unknown protocol.
        try
        {
@@ -44,12 +44,55 @@ public class DataConnectionFormTests : BunitContext
    }
    [Fact]
-    public void NoProtocolDropdown_IsRendered()
+    public void ProtocolDropdown_IsRendered_OnCreate_WithBothProtocols()
    {
        var cut = RenderForCreateSite(1);
        Assert.DoesNotContain("Custom", cut.Markup);
        var labels = cut.FindAll("label").Select(l => l.TextContent.Trim()).ToList();
-        Assert.DoesNotContain(labels, l => l == "Protocol");
+        Assert.Contains(labels, l => l == "Protocol");
        // The protocol select offers OPC UA and MxGateway.
        var optionTexts = cut.FindAll("option").Select(o => o.TextContent.Trim()).ToList();
        Assert.Contains("OPC UA", optionTexts);
        Assert.Contains("MxGateway", optionTexts);
    }
    [Fact]
    public async Task Save_MxGateway_PersistsTypedJsonAndProtocolMxGateway()
    {
        DataConnection? captured = null;
        await _siteRepo.AddDataConnectionAsync(
            Arg.Do<DataConnection>(d => captured = d));
        var cut = RenderForCreateSite(1);
        // Switch protocol to MxGateway — re-renders with the MxGateway editor.
        cut.FindAll("select")
           .First(s => s.QuerySelectorAll("option").Any(o => o.TextContent.Trim() == "MxGateway"))
           .Change("MxGateway");
        // Name (skip readonly Site plaintext input; MxGateway editor inputs carry placeholders).
        cut.FindAll("input[type='text']")
           .First(i => !i.HasAttribute("readonly") && i.GetAttribute("placeholder") is null)
           .Change("MX-1");
        // Gateway endpoint
        cut.FindAll("input[type='text']")
           .First(i => i.GetAttribute("placeholder")?.StartsWith("http://") == true)
           .Change("http://gw:5000");
        // API key (password input)
        cut.FindAll("input[type='password']")
           .First(i => i.GetAttribute("placeholder")?.Contains("API key") == true)
           .Change("secret");
        await cut.FindAll("button")
                 .First(b => b.TextContent.Trim() == "Save").ClickAsync(new());
        Assert.NotNull(captured);
        Assert.Equal("MxGateway", captured!.Protocol);
        Assert.NotNull(captured.PrimaryConfiguration);
        using var doc = JsonDocument.Parse(captured.PrimaryConfiguration!);
        Assert.Equal("http://gw:5000",
            doc.RootElement.GetProperty("endpoint").GetString());
    }
    [Fact]
@@ -44,10 +44,10 @@ public class InstanceConfigureAuditDrillinTests : BunitContext
        Services.AddSingleton(new InstanceService(_templateRepo, Substitute.For<IAuditService>()));
        Services.AddSingleton(Substitute.For<IFlatteningPipeline>());
-        // The page renders <OpcUaBrowserDialog/> and <TestBindingsDialog/> at
+        // The page renders <NodeBrowserDialog/> and <TestBindingsDialog/> at
        // the bottom; their @inject directives need a registered service even
        // though this test doesn't open either dialog.
-        Services.AddSingleton(Substitute.For<IOpcUaBrowseService>());
+        Services.AddSingleton(Substitute.For<IBrowseService>());
        Services.AddSingleton(Substitute.For<IBindingTester>());
        // Auth: a system-wide Deployment user so SiteScope grants everything.
@@ -3,7 +3,7 @@ using ZB.MOM.WW.ScadaBridge.Commons.Messages.Management;
 namespace ZB.MOM.WW.ScadaBridge.Commons.Tests.Messages;
 /// <summary>
-/// Verifies that <see cref="BrowseOpcUaNodeCommand"/> is discovered by
+/// Verifies that <see cref="BrowseNodeCommand"/> is discovered by
 /// <see cref="ManagementCommandRegistry"/> so it travels over the management
 /// boundary as a known command (resolvable by wire name and round-trippable
 /// through <c>GetCommandName</c> / <c>Resolve</c>).
