put commands in the top level

This reverts commit 9ec1eae62e.

.github/actions/spell-check/expect.txt

@@ -218,6 +218,7 @@ coclass
 CODENAME
 codereview
 Codespaces
+Coen
 COINIT
 colid
 colorconv
@@ -1383,6 +1384,7 @@ RIGHTSCROLLBAR
 riid
 RKey
 RNumber
+Rns
 rop
 ROUNDSMALL
 ROWSETEXT

.pipelines/v2/release.yml

@@ -38,6 +38,11 @@ parameters:
     displayName: "Build Using Visual Studio Preview"
     default: false
 
+  - name: enableAOT
+    type: boolean
+    displayName: "Enable AOT (Ahead-of-Time) Compilation for CmdPal"
+    default: true
+
 name: $(BuildDefinitionName)_$(date:yyMM).$(date:dd)$(rev:rrr)
 
 variables:
@@ -95,7 +100,7 @@ extends:
                 useManagedIdentity: $(SigningUseManagedIdentity)
                 clientId: $(SigningOriginalClientId)
               # Have msbuild use the release nuget config profile
-              additionalBuildOptions: /p:RestoreConfigFile="$(Build.SourcesDirectory)\.pipelines\release-nuget.config"
+              additionalBuildOptions: /p:RestoreConfigFile="$(Build.SourcesDirectory)\.pipelines\release-nuget.config" /p:EnableCmdPalAOT=${{ parameters.enableAOT }}
               beforeBuildSteps:
                 # Sets versions for all PowerToy created DLLs
                 - pwsh: |-

.pipelines/v2/templates/job-test-project.yml

@@ -160,6 +160,7 @@ jobs:
         vsTestVersion: 'toolsInstaller'
         uiTests: true
         rerunFailedTests: true
+        testRunTitle: 'UITests_${{ parameters.platform }}_${{ parameters.installMode }}'
         # Since UITests-FancyZonesEditor.dll is generated in both UITests-FancyZonesEditor and UITests-FancyZones, removed one to avoid duplicate test runs
         testAssemblyVer2: |
           **\*UITest*.dll
@@ -182,6 +183,7 @@ jobs:
           vsTestVersion: 'toolsInstaller'
           uiTests: true
           rerunFailedTests: true
+          testRunTitle: 'UITests_${{ parameters.platform }}_${{ parameters.installMode }}'
           testAssemblyVer2: |
             **\*${{ module }}*.dll
             !**\obj\**

.pipelines/verifyDepsJsonLibraryVersions.ps1

@@ -19,7 +19,7 @@ Get-ChildItem $targetDir -Recurse -Filter *.deps.json -Exclude *UITest*,MouseJum
     # Temporarily exclude All UI-Test, Fuzzer-Test projects because of Appium.WebDriver dependencies
     $depsJsonFullFileName = $_.FullName
 
-    if ($depsJsonFullFileName -like "*CmdPal*") {
+    if ($depsJsonFullFileName -like "*CmdPal*" -or $depsJsonFullFileName -like "*CommandPalette*") {
         return
     }
 

Directory.Packages.props

@@ -9,6 +9,7 @@
     <PackageVersion Include="Microsoft.Bot.AdaptiveExpressions.Core" Version="4.23.0" />
     <PackageVersion Include="Appium.WebDriver" Version="4.4.5" />
     <PackageVersion Include="Azure.AI.OpenAI" Version="1.0.0-beta.17" />
+    <PackageVersion Include="CoenM.ImageSharp.ImageHash" Version="1.3.6" />
     <PackageVersion Include="CommunityToolkit.Common" Version="8.4.0" />
     <PackageVersion Include="CommunityToolkit.Mvvm" Version="8.4.0" />
     <PackageVersion Include="CommunityToolkit.WinUI.Animations" Version="8.2.250402" />
@@ -21,6 +22,7 @@
     <PackageVersion Include="CommunityToolkit.WinUI.Extensions" Version="8.2.250402" />
     <PackageVersion Include="CommunityToolkit.WinUI.UI.Controls.DataGrid" Version="7.1.2" />
     <PackageVersion Include="CommunityToolkit.WinUI.UI.Controls.Markdown" Version="7.1.2" />
+    <PackageVersion Include="CommunityToolkit.Labs.WinUI.Controls.MarkdownTextBlock" Version="0.1.250703-build.2173" />
     <PackageVersion Include="ControlzEx" Version="6.0.0" />
     <PackageVersion Include="HelixToolkit" Version="2.24.0" />
     <PackageVersion Include="HelixToolkit.Core.Wpf" Version="2.24.0" />

NOTICE.md

@@ -1496,7 +1496,9 @@ SOFTWARE.
 - AdaptiveCards.Templating 2.0.5
 - Appium.WebDriver 4.4.5
 - Azure.AI.OpenAI 1.0.0-beta.17
+- CoenM.ImageSharp.ImageHash 1.3.6
 - CommunityToolkit.Common 8.4.0
+- CommunityToolkit.Labs.WinUI.Controls.MarkdownTextBlock 0.1.250703-build.2173
 - CommunityToolkit.Mvvm 8.4.0
 - CommunityToolkit.WinUI.Animations 8.2.250402
 - CommunityToolkit.WinUI.Collections 8.2.250402
@@ -1579,4 +1581,3 @@ SOFTWARE.
 - WinUIEx 2.2.0
 - WPF-UI 3.0.5
 - WyHash 1.0.5
-

PowerToys.sln

@@ -736,6 +736,14 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ManagedCsWin32", "src\commo
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "PowerRenameUITest", "src\modules\powerrename\PowerRenameUITest\PowerRenameUITest.csproj", "{9D3F3793-EFE3-4525-8782-238015DABA62}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Microsoft.CmdPal.Ext.Actions", "src\modules\cmdpal\ext\MIcrosoft.CmdPal.Ext.Actions\Microsoft.CmdPal.Ext.Actions.csproj", "{0A4D5CD7-C03D-63C6-E1C5-A8CB1BB4FD80}"
+EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Core", "Core", "{02EA681E-C7D8-13C7-8484-4AC65E1B71E8}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Microsoft.CmdPal.Core.ViewModels", "src\modules\cmdpal\Microsoft.CmdPal.Core.ViewModels\Microsoft.CmdPal.Core.ViewModels.csproj", "{24133F7F-C1D1-DE04-EFA8-F5D5467FE027}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Microsoft.CmdPal.UITests", "src\modules\cmdpal\Microsoft.CmdPal.UITests\Microsoft.CmdPal.UITests.csproj", "{840455DF-5634-51BB-D937-9D7D32F0B0C2}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|ARM64 = Debug|ARM64
@@ -2718,6 +2726,14 @@ Global
 		{14AFD976-B4D2-49D0-9E6C-AA93CC061B8A}.Release|ARM64.Build.0 = Release|ARM64
 		{14AFD976-B4D2-49D0-9E6C-AA93CC061B8A}.Release|x64.ActiveCfg = Release|x64
 		{14AFD976-B4D2-49D0-9E6C-AA93CC061B8A}.Release|x64.Build.0 = Release|x64
+		{24133F7F-C1D1-DE04-EFA8-F5D5467FE027}.Debug|ARM64.ActiveCfg = Debug|ARM64
+		{24133F7F-C1D1-DE04-EFA8-F5D5467FE027}.Debug|ARM64.Build.0 = Debug|ARM64
+		{24133F7F-C1D1-DE04-EFA8-F5D5467FE027}.Debug|x64.ActiveCfg = Debug|x64
+		{24133F7F-C1D1-DE04-EFA8-F5D5467FE027}.Debug|x64.Build.0 = Debug|x64
+		{24133F7F-C1D1-DE04-EFA8-F5D5467FE027}.Release|ARM64.ActiveCfg = Release|ARM64
+		{24133F7F-C1D1-DE04-EFA8-F5D5467FE027}.Release|ARM64.Build.0 = Release|ARM64
+		{24133F7F-C1D1-DE04-EFA8-F5D5467FE027}.Release|x64.ActiveCfg = Release|x64
+		{24133F7F-C1D1-DE04-EFA8-F5D5467FE027}.Release|x64.Build.0 = Release|x64
 		{9D3F3793-EFE3-4525-8782-238015DABA62}.Debug|ARM64.ActiveCfg = Debug|ARM64
 		{9D3F3793-EFE3-4525-8782-238015DABA62}.Debug|ARM64.Build.0 = Debug|ARM64
 		{9D3F3793-EFE3-4525-8782-238015DABA62}.Debug|x64.ActiveCfg = Debug|x64
@@ -2726,6 +2742,22 @@ Global
 		{9D3F3793-EFE3-4525-8782-238015DABA62}.Release|ARM64.Build.0 = Release|ARM64
 		{9D3F3793-EFE3-4525-8782-238015DABA62}.Release|x64.ActiveCfg = Release|x64
 		{9D3F3793-EFE3-4525-8782-238015DABA62}.Release|x64.Build.0 = Release|x64
+		{0A4D5CD7-C03D-63C6-E1C5-A8CB1BB4FD80}.Debug|ARM64.ActiveCfg = Debug|ARM64
+		{0A4D5CD7-C03D-63C6-E1C5-A8CB1BB4FD80}.Debug|ARM64.Build.0 = Debug|ARM64
+		{0A4D5CD7-C03D-63C6-E1C5-A8CB1BB4FD80}.Debug|x64.ActiveCfg = Debug|x64
+		{0A4D5CD7-C03D-63C6-E1C5-A8CB1BB4FD80}.Debug|x64.Build.0 = Debug|x64
+		{0A4D5CD7-C03D-63C6-E1C5-A8CB1BB4FD80}.Release|ARM64.ActiveCfg = Release|ARM64
+		{0A4D5CD7-C03D-63C6-E1C5-A8CB1BB4FD80}.Release|ARM64.Build.0 = Release|ARM64
+		{0A4D5CD7-C03D-63C6-E1C5-A8CB1BB4FD80}.Release|x64.ActiveCfg = Release|x64
+		{0A4D5CD7-C03D-63C6-E1C5-A8CB1BB4FD80}.Release|x64.Build.0 = Release|x64
+		{840455DF-5634-51BB-D937-9D7D32F0B0C2}.Debug|ARM64.ActiveCfg = Debug|ARM64
+		{840455DF-5634-51BB-D937-9D7D32F0B0C2}.Debug|ARM64.Build.0 = Debug|ARM64
+		{840455DF-5634-51BB-D937-9D7D32F0B0C2}.Debug|x64.ActiveCfg = Debug|x64
+		{840455DF-5634-51BB-D937-9D7D32F0B0C2}.Debug|x64.Build.0 = Debug|x64
+		{840455DF-5634-51BB-D937-9D7D32F0B0C2}.Release|ARM64.ActiveCfg = Release|ARM64
+		{840455DF-5634-51BB-D937-9D7D32F0B0C2}.Release|ARM64.Build.0 = Release|ARM64
+		{840455DF-5634-51BB-D937-9D7D32F0B0C2}.Release|x64.ActiveCfg = Release|x64
+		{840455DF-5634-51BB-D937-9D7D32F0B0C2}.Release|x64.Build.0 = Release|x64
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -3010,7 +3042,11 @@ Global
 		{43E779F3-D83C-48B1-BA8D-1912DBD76FC9} = {A2221D7E-55E7-4BEA-90D1-4F162D670BBF}
 		{2CF78CF7-8FEB-4BE1-9591-55FA25B48FC6} = {1AFB6476-670D-4E80-A464-657E01DFF482}
 		{14AFD976-B4D2-49D0-9E6C-AA93CC061B8A} = {1AFB6476-670D-4E80-A464-657E01DFF482}
+		{02EA681E-C7D8-13C7-8484-4AC65E1B71E8} = {3846508C-77EB-4034-A702-F8BB263C4F79}
+		{24133F7F-C1D1-DE04-EFA8-F5D5467FE027} = {02EA681E-C7D8-13C7-8484-4AC65E1B71E8}
 		{9D3F3793-EFE3-4525-8782-238015DABA62} = {89E20BCE-EB9C-46C8-8B50-E01A82E6FDC3}
+		{0A4D5CD7-C03D-63C6-E1C5-A8CB1BB4FD80} = {ECB8E0D1-7603-4E5C-AB10-D1E545E6F8E2}
+		{840455DF-5634-51BB-D937-9D7D32F0B0C2} = {7520A2FE-00A2-49B8-83ED-DB216E874C04}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {C3A2F9D1-7930-4EF4-A6FC-7EE0A99821D0}

