diff --git a/NuGet.config b/NuGet.config
index c575f309fa0..0f94e3b8470 100644
--- a/NuGet.config
+++ b/NuGet.config
@@ -41,9 +41,6 @@
   -->
   <packageSourceMapping>
     <clear />
-    <packageSource key="general-testing">
-      <package pattern="microsoft.commonlanguageserverProtocol.*" />
-    </packageSource>
     <packageSource key="dotnet-core-internal-tooling">
       <package pattern="microsoft.*" />
     </packageSource>
diff --git a/eng/Version.Details.xml b/eng/Version.Details.xml
index 3d75f97f395..264d9ef9ded 100644
--- a/eng/Version.Details.xml
+++ b/eng/Version.Details.xml
@@ -23,6 +23,10 @@
       <Uri>https://github.com/dotnet/roslyn</Uri>
       <Sha>f6725f6f04ce03574fcf89faa4b20b72ef83e4dd</Sha>
     </Dependency>
+    <Dependency Name="Microsoft.CodeAnalysis.ExternalAccess.RazorCompiler" Version="4.7.0-2.23301.2">
+      <Uri>https://github.com/dotnet/roslyn</Uri>
+      <Sha>f6725f6f04ce03574fcf89faa4b20b72ef83e4dd</Sha>
+    </Dependency>
     <Dependency Name="Microsoft.CodeAnalysis.ExternalAccess.OmniSharp.CSharp" Version="4.7.0-2.23301.2">
       <Uri>https://github.com/dotnet/roslyn</Uri>
       <Sha>f6725f6f04ce03574fcf89faa4b20b72ef83e4dd</Sha>
diff --git a/eng/Versions.props b/eng/Versions.props
index 52bbe9f007d..82fafac8315 100644
--- a/eng/Versions.props
+++ b/eng/Versions.props
@@ -55,6 +55,7 @@
     <MicrosoftNetCompilersToolsetPackageVersion>4.7.0-2.23301.2</MicrosoftNetCompilersToolsetPackageVersion>
     <MicrosoftCommonLanguageServerProtocolFrameworkPackageVersion>4.7.0-2.23301.2</MicrosoftCommonLanguageServerProtocolFrameworkPackageVersion>
     <MicrosoftCodeAnalysisExternalAccessRazorPackageVersion>4.7.0-2.23301.2</MicrosoftCodeAnalysisExternalAccessRazorPackageVersion>
+    <MicrosoftCodeAnalysisExternalAccessRazorCompilerPackageVersion>4.7.0-2.23301.2</MicrosoftCodeAnalysisExternalAccessRazorCompilerPackageVersion>
     <MicrosoftCodeAnalysisExternalAccessOmniSharpCSharpPackageVersion>4.7.0-2.23301.2</MicrosoftCodeAnalysisExternalAccessOmniSharpCSharpPackageVersion>
     <MicrosoftCodeAnalysisCommonPackageVersion>4.7.0-2.23301.2</MicrosoftCodeAnalysisCommonPackageVersion>
     <MicrosoftCodeAnalysisCSharpPackageVersion>4.7.0-2.23301.2</MicrosoftCodeAnalysisCSharpPackageVersion>
diff --git a/src/Compiler/Directory.Packages.props b/src/Compiler/Directory.Packages.props
index 40aa45d5718..6da3e951670 100644
--- a/src/Compiler/Directory.Packages.props
+++ b/src/Compiler/Directory.Packages.props
@@ -11,6 +11,7 @@
     <PackageVersion Include="Microsoft.CodeAnalysis.Common" Version="$(MicrosoftCodeAnalysisCommonPackageVersion)" />
     <PackageVersion Include="Microsoft.CodeAnalysis.CSharp" Version="$(MicrosoftCodeAnalysisCSharpPackageVersion)" />
     <PackageVersion Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="$(MicrosoftCodeAnalysisCSharpWorkspacesPackageVersion)" />
+    <PackageVersion Include="Microsoft.CodeAnalysis.ExternalAccess.RazorCompiler" Version="$(MicrosoftCodeAnalysisExternalAccessRazorCompilerPackageVersion)" />
     <PackageVersion Include="Microsoft.CodeAnalysis.Workspaces.MSBuild" Version="$(MicrosoftCodeAnalysisWorkspacesMSBuildPackageVersion)" />
     <PackageVersion Include="Microsoft.CSharp" Version="$(MicrosoftCSharpVersion)" />
     <PackageVersion Include="Microsoft.Css.Parser" Version="$(MicrosoftCssParserVersion)" />
diff --git a/src/Compiler/Microsoft.NET.Sdk.Razor.SourceGenerators/Microsoft.NET.Sdk.Razor.SourceGenerators.csproj b/src/Compiler/Microsoft.NET.Sdk.Razor.SourceGenerators/Microsoft.NET.Sdk.Razor.SourceGenerators.csproj
index 682739d6978..2f041fd36fe 100644
--- a/src/Compiler/Microsoft.NET.Sdk.Razor.SourceGenerators/Microsoft.NET.Sdk.Razor.SourceGenerators.csproj
+++ b/src/Compiler/Microsoft.NET.Sdk.Razor.SourceGenerators/Microsoft.NET.Sdk.Razor.SourceGenerators.csproj
@@ -16,6 +16,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.CodeAnalysis.CSharp" />
+    <PackageReference Include="Microsoft.CodeAnalysis.ExternalAccess.RazorCompiler" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/src/Compiler/Microsoft.NET.Sdk.Razor.SourceGenerators/RazorSourceGenerationOptions.cs b/src/Compiler/Microsoft.NET.Sdk.Razor.SourceGenerators/RazorSourceGenerationOptions.cs
index 1ba18073342..354ecfac433 100644
--- a/src/Compiler/Microsoft.NET.Sdk.Razor.SourceGenerators/RazorSourceGenerationOptions.cs
+++ b/src/Compiler/Microsoft.NET.Sdk.Razor.SourceGenerators/RazorSourceGenerationOptions.cs
@@ -25,7 +25,7 @@ internal sealed class RazorSourceGenerationOptions : IEquatable<RazorSourceGener
         public LanguageVersion CSharpLanguageVersion { get; set; } = LanguageVersion.CSharp10;
 