@@ -11,13 +11,13 @@ namespace ZB.MOM.WW.ScadaBridge.Commons.Tests.Messages;
 public class BrowseCommandsRegistryTests
 {
    [Fact]
-    public void Registry_discovers_BrowseOpcUaNodeCommand()
+    public void Registry_discovers_BrowseNodeCommand()
    {
        // GetCommandName throws ArgumentException for any type the registry
        // does not contain, so a successful call here is proof of discovery.
-        var name = ManagementCommandRegistry.GetCommandName(typeof(BrowseOpcUaNodeCommand));
+        var name = ManagementCommandRegistry.GetCommandName(typeof(BrowseNodeCommand));
-        Assert.Equal("BrowseOpcUaNode", name);
+        Assert.Equal("BrowseNode", name);
-        Assert.Equal(typeof(BrowseOpcUaNodeCommand), ManagementCommandRegistry.Resolve(name));
+        Assert.Equal(typeof(BrowseNodeCommand), ManagementCommandRegistry.Resolve(name));
    }
 }
@@ -0,0 +1,84 @@
 using ZB.MOM.WW.ScadaBridge.Commons.Serialization;
 using ZB.MOM.WW.ScadaBridge.Commons.Types.DataConnections;
 namespace ZB.MOM.WW.ScadaBridge.Commons.Tests.Types.DataConnections;
 public class MxGatewayEndpointConfigSerializerTests
 {
    [Fact]
    public void Serialize_then_Deserialize_round_trips_all_fields()
    {
        var original = new MxGatewayEndpointConfig
        {
            Endpoint = "https://gw:5001",
            ApiKey = "secret-key",
            ClientName = "client-a",
            WriteUserId = 7,
            UseTls = true,
            CaFile = "/certs/ca.pem",
            ServerName = "gw.local",
            ReadTimeoutMs = 1234
        };
        var json = MxGatewayEndpointConfigSerializer.Serialize(original);
        var round = MxGatewayEndpointConfigSerializer.Deserialize(json);
        Assert.Equal(original.Endpoint, round.Endpoint);
        Assert.Equal(original.ApiKey, round.ApiKey);
        Assert.Equal(original.ClientName, round.ClientName);
        Assert.Equal(original.WriteUserId, round.WriteUserId);
        Assert.Equal(original.UseTls, round.UseTls);
        Assert.Equal(original.CaFile, round.CaFile);
        Assert.Equal(original.ServerName, round.ServerName);
        Assert.Equal(original.ReadTimeoutMs, round.ReadTimeoutMs);
    }
    [Theory]
    [InlineData(null)]
    [InlineData("")]
    [InlineData("   ")]
    [InlineData("{ not valid json")]
    public void Deserialize_null_blank_or_malformed_returns_default(string? json)
    {
        var def = new MxGatewayEndpointConfig();
        var result = MxGatewayEndpointConfigSerializer.Deserialize(json);
        Assert.Equal(def.Endpoint, result.Endpoint);
        Assert.Equal(def.ReadTimeoutMs, result.ReadTimeoutMs);
    }
    [Fact]
    public void ToFlatDict_FromFlatDict_round_trips()
    {
        var original = new MxGatewayEndpointConfig
        {
            Endpoint = "http://x:5000",
            ApiKey = "k",
            ClientName = "c",
            WriteUserId = 3,
            UseTls = true,
            CaFile = "/ca",
            ServerName = "s",
            ReadTimeoutMs = 999
        };
        var dict = MxGatewayEndpointConfigSerializer.ToFlatDict(original);
        var round = MxGatewayEndpointConfigSerializer.FromFlatDict(dict);
        Assert.Equal(original.Endpoint, round.Endpoint);
        Assert.Equal(original.ApiKey, round.ApiKey);
        Assert.Equal(original.ClientName, round.ClientName);
        Assert.Equal(original.WriteUserId, round.WriteUserId);
        Assert.Equal(original.UseTls, round.UseTls);
        Assert.Equal(original.CaFile, round.CaFile);
        Assert.Equal(original.ServerName, round.ServerName);
        Assert.Equal(original.ReadTimeoutMs, round.ReadTimeoutMs);