doc/thirdPartyRunPlugins.md

@@ -47,6 +47,8 @@ Contact the developers of a plugin directly for assistance with a specific plugi
 | [Weather](https://github.com/ruslanlap/PowerToysRun-Weather) | [ruslanlap](https://github.com/ruslanlap) | Get real-time weather information directly from PowerToys Run. |
 | [Pomodoro](https://github.com/ruslanlap/PowerToysRun-Pomodoro) | [ruslanlap](https://github.com/ruslanlap) | Manage Pomodoro productivity sessions directly from PowerToys Run. |
 | [Definition](https://github.com/ruslanlap/PowerToysRun-Definition) | [ruslanlap](https://github.com/ruslanlap) | Lookup word definitions, phonetics, and synonyms directly in PowerToys Run. |
+| [Hotkeys](https://github.com/ruslanlap/PowerToysRun-Hotkeys) | [ruslanlap](https://github.com/ruslanlap) | Create, manage, and trigger custom keyboard shortcuts directly from PowerToys Run. |
+| [RandomGen](https://github.com/ruslanlap/PowerToysRun-RandomGen) | [ruslanlap](https://github.com/ruslanlap) | 🎲 Generate random data instantly with a single keystroke. Perfect for developers, testers, designers, and anyone who needs quick access to random data. Features include secure passwords, PINs, names, business data, dates, numbers, GUIDs, color codes, and more. Especially useful for designers who need random color codes and placeholder content. |
 
 ## Extending software plugins
 

nuget.config

@@ -2,10 +2,10 @@
 <configuration>
 	<packageSources>
 		<clear />
-		<add key="nuget.org" value="https://api.nuget.org/v3/index.json" />
+		<add key="PowerToysPublicDependencies" value="https://pkgs.dev.azure.com/shine-oss/PowerToys/_packaging/PowerToysPublicDependencies/nuget/v3/index.json" />
 	</packageSources>
 	<packageSourceMapping>
-		<packageSource key="nuget.org">
+		<packageSource key="PowerToysPublicDependencies">
 			<package pattern="*" />
 		</packageSource>
 	</packageSourceMapping>

src/Common.Dotnet.AotCompatibility.props

@@ -7,6 +7,7 @@
     <CsWinRTAotWarningLevel>2</CsWinRTAotWarningLevel>
 
     <!-- Suppress DynamicallyAccessedMemberTypes.PublicParameterlessConstructor in fallback code path of Windows SDK projection -->
-    <WarningsNotAsErrors>IL2081;CsWinRT1028;$(WarningsNotAsErrors)</WarningsNotAsErrors>
+    <!-- Suppress CA1416 for Windows-specific APIs that are used in PowerToys which only runs on Windows 10.0.19041.0+ -->
+    <WarningsNotAsErrors>IL2081;CsWinRT1028;CA1416;$(WarningsNotAsErrors)</WarningsNotAsErrors>
   </PropertyGroup>
 </Project>

src/common/UITestAutomation/ModuleConfigData.cs

@@ -32,6 +32,7 @@ namespace Microsoft.PowerToys.UITest
         Runner,
         Workspaces,
         PowerRename,
+        CommandPalette,
     }
 
     /// <summary>
@@ -104,6 +105,7 @@ namespace Microsoft.PowerToys.UITest
                 [PowerToysModule.Runner] = new ModuleInfo("PowerToys.exe", "PowerToys"),
                 [PowerToysModule.Workspaces] = new ModuleInfo("PowerToys.WorkspacesEditor.exe", "Workspaces Editor"),
                 [PowerToysModule.PowerRename] = new ModuleInfo("PowerToys.PowerRename.exe", "PowerRename", "WinUI3Apps"),
+                [PowerToysModule.CommandPalette] = new ModuleInfo("Microsoft.CmdPal.UI.exe", "PowerToys Command Palette", "WinUI3Apps\\CmdPal"),
             };
         }
 

src/common/UITestAutomation/UITestAutomation.csproj

@@ -20,6 +20,7 @@
     <PackageReference Include="System.Net.Http" />
     <PackageReference Include="System.Private.Uri" />
     <PackageReference Include="System.Text.RegularExpressions" />
+    <PackageReference Include="CoenM.ImageSharp.ImageHash" />
   </ItemGroup>
 
 </Project>

src/common/UITestAutomation/VisualAssert.cs

@@ -6,7 +6,11 @@ using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
 using System.Drawing;
 using System.IO;
+using CoenM.ImageHash;
+using CoenM.ImageHash.HashAlgorithms;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
+using SixLabors.ImageSharp;
+using SixLabors.ImageSharp.PixelFormats;
 
 namespace Microsoft.PowerToys.UITest
 {
@@ -127,34 +131,75 @@ namespace Microsoft.PowerToys.UITest
         }
 
         /// <summary>
-        /// Test if two images are equal bit-by-bit
+        /// Test if two images are equal using ImageHash comparison
         /// </summary>
         /// <param name="baselineImage">baseline image</param>
         /// <param name="testImage">test image</param>
         /// <returns>true if are equal,otherwise false</returns>
         private static bool AreEqual(Bitmap baselineImage, Bitmap testImage)
         {
-            if (baselineImage.Width != testImage.Width || baselineImage.Height != testImage.Height)
+            try
             {
-                return false;
+                // Define a threshold for similarity percentage
+                const int SimilarityThreshold = 95;
+
+                // Use CoenM.ImageHash for perceptual hash comparison
+                var hashAlgorithm = new AverageHash();
+
+                // Convert System.Drawing.Bitmap to SixLabors.ImageSharp.Image
+                using var baselineImageSharp = ConvertBitmapToImageSharp(baselineImage);
+                using var testImageSharp = ConvertBitmapToImageSharp(testImage);
+
+                // Calculate hashes for both images
+                var baselineHash = hashAlgorithm.Hash(baselineImageSharp);
+                var testHash = hashAlgorithm.Hash(testImageSharp);
+
+                // Compare hashes using CompareHash method
+                // Returns similarity percentage (0-100, where 100 is identical)
+                var similarity = CompareHash.Similarity(baselineHash, testHash);
+
+                // Consider images equal if similarity is very high
+                // Allow for minor rendering differences (threshold can be adjusted)
+                return similarity >= SimilarityThreshold; // 95% similarity threshold
             }
-
-            // WinAppDriver sometimes adds a border to the screenshot (around 2 pix width), and it is not always consistent.
-            // So we exclude the border when comparing the images, and usually it is the edge of the windows, won't affect the comparison.
-            int excludeBorderWidth = 5, excludeBorderHeight = 5;
-
-            for (int x = excludeBorderWidth; x < baselineImage.Width - excludeBorderWidth; x++)
+            catch
             {
-                for (int y = excludeBorderHeight; y < baselineImage.Height - excludeBorderHeight; y++)
+                // Fallback to pixel-by-pixel comparison if hash comparison fails
+                if (baselineImage.Width != testImage.Width || baselineImage.Height != testImage.Height)
                 {
-                    if (!VisualHelper.PixIsSame(baselineImage.GetPixel(x, y), testImage.GetPixel(x, y)))
+                    return false;
+                }
+
+                // WinAppDriver sometimes adds a border to the screenshot (around 2 pix width), and it is not always consistent.
+                // So we exclude the border when comparing the images, and usually it is the edge of the windows, won't affect the comparison.
+                int excludeBorderWidth = 5, excludeBorderHeight = 5;
+
+                for (int x = excludeBorderWidth; x < baselineImage.Width - excludeBorderWidth; x++)
+                {
+                    for (int y = excludeBorderHeight; y < baselineImage.Height - excludeBorderHeight; y++)
                     {
-                        return false;
+                        if (!VisualHelper.PixIsSame(baselineImage.GetPixel(x, y), testImage.GetPixel(x, y)))
+                        {
+                            return false;
+                        }
                     }
                 }
-            }
 
-            return true;
+                return true;
+            }
+        }
+
+        /// <summary>
+        /// Convert System.Drawing.Bitmap to SixLabors.ImageSharp.Image
+        /// </summary>
+        /// <param name="bitmap">The bitmap to convert</param>
+        /// <returns>ImageSharp Image</returns>
+        private static Image<Rgba32> ConvertBitmapToImageSharp(Bitmap bitmap)
+        {
+            using var memoryStream = new MemoryStream();
+            bitmap.Save(memoryStream, System.Drawing.Imaging.ImageFormat.Png);
+            memoryStream.Position = 0;
+            return SixLabors.ImageSharp.Image.Load<Rgba32>(memoryStream);
         }
     }
 }

src/modules/cmdpal/.wt.json

@@ -26,6 +26,11 @@
             "input": "pushd .\\ExtensionTemplate\\ ; git archive -o ..\\Microsoft.CmdPal.UI.ViewModels\\Assets\\template.zip HEAD -- .\\TemplateCmdPalExtension\\ ; popd",
             "name": "Update template project",
             "description": "zips up the ExtensionTemplate into our assets. Run this in the cmdpal/ directory."
+        },
+        {
+            "input": "pwsh -c .\\clean-sdk.ps1",
+            "name": "Delete old extensions output",
+            "description": "Delete old extensions output directory.\r\nUse this after regenerating the interface, otherwise it will not pass fast up to date checks."
         }
     ]
 }

src/modules/cmdpal/Microsoft.CmdPal.Common/Services/IExtensionService.cs

@@ -19,13 +19,13 @@ public interface IExtensionService
 
     Task SignalStopExtensionsAsync();
 
-    public event TypedEventHandler<IExtensionService, IEnumerable<IExtensionWrapper>>? OnExtensionAdded;
+    event TypedEventHandler<IExtensionService, IEnumerable<IExtensionWrapper>>? OnExtensionAdded;
 
-    public event TypedEventHandler<IExtensionService, IEnumerable<IExtensionWrapper>>? OnExtensionRemoved;
+    event TypedEventHandler<IExtensionService, IEnumerable<IExtensionWrapper>>? OnExtensionRemoved;
 
-    public void EnableExtension(string extensionUniqueId);
+    void EnableExtension(string extensionUniqueId);
 
-    public void DisableExtension(string extensionUniqueId);
+    void DisableExtension(string extensionUniqueId);
 
     ///// <summary>
     ///// Gets a boolean indicating whether the extension was disabled due to the corresponding Windows optional feature