         /// <summary>
-        /// Gets a flag that determines if localized component names should be supported.</c>.
+        /// Gets a flag that determines if localized component names should be supported.
         /// </summary>
         public bool SupportLocalizedComponentNames { get; set; } = false;
 
diff --git a/src/Compiler/Microsoft.NET.Sdk.Razor.SourceGenerators/RazorSourceGenerator.RazorProviders.cs b/src/Compiler/Microsoft.NET.Sdk.Razor.SourceGenerators/RazorSourceGenerator.RazorProviders.cs
index 4fa23ad802d..8c4fa6479ac 100644
--- a/src/Compiler/Microsoft.NET.Sdk.Razor.SourceGenerators/RazorSourceGenerator.RazorProviders.cs
+++ b/src/Compiler/Microsoft.NET.Sdk.Razor.SourceGenerators/RazorSourceGenerator.RazorProviders.cs
@@ -28,6 +28,12 @@ private static bool GetSuppressionStatus(AnalyzerConfigOptionsProvider optionsPr
                 && suppressRazorSourceGenerator == "true";
         }
 
+        private static bool GetHostOutputsEnabledStatus(AnalyzerConfigOptionsProvider optionsProvider, CancellationToken _)
+        {
+            return optionsProvider.GlobalOptions.TryGetValue("build_property.EnableRazorHostOutputs", out var enableRazorHostOutputs)
+                && enableRazorHostOutputs == "true";
+        }
+
         private static (RazorSourceGenerationOptions?, Diagnostic?) ComputeRazorSourceGeneratorOptions((AnalyzerConfigOptionsProvider, ParseOptions) pair, CancellationToken ct)
         {
             Log.ComputeRazorSourceGeneratorOptions();
diff --git a/src/Compiler/Microsoft.NET.Sdk.Razor.SourceGenerators/RazorSourceGenerator.cs b/src/Compiler/Microsoft.NET.Sdk.Razor.SourceGenerators/RazorSourceGenerator.cs
index 4fd80d7e3b6..f555839bcf0 100644
--- a/src/Compiler/Microsoft.NET.Sdk.Razor.SourceGenerators/RazorSourceGenerator.cs
+++ b/src/Compiler/Microsoft.NET.Sdk.Razor.SourceGenerators/RazorSourceGenerator.cs
@@ -9,6 +9,7 @@
 using Microsoft.AspNetCore.Razor.Language;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.ExternalAccess.RazorCompiler;
 
 namespace Microsoft.NET.Sdk.Razor.SourceGenerators
 {
@@ -24,11 +25,11 @@ public void Initialize(IncrementalGeneratorInitializationContext context)
             var compilation = context.CompilationProvider;
 
             // determine if we should suppress this run and filter out all the additional files if so
-            var isGeneratorSuppressed = context.AnalyzerConfigOptionsProvider.Select(GetSuppressionStatus);
+            var isGeneratorSuppressed = analyzerConfigOptions.Select(GetSuppressionStatus);
             var additionalTexts = context.AdditionalTextsProvider
-                 .Combine(isGeneratorSuppressed)
-                 .Where(pair => !pair.Right)
-                 .Select((pair, _) => pair.Left);
+                .Combine(isGeneratorSuppressed)
+                .Where(pair => !pair.Right)
+                .Select((pair, _) => pair.Left);
 
             var razorSourceGeneratorOptions = analyzerConfigOptions
                 .Combine(parseOptions)
@@ -68,7 +69,6 @@ public void Initialize(IncrementalGeneratorInitializationContext context)
                 .Combine(razorSourceGeneratorOptions)
                 .Select(static (pair, _) =>
                 {
-
                     var ((sourceItem, importFiles), razorSourceGeneratorOptions) = pair;
                     RazorSourceGeneratorEventSource.Log.GenerateDeclarationCodeStart(sourceItem.FilePath);
 
@@ -204,26 +204,39 @@ public void Initialize(IncrementalGeneratorInitializationContext context)
                     return allTagHelpers;
                 });
 
-            var generatedOutput = sourceItems
+            var withOptions = sourceItems
                 .Combine(importFiles.Collect())
                 .Combine(allTagHelpers)
-                .Combine(razorSourceGeneratorOptions)
-                .Select(static (pair, _) =>
+                .Combine(razorSourceGeneratorOptions);
+
+            var withOptionsDesignTime = withOptions
+                .Combine(analyzerConfigOptions.Select(GetHostOutputsEnabledStatus))
+                .Where(pair => pair.Right)
+                .Select((pair, _) => pair.Left);
+
+            IncrementalValuesProvider<(string, RazorCodeDocument)> processed(bool designTime) => (designTime ? withOptionsDesignTime : withOptions)
+                .Select((pair, _) =>
                 {
                     var (((sourceItem, imports), allTagHelpers), razorSourceGeneratorOptions) = pair;
 
-                    RazorSourceGeneratorEventSource.Log.RazorCodeGenerateStart(sourceItem.FilePath);
-
-                    // Add a generated suffix so tools, such as coverlet, consider the file to be generated
-                    var hintName = GetIdentifierFromPath(sourceItem.RelativePhysicalPath) + ".g.cs";
+                    var kind = designTime ? "DesignTime" : "Runtime";
+                    RazorSourceGeneratorEventSource.Log.RazorCodeGenerateStart(sourceItem.FilePath, kind);
 
                     var projectEngine = GetGenerationProjectEngine(allTagHelpers, sourceItem, imports, razorSourceGeneratorOptions);
 