    }
    [Fact]
    public void FromFlatDict_invalid_numeric_falls_back_to_default()
    {
        var back = MxGatewayEndpointConfigSerializer.FromFlatDict(
            new Dictionary<string, string> { ["ReadTimeoutMs"] = "not-a-number" });
        Assert.Equal(new MxGatewayEndpointConfig().ReadTimeoutMs, back.ReadTimeoutMs);
    }
 }
@@ -0,0 +1,77 @@
 using ZB.MOM.WW.ScadaBridge.Commons.Types.DataConnections;
 using ZB.MOM.WW.ScadaBridge.Commons.Types.Flattening;
 using ZB.MOM.WW.ScadaBridge.Commons.Validators;
 namespace ZB.MOM.WW.ScadaBridge.Commons.Tests.Validators;
 public class MxGatewayEndpointConfigValidatorTests
 {
    private static MxGatewayEndpointConfig Valid() => new()
    {
        Endpoint = "http://gw:5000",
        ApiKey = "key",
    };
    [Fact]
    public void Validate_ValidConfig_IsValid()
    {
        var result = MxGatewayEndpointConfigValidator.Validate(Valid());
        Assert.True(result.IsValid);
        Assert.Empty(result.Errors);
    }
    [Fact]
    public void Validate_MissingEndpoint_Fails()
    {
        var c = Valid();
        c.Endpoint = "";
        var r = MxGatewayEndpointConfigValidator.Validate(c);
        Assert.False(r.IsValid);
        Assert.Contains(r.Errors, e =>
            e.EntityName == "Endpoint"
            && e.Category == ValidationCategory.ConnectionConfig
            && e.Message.Contains("required", StringComparison.OrdinalIgnoreCase));
    }
    [Theory]
    [InlineData("opc.tcp://x:4840")]
    [InlineData("ftp://x")]
    [InlineData("not a url")]
    public void Validate_BadEndpointScheme_Fails(string url)
    {
        var c = Valid();
        c.Endpoint = url;
        var r = MxGatewayEndpointConfigValidator.Validate(c);
        Assert.False(r.IsValid);
        Assert.Contains(r.Errors, e => e.EntityName == "Endpoint");
    }
    [Fact]
    public void Validate_MissingApiKey_Fails()
    {
        var c = Valid();
        c.ApiKey = "";
        var r = MxGatewayEndpointConfigValidator.Validate(c);
        Assert.False(r.IsValid);
        Assert.Contains(r.Errors, e => e.EntityName == "ApiKey");
    }
    [Fact]
    public void Validate_NonPositiveReadTimeout_Fails()
    {
        var c = Valid();
        c.ReadTimeoutMs = 0;
        var r = MxGatewayEndpointConfigValidator.Validate(c);
        Assert.False(r.IsValid);
        Assert.Contains(r.Errors, e => e.EntityName == "ReadTimeoutMs");
    }
    [Fact]
    public void Validate_PrefixedFieldNames_AppearInErrors()
    {
        var c = Valid();
        c.Endpoint = "";
        var r = MxGatewayEndpointConfigValidator.Validate(c, "Primary.");
        Assert.Contains(r.Errors, e => e.EntityName == "Primary.Endpoint");
    }
 }
@@ -14,7 +14,7 @@ namespace ZB.MOM.WW.ScadaBridge.DataConnectionLayer.Tests.Actors;
 /// Task 10 (opcua-tag-browser): the site-side
 /// <see cref="DataConnectionManagerActor"/> + child
 /// <see cref="DataConnectionActor"/> together resolve
-/// <see cref="BrowseOpcUaNodeCommand"/> against the live adapter and surface
+/// <see cref="BrowseNodeCommand"/> against the live adapter and surface
 /// every browse outcome as a typed <see cref="BrowseFailure"/>. The split is:
 /// the manager owns <see cref="BrowseFailureKind.ConnectionNotFound"/> (only it
 /// knows the per-site connection set); everything else lives in the child where
@@ -50,9 +50,9 @@ public class DataConnectionManagerBrowseHandlerTests : TestKit
        // No CreateConnectionCommand sent — the manager has zero children, so a
        // browse against any name must be rejected with ConnectionNotFound
        // (the manager is the only actor with site-level visibility).