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/AppExtensionHost.cs

@@ -0,0 +1,168 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Collections.ObjectModel;
+using System.Diagnostics;
+using ManagedCommon;
+using Microsoft.CommandPalette.Extensions;
+using Microsoft.CommandPalette.Extensions.Toolkit;
+using Windows.Foundation;
+
+namespace Microsoft.CmdPal.Core.ViewModels;
+
+public abstract partial class AppExtensionHost : IExtensionHost
+{
+    private static readonly GlobalLogPageContext _globalLogPageContext = new();
+
+    private static ulong _hostingHwnd;
+
+    public static ObservableCollection<LogMessageViewModel> LogMessages { get; } = [];
+
+    public ulong HostingHwnd => _hostingHwnd;
+
+    public string LanguageOverride => string.Empty;
+
+    public ObservableCollection<StatusMessageViewModel> StatusMessages { get; } = [];
+
+    public static void SetHostHwnd(ulong hostHwnd) => _hostingHwnd = hostHwnd;
+
+    public void DebugLog(string message)
+    {
+#if DEBUG
+        this.ProcessLogMessage(new LogMessage(message));
+#endif
+    }
+
+    public IAsyncAction HideStatus(IStatusMessage? message)
+    {
+        if (message == null)
+        {
+            return Task.CompletedTask.AsAsyncAction();
+        }
+
+        _ = Task.Run(() =>
+        {
+            ProcessHideStatusMessage(message);
+        });
+        return Task.CompletedTask.AsAsyncAction();
+    }
+
+    public void Log(string message)
+    {
+        this.ProcessLogMessage(new LogMessage(message));
+    }
+
+    public IAsyncAction LogMessage(ILogMessage? message)
+    {
+        if (message == null)
+        {
+            return Task.CompletedTask.AsAsyncAction();
+        }
+
+        Logger.LogDebug(message.Message);
+
+        _ = Task.Run(() =>
+        {
+            ProcessLogMessage(message);
+        });
+
+        // We can't just make a LogMessageViewModel : ExtensionObjectViewModel
+        // because we don't necessarily know the page context. Butts.
+        return Task.CompletedTask.AsAsyncAction();
+    }
+
+    public void ProcessHideStatusMessage(IStatusMessage message)
+    {
+        Task.Factory.StartNew(
+            () =>
+            {
+                try
+                {
+                    var vm = StatusMessages.Where(messageVM => messageVM.Model.Unsafe == message).FirstOrDefault();
+                    if (vm != null)
+                    {
+                        StatusMessages.Remove(vm);
+                    }
+                }
+                catch
+                {
+                }
+            },
+            CancellationToken.None,
+            TaskCreationOptions.None,
+            _globalLogPageContext.Scheduler);
+    }
+
+    public void ProcessLogMessage(ILogMessage message)
+    {
+        var vm = new LogMessageViewModel(message, _globalLogPageContext);
+        vm.SafeInitializePropertiesSynchronous();
+
+        Task.Factory.StartNew(
+            () =>
+            {
+                LogMessages.Add(vm);
+            },
+            CancellationToken.None,
+            TaskCreationOptions.None,
+            _globalLogPageContext.Scheduler);
+    }
+
+    public void ProcessStatusMessage(IStatusMessage message, StatusContext context)
+    {
+        // If this message is already in the list of messages, just bring it to the top
+        var oldVm = StatusMessages.Where(messageVM => messageVM.Model.Unsafe == message).FirstOrDefault();
+        if (oldVm != null)
+        {
+            Task.Factory.StartNew(
+                () =>
+                {
+                    StatusMessages.Remove(oldVm);
+                    StatusMessages.Add(oldVm);
+                },
+                CancellationToken.None,
+                TaskCreationOptions.None,
+                _globalLogPageContext.Scheduler);
+            return;
+        }
+
+        var vm = new StatusMessageViewModel(message, new(_globalLogPageContext));
+        vm.SafeInitializePropertiesSynchronous();
+
+        Task.Factory.StartNew(
+            () =>
+            {
+                StatusMessages.Add(vm);
+            },
+            CancellationToken.None,
+            TaskCreationOptions.None,
+            _globalLogPageContext.Scheduler);
+    }
+
+    public IAsyncAction ShowStatus(IStatusMessage? message, StatusContext context)
+    {
+        if (message == null)
+        {
+            return Task.CompletedTask.AsAsyncAction();
+        }
+
+        Debug.WriteLine(message.Message);
+
+        _ = Task.Run(() =>
+        {
+            ProcessStatusMessage(message, context);
+        });
+
+        return Task.CompletedTask.AsAsyncAction();
+    }
+
+    public abstract string? GetExtensionDisplayName();
+}
+
+public interface IAppHostService
+{
+    AppExtensionHost GetDefaultHost();
+
+    AppExtensionHost GetHostForCommand(object? context, AppExtensionHost? currentHost);
+}

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/ArgumentItemViewModel.cs

@@ -0,0 +1,162 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using CommunityToolkit.Mvvm.Messaging;
+using Microsoft.CmdPal.Core.ViewModels.Messages;
+using Microsoft.CmdPal.Core.ViewModels.Models;
+using Microsoft.CommandPalette.Extensions;
+
+namespace Microsoft.CmdPal.Core.ViewModels;
+
+public partial class ArgumentItemViewModel : ExtensionObjectViewModel
+{
+    public ExtensionObject<ICommandArgument> Model => _model;
+
+    private readonly ExtensionObject<ICommandArgument> _model = new(null);
+
+    public ParameterType Type { get; private set; }
+
+    public string Name { get; private set; } = string.Empty;
+
+    public bool Required { get; private set; }
+
+    private string ModelDisplayName { get; set; } = string.Empty;
+
+    public string DisplayName => string.IsNullOrEmpty(ModelDisplayName) ? Name : ModelDisplayName;
+
+    // TODO! This should be an ExtensionObject<object> since it's out-of-proc
+    public object? Value
+    {
+        get; set
+        {
+            field = value;
+            SafeSetValue(value);
+        }
+    }
+
+    public ArgumentItemViewModel(ExtensionObject<ICommandArgument> model, WeakReference<IPageContext> pageContext)
+        : base(pageContext)
+    {
+        _model = model;
+    }
+
+    public override void InitializeProperties()
+    {
+        var model = _model.Unsafe;
+        if (model == null)
+        {
+            return;
+        }
+
+        Type = model.Type;
+        Name = model.Name;
+        Required = model.Required;
+        Value = model.Value;
+        ModelDisplayName = model.DisplayName;
+
+        // Register for property changes
+        model.PropChanged += Model_PropChanged;
+    }
+
+    private void Model_PropChanged(object sender, IPropChangedEventArgs args)
+    {
+        try
+        {
+            FetchProperty(args.PropertyName);
+        }
+        catch (Exception ex)
+        {
+            ShowException(ex);
+        }
+    }
+
+    protected virtual void FetchProperty(string propertyName)
+    {
+        var model = this._model.Unsafe;
+        if (model == null)
+        {
+            return; // throw?
+        }
+
+        switch (propertyName)
+        {
+            case nameof(ICommandArgument.Type):
+                if (model.Type == Type)
+                {
+                    return;
+                }
+
+                Type = model.Type;
+                break;
+            case nameof(ICommandArgument.Name):
+                if (model.Name == Name)
+                {
+                    return;
+                }
+
+                Name = model.Name;
+                UpdateProperty(nameof(DisplayName));
+                break;
+            case nameof(ICommandArgument.Required):
+                if (model.Required == Required)
+                {
+                    return;
+                }
+
+                Required = model.Required;
+                break;
+            case nameof(ICommandArgument.Value):
+                if (model.Value == Value)
+                {
+                    return;
+                }
+
+                Value = model.Value;
+                break;
+            case nameof(ICommandArgument.DisplayName):
+                if (model.DisplayName == ModelDisplayName)
+                {
+                    return;
+                }
+
+                ModelDisplayName = model.DisplayName;
+                break;
+        }
+
+        UpdateProperty(propertyName);
+    }
+
+    private void SafeSetValue(object? value)
+    {
+        _ = Task.Run(() => SafeSetValueSynchronous(value));
+    }
+
+    private void SafeSetValueSynchronous(object? value)
+    {
+        try
+        {
+            var model = _model.Unsafe;
+            if (model == null)
+            {
+                return;
+            }
+
+            model.Value = value;
+        }
+        catch
+        {
+        }
+    }
+
+    public void OpenPicker()
+    {
+        var model = _model.Unsafe;
+        if (model == null)
+        {
+            return;
+        }
+
+        WeakReferenceMessenger.Default.Send<RequestOpenPickerMessage>(new(_model));
+    }
+}

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/ArgumentsViewModel.cs

@@ -0,0 +1,21 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Collections.ObjectModel;
+using System.ComponentModel;
+using System.Runtime.CompilerServices;
+
+namespace Microsoft.CmdPal.Core.ViewModels;
+
+public partial class ArgumentsViewModel : INotifyPropertyChanged
+{
+    public ObservableCollection<ArgumentItemViewModel> Arguments { get; } = new();
+
+    public event PropertyChangedEventHandler? PropertyChanged;
+
+    protected void OnPropertyChanged([CallerMemberName] string? propertyName = null)
+    {
+        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
+    }
+}

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/CommandBarViewModel.cs

@@ -1,15 +1,15 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
 using System.Collections.ObjectModel;
 using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Messaging;
-using Microsoft.CmdPal.UI.ViewModels.Messages;
+using Microsoft.CmdPal.Core.ViewModels.Messages;
 using Microsoft.CommandPalette.Extensions.Toolkit;
 using Windows.System;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class CommandBarViewModel : ObservableObject,
     IRecipient<UpdateCommandBarMessage>
@@ -149,11 +149,12 @@ public partial class CommandBarViewModel : ObservableObject,
 
         if (command.HasMoreCommands)
         {
+            WeakReferenceMessenger.Default.Send<PerformCommandMessage>(new(command));
             return ContextKeybindingResult.KeepOpen;
         }
         else
         {
-            WeakReferenceMessenger.Default.Send<PerformCommandMessage>(new(command.Command.Model, command.Model));
+            WeakReferenceMessenger.Default.Send<PerformCommandMessage>(new(command));
             return ContextKeybindingResult.Hide;
         }
     }

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/CommandContextItemViewModel.cs

@@ -1,13 +1,11 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using CommunityToolkit.Mvvm.Messaging;
-using Microsoft.CmdPal.UI.ViewModels.Messages;
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class CommandContextItemViewModel(ICommandContextItem contextItem, WeakReference<IPageContext> context) : CommandItemViewModel(new(contextItem), context), IContextItemViewModel
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/CommandItemViewModel.cs

@@ -1,13 +1,14 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Messages;
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using System.Collections.ObjectModel;
+using Microsoft.CmdPal.Core.ViewModels.Messages;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 using Microsoft.CommandPalette.Extensions.Toolkit;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class CommandItemViewModel : ExtensionObjectViewModel, ICommandBarContext
 {
@@ -62,6 +63,10 @@ public partial class CommandItemViewModel : ExtensionObjectViewModel, ICommandBa
 
     public bool ShouldBeVisible => !string.IsNullOrEmpty(Name);
 
+    public bool HasParameters => Command.HasParameters;
+
+    public ObservableCollection<ArgumentItemViewModel> Parameters => Command.Parameters;
+
     public List<IContextItemViewModel> AllCommands
     {
         get
@@ -181,14 +186,9 @@ public partial class CommandItemViewModel : ExtensionObjectViewModel, ICommandBa
             MoreCommands = more
                 .Select(item =>
                 {
-                    if (item is ICommandContextItem contextItem)
-                    {
-                        return new CommandContextItemViewModel(contextItem, PageContext) as IContextItemViewModel;
-                    }
-                    else
-                    {
-                        return new SeparatorContextItemViewModel() as IContextItemViewModel;
-                    }
+                    return item is ICommandContextItem contextItem
+                        ? new CommandContextItemViewModel(contextItem, PageContext)
+                        : new SeparatorContextItemViewModel() as IContextItemViewModel;
                 })
                 .ToList();
         }
@@ -338,14 +338,9 @@ public partial class CommandItemViewModel : ExtensionObjectViewModel, ICommandBa
                     var newContextMenu = more
                         .Select(item =>
                         {
-                            if (item is CommandContextItem contextItem)
-                            {
-                                return new CommandContextItemViewModel(contextItem, PageContext) as IContextItemViewModel;
-                            }
-                            else
-                            {
-                                return new SeparatorContextItemViewModel() as IContextItemViewModel;
-                            }
+                            return item is CommandContextItem contextItem
+                                ? new CommandContextItemViewModel(contextItem, PageContext)
+                                : new SeparatorContextItemViewModel() as IContextItemViewModel;
                         })
                         .ToList();
                     lock (MoreCommands)

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/CommandViewModel.cs

@@ -1,11 +1,12 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using System.Collections.ObjectModel;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class CommandViewModel : ExtensionObjectViewModel
 {
@@ -29,6 +30,10 @@ public partial class CommandViewModel : ExtensionObjectViewModel
 
     public IconInfoViewModel Icon { get; private set; }
 
+    public bool HasParameters { get; set; }
+
+    public ObservableCollection<ArgumentItemViewModel> Parameters { get; private set; } = new();
+
     public CommandViewModel(ICommand? command, WeakReference<IPageContext> pageContext)
         : base(pageContext)
     {
@@ -51,6 +56,7 @@ public partial class CommandViewModel : ExtensionObjectViewModel
 