-                    var codeDocument = projectEngine.Process(sourceItem);
-                    var csharpDocument = codeDocument.GetCSharpDocument();
+                    var codeDocument = designTime
+                        ? projectEngine.ProcessDesignTime(sourceItem)
+                        : projectEngine.Process(sourceItem);
+
+                    RazorSourceGeneratorEventSource.Log.RazorCodeGenerateStop(sourceItem.FilePath, kind);
+                    return (filePath: sourceItem.RelativePhysicalPath, codeDocument);
+                });
 
-                    RazorSourceGeneratorEventSource.Log.RazorCodeGenerateStop(sourceItem.FilePath);
-                    return (hintName, csharpDocument);
+            var csharpDocuments = processed(designTime: false)
+                .Select(static (pair, _) =>
+                {
+                    var (filePath, document) = pair;
+                    return (filePath, csharpDocument: document.GetCSharpDocument());
                 })
                 .WithLambdaComparer(static (a, b) =>
                 {
@@ -236,9 +249,13 @@ public void Initialize(IncrementalGeneratorInitializationContext context)
                     return string.Equals(a.csharpDocument.GeneratedCode, b.csharpDocument.GeneratedCode, StringComparison.Ordinal);
                 }, static a => StringComparer.Ordinal.GetHashCode(a.csharpDocument));
 
-            context.RegisterSourceOutput(generatedOutput, static (context, pair) =>
+            context.RegisterImplementationSourceOutput(csharpDocuments, static (context, pair) =>
             {
-                var (hintName, csharpDocument) = pair;
+                var (filePath, csharpDocument) = pair;
+
+                // Add a generated suffix so tools, such as coverlet, consider the file to be generated
+                var hintName = GetIdentifierFromPath(filePath) + ".g.cs";
+
                 RazorSourceGeneratorEventSource.Log.AddSyntaxTrees(hintName);
                 for (var i = 0; i < csharpDocument.Diagnostics.Count; i++)
                 {
@@ -249,6 +266,14 @@ public void Initialize(IncrementalGeneratorInitializationContext context)
 
                 context.AddSource(hintName, csharpDocument.GeneratedCode);
             });
+
+            context.RegisterHostOutput(processed(designTime: true), static (context, pair, _) =>
+            {
+                var (filePath, document) = pair;
+                var hintName = GetIdentifierFromPath(filePath);
+                context.AddOutput(hintName + ".rsg.cs", document.GetCSharpDocument().GeneratedCode);
+                context.AddOutput(hintName + ".rsg.html", document.GetHtmlDocument().GeneratedCode);
+            });
         }
     }
 }
diff --git a/src/Compiler/Microsoft.NET.Sdk.Razor.SourceGenerators/RazorSourceGeneratorEventSource.cs b/src/Compiler/Microsoft.NET.Sdk.Razor.SourceGenerators/RazorSourceGeneratorEventSource.cs
index 758d0069b8b..8ef7ac0f98a 100644
--- a/src/Compiler/Microsoft.NET.Sdk.Razor.SourceGenerators/RazorSourceGeneratorEventSource.cs
+++ b/src/Compiler/Microsoft.NET.Sdk.Razor.SourceGenerators/RazorSourceGeneratorEventSource.cs
@@ -42,11 +42,11 @@ private RazorSourceGeneratorEventSource() { }
 
         private const int RazorCodeGenerateStartId = 10;
         [Event(RazorCodeGenerateStartId, Level = EventLevel.Informational)]
-        public void RazorCodeGenerateStart(string file) => WriteEvent(RazorCodeGenerateStartId, file);
+        public void RazorCodeGenerateStart(string file, string kind) => WriteEvent(RazorCodeGenerateStartId, file, kind);
 
         private const int RazorCodeGenerateStopId = 11;
         [Event(RazorCodeGenerateStopId, Level = EventLevel.Informational)]
-        public void RazorCodeGenerateStop(string file) => WriteEvent(RazorCodeGenerateStopId, file);
+        public void RazorCodeGenerateStop(string file, string kind) => WriteEvent(RazorCodeGenerateStopId, file, kind);
 
         private const int AddSyntaxTreesId = 12;
         [Event(AddSyntaxTreesId, Level = EventLevel.Informational)]
diff --git a/src/Compiler/test/Microsoft.NET.Sdk.Razor.SourceGenerators.Tests/RazorSourceGeneratorTests.cs b/src/Compiler/test/Microsoft.NET.Sdk.Razor.SourceGenerators.Tests/RazorSourceGeneratorTests.cs
index ac3400bba12..b98a89d8fde 100644
--- a/src/Compiler/test/Microsoft.NET.Sdk.Razor.SourceGenerators.Tests/RazorSourceGeneratorTests.cs
+++ b/src/Compiler/test/Microsoft.NET.Sdk.Razor.SourceGenerators.Tests/RazorSourceGeneratorTests.cs
@@ -97,6 +97,99 @@ public class MyModel { }
             Assert.Equal(2, result.GeneratedSources.Length);
         }
 
