diff --git a/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Shared/Uns/TagEditors/HistorianWonderwareTagConfigEditor.razor b/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Shared/Uns/TagEditors/HistorianWonderwareTagConfigEditor.razor
new file mode 100644
index 00000000..8a5ee6eb
--- /dev/null
+++ b/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Shared/Uns/TagEditors/HistorianWonderwareTagConfigEditor.razor
@@ -0,0 +1,43 @@
+@using ZB.MOM.WW.OtOpcUa.AdminUI.Uns.TagEditors
+
+<div class="row g-2">
+    <div class="col-md-12"><label class="form-label">Historian tagname (FullName)</label>
+        <input type="text" class="form-control form-control-sm mono" value="@_m.FullName"
+               placeholder="Reactor1.Temperature"
+               @onchange="@(e => Update(() => _m.FullName = e.Value?.ToString() ?? string.Empty))" />
+        <div class="form-text">The AVEVA Historian tagname the driver reads against.</div></div>
+    <div class="col-md-12">
+        <div class="form-check form-switch">
+            <input type="checkbox" class="form-check-input" checked="@_m.IsHistorized"
+                   @onchange="@(e => Update(() => _m.IsHistorized = e.Value is true))" />
+            <label class="form-check-label">Historized (expose OPC UA HistoryRead)</label>
+        </div>
+    </div>
+    <div class="col-md-12"><label class="form-label">Historian tagname override (optional)</label>
+        <input type="text" class="form-control form-control-sm mono" value="@_m.HistorianTagname"
+               @onchange="@(e => Update(() => _m.HistorianTagname = e.Value?.ToString() ?? string.Empty))" />
+        <div class="form-text">Blank defaults the historian tagname to the FullName above.</div></div>
+</div>
+
+@code {
+    [Parameter] public string? ConfigJson { get; set; }
+    [Parameter] public EventCallback<string> ConfigJsonChanged { get; set; }
+
+    private HistorianWonderwareTagConfigModel _m = new();
+    private string? _lastConfigJson;
+
+    // Re-parse only when the incoming JSON actually changes, so an unrelated parent re-render
+    // (Blazor Server live-status pushes do this) can't reset the user's in-progress edits.
+    protected override void OnParametersSet()
+    {
+        if (ConfigJson == _lastConfigJson) { return; }
+        _lastConfigJson = ConfigJson;
+        _m = HistorianWonderwareTagConfigModel.FromJson(ConfigJson);
+    }
+
+    private async Task Update(Action apply)
+    {
+        apply();
+        await ConfigJsonChanged.InvokeAsync(_m.ToJson());
+    }
+}
diff --git a/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Shared/Uns/TagEditors/OpcUaClientTagConfigEditor.razor b/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Shared/Uns/TagEditors/OpcUaClientTagConfigEditor.razor
new file mode 100644
index 00000000..1a1721b9
--- /dev/null
+++ b/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Shared/Uns/TagEditors/OpcUaClientTagConfigEditor.razor
@@ -0,0 +1,43 @@
+@using ZB.MOM.WW.OtOpcUa.AdminUI.Uns.TagEditors
+
+<div class="row g-2">
+    <div class="col-md-12"><label class="form-label">Upstream node reference (FullName)</label>
+        <input type="text" class="form-control form-control-sm mono" value="@_m.FullName"
+               placeholder="nsu=urn:server:ns;s=Line3.Temp"
+               @onchange="@(e => Update(() => _m.FullName = e.Value?.ToString() ?? string.Empty))" />
+        <div class="form-text">The remote OPC UA NodeId the driver reads/writes/subscribes against. Use the browse picker on the driver page to find it.</div></div>
+    <div class="col-md-12">
+        <div class="form-check form-switch">
+            <input type="checkbox" class="form-check-input" checked="@_m.IsHistorized"
+                   @onchange="@(e => Update(() => _m.IsHistorized = e.Value is true))" />
+            <label class="form-check-label">Historized (expose OPC UA HistoryRead)</label>
+        </div>
+    </div>
+    <div class="col-md-12"><label class="form-label">Historian tagname override (optional)</label>
+        <input type="text" class="form-control form-control-sm mono" value="@_m.HistorianTagname"
+               @onchange="@(e => Update(() => _m.HistorianTagname = e.Value?.ToString() ?? string.Empty))" />
+        <div class="form-text">Blank defaults the historian tagname to the FullName above.</div></div>
+</div>
+
+@code {
+    [Parameter] public string? ConfigJson { get; set; }
+    [Parameter] public EventCallback<string> ConfigJsonChanged { get; set; }
+
+    private OpcUaClientTagConfigModel _m = new();
+    private string? _lastConfigJson;
+
+    // Re-parse only when the incoming JSON actually changes, so an unrelated parent re-render
+    // (Blazor Server live-status pushes do this) can't reset the user's in-progress edits.
