DYN-9355: add MCP server startup preference and toggle

src/DynamoCore/Configuration/PreferenceSettings.cs

@@ -76,6 +76,7 @@ private readonly static Lazy<PreferenceSettings>
         private bool isEnablePersistExtensionsEnabled;
         private bool isAutoSyncDocumentBrowser = true;
         private bool isStaticSplashScreenEnabled;
+        private bool isMcpServerEnabledOnStartup;
         private bool isTimeStampIncludedInExportFilePath;
         private bool isCreatedFromValidFile = true;
         private string backupLocation;
@@ -825,6 +826,24 @@ public bool EnableStaticSplashScreen
             }
         }
 
+        /// <summary>
+        /// This defines whether the Dynamo MCP (Model Context Protocol) server starts
+        /// automatically when Dynamo launches. When false, the server stays off until the
+        /// user enables it from the MCP extension's Extensions-menu toggle (DYN-9355).
+        /// </summary>
+        public bool EnableMcpServerOnStartup
+        {
+            get
+            {
+                return isMcpServerEnabledOnStartup;
+            }
+            set
+            {
+                isMcpServerEnabledOnStartup = value;
+                RaisePropertyChanged(nameof(EnableMcpServerOnStartup));
+            }
+        }
+
         /// <summary>
         /// This defines if the user is agree to the ML Automcomplete Terms of Use
         /// </summary>
@@ -1100,6 +1119,7 @@ public PreferenceSettings()
             HideAutocompleteMethodOptions = false;
             EnableNotificationCenter = true;
             isStaticSplashScreenEnabled = true;
+            isMcpServerEnabledOnStartup = false;
             isTimeStampIncludedInExportFilePath = true;
             DefaultPythonEngine = string.Empty;
             ViewExtensionSettings = new List<ViewExtensionSettings>();

src/DynamoCore/PublicAPI.Unshipped.txt

@@ -1,3 +1,5 @@
+Dynamo.Configuration.PreferenceSettings.EnableMcpServerOnStartup.get -> bool
+Dynamo.Configuration.PreferenceSettings.EnableMcpServerOnStartup.set -> void
 Dynamo.Graph.Nodes.IValueSchemaProvider
 Dynamo.Graph.Nodes.IValueSchemaProvider.IsListValue.get -> bool
 Dynamo.Graph.Nodes.IValueSchemaProvider.ValueTypeId.get -> string

src/DynamoCoreWpf/Properties/Resources.en-US.resx

@@ -740,6 +740,14 @@ Don't worry, you'll have the option to save your work.</value>
     <value>Experimental</value>
     <comment>Preferences | Features | Experimental</comment>
   </data>
+  <data name="PreferencesViewEnableMcpServerOnStartup" xml:space="preserve">
+    <value>Start the MCP server when Dynamo launches</value>
+    <comment>Preferences | Features | Experimental</comment>
+  </data>
+  <data name="PreferencesViewEnableMcpServerOnStartupTooltip" xml:space="preserve">
+    <value>When enabled, the Dynamo MCP server starts automatically with Dynamo. When disabled, you can still turn it on at any time from the Extensions menu without restarting Dynamo.</value>
+    <comment>Preferences | Features | Experimental</comment>
+  </data>
   <data name="DynamoViewSettingMenu" xml:space="preserve">
     <value>_Settings</value>
     <comment>Setting menu</comment>

src/DynamoCoreWpf/Properties/Resources.resx

@@ -600,6 +600,14 @@
     <value>Experimental</value>
     <comment>Preferences | Features | Experimental</comment>
   </data>
+  <data name="PreferencesViewEnableMcpServerOnStartup" xml:space="preserve">
+    <value>Start the MCP server when Dynamo launches</value>
+    <comment>Preferences | Features | Experimental</comment>
+  </data>
+  <data name="PreferencesViewEnableMcpServerOnStartupTooltip" xml:space="preserve">
+    <value>When enabled, the Dynamo MCP server starts automatically with Dynamo. When disabled, you can still turn it on at any time from the Extensions menu without restarting Dynamo.</value>
+    <comment>Preferences | Features | Experimental</comment>
+  </data>
   <data name="PreferencesViewEnableTSplineNodes" xml:space="preserve">
     <value>Enable T-Spline nodes</value>
     <comment>Preferences | Features | Experimental | Enable T-Spline nodes</comment>

src/DynamoCoreWpf/ViewModels/Menu/PreferencesViewModel.cs

@@ -401,6 +401,24 @@ public bool StaticSplashScreenEnabled
             }
         }
 