         Id = model.Id ?? string.Empty;
         Name = model.Name ?? string.Empty;
+
         IsFastInitialized = true;
     }
 
@@ -80,6 +86,22 @@ public partial class CommandViewModel : ExtensionObjectViewModel
             UpdateProperty(nameof(Icon));
         }
 
+        // TODO! we can probably make this a slow initialization
+        if (model is IInvokableCommandWithParameters withParams)
+        {
+            HasParameters = true;
+
+            if (withParams.Parameters is ICommandArgument[] parameters)
+            {
+                foreach (var p in parameters)
+                {
+                    var paramViewModel = new ArgumentItemViewModel(new(p), PageContext);
+                    paramViewModel.InitializeProperties();
+                    Parameters.Add(paramViewModel);
+                }
+            }
+        }
+
         model.PropChanged += Model_PropChanged;
     }
 

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/ConfirmResultViewModel.cs

@@ -1,11 +1,11 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class ConfirmResultViewModel(IConfirmationArgs _args, WeakReference<IPageContext> context) :
     ExtensionObjectViewModel(context)

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/ContentPageViewModel.cs

@@ -7,12 +7,12 @@ using System.Diagnostics.CodeAnalysis;
 using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Input;
 using CommunityToolkit.Mvvm.Messaging;
-using Microsoft.CmdPal.UI.ViewModels.Messages;
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Messages;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 using Microsoft.CommandPalette.Extensions.Toolkit;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class ContentPageViewModel : PageViewModel, ICommandBarContext
 {
@@ -47,7 +47,7 @@ public partial class ContentPageViewModel : PageViewModel, ICommandBarContext
 
     // Remember - "observable" properties from the model (via PropChanged)
     // cannot be marked [ObservableProperty]
-    public ContentPageViewModel(IContentPage model, TaskScheduler scheduler, CommandPaletteHost host)
+    public ContentPageViewModel(IContentPage model, TaskScheduler scheduler, AppExtensionHost host)
         : base(model, scheduler, host)
     {
         _model = new(model);
@@ -91,16 +91,12 @@ public partial class ContentPageViewModel : PageViewModel, ICommandBarContext
         });
     }
 
-    public static ContentViewModel? ViewModelFromContent(IContent content, WeakReference<IPageContext> context)
+    public virtual ContentViewModel? ViewModelFromContent(IContent content, WeakReference<IPageContext> context)
     {
-        ContentViewModel? viewModel = content switch
-        {
-            IFormContent form => new ContentFormViewModel(form, context),
-            IMarkdownContent markdown => new ContentMarkdownViewModel(markdown, context),
-            ITreeContent tree => new ContentTreeViewModel(tree, context),
-            _ => null,
-        };
-        return viewModel;
+        // The core ContentPageViewModel doesn't actually handle any content,
+        // so we just return null here.
+        // The real content is handled by the derived class CommandPaletteContentPageViewModel
+        return null;
     }
 
     public override void InitializeProperties()
@@ -115,15 +111,15 @@ public partial class ContentPageViewModel : PageViewModel, ICommandBarContext
 
         Commands = model.Commands
                 .ToList()
-                .Select(item =>
+                .Select<IContextItem, IContextItemViewModel>(item =>
                 {
                     if (item is CommandContextItem contextItem)
                     {
-                        return new CommandContextItemViewModel(contextItem, PageContext) as IContextItemViewModel;
+                        return new CommandContextItemViewModel(contextItem, PageContext);
                     }
                     else
                     {
-                        return new SeparatorContextItemViewModel() as IContextItemViewModel;
+                        return new SeparatorContextItemViewModel();
                     }
                 })
                 .ToList();
@@ -182,7 +178,7 @@ public partial class ContentPageViewModel : PageViewModel, ICommandBarContext
                                 }
                                 else
                                 {
-                                    return new SeparatorContextItemViewModel() as IContextItemViewModel;
+                                    return new SeparatorContextItemViewModel();
                                 }
                             })
                             .ToList();
@@ -254,7 +250,7 @@ public partial class ContentPageViewModel : PageViewModel, ICommandBarContext
     {
         if (PrimaryCommand != null)
         {
-            WeakReferenceMessenger.Default.Send<PerformCommandMessage>(new(PrimaryCommand.Command.Model, PrimaryCommand.Model));
+            WeakReferenceMessenger.Default.Send<PerformCommandMessage>(new(PrimaryCommand));
         }
     }
 
@@ -264,7 +260,7 @@ public partial class ContentPageViewModel : PageViewModel, ICommandBarContext
     {
         if (SecondaryCommand != null)
         {
-            WeakReferenceMessenger.Default.Send<PerformCommandMessage>(new(SecondaryCommand.Command.Model, SecondaryCommand.Model));
+            WeakReferenceMessenger.Default.Send<PerformCommandMessage>(new(SecondaryCommand));
         }
     }
 

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/ContentViewModel.cs

@@ -1,8 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public abstract partial class ContentViewModel(WeakReference<IPageContext> context) :
     ExtensionObjectViewModel(context)

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/ContextMenuViewModel.cs

@@ -5,13 +5,13 @@
 using System.Collections.ObjectModel;
 using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Messaging;
-using Microsoft.CmdPal.UI.ViewModels.Messages;
+using Microsoft.CmdPal.Core.ViewModels.Messages;
 using Microsoft.CommandPalette.Extensions;
 using Microsoft.CommandPalette.Extensions.Toolkit;
 using Microsoft.Diagnostics.Utilities;
 using Windows.System;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class ContextMenuViewModel : ObservableObject,
     IRecipient<UpdateCommandBarMessage>,
@@ -22,15 +22,8 @@ public partial class ContextMenuViewModel : ObservableObject,
         get => field;
         set
         {
-            if (field != null)
-            {
-                field.PropertyChanged -= SelectedItemPropertyChanged;
-            }
-
             field = value;
-            SetSelectedItem(value);
-
-            OnPropertyChanged(nameof(SelectedItem));
+            UpdateContextItems();
         }
     }
 
@@ -68,33 +61,6 @@ public partial class ContextMenuViewModel : ObservableObject,
         OnPropertyChanged(nameof(FilterOnTop));
     }
 
-    private void SetSelectedItem(ICommandBarContext? value)
-    {
-        if (value != null)
-        {
-            value.PropertyChanged += SelectedItemPropertyChanged;
-        }
-        else
-        {
-            if (SelectedItem != null)
-            {
-                SelectedItem.PropertyChanged -= SelectedItemPropertyChanged;
-            }
-        }
-
-        UpdateContextItems();
-    }
-
-    private void SelectedItemPropertyChanged(object? sender, System.ComponentModel.PropertyChangedEventArgs e)
-    {
-        switch (e.PropertyName)
-        {
-            case nameof(SelectedItem.HasMoreCommands):
-                UpdateContextItems();
-                break;
-        }
-    }
-
     public void UpdateContextItems()
     {
         if (SelectedItem != null)
@@ -259,7 +225,7 @@ public partial class ContextMenuViewModel : ObservableObject,
         }
         else
         {
-            WeakReferenceMessenger.Default.Send<PerformCommandMessage>(new(command.Command.Model, command.Model));
+            WeakReferenceMessenger.Default.Send<PerformCommandMessage>(new(command));
             UpdateContextItems();
             return ContextKeybindingResult.Hide;
         }

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/DetailsCommandsViewModel.cs

@@ -1,11 +1,11 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class DetailsCommandsViewModel(
     IDetailsElement _detailsElement,

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/DetailsDataViewModel.cs

@@ -1,11 +1,11 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public abstract partial class DetailsDataViewModel(IPageContext context) : ExtensionObjectViewModel(context)
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/DetailsElementViewModel.cs

@@ -1,11 +1,11 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public abstract partial class DetailsElementViewModel(IDetailsElement _detailsElement, WeakReference<IPageContext> context) : ExtensionObjectViewModel(context)
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/DetailsLinkViewModel.cs

@@ -1,11 +1,11 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class DetailsLinkViewModel(
     IDetailsElement _detailsElement,

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/DetailsSeparatorViewModel.cs

@@ -1,11 +1,11 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class DetailsSeparatorViewModel(
     IDetailsElement _detailsElement,

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/DetailsTagsViewModel.cs

@@ -1,11 +1,11 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class DetailsTagsViewModel(
     IDetailsElement _detailsElement,

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/DetailsViewModel.cs

@@ -1,11 +1,11 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class DetailsViewModel(IDetails _details, WeakReference<IPageContext> context) : ExtensionObjectViewModel(context)
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/ExtensionObjectViewModel.cs

@@ -1,11 +1,11 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
 using CommunityToolkit.Mvvm.ComponentModel;
 using ManagedCommon;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public abstract partial class ExtensionObjectViewModel : ObservableObject
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/GlobalLogPageContext.cs

@@ -2,7 +2,7 @@
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public class GlobalLogPageContext : IPageContext
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/IContextItemViewModel.cs

@@ -8,7 +8,7 @@ using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public interface IContextItemViewModel
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/IRootPageService.cs

@@ -0,0 +1,37 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace Microsoft.CmdPal.Core.ViewModels;
+
+public interface IRootPageService
+{
+    /// <summary>
+    /// Gets the root page of the command palette. Return any IPage implementation that
+    /// represents the root view of this instance of the command palette.
+    /// </summary>
+    Microsoft.CommandPalette.Extensions.IPage GetRootPage();
+
+    /// <summary>
+    /// Pre-loads any necessary data or state before the root page is loaded.
+    /// This will be awaited before the root page and the user can do anything,
+    /// so ideally it should be quick and not block the UI thread for long.
+    /// </summary>
+    Task PreLoadAsync();
+
+    /// <summary>
+    /// Do any loading work that can be done after the root page is loaded and
+    /// displayed to the user.
+    /// This is run asynchronously, on a background thread.
+    /// </summary>
+    Task PostLoadRootPageAsync();
+
+    /// <summary>
+    /// Called when a command is performed. The context is the
+    /// sender context for the invoked command. This is typically the IListItem
+    /// or ICommandContextItem that was used to invoke the command.
+    /// </summary>
+    void OnPerformCommand(object? context, bool topLevel, AppExtensionHost? currentHost);
+
+    void GoHome();
+}

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/IconDataViewModel.cs

@@ -1,13 +1,13 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
 using CommunityToolkit.Mvvm.ComponentModel;
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 using Windows.Storage.Streams;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class IconDataViewModel : ObservableObject, IIconData
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/IconInfoViewModel.cs

@@ -1,12 +1,12 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
 using CommunityToolkit.Mvvm.ComponentModel;
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class IconInfoViewModel : ObservableObject, IIconInfo
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/ListItemViewModel.cs

@@ -1,13 +1,13 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
 using System.Diagnostics.CodeAnalysis;
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 using Microsoft.CommandPalette.Extensions.Toolkit;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class ListItemViewModel(IListItem model, WeakReference<IPageContext> context)
     : CommandItemViewModel(new(model), context)

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/ListViewModel.cs

@@ -1,4 +1,4 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
@@ -6,13 +6,13 @@ using System.Collections.ObjectModel;
 using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Input;
 using CommunityToolkit.Mvvm.Messaging;
-using Microsoft.CmdPal.UI.ViewModels.Messages;
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Messages;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 using Microsoft.CommandPalette.Extensions.Toolkit;
 using Windows.Foundation;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class ListViewModel : PageViewModel, IDisposable
 {
@@ -72,7 +72,7 @@ public partial class ListViewModel : PageViewModel, IDisposable
         }
     }
 