+    protected override void OnParametersSet()
+    {
+        if (ConfigJson == _lastConfigJson) { return; }
+        _lastConfigJson = ConfigJson;
+        _m = OpcUaClientTagConfigModel.FromJson(ConfigJson);
+    }
+
+    private async Task Update(Action apply)
+    {
+        apply();
+        await ConfigJsonChanged.InvokeAsync(_m.ToJson());
+    }
+}
diff --git a/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Uns/TagEditors/HistorianWonderwareTagConfigModel.cs b/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Uns/TagEditors/HistorianWonderwareTagConfigModel.cs
new file mode 100644
index 00000000..68dc6054
--- /dev/null
+++ b/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Uns/TagEditors/HistorianWonderwareTagConfigModel.cs
@@ -0,0 +1,62 @@
+using System.Text.Json.Nodes;
+
+namespace ZB.MOM.WW.OtOpcUa.AdminUI.Uns.TagEditors;
+
+/// <summary>Typed working model for a Wonderware (AVEVA) Historian equipment tag's TagConfig JSON. The
+/// tag binds to a historian tag by its full reference (<c>FullName</c> — the historian tagname/source
+/// the driver reads against), plus the optional driver-agnostic server-side HistoryRead intent
+/// (<c>isHistorized</c> / <c>historianTagname</c>). Preserves unrecognised JSON keys across a load→save.</summary>
+/// <remarks>
+///     The <c>FullName</c> key is intentionally PascalCase: the deploy-time composer + node walker
+///     (<c>Phase7Composer.ExtractTagFullName</c>, <c>EquipmentNodeWalker</c>) read it via a
+///     case-sensitive <c>TryGetProperty("FullName", …)</c>, so the editor MUST persist that exact
+///     casing. The history keys (<c>isHistorized</c> / <c>historianTagname</c>) are camelCase to match
+///     <c>Phase7Composer.ExtractTagHistorize</c>.
+/// </remarks>
+public sealed class HistorianWonderwareTagConfigModel
+{
+    /// <summary>Historian tagname/source the tag binds to (the driver-side full reference). Required.</summary>
+    public string FullName { get; set; } = "";
+
+    /// <summary>Whether the server exposes OPC UA HistoryRead over this tag's variable node.</summary>
+    public bool IsHistorized { get; set; }
+
+    /// <summary>Optional historian tagname override; blank means the historian tagname defaults to <see cref="FullName"/>.</summary>
+    public string HistorianTagname { get; set; } = "";
+
+    private JsonObject _bag = new();
+
+    /// <summary>Loads a model from a TagConfig JSON string, defaulting any absent field and retaining
+    /// every original key (so fields this editor doesn't expose survive a load→save).</summary>
+    /// <param name="json">The tag's TagConfig JSON (null/blank/malformed ⇒ defaults).</param>
+    public static HistorianWonderwareTagConfigModel FromJson(string? json)
+    {
+        var o = TagConfigJson.ParseOrNew(json);
+        return new HistorianWonderwareTagConfigModel
+        {
+            FullName = TagConfigJson.GetString(o, "FullName") ?? "",
+            IsHistorized = TagConfigJson.GetBool(o, "isHistorized"),
+            HistorianTagname = TagConfigJson.GetString(o, "historianTagname") ?? "",
+            _bag = o,
+        };
+    }
+
+    /// <summary>Serialises this model back to a TagConfig JSON string over the preserved key bag.