+        [Fact]
+        public async Task SourceGenerator_RazorFiles_DesignTime()
+        {
+            // Arrange
+            var project = CreateTestProject(new()
+            {
+                ["Pages/Index.razor"] = "<h1>Hello world</h1>",
+            });
+
+            var compilation = await project.GetCompilationAsync();
+            var (driver, additionalTexts, optionsProvider) = await GetDriverWithAdditionalTextAndProviderAsync(project, hostOutputs: true);
+
+            // Enable design-time.
+            var options = optionsProvider.Clone();
+            options.TestGlobalOptions["build_property.RazorDesignTime"] = "true";
+            options.TestGlobalOptions["build_property.EnableRazorHostOutputs"] = "true";
+            var driver2 = driver.WithUpdatedAnalyzerConfigOptions(options);
+
+            var result = RunGenerator(compilation!, ref driver2);
+
+            var pageOutput =
+@"#pragma checksum ""Pages/Index.razor"" ""{ff1816ec-aa5e-4d10-87f7-6f4963833460}"" ""6b5db227a6aa2228c777b0771108b184b1fc5df3""
+// <auto-generated/>
+#pragma warning disable 1591
+namespace MyApp.Pages
+{
+    #line hidden
+    using global::System;
+    using global::System.Collections.Generic;
+    using global::System.Linq;
+    using global::System.Threading.Tasks;
+    using global::Microsoft.AspNetCore.Components;
+    public partial class Index : global::Microsoft.AspNetCore.Components.ComponentBase
+    {
+        #pragma warning disable 1998
+        protected override void BuildRenderTree(global::Microsoft.AspNetCore.Components.Rendering.RenderTreeBuilder __builder)
+        {
+            __builder.AddMarkupContent(0, ""<h1>Hello world</h1>"");
+        }
+        #pragma warning restore 1998
+    }
+}
+#pragma warning restore 1591
+";
+            result.VerifyPageOutput(pageOutput);
+
+            result.VerifyHostOutput(
+                (@"Pages_Index_razor.rsg.cs", @"// <auto-generated/>
+#pragma warning disable 1591
+namespace MyApp.Pages
+{
+    #line hidden
+    using global::System;
+    using global::System.Collections.Generic;
+    using global::System.Linq;
+    using global::System.Threading.Tasks;
+    using global::Microsoft.AspNetCore.Components;
+    public partial class Index : global::Microsoft.AspNetCore.Components.ComponentBase
+    {
+        #pragma warning disable 219
+        private void __RazorDirectiveTokenHelpers__() {
+        }
+        #pragma warning restore 219
+        #pragma warning disable 0414
+        private static object __o = null;
+        #pragma warning restore 0414
+        #pragma warning disable 1998
+        protected override void BuildRenderTree(global::Microsoft.AspNetCore.Components.Rendering.RenderTreeBuilder __builder)
+        {
+        }
+        #pragma warning restore 1998
+    }
+}
+#pragma warning restore 1591
+"),
+                (@"Pages_Index_razor.rsg.html", @"<h1>Hello world</h1>"));
+
+            Assert.Empty(result.Diagnostics);
+            Assert.Single(result.GeneratedSources);
+
+            // Enable design-time without host outputs.
+            options = optionsProvider.Clone();
+            options.TestGlobalOptions["build_property.RazorDesignTime"] = "true";
+            driver2 = driver.WithUpdatedAnalyzerConfigOptions(options);
+
+            result = RunGenerator(compilation!, ref driver2);
+            result.VerifyPageOutput(pageOutput);
+            result.VerifyHostOutput();
+
+            Assert.Empty(result.Diagnostics);
+            Assert.Single(result.GeneratedSources);
+        }
+
         [Fact]
         public async Task SourceGeneratorEvents_RazorFiles_Works()
         {
@@ -164,70 +257,21 @@ protected override void BuildRenderTree(global::Microsoft.AspNetCore.Components.
 
             Assert.Collection(eventListener.Events,
                 e => Assert.Equal("ComputeRazorSourceGeneratorOptions", e.EventName),
-                e =>
-                {
-                    Assert.Equal("GenerateDeclarationCodeStart", e.EventName);
-                    var file = Assert.Single(e.Payload);
-                    Assert.Equal("/Pages/Index.razor", file);
-                },
-                e =>
-                {
-                    Assert.Equal("GenerateDeclarationCodeStop", e.EventName);
-                    var file = Assert.Single(e.Payload);
-                    Assert.Equal("/Pages/Index.razor", file);
-                },
-                e =>
-                {
-                    Assert.Equal("GenerateDeclarationCodeStart", e.EventName);
-                    var file = Assert.Single(e.Payload);
-                    Assert.Equal("/Pages/Counter.razor", file);
-                },
-                e =>
-                {
-                    Assert.Equal("GenerateDeclarationCodeStop", e.EventName);
-                    var file = Assert.Single(e.Payload);
-                    Assert.Equal("/Pages/Counter.razor", file);
-                },
+                e => e.AssertSingleItem("GenerateDeclarationCodeStart", "/Pages/Index.razor"),
+                e => e.AssertSingleItem("GenerateDeclarationCodeStop", "/Pages/Index.razor"),
+                e => e.AssertSingleItem("GenerateDeclarationCodeStart", "/Pages/Counter.razor"),
+                e => e.AssertSingleItem("GenerateDeclarationCodeStop", "/Pages/Counter.razor"),
                 e => Assert.Equal("DiscoverTagHelpersFromCompilationStart", e.EventName),
                 e => Assert.Equal("DiscoverTagHelpersFromCompilationStop", e.EventName),
                 e => Assert.Equal("DiscoverTagHelpersFromReferencesStart", e.EventName),
                 e => Assert.Equal("DiscoverTagHelpersFromReferencesStop", e.EventName),
-                e =>
-                {
-                    Assert.Equal("RazorCodeGenerateStart", e.EventName);
-                    var file = Assert.Single(e.Payload);
-                    Assert.Equal("/Pages/Index.razor", file);
-                },
-                e =>
-                {
-                    Assert.Equal("RazorCodeGenerateStop", e.EventName);
-                    var file = Assert.Single(e.Payload);
-                    Assert.Equal("/Pages/Index.razor", file);
-                },
-                e =>
-                {
-                    Assert.Equal("RazorCodeGenerateStart", e.EventName);
-                    var file = Assert.Single(e.Payload);
-                    Assert.Equal("/Pages/Counter.razor", file);
-                },
-                e =>
-                {
-                    Assert.Equal("RazorCodeGenerateStop", e.EventName);
-                    var file = Assert.Single(e.Payload);
-                    Assert.Equal("/Pages/Counter.razor", file);
-                },
-                e =>
-                {
-                    Assert.Equal("AddSyntaxTrees", e.EventName);
-                    var file = Assert.Single(e.Payload);
-                    Assert.Equal("Pages_Index_razor.g.cs", file);
-                },
-                e =>
-                {
-                    Assert.Equal("AddSyntaxTrees", e.EventName);
-                    var file = Assert.Single(e.Payload);
-                    Assert.Equal("Pages_Counter_razor.g.cs", file);
-                });
+                e => e.AssertPair("RazorCodeGenerateStart", "/Pages/Index.razor", "Runtime"),
+                e => e.AssertPair("RazorCodeGenerateStop", "/Pages/Index.razor", "Runtime"),
+                e => e.AssertPair("RazorCodeGenerateStart", "/Pages/Counter.razor", "Runtime"),
+                e => e.AssertPair("RazorCodeGenerateStop", "/Pages/Counter.razor", "Runtime"),
+                e => e.AssertSingleItem("AddSyntaxTrees", "Pages_Index_razor.g.cs"),
+                e => e.AssertSingleItem("AddSyntaxTrees", "Pages_Counter_razor.g.cs")
+            );
         }
 
