diff --git a/src/ZB.MOM.WW.ScadaBridge.CentralUI/Components/Pages/Deployment/InstanceConfigure.razor b/src/ZB.MOM.WW.ScadaBridge.CentralUI/Components/Pages/Deployment/InstanceConfigure.razor
index 109cb0ca..ddd95f87 100644
--- a/src/ZB.MOM.WW.ScadaBridge.CentralUI/Components/Pages/Deployment/InstanceConfigure.razor
+++ b/src/ZB.MOM.WW.ScadaBridge.CentralUI/Components/Pages/Deployment/InstanceConfigure.razor
@@ -9,6 +9,7 @@
 @using ZB.MOM.WW.ScadaBridge.TemplateEngine.Flattening
 @using ZB.MOM.WW.ScadaBridge.TemplateEngine.Services
 @using ZB.MOM.WW.ScadaBridge.DeploymentManager
+@using ZB.MOM.WW.ScadaBridge.CentralUI.Components.Dialogs
 @attribute [Authorize(Policy = AuthorizationPolicies.RequireDeployment)]
 @inject ITemplateEngineRepository TemplateEngineRepository
 @inject ISiteRepository SiteRepository
@@ -108,17 +109,22 @@
                                 <th>Attribute</th>
                                 <th>Tag Path</th>
                                 <th style="width: 280px;">Connection</th>
+                                <th>Override</th>
+                                <th style="width: 110px;"></th>
                             </tr>
                         </thead>
                         <tbody>
                             @foreach (var attr in _bindingDataSourceAttrs)
                             {
+                                var connId = GetBindingConnectionId(attr.Name);
+                                var canBrowse = connId > 0;
+                                var isOpcUa = IsOpcUa(connId);
                                 <tr>
                                     <td class="small">@attr.Name</td>
                                     <td class="small text-muted font-monospace">@attr.DataSourceReference</td>
                                     <td>
                                         <select class="form-select form-select-sm"
-                                                value="@GetBindingConnectionId(attr.Name)"
+                                                value="@connId"
                                                 @onchange="(e) => OnBindingChanged(attr.Name, e)">
                                             <option value="0">— none —</option>
                                             @foreach (var c in _siteConnections)
@@ -127,6 +133,23 @@
                                             }
                                         </select>
                                     </td>
+                                    <td>
+                                        <input class="form-control form-control-sm"
+                                               value="@GetOverrideForAttr(attr.Name)"
+                                               @onchange="(e) => OnOverrideForAttrChanged(attr.Name, e)"
+                                               placeholder="@(attr.DataSourceReference ?? "(no default)")" />
+                                    </td>
+                                    <td>
+                                        @if (isOpcUa)
+                                        {
+                                            <button class="btn btn-sm btn-outline-primary"
+                                                    disabled="@(!canBrowse)"
+                                                    title="@(canBrowse ? "Browse OPC UA address space" : "Pick a connection first")"
+                                                    @onclick="() => OpenBrowser(attr.Name)">
+                                                Browse…
+                                            </button>
+                                        }
+                                    </td>
                                 </tr>
                             }
                         </tbody>
@@ -331,6 +354,14 @@
                 </div>
             </div>
         </div>
+
+        @* 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"
+                            SiteId="@_browserSiteIdentifier"
+                            ConnectionName="@_browserConnectionName"
+                            InitialNodeId="@_browserInitial"
+                            OnSelected="OnBrowserSelected" />
     }
 </div>
 
@@ -350,8 +381,24 @@
     private List<TemplateAttribute> _bindingDataSourceAttrs = new();
     private List<DataConnection> _siteConnections = new();
     private Dictionary<string, int> _bindingSelections = new();
+    /// <summary>
+    /// Per-attribute <c>DataSourceReferenceOverride</c> values (Task 18). Mirrors
+    /// <see cref="_bindingSelections"/> by attribute name. Loaded from the
+    /// existing <see cref="InstanceConnectionBinding"/> rows on init; round-tripped
+    /// through <see cref="ConnectionBinding"/> on <c>SaveBindings</c>.
+    /// </summary>
+    private Dictionary<string, string?> _bindingOverrides = new();
     private int _bulkConnectionId;
 