+    /// <c>FullName</c> is written PascalCase (the composer/walker contract key); the history keys are
+    /// written camelCase and dropped when default (absent <c>isHistorized</c> ⇒ false at the composer;
+    /// blank <c>historianTagname</c> ⇒ defaults to <c>FullName</c>).</summary>
+    public string ToJson()
+    {
+        TagConfigJson.Set(_bag, "FullName", FullName.Trim());
+        // Drop isHistorized when false so the persisted blob stays minimal and matches the
+        // composer's "absent ⇒ false" convention; same for a blank historianTagname override.
+        TagConfigJson.Set(_bag, "isHistorized", IsHistorized ? true : null);
+        TagConfigJson.Set(_bag, "historianTagname",
+            string.IsNullOrWhiteSpace(HistorianTagname) ? null : HistorianTagname.Trim());
+        return TagConfigJson.Serialize(_bag);
+    }
+
+    /// <summary>Validation hook; returns an error message or null when the model is valid.</summary>
+    public string? Validate()
+        => string.IsNullOrWhiteSpace(FullName) ? "A historian tagname (FullName) is required." : null;
+}
diff --git a/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Uns/TagEditors/OpcUaClientTagConfigModel.cs b/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Uns/TagEditors/OpcUaClientTagConfigModel.cs
new file mode 100644
index 00000000..ef65da78
--- /dev/null
+++ b/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Uns/TagEditors/OpcUaClientTagConfigModel.cs
@@ -0,0 +1,63 @@
+using System.Text.Json.Nodes;
+
+namespace ZB.MOM.WW.OtOpcUa.AdminUI.Uns.TagEditors;
+
+/// <summary>Typed working model for an OPC UA Client (gateway) equipment tag's TagConfig JSON. The tag
+/// is bound to the upstream OPC UA server node by its full reference (<c>FullName</c> — the persisted
+/// stable <c>nsu=…;s=…</c> or plain <c>ns=2;s=…</c> NodeId the driver reads/writes/subscribes against),
+/// plus the optional driver-agnostic server-side HistoryRead intent (<c>isHistorized</c> /
+/// <c>historianTagname</c>). Preserves unrecognised JSON keys across a load→save.</summary>
+/// <remarks>
+///     The <c>FullName</c> key is intentionally PascalCase: the deploy-time composer + node walker
+///     (<c>Phase7Composer.ExtractTagFullName</c>, <c>EquipmentNodeWalker</c>) read it via a
+///     case-sensitive <c>TryGetProperty("FullName", …)</c>, so the editor MUST persist that exact
+///     casing. The history keys (<c>isHistorized</c> / <c>historianTagname</c>) are camelCase to match
+///     <c>Phase7Composer.ExtractTagHistorize</c>.