-    public ListViewModel(IListPage model, TaskScheduler scheduler, CommandPaletteHost host)
+    public ListViewModel(IListPage model, TaskScheduler scheduler, AppExtensionHost host)
         : base(model, scheduler, host)
     {
         _model = new(model);
@@ -132,7 +132,11 @@ public partial class ListViewModel : PageViewModel, IDisposable
 
         try
         {
+            var stopwatch = System.Diagnostics.Stopwatch.StartNew();
+            stopwatch.Start();
+
             var newItems = _model.Unsafe!.GetItems();
+            var getItemsTime = stopwatch.ElapsedMilliseconds;
 
             // Collect all the items into new viewmodels
             Collection<ListItemViewModel> newViewModels = [];
@@ -158,10 +162,7 @@ public partial class ListViewModel : PageViewModel, IDisposable
             }
 
             // Cancel any ongoing search
-            if (_cancellationTokenSource != null)
-            {
-                _cancellationTokenSource.Cancel();
-            }
+            _cancellationTokenSource?.Cancel();
 
             lock (_listLock)
             {
@@ -172,6 +173,13 @@ public partial class ListViewModel : PageViewModel, IDisposable
 
             // TODO: Iterate over everything in Items, and prune items from the
             // cache if we don't need them anymore
+            stopwatch.Stop();
+            var initializeTime = stopwatch.ElapsedMilliseconds - getItemsTime;
+            WeakReferenceMessenger.Default.Send<FetchItemsMetricsMessage>(new(
+                newViewModels.Count,
+                getItemsTime,
+                initializeTime
+            ));
         }
         catch (Exception ex)
         {
@@ -300,13 +308,12 @@ public partial class ListViewModel : PageViewModel, IDisposable
     {
         if (item != null)
         {
-            WeakReferenceMessenger.Default.Send<PerformCommandMessage>(new(item.Command.Model, item.Model));
+            WeakReferenceMessenger.Default.Send<PerformCommandMessage>(new(item));
         }
         else if (ShowEmptyContent && EmptyContent.PrimaryCommand?.Model.Unsafe != null)
         {
             WeakReferenceMessenger.Default.Send<PerformCommandMessage>(new(
-                EmptyContent.PrimaryCommand.Command.Model,
-                EmptyContent.PrimaryCommand.Model));
+                EmptyContent.PrimaryCommand));
         }
     }
 
@@ -318,14 +325,13 @@ public partial class ListViewModel : PageViewModel, IDisposable
         {
             if (item.SecondaryCommand != null)
             {
-                WeakReferenceMessenger.Default.Send<PerformCommandMessage>(new(item.SecondaryCommand.Command.Model, item.Model));
+                WeakReferenceMessenger.Default.Send<PerformCommandMessage>(new(item.SecondaryCommand, item));
             }
         }
         else if (ShowEmptyContent && EmptyContent.SecondaryCommand?.Model.Unsafe != null)
         {
             WeakReferenceMessenger.Default.Send<PerformCommandMessage>(new(
-                EmptyContent.SecondaryCommand.Command.Model,
-                EmptyContent.SecondaryCommand.Model));
+                EmptyContent.SecondaryCommand));
         }
     }
 
@@ -373,6 +379,15 @@ public partial class ListViewModel : PageViewModel, IDisposable
                }
 
                TextToSuggest = item.TextToSuggest;
+
+               if (item.HasParameters)
+               {
+                   WeakReferenceMessenger.Default.Send<UpdateParametersMessage>(new(item.Parameters));
+               }
+               else
+               {
+                   WeakReferenceMessenger.Default.Send<UpdateParametersMessage>(new(null));
+               }
            });
 
         _lastSelectedItem = item;

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/LoadingPageViewModel.cs

@@ -1,15 +1,15 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class LoadingPageViewModel : PageViewModel
 {
-    public LoadingPageViewModel(IPage? model, TaskScheduler scheduler)
-        : base(model, scheduler, CommandPaletteHost.Instance)
+    public LoadingPageViewModel(IPage? model, TaskScheduler scheduler, AppExtensionHost host)
+        : base(model, scheduler, host)
     {
         ModelIsLoading = true;
         IsInitialized = false;

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/LogMessageViewModel.cs

@@ -2,10 +2,10 @@
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class LogMessageViewModel : ExtensionObjectViewModel
 {
@@ -13,8 +13,6 @@ public partial class LogMessageViewModel : ExtensionObjectViewModel
 
     public string Message { get; private set; } = string.Empty;
 
-    public string ExtensionPfn { get; set; } = string.Empty;
-
     public LogMessageViewModel(ILogMessage message, IPageContext context)
         : base(context)
     {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/ActivateSecondaryCommandMessage.cs

@@ -1,8 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 /// <summary>
 /// Used to perform a list item's secondary command when the user presses ctrl+enter in the search box

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/ActivateSelectedListItemMessage.cs

@@ -2,7 +2,7 @@
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 /// <summary>
 /// Used to perform a list item's command when the user presses enter in the search box

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/BeginInvokeMessage.cs

@@ -1,7 +1,7 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record BeginInvokeMessage;

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/ClearSearchMessage.cs

@@ -1,8 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record ClearSearchMessage()
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/CloseContextMenuMessage.cs

@@ -2,7 +2,7 @@
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 /// <summary>
 /// Used to announce that a context menu should close

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/CmdPalInvokeResultMessage.cs

@@ -1,7 +1,7 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record CmdPalInvokeResultMessage(Microsoft.CommandPalette.Extensions.CommandResultKind Kind);

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/DismissMessage.cs

@@ -1,8 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record DismissMessage()
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/FetchItemsMetricsMessage.cs

@@ -0,0 +1,9 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
+
+public record FetchItemsMetricsMessage(int ItemCount, long GetItemsTime, long InitializeItemsTime)
+{
+}

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/FocusSearchBoxMessage.cs

@@ -1,8 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record FocusSearchBoxMessage()
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/GoBackMessage.cs

@@ -1,8 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record GoBackMessage(bool WithAnimation = true, bool FocusSearch = true)
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/GoHomeMessage.cs

@@ -1,8 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 // TODO! sticking these properties here feels like leaking the UI into the models
 public record GoHomeMessage(bool WithAnimation = true, bool FocusSearch = true)

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/HandleCommandResultMessage.cs

@@ -1,11 +1,11 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record HandleCommandResultMessage(ExtensionObject<ICommandResult> Result)
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/HideDetailsMessage.cs

@@ -1,11 +1,11 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record HideDetailsMessage()
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/HotkeySummonMessage.cs

@@ -1,8 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record HotkeySummonMessage(string CommandId, IntPtr Hwnd)
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/LaunchUriMessage.cs

@@ -1,11 +1,11 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record LaunchUriMessage(Uri Uri)
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/NavigateBackMessage.cs

@@ -1,8 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record NavigateBackMessage(bool FromBackspace = false)
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/NavigateNextCommand.cs

@@ -1,8 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 /// <summary>
 /// Used to navigate to the next command in the page when pressing the Down key in the SearchBox.

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/NavigatePreviousCommand.cs

@@ -1,8 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 /// <summary>
 /// Used to navigate to the previous command in the page when pressing the Down key in the SearchBox.

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/NavigateToPageMessage.cs

@@ -1,8 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record NavigateToPageMessage(PageViewModel Page, bool WithAnimation)
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/OpenContextMenuMessage.cs

@@ -1,4 +1,4 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
@@ -6,7 +6,7 @@ using Microsoft.UI.Xaml;
 using Microsoft.UI.Xaml.Controls.Primitives;
 using Windows.Foundation;
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 /// <summary>
 /// Used to announce the context menu should open

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/OpenSettingsMessage.cs

@@ -1,10 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.BuiltinCommands;
-
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record OpenSettingsMessage()
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/PerformCommandMessage.cs

@@ -1,11 +1,11 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 /// <summary>
 /// Used to do a command - navigate to a page or invoke it
@@ -18,21 +18,13 @@ public record PerformCommandMessage
 
     public bool WithAnimation { get; set; } = true;
 
-    public CommandPaletteHost? ExtensionHost { get; private set; }
-
-    public PerformCommandMessage(ExtensionObject<ICommand> command)
-    {
-        Command = command;
-        Context = null;
-    }
-
-    public PerformCommandMessage(TopLevelViewModel topLevelCommand)
-    {
-        Command = topLevelCommand.CommandViewModel.Model;
-        Context = null;
-        ExtensionHost = topLevelCommand.ExtensionHost;
-    }
+    public ICommandArgument?[] Arguments { get; set; } = [];
 
+    // public PerformCommandMessage(ExtensionObject<ICommand> command)
+    // {
+    //    Command = command;
+    //    Context = null;
+    // }
     public PerformCommandMessage(ExtensionObject<ICommand> command, ExtensionObject<IListItem> context)
     {
         Command = command;
@@ -57,6 +49,16 @@ public record PerformCommandMessage
         Context = contextCommand.Model.Unsafe;
     }
 
+    public PerformCommandMessage(CommandItemViewModel item, CommandItemViewModel? context = null)
+    {
+        Command = item.Command.Model;
+        Context = context?.Model.Unsafe ?? item.Model.Unsafe;
+        if (item.Parameters != null && item.Parameters.Any())
+        {
+            Arguments = item.Parameters.Select(p => p.Model.Unsafe).ToArray();
+        }
+    }
+
     public PerformCommandMessage(ConfirmResultViewModel vm)
     {
         Command = vm.PrimaryCommand.Model;

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/QuitMessage.cs

@@ -1,10 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.BuiltinCommands;
-
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 /// <summary>
 /// Message which closes the application. Used by <see cref="QuitCommand"/> via <see cref="BuiltInsCommandProvider"/>.

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/ReloadCommandsMessage.cs

@@ -1,8 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record ReloadCommandsMessage()
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/RequestOpenPickerMessage.cs

@@ -0,0 +1,12 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using Microsoft.CmdPal.Core.ViewModels.Models;
+using Microsoft.CommandPalette.Extensions;
+
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
+
+public record RequestOpenPickerMessage(ExtensionObject<ICommandArgument> Argument)
+{
+}

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/SettingsWindowClosedMessage.cs

@@ -1,8 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record SettingsWindowClosedMessage
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/ShowConfirmationMessage.cs

@@ -1,8 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record ShowConfirmationMessage(Microsoft.CommandPalette.Extensions.IConfirmationArgs? Args)
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/ShowDetailsMessage.cs

@@ -1,11 +1,11 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record ShowDetailsMessage(DetailsViewModel Details)
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/ShowToastMessage.cs

@@ -1,8 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record ShowToastMessage(string Message)
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/ShowWindowMessage.cs

@@ -1,8 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record ShowWindowMessage(IntPtr Hwnd)
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/TryCommandKeybindingMessage.cs

@@ -1,10 +1,10 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
 using Windows.System;
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record TryCommandKeybindingMessage(bool Ctrl, bool Alt, bool Shift, bool Win, VirtualKey Key)
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/UpdateCommandBarMessage.cs

@@ -1,11 +1,11 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
 using System.ComponentModel;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 /// <summary>
 /// Used to update the command bar at the bottom to reflect the commands for a list item

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/UpdateFallbackItemsMessage.cs

@@ -1,8 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record UpdateFallbackItemsMessage()
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/UpdateParametersMessage.cs

@@ -0,0 +1,9 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
+
+public record UpdateParametersMessage(IEnumerable<ArgumentItemViewModel>? Parameters)
+{
+}

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Microsoft.CmdPal.Core.ViewModels.csproj