+        /// <summary>
+        /// Controls the IsChecked property in the "start MCP server on launch" toggle button.
+        /// When enabled, the Dynamo MCP server starts automatically with Dynamo; otherwise it
+        /// stays off until enabled from the MCP extension's Extensions-menu toggle (DYN-9355).
+        /// </summary>
+        public bool McpServerEnabledOnStartup
+        {
+            get
+            {
+                return preferenceSettings.EnableMcpServerOnStartup;
+            }
+            set
+            {
+                preferenceSettings.EnableMcpServerOnStartup = value;
+                RaisePropertyChanged(nameof(McpServerEnabledOnStartup));
+            }
+        }
+
         /// <summary>
         /// Controls the IsChecked property in the selecting to include timestamp for export path section
         /// </summary>
@@ -1287,9 +1305,9 @@ public bool IsExperimentalExpanderVisible
         {
             get
             {
-                // Hide for now since panel nodes are OOTB and no other experimental features
-                // Keep infrastructure for future experimental features
-                return false;
+                // Visible now that the Experimental section hosts the MCP server startup
+                // toggle (DYN-9355). Previously hidden when the section had no features.
+                return true;
             }
         }
 

src/DynamoCoreWpf/Views/Menu/PreferencesView.xaml

@@ -1100,7 +1100,30 @@
                                         <RowDefinition Height="Auto"/>
                                         <RowDefinition Height="*"/>
                                     </Grid.RowDefinitions>
-                                        <!-- Empty for now, ready for future experimental features -->
+                                    <!--This Grid row contains the MCP server startup toggle (DYN-9355)-->
+                                    <StackPanel Orientation="Horizontal" Margin="0,12,0,0" Grid.Row="0">
+                                        <ToggleButton Name="McpServerToggle"
+                                                      Width="{StaticResource ToggleButtonWidth}"
+                                                      Height="{StaticResource ToggleButtonHeight}"
+                                                      VerticalAlignment="Center"
+                                                      IsChecked="{Binding Path=McpServerEnabledOnStartup}"
+                                                      Style="{StaticResource EllipseToggleButton1}"/>
+                                        <Label Content="{x:Static p:Resources.PreferencesViewEnableMcpServerOnStartup}"
+                                               Margin="10,0,0,0"
+                                               VerticalAlignment="Center"
+                                               Foreground="{StaticResource PreferencesWindowFontColor}"/>
+                                        <Image Name="McpServerIcon"
+                                               Width="14"
+                                               Height="14"
+                                               Margin="10,0,0,0"
+                                               HorizontalAlignment="Left"
+                                               VerticalAlignment="Center"
+                                               Style="{StaticResource QuestionIcon}">
+                                            <Image.ToolTip>
+                                                <ToolTip Content="{x:Static p:Resources.PreferencesViewEnableMcpServerOnStartupTooltip}" Style="{StaticResource GenericToolTipLight}"/>
+                                            </Image.ToolTip>
+                                        </Image>
+                                    </StackPanel>
                                     </Grid>
                             </Expander>
 

test/DynamoCoreTests/Configuration/PreferenceSettingsTests.cs

@@ -427,6 +427,32 @@ public void TestImportCopySettings()
             Assert.IsTrue(checkEquality.SamePropertyValues.Count == checkEquality.Properties.Count);
         }
 
+        [Test]
+        [Category("UnitTests")]
+        public void WhenSettingsAreNewThenMcpServerOnStartupDefaultsToFalse()
+        {
+            // The MCP server must stay off unless the user opts in (DYN-9355).
+            var settings = new PreferenceSettings();
+
+            Assert.IsFalse(settings.EnableMcpServerOnStartup);
+        }
+
+        [Test]
+        [Category("UnitTests")]
+        public void WhenMcpServerOnStartupIsEnabledThenItPersistsAcrossSaveAndLoad()
+        {
+            // Use a unique file under the per-test TempFolder, which UnitTestBase cleans up on teardown.
+            string tempPath = GetNewFileNameOnTempPath("xml");
+
+            var settings = new PreferenceSettings();
+            settings.EnableMcpServerOnStartup = true;
+
+            settings.Save(tempPath);
+            var loadedSettings = PreferenceSettings.Load(tempPath);
+
+            Assert.IsTrue(loadedSettings.EnableMcpServerOnStartup);
+        }
+
         [Test]
         [Category("UnitTests")]
         public void TestTaintedFile()

test/settings/DynamoSettings-NewSettings.xml

@@ -87,6 +87,7 @@
   <IsAutoSyncDocumentBrowser>false</IsAutoSyncDocumentBrowser>
   <EnableNotificationCenter>false</EnableNotificationCenter>
   <EnableStaticSplashScreen>false</EnableStaticSplashScreen>
+  <EnableMcpServerOnStartup>true</EnableMcpServerOnStartup>
   <IsMLAutocompleteTOUApproved>false</IsMLAutocompleteTOUApproved>
   <IsTimeStampIncludedInExportFilePath>false</IsTimeStampIncludedInExportFilePath>
   <EnablePersistExtensions>true</EnablePersistExtensions>