         [Fact]
@@ -413,36 +457,12 @@ protected override void BuildRenderTree(global::Microsoft.AspNetCore.Components.
             Assert.Equal(2, result.GeneratedSources.Length);
 
             Assert.Collection(eventListener.Events,
-               e =>
-               {
-                   Assert.Equal("GenerateDeclarationCodeStart", e.EventName);
-                   var file = Assert.Single(e.Payload);
-                   Assert.Equal("/Pages/Counter.razor", file);
-               },
-               e =>
-               {
-                   Assert.Equal("GenerateDeclarationCodeStop", e.EventName);
-                   var file = Assert.Single(e.Payload);
-                   Assert.Equal("/Pages/Counter.razor", file);
-               },
-               e =>
-               {
-                   Assert.Equal("RazorCodeGenerateStart", e.EventName);
-                   var file = Assert.Single(e.Payload);
-                   Assert.Equal("/Pages/Counter.razor", file);
-               },
-               e =>
-               {
-                   Assert.Equal("RazorCodeGenerateStop", e.EventName);
-                   var file = Assert.Single(e.Payload);
-                   Assert.Equal("/Pages/Counter.razor", file);
-               },
-               e =>
-               {
-                   Assert.Equal("AddSyntaxTrees", e.EventName);
-                   var file = Assert.Single(e.Payload);
-                   Assert.Equal("Pages_Counter_razor.g.cs", file);
-               });
+               e => e.AssertSingleItem("GenerateDeclarationCodeStart", "/Pages/Counter.razor"),
+               e => e.AssertSingleItem("GenerateDeclarationCodeStop", "/Pages/Counter.razor"),
+               e => e.AssertPair("RazorCodeGenerateStart", "/Pages/Counter.razor", "Runtime"),
+               e => e.AssertPair("RazorCodeGenerateStop", "/Pages/Counter.razor", "Runtime"),
+               e => e.AssertSingleItem("AddSyntaxTrees", "Pages_Counter_razor.g.cs")
+            );
         }
 
         [Fact]
@@ -787,38 +807,14 @@ protected override void BuildRenderTree(global::Microsoft.AspNetCore.Components.
             Assert.Equal(2, result.GeneratedSources.Length);
 
             Assert.Collection(eventListener.Events,
-               e =>
-               {
-                   Assert.Equal("GenerateDeclarationCodeStart", e.EventName);
-                   var file = Assert.Single(e.Payload);
-                   Assert.Equal("/Pages/Counter.razor", file);
-               },
-               e =>
-               {
-                   Assert.Equal("GenerateDeclarationCodeStop", e.EventName);
-                   var file = Assert.Single(e.Payload);
-                   Assert.Equal("/Pages/Counter.razor", file);
-               },
+               e => e.AssertSingleItem("GenerateDeclarationCodeStart", "/Pages/Counter.razor"),
+               e => e.AssertSingleItem("GenerateDeclarationCodeStop", "/Pages/Counter.razor"),
                e => Assert.Equal("DiscoverTagHelpersFromCompilationStart", e.EventName),
                e => Assert.Equal("DiscoverTagHelpersFromCompilationStop", e.EventName),
-               e =>
-               {
-                   Assert.Equal("RazorCodeGenerateStart", e.EventName);
-                   var file = Assert.Single(e.Payload);
-                   Assert.Equal("/Pages/Counter.razor", file);
-               },
-               e =>
-               {
-                   Assert.Equal("RazorCodeGenerateStop", e.EventName);
-                   var file = Assert.Single(e.Payload);
-                   Assert.Equal("/Pages/Counter.razor", file);
-               },
-               e =>
-               {
-                   Assert.Equal("AddSyntaxTrees", e.EventName);
-                   var file = Assert.Single(e.Payload);
-                   Assert.Equal("Pages_Counter_razor.g.cs", file);
-               });
+               e => e.AssertPair("RazorCodeGenerateStart", "/Pages/Counter.razor", "Runtime"),
+               e => e.AssertPair("RazorCodeGenerateStop", "/Pages/Counter.razor", "Runtime"),
+               e => e.AssertSingleItem("AddSyntaxTrees", "Pages_Counter_razor.g.cs")
+            );
         }
 
         [Fact]
@@ -967,50 +963,16 @@ protected override void BuildRenderTree(global::Microsoft.AspNetCore.Components.
             Assert.Equal(2, result.GeneratedSources.Length);
 