+/// </remarks>
+public sealed class OpcUaClientTagConfigModel
+{
+    /// <summary>Upstream OPC UA node reference the tag binds to (the driver-side full reference). Required.</summary>
+    public string FullName { get; set; } = "";
+
+    /// <summary>Whether the server exposes OPC UA HistoryRead over this tag's variable node.</summary>
+    public bool IsHistorized { get; set; }
+
+    /// <summary>Optional historian tagname override; blank means the historian tagname defaults to <see cref="FullName"/>.</summary>
+    public string HistorianTagname { get; set; } = "";
+
+    private JsonObject _bag = new();
+
+    /// <summary>Loads a model from a TagConfig JSON string, defaulting any absent field and retaining
+    /// every original key (so fields this editor doesn't expose survive a load→save).</summary>
+    /// <param name="json">The tag's TagConfig JSON (null/blank/malformed ⇒ defaults).</param>
+    public static OpcUaClientTagConfigModel FromJson(string? json)
+    {
+        var o = TagConfigJson.ParseOrNew(json);
+        return new OpcUaClientTagConfigModel
+        {
+            FullName = TagConfigJson.GetString(o, "FullName") ?? "",
+            IsHistorized = TagConfigJson.GetBool(o, "isHistorized"),
+            HistorianTagname = TagConfigJson.GetString(o, "historianTagname") ?? "",
+            _bag = o,
+        };
+    }
+
+    /// <summary>Serialises this model back to a TagConfig JSON string over the preserved key bag.
+    /// <c>FullName</c> is written PascalCase (the composer/walker contract key); the history keys are
+    /// written camelCase and dropped when default (absent <c>isHistorized</c> ⇒ false at the composer;
+    /// blank <c>historianTagname</c> ⇒ defaults to <c>FullName</c>).</summary>
+    public string ToJson()
+    {
+        TagConfigJson.Set(_bag, "FullName", FullName.Trim());
+        // Drop isHistorized when false so the persisted blob stays minimal and matches the
+        // composer's "absent ⇒ false" convention; same for a blank historianTagname override.
+        TagConfigJson.Set(_bag, "isHistorized", IsHistorized ? true : null);
+        TagConfigJson.Set(_bag, "historianTagname",
+            string.IsNullOrWhiteSpace(HistorianTagname) ? null : HistorianTagname.Trim());
+        return TagConfigJson.Serialize(_bag);
+    }
+
+    /// <summary>Validation hook; returns an error message or null when the model is valid.</summary>
+    public string? Validate()
+        => string.IsNullOrWhiteSpace(FullName) ? "An upstream node reference (FullName) is required." : null;
+}
diff --git a/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Uns/TagEditors/TagConfigEditorMap.cs b/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Uns/TagEditors/TagConfigEditorMap.cs
index 378db6ec..dc929706 100644
--- a/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Uns/TagEditors/TagConfigEditorMap.cs
+++ b/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Uns/TagEditors/TagConfigEditorMap.cs
@@ -16,6 +16,8 @@ public static class TagConfigEditorMap
             ["AbLegacy"]  = typeof(Components.Shared.Uns.TagEditors.AbLegacyTagConfigEditor),
             ["TwinCat"]   = typeof(Components.Shared.Uns.TagEditors.TwinCATTagConfigEditor),
             ["Focas"]     = typeof(Components.Shared.Uns.TagEditors.FocasTagConfigEditor),
+            ["OpcUaClient"]          = typeof(Components.Shared.Uns.TagEditors.OpcUaClientTagConfigEditor),
+            ["Historian.Wonderware"] = typeof(Components.Shared.Uns.TagEditors.HistorianWonderwareTagConfigEditor),
         };
 
     /// <summary>Returns the editor component type for a driver type, or null if none is registered.</summary>
diff --git a/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Uns/TagEditors/TagConfigJson.cs b/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Uns/TagEditors/TagConfigJson.cs
index 673dd433..8f317a4c 100644
--- a/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Uns/TagEditors/TagConfigJson.cs
+++ b/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Uns/TagEditors/TagConfigJson.cs
@@ -29,6 +29,10 @@ public static class TagConfigJson