-        manager.Tell(new BrowseOpcUaNodeCommand("unknown-connection", ParentNodeId: null));
+        manager.Tell(new BrowseNodeCommand("unknown-connection", ParentNodeId: null));
-        var reply = ExpectMsg<BrowseOpcUaNodeResult>();
+        var reply = ExpectMsg<BrowseNodeResult>();
        Assert.NotNull(reply.Failure);
        Assert.Equal(BrowseFailureKind.ConnectionNotFound, reply.Failure!.Kind);
        Assert.Empty(reply.Children);
@@ -80,9 +80,9 @@ public class DataConnectionManagerBrowseHandlerTests : TestKit
            () => _factory.ReceivedCalls().Any(c => c.GetMethodInfo().Name == "Create"),
            TimeSpan.FromSeconds(2));
-        manager.Tell(new BrowseOpcUaNodeCommand("conn-bare", ParentNodeId: null));
+        manager.Tell(new BrowseNodeCommand("conn-bare", ParentNodeId: null));
-        var reply = ExpectMsg<BrowseOpcUaNodeResult>(TimeSpan.FromSeconds(3));
+        var reply = ExpectMsg<BrowseNodeResult>(TimeSpan.FromSeconds(3));
        Assert.NotNull(reply.Failure);
        Assert.Equal(BrowseFailureKind.NotBrowsable, reply.Failure!.Kind);
        Assert.Empty(reply.Children);
@@ -120,9 +120,9 @@ public class DataConnectionManagerBrowseHandlerTests : TestKit
            () => _factory.ReceivedCalls().Any(c => c.GetMethodInfo().Name == "Create"),
            TimeSpan.FromSeconds(2));
-        manager.Tell(new BrowseOpcUaNodeCommand("conn-ok", ParentNodeId: null));
+        manager.Tell(new BrowseNodeCommand("conn-ok", ParentNodeId: null));
-        var reply = ExpectMsg<BrowseOpcUaNodeResult>(TimeSpan.FromSeconds(3));
+        var reply = ExpectMsg<BrowseNodeResult>(TimeSpan.FromSeconds(3));
        Assert.Null(reply.Failure);
        Assert.Equal(2, reply.Children.Count);
        Assert.Equal("ns=2;s=A", reply.Children[0].NodeId);
@@ -155,9 +155,9 @@ public class DataConnectionManagerBrowseHandlerTests : TestKit
            () => _factory.ReceivedCalls().Any(c => c.GetMethodInfo().Name == "Create"),
            TimeSpan.FromSeconds(2));
-        manager.Tell(new BrowseOpcUaNodeCommand("conn-down", ParentNodeId: null));
+        manager.Tell(new BrowseNodeCommand("conn-down", ParentNodeId: null));
-        var reply = ExpectMsg<BrowseOpcUaNodeResult>(TimeSpan.FromSeconds(3));
+        var reply = ExpectMsg<BrowseNodeResult>(TimeSpan.FromSeconds(3));
        Assert.NotNull(reply.Failure);
        Assert.Equal(BrowseFailureKind.ConnectionNotConnected, reply.Failure!.Kind);
        Assert.Empty(reply.Children);
@@ -0,0 +1,65 @@
 using ZB.MOM.WW.ScadaBridge.DataConnectionLayer.Adapters;
 namespace ZB.MOM.WW.ScadaBridge.DataConnectionLayer.Tests.Adapters;
 /// <summary>
 /// In-memory fake <see cref="IMxGatewayClient"/> for adapter unit tests. Lets tests
 /// drive the event loop (push updates / fault the stream) and stub read/write/browse.
