Support .NET 9

.github/workflows/build.yml

@@ -52,7 +52,7 @@ jobs:
       with:
         dotnet-version: |
           6.0.x
-          7.0.x
+          8.0.x
 
     - name: Setup .NET SDK
       uses: actions/setup-dotnet@6bd8b7f7774af54e05809fcc5431931b3eb1ddee # v4.0.1

Directory.Build.props

@@ -20,18 +20,12 @@
     <ManagePackageVersionsCentrally>true</ManagePackageVersionsCentrally>
     <NeutralLanguage>en-US</NeutralLanguage>
     <!--
-    TODO Remove deprecated TFMs
-    -->
-    <CheckEolTargetFramework>false</CheckEolTargetFramework>
-    <NoWarn>$(NoWarn);NETSDK1138</NoWarn>
-    <!--
-    TODO Update packages to resolve vulnerability warnings
-    -->
-    <NoWarn>$(NoWarn);NU1902;NU1903</NoWarn>
-    <!--
     TODO Fix warning from Swashbuckle.AspNetCore with dotnet pack
     -->
     <NoWarn>$(NoWarn);NU5128</NoWarn>
+    <!-- TODO Remove once .NET 9.0.0 is released -->
+    <NoWarn>$(NoWarn);NU5104</NoWarn>
+    <NuGetAuditMode>direct</NuGetAuditMode>
     <!--
     TODO Go through the code and add nullable annotations
     <Nullable>enable</Nullable>
@@ -49,7 +43,7 @@
     <SymbolPackageFormat>snupkg</SymbolPackageFormat>
     <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
     <UseArtifactsOutput>true</UseArtifactsOutput>
-    <VersionPrefix>6.9.1</VersionPrefix>
+    <VersionPrefix>7.0.0</VersionPrefix>
     <WarnOnPackingNonPackableProject>false</WarnOnPackingNonPackableProject>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(GITHUB_ACTIONS)' != '' ">

Directory.Packages.props

@@ -21,8 +21,8 @@
     <PackageVersion Include="Microsoft.AspNetCore.TestHost" Version="6.0.32" />
     <PackageVersion Include="Microsoft.CodeAnalysis.PublicApiAnalyzers" Version="3.3.4" />
     <PackageVersion Include="Microsoft.Extensions.FileProviders.Embedded" Version="2.1.0" />
-    <PackageVersion Include="Microsoft.OpenApi" Version="1.6.14" />
-    <PackageVersion Include="Microsoft.OpenApi.Readers" Version="1.6.14" />
+    <PackageVersion Include="Microsoft.OpenApi" Version="1.6.22" />
+    <PackageVersion Include="Microsoft.OpenApi.Readers" Version="1.6.22" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.10.0" />
     <PackageVersion Include="Newtonsoft.Json" Version="13.0.3" />
     <PackageVersion Include="NSubstitute" Version="5.1.0" />

global.json

@@ -1,6 +1,6 @@
 {
   "sdk": {
-    "version": "8.0.403",
+    "version": "9.0.100-rc.2.24474.11",
     "allowPrerelease": false,
     "rollForward": "latestMajor"
   }

src/Swashbuckle.AspNetCore.Annotations/Swashbuckle.AspNetCore.Annotations.csproj

@@ -8,7 +8,7 @@
     <NoWarn>$(NoWarn);1591</NoWarn>
     <PackageTags>swagger;documentation;discovery;help;webapi;aspnet;aspnetcore;annotations</PackageTags>
     <SignAssembly>true</SignAssembly>
-    <TargetFrameworks>netstandard2.0;netcoreapp3.0;net5.0;net6.0;net7.0;net8.0</TargetFrameworks>
+    <TargetFrameworks>net9.0;net8.0;net6.0;netstandard2.0</TargetFrameworks>
   </PropertyGroup>
 
   <ItemGroup>

src/Swashbuckle.AspNetCore.ApiTesting.Xunit/Swashbuckle.AspNetCore.ApiTesting.Xunit.csproj

@@ -7,7 +7,7 @@
     <IsTestProject>false</IsTestProject>
     <NoWarn>$(NoWarn);1591</NoWarn>
     <PackageTags>swagger;openapi;test-first;spec-first;testing;aspnetcore;xunit</PackageTags>
-    <TargetFrameworks>netstandard2.0;netcoreapp3.0;net5.0;net6.0;net7.0;net8.0</TargetFrameworks>
+    <TargetFrameworks>net9.0;net8.0;net6.0;netstandard2.0</TargetFrameworks>
   </PropertyGroup>
 
   <ItemGroup>

src/Swashbuckle.AspNetCore.ApiTesting/Swashbuckle.AspNetCore.ApiTesting.csproj

@@ -6,7 +6,7 @@
     <IsPackable>true</IsPackable>
     <NoWarn>$(NoWarn);1591</NoWarn>
     <PackageTags>swagger;openapi;test-first;spec-first;testing;aspnetcore</PackageTags>
-    <TargetFrameworks>netstandard2.0;netcoreapp3.0;net5.0;net6.0;net7.0;net8.0</TargetFrameworks>
+    <TargetFrameworks>net9.0;net8.0;net6.0;netstandard2.0</TargetFrameworks>
   </PropertyGroup>
 