     public static int GetInt(JsonObject o, string name, int fallback = 0)
         => o.TryGetPropertyValue(name, out var n) && n is JsonValue v && v.TryGetValue<int>(out var i) ? i : fallback;
 
+    /// <summary>Reads a bool value, or <paramref name="fallback"/> if absent/null/non-boolean (incl. object/array/number/string nodes).</summary>
+    public static bool GetBool(JsonObject o, string name, bool fallback = false)
+        => o.TryGetPropertyValue(name, out var n) && n is JsonValue v && v.TryGetValue<bool>(out var b) ? b : fallback;
+
     /// <summary>Reads an enum by its serialised name, or <paramref name="fallback"/> if absent/unparseable.</summary>
     public static TEnum GetEnum<TEnum>(JsonObject o, string name, TEnum fallback) where TEnum : struct, Enum
         => GetString(o, name) is { } s && Enum.TryParse<TEnum>(s, ignoreCase: true, out var v) ? v : fallback;
diff --git a/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Uns/TagEditors/TagConfigValidator.cs b/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Uns/TagEditors/TagConfigValidator.cs
index 8e5f8722..e37b3d44 100644
--- a/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Uns/TagEditors/TagConfigValidator.cs
+++ b/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Uns/TagEditors/TagConfigValidator.cs
@@ -18,6 +18,8 @@ public static class TagConfigValidator
             ["AbLegacy"]  = j => AbLegacyTagConfigModel.FromJson(j).Validate(),
             ["TwinCat"]   = j => TwinCATTagConfigModel.FromJson(j).Validate(),
             ["Focas"]     = j => FocasTagConfigModel.FromJson(j).Validate(),
+            ["OpcUaClient"]          = j => OpcUaClientTagConfigModel.FromJson(j).Validate(),
+            ["Historian.Wonderware"] = j => HistorianWonderwareTagConfigModel.FromJson(j).Validate(),
         };
 
     /// <summary>
diff --git a/tests/Server/ZB.MOM.WW.OtOpcUa.AdminUI.Tests/Uns/HistorianWonderwareTagConfigModelTests.cs b/tests/Server/ZB.MOM.WW.OtOpcUa.AdminUI.Tests/Uns/HistorianWonderwareTagConfigModelTests.cs
new file mode 100644
index 00000000..8d976d65
--- /dev/null
+++ b/tests/Server/ZB.MOM.WW.OtOpcUa.AdminUI.Tests/Uns/HistorianWonderwareTagConfigModelTests.cs
@@ -0,0 +1,114 @@
+using Shouldly;
+using Xunit;
+using ZB.MOM.WW.OtOpcUa.AdminUI.Uns.TagEditors;
+
+namespace ZB.MOM.WW.OtOpcUa.AdminUI.Tests.Uns;
+
+public sealed class HistorianWonderwareTagConfigModelTests
+{
+    [Theory]
+    [InlineData(null)]
+    [InlineData("")]
+    [InlineData("   ")]
+    [InlineData("{}")]
+    public void FromJson_returns_defaults_for_empty_input(string? json)
+    {
+        var m = HistorianWonderwareTagConfigModel.FromJson(json);
+
+        m.FullName.ShouldBe("");
+        m.IsHistorized.ShouldBeFalse();
+        m.HistorianTagname.ShouldBe("");
+    }
+
+    [Fact]
+    public void FromJson_reads_all_fields()
+    {
+        var m = HistorianWonderwareTagConfigModel.FromJson(
+            """{"FullName":"SysTimeSec","isHistorized":true,"historianTagname":"Reactor1.Temp"}""");
+
+        m.FullName.ShouldBe("SysTimeSec");
+        m.IsHistorized.ShouldBeTrue();
+        m.HistorianTagname.ShouldBe("Reactor1.Temp");
+    }
+
+    [Fact]
+    public void Round_trip_preserves_all_fields()
+    {
+        var m = new HistorianWonderwareTagConfigModel
+        {
+            FullName = "Reactor1.Temp",
+            IsHistorized = true,
+            HistorianTagname = "Reactor1.Temp.Override",
+        };
+
+        var json = m.ToJson();
+        var m2 = HistorianWonderwareTagConfigModel.FromJson(json);
+
+        m2.FullName.ShouldBe("Reactor1.Temp");
+        m2.IsHistorized.ShouldBeTrue();
+        m2.HistorianTagname.ShouldBe("Reactor1.Temp.Override");
+    }
+
+    [Fact]
+    public void ToJson_emits_PascalCase_FullName_and_camelCase_history_keys()
+    {
+        var m = new HistorianWonderwareTagConfigModel
+        {
+            FullName = "Reactor1.Temp",
+            IsHistorized = true,
+            HistorianTagname = "Reactor1.Temp.Override",
+        };
+
+        var json = m.ToJson();
+
+        // FullName is the composer/walker contract key — PascalCase, case-sensitive.