 /// </summary>
 public sealed class FakeMxGatewayClient : IMxGatewayClient, IMxGatewayClientFactory
 {
    public MxGatewayConnectionOptions? ConnectedWith;
    public readonly List<string> Subscribed = new();
    public readonly List<string> Unsubscribed = new();
    public readonly TaskCompletionSource EventLoopGate = new(TaskCreationOptions.RunContinuationsAsynchronously);
    public Action<MxValueUpdate>? OnUpdate;
    public Func<IReadOnlyList<string>, IReadOnlyList<MxReadOutcome>>? ReadHandler;
    public Func<IReadOnlyList<(string TagPath, object? Value)>, IReadOnlyList<MxWriteOutcome>>? WriteHandler;
    public Func<string?, (IReadOnlyList<MxBrowseChild>, bool)>? BrowseHandler;
    private int _nextHandle;
    public IMxGatewayClient Create() => this;
    public Task ConnectAsync(MxGatewayConnectionOptions o, CancellationToken ct = default)
    {
        ConnectedWith = o;
        return Task.CompletedTask;
    }
    public Task DisconnectAsync(CancellationToken ct = default) => Task.CompletedTask;
    public Task<string> SubscribeAsync(string tag, CancellationToken ct = default)
    {
        var id = (++_nextHandle).ToString();
        Subscribed.Add(tag);
        return Task.FromResult(id);
    }
    public Task UnsubscribeAsync(string id, CancellationToken ct = default)
    {
        Unsubscribed.Add(id);
        return Task.CompletedTask;
    }
    public Task<IReadOnlyList<MxReadOutcome>> ReadAsync(IReadOnlyList<string> tags, CancellationToken ct = default)
        => Task.FromResult(ReadHandler!(tags));
    public Task<IReadOnlyList<MxWriteOutcome>> WriteAsync(IReadOnlyList<(string TagPath, object? Value)> w, CancellationToken ct = default)
        => Task.FromResult(WriteHandler!(w));
    public Task<(IReadOnlyList<MxBrowseChild> Children, bool Truncated)> BrowseChildrenAsync(string? p, CancellationToken ct = default)
        => Task.FromResult(BrowseHandler!(p));
    public async Task RunEventLoopAsync(Action<MxValueUpdate> onUpdate, CancellationToken ct = default)
    {
        OnUpdate = onUpdate;
        using var reg = ct.Register(() => EventLoopGate.TrySetResult());
        await EventLoopGate.Task;          // test completes this to end the loop…
        ct.ThrowIfCancellationRequested(); // …or FaultEventLoop() faults it to simulate a stream break
    }
    public ValueTask DisposeAsync() => ValueTask.CompletedTask;
    /// <summary>Simulate a stream break so the adapter raises Disconnected.</summary>
    public void FaultEventLoop() => EventLoopGate.TrySetException(new Exception("stream broke"));
 }
@@ -0,0 +1,259 @@
 using Microsoft.Extensions.Logging.Abstractions;
 using ZB.MOM.WW.ScadaBridge.Commons.Interfaces.Protocol;
 using ZB.MOM.WW.ScadaBridge.Commons.Types.Enums;
 using ZB.MOM.WW.ScadaBridge.DataConnectionLayer.Adapters;
 namespace ZB.MOM.WW.ScadaBridge.DataConnectionLayer.Tests.Adapters;
 public class MxGatewayDataConnectionTests
 {
    private static MxGatewayDataConnection NewAdapter(FakeMxGatewayClient fake) =>
        new(fake, NullLogger<MxGatewayDataConnection>.Instance);
    private static Dictionary<string, string> Details(int writeUserId = 0) => new()
    {
        ["Endpoint"] = "http://gw:5000",
        ["ApiKey"] = "key",
        ["ClientName"] = "client-a",
        ["WriteUserId"] = writeUserId.ToString(),
        ["ReadTimeoutMs"] = "2000",
    };
    // ── Task 6: connect / status / Disconnected ──
    [Fact]
    public async Task ConnectAsync_resolves_options_and_sets_status_connected()
    {
        var fake = new FakeMxGatewayClient();
        var adapter = NewAdapter(fake);
        await adapter.ConnectAsync(Details(writeUserId: 7));
        Assert.Equal(ConnectionHealth.Connected, adapter.Status);
        Assert.NotNull(fake.ConnectedWith);
        Assert.Equal("http://gw:5000", fake.ConnectedWith!.Endpoint);
        Assert.Equal("client-a", fake.ConnectedWith.ClientName);
        Assert.Equal(7, fake.ConnectedWith.WriteUserId);
    }
    [Fact]
    public async Task ConnectAsync_blank_client_name_defaults_to_scadabridge()
    {
        var fake = new FakeMxGatewayClient();
        var adapter = NewAdapter(fake);
        var details = Details();
        details["ClientName"] = "";
        await adapter.ConnectAsync(details);
        Assert.Equal("scadabridge", fake.ConnectedWith!.ClientName);
    }
    [Fact]
    public async Task Disconnected_fires_exactly_once_when_event_loop_faults()
    {
        var fake = new FakeMxGatewayClient();
        var adapter = NewAdapter(fake);
        int raised = 0;
        adapter.Disconnected += () => Interlocked.Increment(ref raised);
        await adapter.ConnectAsync(Details());
        // Wait for the event loop to attach.