@@ -0,0 +1,60 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <Import Project="..\..\..\Common.Dotnet.CsWinRT.props" />
+  <Import Project="..\..\..\Common.Dotnet.AotCompatibility.props" />
+
+  <PropertyGroup>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <AppendTargetFrameworkToOutputPath>false</AppendTargetFrameworkToOutputPath>
+    <AppendRuntimeIdentifierToOutputPath>false</AppendRuntimeIdentifierToOutputPath>
+    <OutputPath>$(SolutionDir)$(Platform)\$(Configuration)\WinUI3Apps\CmdPal</OutputPath>
+    <!-- For MVVM Toolkit Partial Properties/AOT support -->
+    <LangVersion>preview</LangVersion>
+    <!-- Disable SA1313 for Primary Constructor fields conflict https://learn.microsoft.com/dotnet/csharp/programming-guide/classes-and-structs/instance-constructors#primary-constructors  -->
+    <NoWarn>SA1313;</NoWarn>
+  </PropertyGroup>
+
+  <PropertyGroup>
+    <CsWinRTAotOptimizerEnabled>true</CsWinRTAotOptimizerEnabled>
+  </PropertyGroup>
+	
+  <ItemGroup>
+    <PackageReference Include="CommunityToolkit.Common" />
+    <PackageReference Include="CommunityToolkit.Mvvm" />
+
+    <PackageReference Include="Microsoft.Windows.CsWin32">
+      <PrivateAssets>all</PrivateAssets>
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>
+    </PackageReference>
+
+    <PackageReference Include="WyHash" />
+
+  </ItemGroup>
+		
+  <ItemGroup>
+    <ProjectReference Include="..\Microsoft.CmdPal.Common\Microsoft.CmdPal.Common.csproj" />
+    <ProjectReference Include="..\extensionsdk\Microsoft.CommandPalette.Extensions.Toolkit\Microsoft.CommandPalette.Extensions.Toolkit.csproj" />
+    <ProjectReference Include="..\..\..\common\ManagedCommon\ManagedCommon.csproj" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Compile Update="Properties\Resources.Designer.cs">
+      <DependentUpon>Resources.resx</DependentUpon>
+      <DesignTime>True</DesignTime>
+      <AutoGen>True</AutoGen>
+    </Compile>
+  </ItemGroup>
+
+
+  <!-- Just mark it as AOT compatible. Do not publish with AOT now. We need fully test before we really publish it as AOT enabled-->
+  <!--<PropertyGroup>
+    <SelfContained>true</SelfContained>
+    <WindowsAppSDKSelfContained>true</WindowsAppSDKSelfContained>
+    <PublishTrimmed>true</PublishTrimmed>
+    <PublishSingleFile>true</PublishSingleFile>
+    --><!-- <DisableRuntimeMarshalling>true</DisableRuntimeMarshalling> --><!--
+    <PublishAot>true</PublishAot>
+	<EnableMsixTooling>true</EnableMsixTooling>
+  </PropertyGroup>-->
+
+</Project>

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Models/ExtensionObject`1.cs

@@ -1,8 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Models;
+namespace Microsoft.CmdPal.Core.ViewModels.Models;
 
 public class ExtensionObject<T>(T? value) // where T : IInspectable
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/NativeMethods.json

@@ -0,0 +1,4 @@
+{
+  "$schema": "https://aka.ms/CsWin32.schema.json",
+  "allowMarshaling": false
+}

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/NativeMethods.txt

@@ -0,0 +1,19 @@
+GetPhysicallyInstalledSystemMemory
+GlobalMemoryStatusEx
+GetSystemInfo
+CoCreateInstance
+SetForegroundWindow
+IsIconic
+RegisterHotKey
+SetWindowLongPtr
+CallWindowProc
+ShowWindow
+SetForegroundWindow
+SetFocus
+SetActiveWindow
+MonitorFromWindow
+GetMonitorInfo
+SHCreateStreamOnFileEx
+CoAllowSetForegroundWindow
+SHCreateStreamOnFileEx
+SHLoadIndirectString

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/PageViewModel.cs

@@ -1,14 +1,14 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
 using System.Collections.ObjectModel;
 using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Input;
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class PageViewModel : ExtensionObjectViewModel, IPageContext
 {
@@ -43,7 +43,7 @@ public partial class PageViewModel : ExtensionObjectViewModel, IPageContext
     public bool ShowSuggestion => !string.IsNullOrEmpty(TextToSuggest) && TextToSuggest != Filter;
 
     [ObservableProperty]
-    public partial CommandPaletteHost ExtensionHost { get; private set; }
+    public partial AppExtensionHost ExtensionHost { get; private set; }
 
     public bool HasStatusMessage => MostRecentStatusMessage != null;
 
@@ -69,7 +69,7 @@ public partial class PageViewModel : ExtensionObjectViewModel, IPageContext
 
     public IconInfoViewModel Icon { get; protected set; }
 
-    public PageViewModel(IPage? model, TaskScheduler scheduler, CommandPaletteHost extensionHost)
+    public PageViewModel(IPage? model, TaskScheduler scheduler, AppExtensionHost extensionHost)
         : base((IPageContext?)null)
     {
         _pageModel = new(model);
@@ -220,7 +220,7 @@ public partial class PageViewModel : ExtensionObjectViewModel, IPageContext
     {
         // Set the extensionHint to the Page Title (if we have one, and one not provided).
         // extensionHint ??= _pageModel?.Unsafe?.Title;
-        extensionHint ??= ExtensionHost.Extension?.ExtensionDisplayName ?? Title;
+        extensionHint ??= ExtensionHost.GetExtensionDisplayName() ?? Title;
         Task.Factory.StartNew(
             () =>
         {
@@ -249,7 +249,19 @@ public partial class PageViewModel : ExtensionObjectViewModel, IPageContext
 
 public interface IPageContext
 {
-    public void ShowException(Exception ex, string? extensionHint = null);
+    void ShowException(Exception ex, string? extensionHint = null);
 
-    public TaskScheduler Scheduler { get; }
+    TaskScheduler Scheduler { get; }
+}
+
+public interface IPageViewModelFactoryService
+{
+    /// <summary>
+    /// Creates a new instance of the page view model for the given page type.
+    /// </summary>
+    /// <param name="page">The page for which to create the view model.</param>
+    /// <param name="nested">Indicates whether the page is not the top-level page.</param>
+    /// <param name="host">The command palette host that will host the page (for status messages)</param>
+    /// <returns>A new instance of the page view model.</returns>
+    PageViewModel? TryCreatePageViewModel(IPage page, bool nested, AppExtensionHost host);
 }

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/PageViewModelFactory.cs

@@ -0,0 +1,27 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using Microsoft.CommandPalette.Extensions;
+
+namespace Microsoft.CmdPal.Core.ViewModels;
+
+public class PageViewModelFactory : IPageViewModelFactoryService
+{
+    private readonly TaskScheduler _scheduler;
+
+    public PageViewModelFactory(TaskScheduler scheduler)
+    {
+        _scheduler = scheduler;
+    }
+
+    public PageViewModel? TryCreatePageViewModel(IPage page, bool nested, AppExtensionHost host)
+    {
+        return page switch
+        {
+            IListPage listPage => new ListViewModel(listPage, _scheduler, host) { IsNested = nested },
+            IContentPage contentPage => new ContentPageViewModel(contentPage, _scheduler, host),
+            _ => null,
+        };
+    }
+}

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/ProgressViewModel.cs

@@ -1,11 +1,11 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class ProgressViewModel : ExtensionObjectViewModel
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/SeparatorContextItemViewModel.cs

@@ -2,10 +2,10 @@
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class SeparatorContextItemViewModel() : IContextItemViewModel, ISeparatorContextItem
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/ShellViewModel.cs

@@ -1,28 +1,24 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using System.Runtime.InteropServices;
-using System.Runtime.Versioning;
 using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Input;
 using CommunityToolkit.Mvvm.Messaging;
 using ManagedCommon;
-using Microsoft.CmdPal.Common.Services;
-using Microsoft.CmdPal.UI.ViewModels.MainPage;
-using Microsoft.CmdPal.UI.ViewModels.Messages;
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Messages;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
-using Microsoft.Extensions.DependencyInjection;
-using WinRT;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class ShellViewModel : ObservableObject,
     IRecipient<PerformCommandMessage>
 {
-    private readonly IServiceProvider _serviceProvider;
+    private readonly IRootPageService _rootPageService;
+    private readonly IAppHostService _appHostService;
     private readonly TaskScheduler _scheduler;
+    private readonly IPageViewModelFactoryService _pageViewModelFactory;
     private readonly Lock _invokeLock = new();
     private Task? _handleInvokeTask;
 
@@ -60,18 +56,24 @@ public partial class ShellViewModel : ObservableObject,
         }
     }
 
-    private MainListPage? _mainListPage;
+    private IPage? _rootPage;
 
-    private IExtensionWrapper? _activeExtension;
     private bool _isNested;
 
     public bool IsNested { get => _isNested; }
 
-    public ShellViewModel(IServiceProvider serviceProvider, TaskScheduler scheduler)
+    public ShellViewModel(
+        TaskScheduler scheduler,
+        IRootPageService rootPageService,
+        IPageViewModelFactoryService pageViewModelFactory,
+        IAppHostService appHostService)
     {
-        _serviceProvider = serviceProvider;
+        _pageViewModelFactory = pageViewModelFactory;
         _scheduler = scheduler;
-        _currentPage = new LoadingPageViewModel(null, _scheduler);
+        _rootPageService = rootPageService;
+        _appHostService = appHostService;
+
+        _currentPage = new LoadingPageViewModel(null, _scheduler, appHostService.GetDefaultHost());
 
         // Register to receive messages
         WeakReferenceMessenger.Default.Register<PerformCommandMessage>(this);
@@ -80,24 +82,27 @@ public partial class ShellViewModel : ObservableObject,
     [RelayCommand]
     public async Task<bool> LoadAsync()
     {
-        var tlcManager = _serviceProvider.GetService<TopLevelCommandManager>();
-        await tlcManager!.LoadBuiltinsAsync();
+        // First, do any loading that the root page service needs to do before we can
+        // display the root page. For example, this might include loading
+        // the built-in commands, or loading the settings.
+        await _rootPageService.PreLoadAsync();
+
         IsLoaded = true;
 
-        // Built-ins have loaded. We can display our page at this point.
-        _mainListPage = new MainListPage(_serviceProvider);
-        WeakReferenceMessenger.Default.Send<PerformCommandMessage>(new(new ExtensionObject<ICommand>(_mainListPage)));
+        // Now that the basics are set up, we can load the root page.
+        _rootPage = _rootPageService.GetRootPage();
 
+        // This sends a message to us to load the root page view model.
+        WeakReferenceMessenger.Default.Send<PerformCommandMessage>(new(new ExtensionObject<ICommand>(_rootPage), new ExtensionObject<ICommandContextItem>(null)));
+
+        // Now that the root page is loaded, do any post-load work that the root page service needs to do.
+        // This runs asynchronously, on a background thread.
+        // This might include starting extensions, for example.
+        // Note: We don't await this, so that we can return immediately.
+        // This is important because we don't want to block the UI thread.
         _ = Task.Run(async () =>
         {
-            // After loading built-ins, and starting navigation, kick off a thread to load extensions.
-            tlcManager.LoadExtensionsCommand.Execute(null);
-
-            await tlcManager.LoadExtensionsCommand.ExecutionTask!;
-            if (tlcManager.LoadExtensionsCommand.ExecutionTask.Status != TaskStatus.RanToCompletion)
-            {
-                // TODO: Handle failure case
-            }
+            await _rootPageService.PostLoadRootPageAsync();
         });
 
         return true;
@@ -170,19 +175,6 @@ public partial class ShellViewModel : ObservableObject,
         }
     }
 
-    public void PerformTopLevelCommand(PerformCommandMessage message)
-    {
-        if (_mainListPage == null)
-        {
-            return;
-        }
-
-        if (message.Context is IListItem listItem)
-        {
-            _mainListPage.UpdateHistory(listItem);
-        }
-    }
-
     public void Receive(PerformCommandMessage message)
     {
         PerformCommand(message);
@@ -196,69 +188,21 @@ public partial class ShellViewModel : ObservableObject,
             return;
         }
 
-        if (!CurrentPage.IsNested)
-        {
-            // on the main page here
-            PerformTopLevelCommand(message);
-        }
+        var host = _appHostService.GetHostForCommand(message.Context, CurrentPage.ExtensionHost);
 