+        json.ShouldContain("\"FullName\":\"Reactor1.Temp\"");
+        json.ShouldNotContain("\"fullName\"", Case.Sensitive);
+        json.ShouldContain("\"isHistorized\":true");
+        json.ShouldContain("\"historianTagname\":\"Reactor1.Temp.Override\"");
+    }
+
+    [Fact]
+    public void ToJson_omits_history_keys_when_default()
+    {
+        var json = new HistorianWonderwareTagConfigModel { FullName = "Reactor1.Temp" }.ToJson();
+
+        json.ShouldContain("\"FullName\":\"Reactor1.Temp\"");
+        json.ShouldNotContain("isHistorized");
+        json.ShouldNotContain("historianTagname");
+    }
+
+    [Fact]
+    public void FromJson_then_ToJson_preserves_unknown_keys()
+    {
+        var json = HistorianWonderwareTagConfigModel
+            .FromJson("""{"FullName":"Reactor1.Temp","deadband":0.5}""")
+            .ToJson();
+
+        json.ShouldContain("deadband");
+        json.ShouldContain("0.5");
+        // and the exposed field still round-trips
+        json.ShouldContain("\"FullName\":\"Reactor1.Temp\"");
+    }
+
+    [Fact]
+    public void ToJson_trims_FullName()
+    {
+        var json = new HistorianWonderwareTagConfigModel { FullName = "  Reactor1.Temp  " }.ToJson();
+
+        json.ShouldContain("\"FullName\":\"Reactor1.Temp\"");
+    }
+
+    [Fact]
+    public void Validate_returns_error_when_FullName_blank()
+    {
+        new HistorianWonderwareTagConfigModel().Validate().ShouldNotBeNullOrEmpty();
+        new HistorianWonderwareTagConfigModel { FullName = "   " }.Validate().ShouldNotBeNullOrEmpty();
+    }
+
+    [Fact]
+    public void Validate_returns_null_when_FullName_present()
+    {
+        new HistorianWonderwareTagConfigModel { FullName = "Reactor1.Temp" }.Validate().ShouldBeNull();
+    }
+}
diff --git a/tests/Server/ZB.MOM.WW.OtOpcUa.AdminUI.Tests/Uns/OpcUaClientTagConfigModelTests.cs b/tests/Server/ZB.MOM.WW.OtOpcUa.AdminUI.Tests/Uns/OpcUaClientTagConfigModelTests.cs
new file mode 100644
index 00000000..6d75d995
--- /dev/null
+++ b/tests/Server/ZB.MOM.WW.OtOpcUa.AdminUI.Tests/Uns/OpcUaClientTagConfigModelTests.cs
@@ -0,0 +1,114 @@
+using Shouldly;
+using Xunit;
+using ZB.MOM.WW.OtOpcUa.AdminUI.Uns.TagEditors;
+
+namespace ZB.MOM.WW.OtOpcUa.AdminUI.Tests.Uns;
+
+public sealed class OpcUaClientTagConfigModelTests
+{
+    [Theory]
+    [InlineData(null)]
+    [InlineData("")]
+    [InlineData("   ")]
+    [InlineData("{}")]
+    public void FromJson_returns_defaults_for_empty_input(string? json)
+    {
+        var m = OpcUaClientTagConfigModel.FromJson(json);
+
+        m.FullName.ShouldBe("");
+        m.IsHistorized.ShouldBeFalse();
+        m.HistorianTagname.ShouldBe("");
+    }
+
+    [Fact]
+    public void FromJson_reads_all_fields()
+    {
+        var m = OpcUaClientTagConfigModel.FromJson(
+            """{"FullName":"nsu=urn:srv;s=Line3.Temp","isHistorized":true,"historianTagname":"Line3_Temp"}""");