        await WaitUntil(() => fake.OnUpdate is not null);
        fake.FaultEventLoop();
        await WaitUntil(() => raised >= 1);
        Assert.Equal(1, raised);
        Assert.Equal(ConnectionHealth.Disconnected, adapter.Status);
    }
    // ── Task 7: subscribe / unsubscribe + event routing ──
    [Fact]
    public async Task Subscribed_tag_update_invokes_callback_with_mapped_TagValue()
    {
        var fake = new FakeMxGatewayClient();
        var adapter = NewAdapter(fake);
        await adapter.ConnectAsync(Details());
        await WaitUntil(() => fake.OnUpdate is not null);
        TagValue? received = null;
        await adapter.SubscribeAsync("Area.Pump.Speed", (_, v) => received = v);
        Assert.Contains("Area.Pump.Speed", fake.Subscribed);
        var ts = DateTimeOffset.UtcNow;
        fake.OnUpdate!(new MxValueUpdate("Area.Pump.Speed", 42.0, QualityCode.Good, ts));
        Assert.NotNull(received);
        Assert.Equal(42.0, received!.Value);
        Assert.Equal(QualityCode.Good, received.Quality);
        Assert.Equal(ts, received.Timestamp);
    }
    [Fact]
    public async Task Unsubscribe_stops_routing_updates()
    {
        var fake = new FakeMxGatewayClient();
        var adapter = NewAdapter(fake);
        await adapter.ConnectAsync(Details());
        await WaitUntil(() => fake.OnUpdate is not null);
        int hits = 0;
        var subId = await adapter.SubscribeAsync("T", (_, _) => hits++);
        await adapter.UnsubscribeAsync(subId);
        fake.OnUpdate!(new MxValueUpdate("T", 1, QualityCode.Good, DateTimeOffset.UtcNow));
        Assert.Equal(0, hits);
        Assert.Contains(subId, fake.Unsubscribed);
    }
    // ── Task 8: read / write + error classification ──
    [Fact]
    public async Task ReadAsync_maps_success_and_failure()
    {
        var fake = new FakeMxGatewayClient
        {
            ReadHandler = tags => tags.Select(t => t == "ok"
                ? new MxReadOutcome(t, true, 5, QualityCode.Good, DateTimeOffset.UtcNow, null)
                : new MxReadOutcome(t, false, null, QualityCode.Bad, default, "bad tag")).ToList()
        };
        var adapter = NewAdapter(fake);
        await adapter.ConnectAsync(Details());
        var ok = await adapter.ReadAsync("ok");
        Assert.True(ok.Success);
        Assert.Equal(5, ok.Value!.Value);
        var bad = await adapter.ReadAsync("nope");
        Assert.False(bad.Success);
        Assert.Equal("bad tag", bad.ErrorMessage);
    }
    [Fact]
    public async Task ReadBatchAsync_returns_dictionary_keyed_by_tag()
    {
        var fake = new FakeMxGatewayClient
        {
            ReadHandler = tags => tags.Select(t =>
                new MxReadOutcome(t, true, t.Length, QualityCode.Good, DateTimeOffset.UtcNow, null)).ToList()
        };
        var adapter = NewAdapter(fake);
        await adapter.ConnectAsync(Details());
        var results = await adapter.ReadBatchAsync(new[] { "aa", "bbb" });
        Assert.Equal(2, results["aa"].Value!.Value);
        Assert.Equal(3, results["bbb"].Value!.Value);
    }
    [Fact]
    public async Task WriteAsync_maps_failure_to_unsuccessful_WriteResult()
    {
        var fake = new FakeMxGatewayClient
        {
            WriteHandler = writes => writes.Select(w =>
                new MxWriteOutcome(w.TagPath, false, "rejected")).ToList()
        };
        var adapter = NewAdapter(fake);
        await adapter.ConnectAsync(Details());
        var r = await adapter.WriteAsync("T", 1);
        Assert.False(r.Success);
        Assert.Equal("rejected", r.ErrorMessage);
    }
    // ── Task 9: WriteBatchAndWait ──
    [Fact]
    public async Task WriteBatchAndWait_returns_true_when_response_matches()
    {
        var writeCalls = new List<string>();
        var fake = new FakeMxGatewayClient
        {
            WriteHandler = writes =>
            {
                writeCalls.AddRange(writes.Select(w => w.TagPath));
                return writes.Select(w => new MxWriteOutcome(w.TagPath, true, null)).ToList();
            },
            // Response path already reads the expected value.