-        IExtensionWrapper? extension = null;
+        _rootPageService.OnPerformCommand(message.Context, !CurrentPage.IsNested, host);
 
         try
         {
-            // In the case that we're coming from a top-level command, the
-            // current page's host is the global instance. We only really want
-            // to use that as the host of last resort.
-            var pageHost = CurrentPage?.ExtensionHost;
-            if (pageHost == CommandPaletteHost.Instance)
-            {
-                pageHost = null;
-            }
-
-            var messageHost = message.ExtensionHost;
-
-            // Use the host from the current page if it has one, else use the
-            // one specified in the PerformMessage for a top-level command,
-            // else just use the global one.
-            CommandPaletteHost host;
-
-            // Top level items can come through without a Extension set on the
-            // message. In that case, the `Context` is actually the
-            // TopLevelViewModel itself, and we can use that to get at the
-            // extension object.
-            extension = pageHost?.Extension ?? messageHost?.Extension ?? null;
-            if (extension == null && message.Context is TopLevelViewModel topLevelViewModel)
-            {
-                extension = topLevelViewModel.ExtensionHost?.Extension;
-                host = pageHost ?? messageHost ?? topLevelViewModel?.ExtensionHost ?? CommandPaletteHost.Instance;
-            }
-            else
-            {
-                host = pageHost ?? messageHost ?? CommandPaletteHost.Instance;
-            }
-
-            if (extension != null)
-            {
-                if (messageHost != null)
-                {
-                    Logger.LogDebug($"Activated top-level command from {extension.ExtensionDisplayName}");
-                }
-                else
-                {
-                    Logger.LogDebug($"Activated command from {extension.ExtensionDisplayName}");
-                }
-            }
-
-            SetActiveExtension(extension);
-
             if (command is IPage page)
             {
                 Logger.LogDebug($"Navigating to page");
 
-                var isMainPage = command is MainListPage;
+                var isMainPage = command == _rootPage;
+                _isNested = !isMainPage;
 
                 // Construct our ViewModel of the appropriate type and pass it the UI Thread context.
-                var pageViewModel = GetViewModelForPage(page, !isMainPage, host);
+                var pageViewModel = _pageViewModelFactory.TryCreatePageViewModel(page, _isNested, host);
                 if (pageViewModel == null)
                 {
                     Logger.LogError($"Failed to create ViewModel for page {page.GetType().Name}");
@@ -267,31 +211,39 @@ public partial class ShellViewModel : ObservableObject,
 
                 // Kick off async loading of our ViewModel
                 LoadPageViewModel(pageViewModel);
-                _isNested = !isMainPage;
-
                 OnUIThread(() => { WeakReferenceMessenger.Default.Send<UpdateCommandBarMessage>(new(null)); });
                 WeakReferenceMessenger.Default.Send<NavigateToPageMessage>(new(pageViewModel, message.WithAnimation));
 
                 // Note: Originally we set our page back in the ViewModel here, but that now happens in response to the Frame navigating triggered from the above
                 // See RootFrame_Navigated event handler.
             }
+            else if (command is IInvokableCommandWithParameters commandWithParams)
+            {
+                Logger.LogDebug($"Invoking command with args");
+
+                // var args = ArgumentsViewModel.Arguments;
+                // var aa = args.Select(a => a.Model.Unsafe).ToArray() ?? [];
+                // message.Arguments = aa;
+                WeakReferenceMessenger.Default.Send<BeginInvokeMessage>();
+                HandleInvokeCommandWithArgs(message, commandWithParams, host);
+            }
             else if (command is IInvokableCommand invokable)
             {
                 Logger.LogDebug($"Invoking command");
 
                 WeakReferenceMessenger.Default.Send<BeginInvokeMessage>();
-                StartInvoke(message, invokable);
+                StartInvoke(message, invokable, host);
             }
         }
         catch (Exception ex)
         {
             // TODO: It would be better to do this as a page exception, rather
             // than a silent log message.
-            CommandPaletteHost.Instance.Log(ex.Message);
+            host?.Log(ex.Message);
         }
     }
 
-    private void StartInvoke(PerformCommandMessage message, IInvokableCommand invokable)
+    private void StartInvoke(PerformCommandMessage message, IInvokableCommand invokable, AppExtensionHost? host)
     {
         // TODO GH #525 This needs more better locking.
         lock (_invokeLock)
@@ -304,13 +256,13 @@ public partial class ShellViewModel : ObservableObject,
             {
                 _handleInvokeTask = Task.Run(() =>
                 {
-                    SafeHandleInvokeCommandSynchronous(message, invokable);
+                    SafeHandleInvokeCommandSynchronous(message, invokable, host);
                 });
             }
         }
     }
 
-    private void SafeHandleInvokeCommandSynchronous(PerformCommandMessage message, IInvokableCommand invokable)
+    private void SafeHandleInvokeCommandSynchronous(PerformCommandMessage message, IInvokableCommand invokable, AppExtensionHost? host)
     {
         try
         {
@@ -330,7 +282,45 @@ public partial class ShellViewModel : ObservableObject,
 
             // TODO: It would be better to do this as a page exception, rather
             // than a silent log message.
-            CommandPaletteHost.Instance.Log(ex.Message);
+            host?.Log(ex.Message);
+        }
+    }
+
+    private void HandleInvokeCommandWithArgs(PerformCommandMessage message, IInvokableCommandWithParameters invokable, AppExtensionHost? host)
+    {
+        // TODO GH #525 This needs more better locking.
+        lock (_invokeLock)
+        {
+            if (_handleInvokeTask != null)
+            {
+                // do nothing - a command is already doing a thing
+            }
+            else
+            {
+                _handleInvokeTask = Task.Run(() =>
+                {
+                    try
+                    {
+                        // Call out to extension process.
+                        // * May fail!
+                        // * May never return!
+                        var result = invokable.InvokeWithArgs(message.Context, message.Arguments);
+
+                        // But if it did succeed, we need to handle the result.
+                        UnsafeHandleCommandResult(result);
+
+                        _handleInvokeTask = null;
+                    }
+                    catch (Exception ex)
+                    {
+                        _handleInvokeTask = null;
+
+                        // TODO: It would be better to do this as a page exception, rather
+                        // than a silent log message.
+                        host?.Log(ex.Message);
+                    }
+                });
+            }
         }
     }
 
@@ -405,54 +395,9 @@ public partial class ShellViewModel : ObservableObject,
         }
     }
 
-    private PageViewModel? GetViewModelForPage(IPage page, bool nested, CommandPaletteHost host)
-    {
-        return page switch
-        {
-            IListPage listPage => new ListViewModel(listPage, _scheduler, host)
-            {
-                IsNested = nested,
-            },
-            IContentPage contentPage => new ContentPageViewModel(contentPage, _scheduler, host),
-            _ => null,
-        };
-    }
-
-    public void SetActiveExtension(IExtensionWrapper? extension)
-    {
-        if (extension != _activeExtension)
-        {
-            // There's not really a CoDisallowSetForegroundWindow, so we don't
-            // need to handle that
-            _activeExtension = extension;
-
-            var extensionWinRtObject = _activeExtension?.GetExtensionObject();
-            if (extensionWinRtObject != null)
-            {
-                try
-                {
-                    unsafe
-                    {
-                        var winrtObj = (IWinRTObject)extensionWinRtObject;
-                        var intPtr = winrtObj.NativeObject.ThisPtr;
-                        var hr = Native.CoAllowSetForegroundWindow(intPtr);
-                        if (hr != 0)
-                        {
-                            Logger.LogWarning($"Error giving foreground rights: 0x{hr.Value:X8}");
-                        }
-                    }
-                }
-                catch (Exception ex)
-                {
-                    Logger.LogError(ex.ToString());
-                }
-            }
-        }
-    }
-
     public void GoHome(bool withAnimation = true, bool focusSearch = true)
     {
-        SetActiveExtension(null);
+        _rootPageService.GoHome();
         WeakReferenceMessenger.Default.Send<GoHomeMessage>(new(withAnimation, focusSearch));
     }
 
@@ -461,20 +406,6 @@ public partial class ShellViewModel : ObservableObject,
         WeakReferenceMessenger.Default.Send<GoBackMessage>(new(withAnimation, focusSearch));
     }
 
-    // You may ask yourself, why aren't we using CsWin32 for this?
-    // The CsWin32 projected version includes some object marshalling, like so:
-    //
-    // HRESULT CoAllowSetForegroundWindow([MarshalAs(UnmanagedType.IUnknown)] object pUnk,...)
-    //
-    // And if you do it like that, then the IForegroundTransfer interface isn't marshalled correctly
-    internal sealed class Native
-    {
-        [DllImport("OLE32.dll", ExactSpelling = true)]
-        [DefaultDllImportSearchPaths(DllImportSearchPath.System32)]
-        [SupportedOSPlatform("windows5.0")]
-        internal static extern unsafe global::Windows.Win32.Foundation.HRESULT CoAllowSetForegroundWindow(nint pUnk, [Optional] void* lpvReserved);
-    }
-
     private void OnUIThread(Action action)
     {
         _ = Task.Factory.StartNew(

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/StatusMessageViewModel.cs

@@ -1,11 +1,11 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class StatusMessageViewModel : ExtensionObjectViewModel
 {
@@ -15,14 +15,10 @@ public partial class StatusMessageViewModel : ExtensionObjectViewModel
 
     public MessageState State { get; private set; } = MessageState.Info;
 
-    public string ExtensionPfn { get; set; } = string.Empty;
-
     public ProgressViewModel? Progress { get; private set; }
 
     public bool HasProgress => Progress != null;
 
-    // public bool IsIndeterminate => Progress != null && Progress.IsIndeterminate;
-    // public double ProgressValue => (Progress?.ProgressPercent ?? 0) / 100.0;
     public StatusMessageViewModel(IStatusMessage message, WeakReference<IPageContext> context)
         : base(context)
     {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/TagViewModel.cs

@@ -1,11 +1,11 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class TagViewModel(ITag _tag, WeakReference<IPageContext> context) : ExtensionObjectViewModel(context)
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/ToastViewModel.cs

@@ -4,9 +4,9 @@
 
 using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Messaging;
-using Microsoft.CmdPal.UI.ViewModels.Messages;
+using Microsoft.CmdPal.Core.ViewModels.Messages;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class ToastViewModel : ObservableObject
 {

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/AliasManager.cs

@@ -4,7 +4,7 @@
 
 using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Messaging;
-using Microsoft.CmdPal.UI.ViewModels.Messages;
+using Microsoft.CmdPal.Core.ViewModels.Messages;
 
 namespace Microsoft.CmdPal.UI.ViewModels;
 
@@ -38,7 +38,8 @@ public partial class AliasManager : ObservableObject
                 if (topLevelCommand != null)
                 {
                     WeakReferenceMessenger.Default.Send<ClearSearchMessage>();
-                    WeakReferenceMessenger.Default.Send<PerformCommandMessage>(new(topLevelCommand));
+
+                    WeakReferenceMessenger.Default.Send<PerformCommandMessage>(topLevelCommand.GetPerformCommandMessage());
                     return true;
                 }
             }

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/CommandPaletteContentPageViewModel.cs

@@ -0,0 +1,28 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using Microsoft.CmdPal.Core.ViewModels;
+using Microsoft.CommandPalette.Extensions;
+
+namespace Microsoft.CmdPal.UI.ViewModels;
+
+public partial class CommandPaletteContentPageViewModel : ContentPageViewModel
+{
+    public CommandPaletteContentPageViewModel(IContentPage model, TaskScheduler scheduler, AppExtensionHost host)
+        : base(model, scheduler, host)
+    {
+    }
+
+    public override ContentViewModel? ViewModelFromContent(IContent content, WeakReference<IPageContext> context)
+    {
+        ContentViewModel? viewModel = content switch
+        {
+            IFormContent form => new ContentFormViewModel(form, context),
+            IMarkdownContent markdown => new ContentMarkdownViewModel(markdown, context),
+            ITreeContent tree => new ContentTreeViewModel(tree, context),
+            _ => null,
+        };
+        return viewModel;
+    }
+}