+
+        m.FullName.ShouldBe("nsu=urn:srv;s=Line3.Temp");
+        m.IsHistorized.ShouldBeTrue();
+        m.HistorianTagname.ShouldBe("Line3_Temp");
+    }
+
+    [Fact]
+    public void Round_trip_preserves_all_fields()
+    {
+        var m = new OpcUaClientTagConfigModel
+        {
+            FullName = "ns=2;s=Line3.Temp",
+            IsHistorized = true,
+            HistorianTagname = "Line3_Temp",
+        };
+
+        var json = m.ToJson();
+        var m2 = OpcUaClientTagConfigModel.FromJson(json);
+
+        m2.FullName.ShouldBe("ns=2;s=Line3.Temp");
+        m2.IsHistorized.ShouldBeTrue();
+        m2.HistorianTagname.ShouldBe("Line3_Temp");
+    }
+
+    [Fact]
+    public void ToJson_emits_PascalCase_FullName_and_camelCase_history_keys()
+    {
+        var m = new OpcUaClientTagConfigModel
+        {
+            FullName = "ns=2;s=Line3.Temp",
+            IsHistorized = true,
+            HistorianTagname = "Line3_Temp",
+        };
+
+        var json = m.ToJson();
+
+        // FullName is the composer/walker contract key — PascalCase, case-sensitive.
+        json.ShouldContain("\"FullName\":\"ns=2;s=Line3.Temp\"");
+        json.ShouldNotContain("\"fullName\"", Case.Sensitive);
+        json.ShouldContain("\"isHistorized\":true");
+        json.ShouldContain("\"historianTagname\":\"Line3_Temp\"");
+    }
+
+    [Fact]
+    public void ToJson_omits_history_keys_when_default()
+    {
+        var json = new OpcUaClientTagConfigModel { FullName = "ns=2;s=X" }.ToJson();
+
+        json.ShouldContain("\"FullName\":\"ns=2;s=X\"");
+        json.ShouldNotContain("isHistorized");
+        json.ShouldNotContain("historianTagname");
+    }
+
+    [Fact]
+    public void FromJson_then_ToJson_preserves_unknown_keys()
+    {
+        var json = OpcUaClientTagConfigModel
+            .FromJson("""{"FullName":"ns=2;s=X","samplingIntervalMs":250}""")
+            .ToJson();
+
+        json.ShouldContain("samplingIntervalMs");
+        json.ShouldContain("250");
+        // and the exposed field still round-trips
+        json.ShouldContain("\"FullName\":\"ns=2;s=X\"");
+    }
+
+    [Fact]
+    public void ToJson_trims_FullName()
+    {
+        var json = new OpcUaClientTagConfigModel { FullName = "  ns=2;s=X  " }.ToJson();
+
+        json.ShouldContain("\"FullName\":\"ns=2;s=X\"");
+    }
+
+    [Fact]
+    public void Validate_returns_error_when_FullName_blank()
+    {
+        new OpcUaClientTagConfigModel().Validate().ShouldNotBeNullOrEmpty();
+        new OpcUaClientTagConfigModel { FullName = "   " }.Validate().ShouldNotBeNullOrEmpty();
+    }
+
+    [Fact]
+    public void Validate_returns_null_when_FullName_present()
+    {
+        new OpcUaClientTagConfigModel { FullName = "ns=2;s=X" }.Validate().ShouldBeNull();
+    }
+}
diff --git a/tests/Server/ZB.MOM.WW.OtOpcUa.AdminUI.Tests/Uns/TagConfigJsonTests.cs b/tests/Server/ZB.MOM.WW.OtOpcUa.AdminUI.Tests/Uns/TagConfigJsonTests.cs