            ReadHandler = tags => tags.Select(t =>
                new MxReadOutcome(t, true, "DONE", QualityCode.Good, DateTimeOffset.UtcNow, null)).ToList()
        };
        var adapter = NewAdapter(fake);
        await adapter.ConnectAsync(Details());
        var ok = await adapter.WriteBatchAndWaitAsync(
            new Dictionary<string, object?> { ["V"] = 1 }, "Flag", 1, "Resp", "DONE",
            TimeSpan.FromSeconds(5));
        Assert.True(ok);
        // Values written before the flag, and the flag itself.
        Assert.Contains("V", writeCalls);
        Assert.Contains("Flag", writeCalls);
    }
    [Fact]
    public async Task WriteBatchAndWait_returns_false_on_timeout()
    {
        var fake = new FakeMxGatewayClient
        {
            WriteHandler = writes => writes.Select(w => new MxWriteOutcome(w.TagPath, true, null)).ToList(),
            ReadHandler = tags => tags.Select(t =>
                new MxReadOutcome(t, true, "NEVER", QualityCode.Good, DateTimeOffset.UtcNow, null)).ToList()
        };
        var adapter = NewAdapter(fake);
        await adapter.ConnectAsync(Details());
        var ok = await adapter.WriteBatchAndWaitAsync(
            new Dictionary<string, object?> { ["V"] = 1 }, "Flag", 1, "Resp", "DONE",
            TimeSpan.FromMilliseconds(300));
        Assert.False(ok);
    }
    // ── Task 10: browse ──
    [Fact]
    public async Task BrowseChildrenAsync_maps_children_and_truncated()
    {
        var fake = new FakeMxGatewayClient
        {
            BrowseHandler = _ => (new List<MxBrowseChild>
            {
                new("Area1", "Area1", BrowseNodeClass.Object, true),
                new("Area1.Pump.Speed", "Speed", BrowseNodeClass.Variable, false),
            }, true)
        };
        var adapter = NewAdapter(fake);
        await adapter.ConnectAsync(Details());
        var result = await adapter.BrowseChildrenAsync(null);
        Assert.True(result.Truncated);
        Assert.Equal(2, result.Children.Count);
        Assert.Equal(BrowseNodeClass.Object, result.Children[0].NodeClass);
        Assert.True(result.Children[0].HasChildren);
        Assert.Equal("Area1.Pump.Speed", result.Children[1].NodeId);
        Assert.Equal(BrowseNodeClass.Variable, result.Children[1].NodeClass);
    }
    [Fact]
    public async Task BrowseChildrenAsync_throws_when_not_connected()
    {
        var fake = new FakeMxGatewayClient();
        var adapter = NewAdapter(fake);
        // Not connected.
        await Assert.ThrowsAsync<ConnectionNotConnectedException>(
            () => adapter.BrowseChildrenAsync(null));
    }
    private static async Task WaitUntil(Func<bool> condition, int timeoutMs = 2000)
    {
        var sw = System.Diagnostics.Stopwatch.StartNew();
        while (!condition() && sw.ElapsedMilliseconds < timeoutMs)
            await Task.Delay(10);
        Assert.True(condition(), "Condition not met within timeout.");
    }
 }
@@ -18,6 +18,16 @@ public class DataConnectionFactoryTests
        Assert.IsType<OpcUaDataConnection>(connection);
    }
    [Fact]
    public void Create_MxGateway_ReturnsMxGatewayAdapter()
    {
        var factory = new DataConnectionFactory(NullLoggerFactory.Instance);
        var connection = factory.Create("MxGateway", new Dictionary<string, string>());
        Assert.IsType<MxGatewayDataConnection>(connection);
    }
    [Fact]
    public void Create_CaseInsensitive()
    {