             Assert.Collection(eventListener.Events,
-               e =>
-               {
-                   Assert.Equal("GenerateDeclarationCodeStart", e.EventName);
-                   var file = Assert.Single(e.Payload);
-                   Assert.Equal("/Pages/Counter.razor", file);
-               },
-               e =>
-               {
-                   Assert.Equal("GenerateDeclarationCodeStop", e.EventName);
-                   var file = Assert.Single(e.Payload);
-                   Assert.Equal("/Pages/Counter.razor", file);
-               },
+               e => e.AssertSingleItem("GenerateDeclarationCodeStart", "/Pages/Counter.razor"),
+               e => e.AssertSingleItem("GenerateDeclarationCodeStop", "/Pages/Counter.razor"),
                e => Assert.Equal("DiscoverTagHelpersFromCompilationStart", e.EventName),
                e => Assert.Equal("DiscoverTagHelpersFromCompilationStop", e.EventName),
-               e =>
-               {
-                   Assert.Equal("RazorCodeGenerateStart", e.EventName);
-                   var file = Assert.Single(e.Payload);
-                   Assert.Equal("/Pages/Index.razor", file);
-               },
-               e =>
-               {
-                   Assert.Equal("RazorCodeGenerateStop", e.EventName);
-                   var file = Assert.Single(e.Payload);
-                   Assert.Equal("/Pages/Index.razor", file);
-               },
-               e =>
-               {
-                   Assert.Equal("RazorCodeGenerateStart", e.EventName);
-                   var file = Assert.Single(e.Payload);
-                   Assert.Equal("/Pages/Counter.razor", file);
-               },
-               e =>
-               {
-                   Assert.Equal("RazorCodeGenerateStop", e.EventName);
-                   var file = Assert.Single(e.Payload);
-                   Assert.Equal("/Pages/Counter.razor", file);
-               },
-               e =>
-               {
-                   Assert.Equal("AddSyntaxTrees", e.EventName);
-                   var file = Assert.Single(e.Payload);
-                   Assert.Equal("Pages_Counter_razor.g.cs", file);
-               });
+               e => e.AssertPair("RazorCodeGenerateStart", "/Pages/Index.razor", "Runtime"),
+               e => e.AssertPair("RazorCodeGenerateStop", "/Pages/Index.razor", "Runtime"),
+               e => e.AssertPair("RazorCodeGenerateStart", "/Pages/Counter.razor", "Runtime"),
+               e => e.AssertPair("RazorCodeGenerateStop", "/Pages/Counter.razor", "Runtime"),
+               e => e.AssertSingleItem("AddSyntaxTrees", "Pages_Counter_razor.g.cs")
+            );
         }
 
         [Fact]
@@ -1145,36 +1107,12 @@ protected override void BuildRenderTree(global::Microsoft.AspNetCore.Components.
                e => Assert.Equal("DiscoverTagHelpersFromCompilationStop", e.EventName),
                e => Assert.Equal("DiscoverTagHelpersFromReferencesStart", e.EventName),
                e => Assert.Equal("DiscoverTagHelpersFromReferencesStop", e.EventName),
-               e =>
-               {
-                   Assert.Equal("RazorCodeGenerateStart", e.EventName);
-                   var file = Assert.Single(e.Payload);
-                   Assert.Equal("/Pages/Index.razor", file);
-               },
-               e =>
-               {
-                   Assert.Equal("RazorCodeGenerateStop", e.EventName);
-                   var file = Assert.Single(e.Payload);
-                   Assert.Equal("/Pages/Index.razor", file);
-               },
-               e =>
-               {
-                   Assert.Equal("RazorCodeGenerateStart", e.EventName);
-                   var file = Assert.Single(e.Payload);
-                   Assert.Equal("/Pages/Counter.razor", file);
-               },
-               e =>
-               {
-                   Assert.Equal("RazorCodeGenerateStop", e.EventName);
-                   var file = Assert.Single(e.Payload);
-                   Assert.Equal("/Pages/Counter.razor", file);
-               },
-               e =>
-               {
-                   Assert.Equal("AddSyntaxTrees", e.EventName);
-                   var file = Assert.Single(e.Payload);
-                   Assert.Equal("Pages_Index_razor.g.cs", file);
-               });
+               e => e.AssertPair("RazorCodeGenerateStart", "/Pages/Index.razor", "Runtime"),
+               e => e.AssertPair("RazorCodeGenerateStop", "/Pages/Index.razor", "Runtime"),
+               e => e.AssertPair("RazorCodeGenerateStart", "/Pages/Counter.razor", "Runtime"),
+               e => e.AssertPair("RazorCodeGenerateStop", "/Pages/Counter.razor", "Runtime"),
+               e => e.AssertSingleItem("AddSyntaxTrees", "Pages_Index_razor.g.cs")
+            );
 
             // Verify caching
             eventListener.Events.Clear();
@@ -1330,42 +1268,13 @@ internal sealed class Views_Shared__Layout : global::Microsoft.AspNetCore.Mvc.Ra
                 e => Assert.Equal("DiscoverTagHelpersFromCompilationStop", e.EventName),
                 e => Assert.Equal("DiscoverTagHelpersFromReferencesStart", e.EventName),
                 e => Assert.Equal("DiscoverTagHelpersFromReferencesStop", e.EventName),
-                e =>
-                {
-                    Assert.Equal("RazorCodeGenerateStart", e.EventName);
-                    var file = Assert.Single(e.Payload);
-                    Assert.Equal("/Pages/Index.cshtml", file);
-                },
-                e =>
-                {
-                    Assert.Equal("RazorCodeGenerateStop", e.EventName);
-                    var file = Assert.Single(e.Payload);
-                    Assert.Equal("/Pages/Index.cshtml", file);
-                },
-                e =>
-                {
-                    Assert.Equal("RazorCodeGenerateStart", e.EventName);
-                    var file = Assert.Single(e.Payload);
-                    Assert.Equal("/Views/Shared/_Layout.cshtml", file);
-                },
-                e =>
-                {
-                    Assert.Equal("RazorCodeGenerateStop", e.EventName);
-                    var file = Assert.Single(e.Payload);
-                    Assert.Equal("/Views/Shared/_Layout.cshtml", file);
-                },
-                e =>
-                {
-                    Assert.Equal("AddSyntaxTrees", e.EventName);
-                    var file = Assert.Single(e.Payload);
-                    Assert.Equal("Pages_Index_cshtml.g.cs", file);
-                },
-                e =>
-                {
-                    Assert.Equal("AddSyntaxTrees", e.EventName);
-                    var file = Assert.Single(e.Payload);
-                    Assert.Equal("Views_Shared__Layout_cshtml.g.cs", file);
-                });
+                e => e.AssertPair("RazorCodeGenerateStart", "/Pages/Index.cshtml", "Runtime"),
+                e => e.AssertPair("RazorCodeGenerateStop", "/Pages/Index.cshtml", "Runtime"),
+                e => e.AssertPair("RazorCodeGenerateStart", "/Views/Shared/_Layout.cshtml", "Runtime"),
+                e => e.AssertPair("RazorCodeGenerateStop", "/Views/Shared/_Layout.cshtml", "Runtime"),
+                e => e.AssertSingleItem("AddSyntaxTrees", "Pages_Index_cshtml.g.cs"),
+                e => e.AssertSingleItem("AddSyntaxTrees", "Views_Shared__Layout_cshtml.g.cs")
+            );
         }
 