index e1d4e454..31a54beb 100644
--- a/tests/Server/ZB.MOM.WW.OtOpcUa.AdminUI.Tests/Uns/TagConfigJsonTests.cs
+++ b/tests/Server/ZB.MOM.WW.OtOpcUa.AdminUI.Tests/Uns/TagConfigJsonTests.cs
@@ -87,6 +87,31 @@ public sealed class TagConfigJsonTests
         TagConfigJson.GetString(obj, "nested").ShouldBeNull();
     }
 
+    [Fact]
+    public void GetBool_reads_a_bool()
+    {
+        var obj = TagConfigJson.ParseOrNew("""{"isHistorized":true}""");
+
+        TagConfigJson.GetBool(obj, "isHistorized").ShouldBeTrue();
+    }
+
+    [Fact]
+    public void GetBool_falls_back_when_absent()
+    {
+        var obj = new JsonObject();
+
+        TagConfigJson.GetBool(obj, "isHistorized", fallback: true).ShouldBeTrue();
+    }
+
+    [Fact]
+    public void GetBool_falls_back_when_value_is_not_a_bool()
+    {
+        var obj = TagConfigJson.ParseOrNew("""{"isHistorized":"yes","other":1}""");
+
+        TagConfigJson.GetBool(obj, "isHistorized").ShouldBeFalse();
+        TagConfigJson.GetBool(obj, "other").ShouldBeFalse();
+    }
+
     [Fact]
     public void GetEnum_parses_by_name_case_insensitive()
     {
diff --git a/tests/Server/ZB.MOM.WW.OtOpcUa.AdminUI.Tests/Uns/TagConfigValidatorTests.cs b/tests/Server/ZB.MOM.WW.OtOpcUa.AdminUI.Tests/Uns/TagConfigValidatorTests.cs
index 328b4f49..160382c3 100644
--- a/tests/Server/ZB.MOM.WW.OtOpcUa.AdminUI.Tests/Uns/TagConfigValidatorTests.cs
+++ b/tests/Server/ZB.MOM.WW.OtOpcUa.AdminUI.Tests/Uns/TagConfigValidatorTests.cs
@@ -12,7 +12,7 @@ public sealed class TagConfigValidatorTests
 
     [Fact]
     public void Unmapped_driver_has_no_typed_validator_so_is_valid()
-        => TagConfigValidator.Validate("OpcUaClient", "{}").ShouldBeNull();
+        => TagConfigValidator.Validate("GalaxyMxGateway", "{}").ShouldBeNull();
 
     [Fact]
     public void Modbus_has_no_required_field_so_empty_config_is_valid()
@@ -25,12 +25,22 @@ public sealed class TagConfigValidatorTests
     [InlineData("AbLegacy")]
     [InlineData("TwinCat")]
     [InlineData("Focas")]
+    [InlineData("OpcUaClient")]
+    [InlineData("Historian.Wonderware")]
     public void Required_field_blank_is_rejected(string driverType)
     {
         TagConfigValidator.Validate(driverType, "{}").ShouldNotBeNullOrEmpty();
         TagConfigValidator.Validate(driverType, null).ShouldNotBeNullOrEmpty();
     }
 
+    [Fact]
+    public void OpcUaClient_with_full_name_is_valid()
+        => TagConfigValidator.Validate("OpcUaClient", """{"FullName":"ns=2;s=Line3.Temp"}""").ShouldBeNull();
+
+    [Fact]
+    public void HistorianWonderware_with_full_name_is_valid()
+        => TagConfigValidator.Validate("Historian.Wonderware", """{"FullName":"Reactor1.Temp"}""").ShouldBeNull();
+
     [Fact]
     public void S7_with_address_is_valid()
         => TagConfigValidator.Validate("S7", """{"address":"DB1.DBW0"}""").ShouldBeNull();