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/CommandPaletteHost.cs

@@ -1,35 +1,19 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using System.Collections.ObjectModel;
-using System.Diagnostics;
-using ManagedCommon;
 using Microsoft.CmdPal.Common.Services;
+using Microsoft.CmdPal.Core.ViewModels;
 using Microsoft.CommandPalette.Extensions;
-using Microsoft.CommandPalette.Extensions.Toolkit;
-using Windows.Foundation;
 
 namespace Microsoft.CmdPal.UI.ViewModels;
 
-public sealed partial class CommandPaletteHost : IExtensionHost
+public sealed partial class CommandPaletteHost : AppExtensionHost, IExtensionHost
 {
     // Static singleton, so that we can access this from anywhere
     // Post MVVM - this should probably be like, a dependency injection thing.
     public static CommandPaletteHost Instance { get; } = new();
 
-    private static readonly GlobalLogPageContext _globalLogPageContext = new();
-
-    private static ulong _hostingHwnd;
-
-    public ulong HostingHwnd => _hostingHwnd;
-
-    public string LanguageOverride => string.Empty;
-
-    public static ObservableCollection<LogMessageViewModel> LogMessages { get; } = [];
-
-    public ObservableCollection<StatusMessageViewModel> StatusMessages { get; } = [];
-
     public IExtensionWrapper? Extension { get; }
 
     private readonly ICommandProvider? _builtInProvider;
@@ -48,145 +32,8 @@ public sealed partial class CommandPaletteHost : IExtensionHost
         _builtInProvider = builtInProvider;
     }
 
-    public IAsyncAction ShowStatus(IStatusMessage? message, StatusContext context)
+    public override string? GetExtensionDisplayName()
     {
-        if (message == null)
-        {
-            return Task.CompletedTask.AsAsyncAction();
-        }
-
-        Debug.WriteLine(message.Message);
-
-        _ = Task.Run(() =>
-        {
-            ProcessStatusMessage(message, context);
-        });
-
-        return Task.CompletedTask.AsAsyncAction();
-    }
-
-    public IAsyncAction HideStatus(IStatusMessage? message)
-    {
-        if (message == null)
-        {
-            return Task.CompletedTask.AsAsyncAction();
-        }
-
-        _ = Task.Run(() =>
-        {
-            ProcessHideStatusMessage(message);
-        });
-        return Task.CompletedTask.AsAsyncAction();
-    }
-
-    public IAsyncAction LogMessage(ILogMessage? message)
-    {
-        if (message == null)
-        {
-            return Task.CompletedTask.AsAsyncAction();
-        }
-
-        Logger.LogDebug(message.Message);
-
-        _ = Task.Run(() =>
-        {
-            ProcessLogMessage(message);
-        });
-
-        // We can't just make a LogMessageViewModel : ExtensionObjectViewModel
-        // because we don't necessarily know the page context. Butts.
-        return Task.CompletedTask.AsAsyncAction();
-    }
-
-    public void ProcessLogMessage(ILogMessage message)
-    {
-        var vm = new LogMessageViewModel(message, _globalLogPageContext);
-        vm.SafeInitializePropertiesSynchronous();
-
-        if (Extension != null)
-        {
-            vm.ExtensionPfn = Extension.PackageFamilyName;
-        }
-
-        Task.Factory.StartNew(
-            () =>
-            {
-                LogMessages.Add(vm);
-            },
-            CancellationToken.None,
-            TaskCreationOptions.None,
-            _globalLogPageContext.Scheduler);
-    }
-
-    public void ProcessStatusMessage(IStatusMessage message, StatusContext context)
-    {
-        // If this message is already in the list of messages, just bring it to the top
-        var oldVm = StatusMessages.Where(messageVM => messageVM.Model.Unsafe == message).FirstOrDefault();
-        if (oldVm != null)
-        {
-            Task.Factory.StartNew(
-                () =>
-                {
-                    StatusMessages.Remove(oldVm);
-                    StatusMessages.Add(oldVm);
-                },
-                CancellationToken.None,
-                TaskCreationOptions.None,
-                _globalLogPageContext.Scheduler);
-            return;
-        }
-
-        var vm = new StatusMessageViewModel(message, new(_globalLogPageContext));
-        vm.SafeInitializePropertiesSynchronous();
-
-        if (Extension != null)
-        {
-            vm.ExtensionPfn = Extension.PackageFamilyName;
-        }
-
-        Task.Factory.StartNew(
-            () =>
-            {
-                StatusMessages.Add(vm);
-            },
-            CancellationToken.None,
-            TaskCreationOptions.None,
-            _globalLogPageContext.Scheduler);
-    }
-
-    public void ProcessHideStatusMessage(IStatusMessage message)
-    {
-        Task.Factory.StartNew(
-            () =>
-            {
-                try
-                {
-                    var vm = StatusMessages.Where(messageVM => messageVM.Model.Unsafe == message).FirstOrDefault();
-                    if (vm != null)
-                    {
-                        StatusMessages.Remove(vm);
-                    }
-                }
-                catch
-                {
-                }
-            },
-            CancellationToken.None,
-            TaskCreationOptions.None,
-            _globalLogPageContext.Scheduler);
-    }
-
-    public static void SetHostHwnd(ulong hostHwnd) => _hostingHwnd = hostHwnd;
-
-    public void DebugLog(string message)
-    {
-#if DEBUG
-        this.ProcessLogMessage(new LogMessage(message));
-#endif
-    }
-
-    public void Log(string message)
-    {
-        this.ProcessLogMessage(new LogMessage(message));
+        return Extension?.ExtensionDisplayName;
     }
 }

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/CommandPalettePageViewModelFactory.cs

@@ -0,0 +1,29 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using Microsoft.CmdPal.Core.ViewModels;
+using Microsoft.CommandPalette.Extensions;
+
+namespace Microsoft.CmdPal.UI.ViewModels;
+
+public class CommandPalettePageViewModelFactory
+    : IPageViewModelFactoryService
+{
+    private readonly TaskScheduler _scheduler;
+
+    public CommandPalettePageViewModelFactory(TaskScheduler scheduler)
+    {
+        _scheduler = scheduler;
+    }
+
+    public PageViewModel? TryCreatePageViewModel(IPage page, bool nested, AppExtensionHost host)
+    {
+        return page switch
+        {
+            IListPage listPage => new ListViewModel(listPage, _scheduler, host) { IsNested = nested },
+            IContentPage contentPage => new CommandPaletteContentPageViewModel(contentPage, _scheduler, host),
+            _ => null,
+        };
+    }
+}

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/CommandProviderWrapper.cs

@@ -4,7 +4,8 @@
 
 using ManagedCommon;
 using Microsoft.CmdPal.Common.Services;
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 using Microsoft.Extensions.DependencyInjection;
 

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/CommandSettingsViewModel.cs

@@ -3,10 +3,11 @@
 // See the LICENSE file in the project root for more information.
 
 using ManagedCommon;
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
+using Microsoft.CmdPal.UI.ViewModels;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class CommandSettingsViewModel(ICommandSettings? _unsafeSettings, CommandProviderWrapper provider, TaskScheduler mainThread)
 {

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/Commands/BuiltInsCommandProvider.cs

@@ -2,7 +2,7 @@
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Messages;
+using Microsoft.CmdPal.Core.ViewModels.Messages;
 using Microsoft.CommandPalette.Extensions;
 using Microsoft.CommandPalette.Extensions.Toolkit;
 
@@ -23,6 +23,12 @@ public partial class BuiltInsCommandProvider : CommandProvider
         [
             new CommandItem(openSettings) { Subtitle = Properties.Resources.builtin_open_settings_subtitle },
             new CommandItem(_newExtension) { Title = _newExtension.Title, Subtitle = Properties.Resources.builtin_new_extension_subtitle },
+            new ListItem(new CommandWithParams() { Name = "Invoke with params 2" })
+            {
+                Title = "Do a thing with a string",
+                Subtitle = "This command requires more input",
+                Icon = new IconInfo("\uE961"),
+            }
         ];
 
     public override IFallbackCommandItem[] FallbackCommands() =>
@@ -40,4 +46,46 @@ public partial class BuiltInsCommandProvider : CommandProvider
     }
 
     public override void InitializeWithHost(IExtensionHost host) => BuiltinsExtensionHost.Instance.Initialize(host);
+
+    internal sealed partial class CommandWithParams : InvokableCommand, IInvokableCommandWithParameters
+    {
+        public ICommandArgument[] Parameters => [new TextParam("Test")];
+
+        public ICommandResult InvokeWithArgs(object sender, ICommandArgument[] args)
+        {
+            if (args.Length > 0)
+            {
+                var arg = args[0];
+                var msg = $"Arg {arg.Name} = {arg.Value}";
+                var toast = new ToastStatusMessage(new StatusMessage() { Message = msg, State = MessageState.Success });
+                toast.Show();
+            }
+            else
+            {
+                var toast = new ToastStatusMessage(new StatusMessage() { Message = "didn't work homes", State = MessageState.Error });
+                toast.Show();
+            }
+
+            return CommandResult.KeepOpen();
+        }
+    }
+
+    internal sealed partial class TextParam(string name, bool required = true) : BaseObservable, ICommandArgument
+    {
+        public string Name => name;
+
+        public bool Required => required;
+
+        public ParameterType Type => ParameterType.Text;
+
+        public object? Value { get; set; }
+
+        public string DisplayName => string.Empty;
+
+        public IIconInfo? Icon => null;
+
+        public void ShowPicker(ulong hostHwnd)
+        {
+        }
+    }
 }

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/Commands/BuiltinsExtensionHost.cs

@@ -2,15 +2,7 @@
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using System.Diagnostics.CodeAnalysis;
-using System.IO.Compression;
-using System.Text.Json;
-using System.Text.Json.Nodes;
 using Microsoft.CmdPal.Common;
-using Microsoft.CmdPal.UI.ViewModels.Messages;
-using Microsoft.CommandPalette.Extensions;
-using Microsoft.CommandPalette.Extensions.Toolkit;
-using Windows.Foundation;
 
 namespace Microsoft.CmdPal.UI.ViewModels.BuiltinCommands;
 

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/Commands/LogMessagesPage.cs

@@ -3,6 +3,7 @@
 // See the LICENSE file in the project root for more information.
 
 using System.Collections.Specialized;
+using Microsoft.CmdPal.Core.ViewModels;
 using Microsoft.CommandPalette.Extensions;
 using Microsoft.CommandPalette.Extensions.Toolkit;
 
@@ -10,7 +11,7 @@ namespace Microsoft.CmdPal.UI.ViewModels.Commands;
 
 public partial class LogMessagesPage : ListPage
 {
-    private readonly List<IListItem> _listItems = new();
+    private readonly List<IListItem> _listItems = [];
 
     public LogMessagesPage()
     {
@@ -31,7 +32,6 @@ public partial class LogMessagesPage : ListPage
                     var li = new ListItem(new NoOpCommand())
                     {
                         Title = logMessageViewModel.Message,
-                        Subtitle = logMessageViewModel.ExtensionPfn,
                     };
                     _listItems.Insert(0, li);
                 }

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/Commands/MainListPage.cs

@@ -6,8 +6,8 @@ using System.Collections.Immutable;
 using System.Collections.Specialized;
 using CommunityToolkit.Mvvm.Messaging;
 using ManagedCommon;
+using Microsoft.CmdPal.Core.ViewModels.Messages;
 using Microsoft.CmdPal.Ext.Apps;
-using Microsoft.CmdPal.UI.ViewModels.Messages;
 using Microsoft.CommandPalette.Extensions;
 using Microsoft.CommandPalette.Extensions.Toolkit;
 using Microsoft.Extensions.DependencyInjection;

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/Commands/NewExtensionFormBase.cs

@@ -6,7 +6,7 @@ using System.Diagnostics.CodeAnalysis;
 using System.IO.Compression;
 using System.Text.Json;
 using System.Text.Json.Nodes;
-using Microsoft.CmdPal.UI.ViewModels.Messages;
+using Microsoft.CmdPal.Core.ViewModels.Messages;
 using Microsoft.CommandPalette.Extensions;
 using Microsoft.CommandPalette.Extensions.Toolkit;
 using Windows.Foundation;