         [Fact, WorkItem("https://github.com/dotnet/razor/issues/7049")]
@@ -1693,24 +1602,10 @@ internal sealed class Views_Shared__Layout : global::Microsoft.AspNetCore.Mvc.Ra
             Assert.Equal(2, result.GeneratedSources.Length);
 
             Assert.Collection(eventListener.Events,
-               e =>
-               {
-                   Assert.Equal("RazorCodeGenerateStart", e.EventName);
-                   var file = Assert.Single(e.Payload);
-                   Assert.Equal("/Views/Shared/_Layout.cshtml", file);
-               },
-                e =>
-                {
-                    Assert.Equal("RazorCodeGenerateStop", e.EventName);
-                    var file = Assert.Single(e.Payload);
-                    Assert.Equal("/Views/Shared/_Layout.cshtml", file);
-                },
-                e =>
-                {
-                    Assert.Equal("AddSyntaxTrees", e.EventName);
-                    var file = Assert.Single(e.Payload);
-                    Assert.Equal("Views_Shared__Layout_cshtml.g.cs", file);
-                });
+               e => e.AssertPair("RazorCodeGenerateStart", "/Views/Shared/_Layout.cshtml", "Runtime"),
+               e => e.AssertPair("RazorCodeGenerateStop", "/Views/Shared/_Layout.cshtml", "Runtime"),
+               e => e.AssertSingleItem("AddSyntaxTrees", "Views_Shared__Layout_cshtml.g.cs")
+            );
         }
 
         [Fact]
@@ -2028,36 +1923,12 @@ public override void Process(TagHelperContext context, TagHelperOutput output)
             Assert.Collection(eventListener.Events,
                e => Assert.Equal("DiscoverTagHelpersFromCompilationStart", e.EventName),
                e => Assert.Equal("DiscoverTagHelpersFromCompilationStop", e.EventName),
-               e =>
-               {
-                   Assert.Equal("RazorCodeGenerateStart", e.EventName);
-                   var file = Assert.Single(e.Payload);
-                   Assert.Equal("/Pages/Index.cshtml", file);
-               },
-                e =>
-                {
-                    Assert.Equal("RazorCodeGenerateStop", e.EventName);
-                    var file = Assert.Single(e.Payload);
-                    Assert.Equal("/Pages/Index.cshtml", file);
-                },
-               e =>
-               {
-                   Assert.Equal("RazorCodeGenerateStart", e.EventName);
-                   var file = Assert.Single(e.Payload);
-                   Assert.Equal("/Views/Shared/_Layout.cshtml", file);
-               },
-                e =>
-                {
-                    Assert.Equal("RazorCodeGenerateStop", e.EventName);
-                    var file = Assert.Single(e.Payload);
-                    Assert.Equal("/Views/Shared/_Layout.cshtml", file);
-                },
-                e =>
-                {
-                    Assert.Equal("AddSyntaxTrees", e.EventName);
-                    var file = Assert.Single(e.Payload);
-                    Assert.Equal("Pages_Index_cshtml.g.cs", file);
-                });
+               e => e.AssertPair("RazorCodeGenerateStart", "/Pages/Index.cshtml", "Runtime"),
+               e => e.AssertPair("RazorCodeGenerateStop", "/Pages/Index.cshtml", "Runtime"),
+               e => e.AssertPair("RazorCodeGenerateStart", "/Views/Shared/_Layout.cshtml", "Runtime"),
+               e => e.AssertPair("RazorCodeGenerateStop", "/Views/Shared/_Layout.cshtml", "Runtime"),
+               e => e.AssertSingleItem("AddSyntaxTrees", "Pages_Index_cshtml.g.cs")
+           );
         }
 
         [Fact]
diff --git a/src/Compiler/test/Microsoft.NET.Sdk.Razor.SourceGenerators.Tests/RazorSourceGeneratorTestsBase.cs b/src/Compiler/test/Microsoft.NET.Sdk.Razor.SourceGenerators.Tests/RazorSourceGeneratorTestsBase.cs
index 496ab7c613a..1c4da81ea38 100644
--- a/src/Compiler/test/Microsoft.NET.Sdk.Razor.SourceGenerators.Tests/RazorSourceGeneratorTestsBase.cs
+++ b/src/Compiler/test/Microsoft.NET.Sdk.Razor.SourceGenerators.Tests/RazorSourceGeneratorTestsBase.cs
@@ -30,6 +30,7 @@
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis.Diagnostics;
+using Microsoft.CodeAnalysis.ExternalAccess.RazorCompiler;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.DependencyModel;
 using Microsoft.Extensions.DependencyModel.Resolution;
@@ -56,10 +57,11 @@ protected static async ValueTask<GeneratorDriver> GetDriverAsync(Project project
         return (result.Item1, result.Item2);
     }
 