+    // 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 string? _browserAttrInEdit;
+    private string _browserSiteIdentifier = "";
+    private string _browserConnectionName = "";
+    private string? _browserInitial;
+    private string _siteIdentifier = "";
+
     // Overrides
     private List<TemplateAttribute> _overrideAttrs = new();
     private Dictionary<string, string?> _overrideValues = new();
@@ -407,7 +454,11 @@
             _templateName = template?.Name ?? $"#{_instance.TemplateId}";
 
             var sites = await SiteRepository.GetAllSitesAsync();
-            _siteName = sites.FirstOrDefault(s => s.Id == _instance.SiteId)?.Name ?? $"#{_instance.SiteId}";
+            var site = sites.FirstOrDefault(s => s.Id == _instance.SiteId);
+            _siteName = site?.Name ?? $"#{_instance.SiteId}";
+            // Task 18: cache the site's machine identifier — the OPC UA browse
+            // dialog routes by SiteIdentifier (string), not the numeric site id.
+            _siteIdentifier = site?.SiteIdentifier ?? "";
 
             // Areas
             _siteAreas = (await TemplateEngineRepository.GetAreasBySiteIdAsync(_instance.SiteId)).ToList();
@@ -420,7 +471,11 @@
             _siteConnections = (await SiteRepository.GetDataConnectionsBySiteIdAsync(_instance.SiteId)).ToList();
             var existingBindings = await TemplateEngineRepository.GetBindingsByInstanceIdAsync(Id);
             foreach (var b in existingBindings)
+            {
                 _bindingSelections[b.AttributeName] = b.DataConnectionId;
+                if (!string.IsNullOrEmpty(b.DataSourceReferenceOverride))
+                    _bindingOverrides[b.AttributeName] = b.DataSourceReferenceOverride;
+            }
 
             // Overrides
             _overrideAttrs = attrs.Where(a => !a.IsLocked).ToList();
@@ -474,12 +529,74 @@
             _bindingSelections[attr.Name] = _bulkConnectionId;
     }
 
+    // ── Task 18: per-attribute override input + OPC UA tag browser ──────────
+
+    private string? GetOverrideForAttr(string attrName)
+        => _bindingOverrides.GetValueOrDefault(attrName);
+
+    private void OnOverrideForAttrChanged(string attrName, ChangeEventArgs e)
+    {
+        var val = e.Value?.ToString();
+        if (string.IsNullOrWhiteSpace(val))
+            _bindingOverrides.Remove(attrName);
+        else
+            _bindingOverrides[attrName] = val;
+    }
+
+    /// <summary>Looks up the template default <c>DataSourceReference</c> for an attribute.</summary>
+    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>
+    private bool IsOpcUa(int connectionId)
+        => connectionId > 0
+           && string.Equals(
+               _siteConnections.FirstOrDefault(c => c.Id == connectionId)?.Protocol,
+               "OpcUa",
+               StringComparison.OrdinalIgnoreCase);
+
+    /// <summary>
+    /// Opens the OPC UA tag browser dialog for the given attribute row. Remembers
+    /// which attribute is being edited so <see cref="OnBrowserSelected"/> can
+    /// write the picked node id back to the right override input.
+    /// </summary>
+    private async Task OpenBrowser(string attrName)
+    {
+        var connId = GetBindingConnectionId(attrName);
+        var conn = _siteConnections.FirstOrDefault(c => c.Id == connId);
+        if (conn is null) return;
+
+        _browserAttrInEdit = attrName;
+        _browserConnectionName = conn.Name;
+        _browserSiteIdentifier = _siteIdentifier;
+        _browserInitial = _bindingOverrides.GetValueOrDefault(attrName)
+                          ?? GetTemplateDefault(attrName);
+
+        if (_browserRef is not null)
+            await _browserRef.ShowAsync();
+    }
+
+    private void OnBrowserSelected(string nodeId)
+    {
+        if (_browserAttrInEdit is null) return;
+        _bindingOverrides[_browserAttrInEdit] = nodeId;
+        _browserAttrInEdit = null;
+    }
+
     private async Task SaveBindings()
     {
         _saving = true;
         try
         {
-            var bindings = _bindingSelections.Select(kv => new ConnectionBinding(kv.Key, kv.Value)).ToList();
+            // Task 18: include the per-attribute DataSourceReferenceOverride on
+            // the wire record so it round-trips through SetConnectionBindingsAsync
+            // into the InstanceConnectionBinding entity.
+            var bindings = _bindingSelections
+                .Select(kv => new ConnectionBinding(
+                    kv.Key,
+                    kv.Value,
+                    _bindingOverrides.GetValueOrDefault(kv.Key)))
+                .ToList();
             var user = await GetCurrentUserAsync();
             var result = await InstanceService.SetConnectionBindingsAsync(Id, bindings, user);
             if (result.IsSuccess)