-    protected static async ValueTask<(GeneratorDriver, ImmutableArray<AdditionalText>, TestAnalyzerConfigOptionsProvider)> GetDriverWithAdditionalTextAndProviderAsync(Project project, Action<TestAnalyzerConfigOptionsProvider>? configureGlobalOptions = null)
+    protected static async ValueTask<(GeneratorDriver, ImmutableArray<AdditionalText>, TestAnalyzerConfigOptionsProvider)> GetDriverWithAdditionalTextAndProviderAsync(Project project, Action<TestAnalyzerConfigOptionsProvider>? configureGlobalOptions = null, bool hostOutputs = false)
     {
         var razorSourceGenerator = new RazorSourceGenerator().AsSourceGenerator();
-        var driver = (GeneratorDriver)CSharpGeneratorDriver.Create(new[] { razorSourceGenerator }, parseOptions: (CSharpParseOptions)project.ParseOptions!, driverOptions: new GeneratorDriverOptions(IncrementalGeneratorOutputKind.None, true));
+        var disabledOutputs = hostOutputs ? IncrementalGeneratorOutputKind.None : (IncrementalGeneratorOutputKind)0b100000;
+        var driver = (GeneratorDriver)CSharpGeneratorDriver.Create(new[] { razorSourceGenerator }, parseOptions: (CSharpParseOptions)project.ParseOptions!, driverOptions: new GeneratorDriverOptions(disabledOutputs, true));
 
         var optionsProvider = new TestAnalyzerConfigOptionsProvider();
         optionsProvider.TestGlobalOptions["build_property.RazorConfiguration"] = "Default";
@@ -409,7 +411,7 @@ public static GeneratorRunResult VerifyPageOutput(this GeneratorRunResult result
     {
         if (expectedOutput.Length == 1 && string.IsNullOrWhiteSpace(expectedOutput[0]))
         {
-            Assert.True(false, GenerateExpectedOutput(result));
+            Assert.True(false, GenerateExpectedPageOutput(result));
         }
         else
         {
@@ -424,6 +426,29 @@ public static GeneratorRunResult VerifyPageOutput(this GeneratorRunResult result
         return result;
     }
 
+    public static GeneratorRunResult VerifyHostOutput(this GeneratorRunResult result, params (string hintName, string text)[] expectedOutputs)
+    {
+        if (expectedOutputs.Length == 1 && string.IsNullOrWhiteSpace(expectedOutputs[0].text))
+        {
+            Assert.True(false, GenerateExpectedHostOutput(result));
+        }
+        else
+        {
+            var hostOutputs = result.GetHostOutputs();
+            Assert.Equal(expectedOutputs.Length, hostOutputs.Length);
+            for (int i = 0; i < hostOutputs.Length; i++)
+            {
+                var expectedOutput = expectedOutputs[i];
+                var actualOutput = hostOutputs[i];
+
+                Assert.Equal(expectedOutput.hintName, actualOutput.Key);
+                Assert.Equal(expectedOutput.text, actualOutput.Value, ignoreWhiteSpaceDifferences: true);
+            }
+        }
+
+        return result;
+    }
+    
     private static string CreateBaselineDirectory(string testPath, string testName)
     {
         var baselineDirectory = Path.Join(
@@ -490,9 +515,9 @@ private static void DeleteUnusedBaselines(string baselineDirectory, HashSet<stri
         }
     }
 
-    private static string GenerateExpectedOutput(GeneratorRunResult result)
+    private static string GenerateExpectedPageOutput(GeneratorRunResult result)
     {
-        StringBuilder sb = new StringBuilder("Generated Output:").AppendLine().AppendLine();
+        StringBuilder sb = new StringBuilder("Generated Page Output:").AppendLine().AppendLine();
         for (int i = 0; i < result.GeneratedSources.Length; i++)
         {
             if (i > 0)
@@ -504,6 +529,22 @@ private static string GenerateExpectedOutput(GeneratorRunResult result)
         return sb.ToString();
     }
 
+    private static string GenerateExpectedHostOutput(GeneratorRunResult result)
+    {
+        StringBuilder sb = new StringBuilder("Generated Host Output:").AppendLine().AppendLine();
+        var hostOutputs = result.GetHostOutputs();
+        for (int i = 0; i < hostOutputs.Length; i++)
+        {
+            if (i > 0)
+            {
+                sb.AppendLine(",");
+            }
+            sb.Append("(@\"").Append(hostOutputs[i].Key.Replace("\"", "\"\"")).Append("\", ");
+            sb.Append("@\"").Append(hostOutputs[i].Value.Replace("\"", "\"\"")).Append("\")");
+        }
+        return sb.ToString();
+    }
+
     public static GeneratorRunResult VerifyOutputsMatch(this GeneratorRunResult actual, GeneratorRunResult expected, params (int index, string replacement)[] diffs)
     {
         Assert.Equal(actual.GeneratedSources.Length, expected.GeneratedSources.Length);
@@ -532,4 +573,19 @@ private static string TrimChecksum(string text)
         Assert.StartsWith("#pragma", trimmed);
         return trimmed.Substring(trimmed.IndexOf('\n') + 1);
     }
+
+    public static void AssertSingleItem(this RazorEventListener.RazorEvent e, string expectedEventName, string expectedFileName)
+    {
+        Assert.Equal(expectedEventName, e.EventName);
+        var file = Assert.Single(e.Payload);
+        Assert.Equal(expectedFileName, file);
+    }
+
+    public static void AssertPair(this RazorEventListener.RazorEvent e, string expectedEventName, string payload1, string payload2)
+    {
+        Assert.Equal(expectedEventName, e.EventName);
+        Assert.Equal(2, e.Payload.Length);
+        Assert.Equal(payload1, e.Payload[0]);
+        Assert.Equal(payload2, e.Payload[1]);
+    }
 }