   <ItemGroup>
@@ -16,29 +16,21 @@
   </ItemGroup>
 
   <ItemGroup Condition=" '$(TargetFramework)' == 'netstandard2.0' ">
-    <PackageReference Include="Microsoft.AspNetCore.Mvc.Testing" VersionOverride="2.1.2" />
-  </ItemGroup>
-
-  <ItemGroup Condition=" '$(TargetFramework)' == 'netcoreapp3.0' ">
-    <PackageReference Include="Microsoft.AspNetCore.Mvc.Testing" VersionOverride="3.0.0" />
-  </ItemGroup>
-
-  <ItemGroup Condition=" '$(TargetFramework)' == 'net5.0' ">
-    <PackageReference Include="Microsoft.AspNetCore.Mvc.Testing" VersionOverride="5.0.0" />
+    <PackageReference Include="Microsoft.AspNetCore.Mvc.Testing" VersionOverride="2.1.3" />
   </ItemGroup>
 
   <ItemGroup Condition=" '$(TargetFramework)' == 'net6.0' ">
     <PackageReference Include="Microsoft.AspNetCore.Mvc.Testing" VersionOverride="6.0.0" />
   </ItemGroup>
 
-  <ItemGroup Condition=" '$(TargetFramework)' == 'net7.0' ">
-    <PackageReference Include="Microsoft.AspNetCore.Mvc.Testing" VersionOverride="7.0.0" />
-  </ItemGroup>
-
   <ItemGroup Condition=" '$(TargetFramework)' == 'net8.0' ">
     <PackageReference Include="Microsoft.AspNetCore.Mvc.Testing" VersionOverride="8.0.0" />
   </ItemGroup>
 
+  <ItemGroup Condition=" '$(TargetFramework)' == 'net9.0' ">
+    <PackageReference Include="Microsoft.AspNetCore.Mvc.Testing" VersionOverride="9.0.0-rc.2.24474.3" />
+  </ItemGroup>
+
   <ItemGroup>
     <PackageReference Include="Microsoft.CodeAnalysis.PublicApiAnalyzers" PrivateAssets="All" />
     <AdditionalFiles Include="PublicAPI\PublicAPI.Shipped.txt" />

src/Swashbuckle.AspNetCore.Cli/CommandRunner.cs

@@ -5,7 +5,7 @@
 
 namespace Swashbuckle.AspNetCore.Cli
 {
-    public class CommandRunner
+    internal class CommandRunner
     {
         private readonly Dictionary<string, string> _argumentDescriptors;
         private readonly Dictionary<string, OptionDescriptor> _optionDescriptors;

src/Swashbuckle.AspNetCore.Cli/HostingApplication.cs

@@ -4,9 +4,7 @@
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Hosting.Server;
 using Microsoft.AspNetCore.Http.Features;
-#if NETCOREAPP3_0_OR_GREATER
 using Microsoft.Extensions.DependencyInjection;
-#endif
 using Microsoft.Extensions.Hosting;
 
 namespace Swashbuckle.AspNetCore.Cli
@@ -19,9 +17,6 @@ internal class HostingApplication
     {
         internal static IServiceProvider GetServiceProvider(Assembly assembly)
         {
-#if NETCOREAPP2_1
-            return null;
-#else
             // We're disabling the default server and the console host lifetime. This will disable:
             // 1. Listening on ports
             // 2. Logging to the console from the default host.
@@ -102,7 +97,6 @@ void OnEntryPointExit(Exception exception)
             }
 
             return null;
-#endif
         }
 
         private class NoopHostLifetime : IHostLifetime

src/Swashbuckle.AspNetCore.Cli/Program.cs

@@ -15,7 +15,7 @@
 
 namespace Swashbuckle.AspNetCore.Cli
 {
-    public class Program
+    internal class Program
     {
         public static int Main(string[] args)
         {

src/Swashbuckle.AspNetCore.Cli/Swashbuckle.AspNetCore.Cli.csproj

@@ -7,16 +7,16 @@
     <OutputType>Exe</OutputType>
     <PackAsTool>true</PackAsTool>
     <PackageId>Swashbuckle.AspNetCore.Cli</PackageId>
-    <TargetFrameworks>netcoreapp2.1;netcoreapp3.0;net5.0;net6.0;net7.0;net8.0</TargetFrameworks>
+    <TargetFrameworks>net9.0;net8.0;net6.0</TargetFrameworks>
     <ToolCommandName>swagger</ToolCommandName>
   </PropertyGroup>
 
   <ItemGroup>
     <ProjectReference Include="..\Swashbuckle.AspNetCore.Swagger\Swashbuckle.AspNetCore.Swagger.csproj" />
   </ItemGroup>
 
-  <ItemGroup Condition=" '$(TargetFramework)' == 'netcoreapp2.1' ">
-    <PackageReference Include="Microsoft.AspNetCore" />
+  <ItemGroup>
+    <InternalsVisibleTo Include="Swashbuckle.AspNetCore.Cli.Test" />
   </ItemGroup>
 
 </Project>

src/Swashbuckle.AspNetCore.Newtonsoft/Swashbuckle.AspNetCore.Newtonsoft.csproj

@@ -6,7 +6,7 @@
     <IsPackable>true</IsPackable>
     <PackageTags>swagger;documentation;discovery;help;webapi;aspnet;aspnetcore;newtonsoft</PackageTags>
     <SignAssembly>true</SignAssembly>
-    <TargetFrameworks>netstandard2.0;netcoreapp3.0;net5.0;net6.0;net7.0;net8.0</TargetFrameworks>
+    <TargetFrameworks>net9.0;net8.0;net6.0;netstandard2.0</TargetFrameworks>
   </PropertyGroup>
 
   <ItemGroup>
@@ -17,26 +17,18 @@
     <PackageReference Include="Microsoft.AspNetCore.Mvc.Formatters.Json" />
   </ItemGroup>
 
-  <ItemGroup Condition=" '$(TargetFramework)' == 'netcoreapp3.0' ">
-    <PackageReference Include="Microsoft.AspNetCore.Mvc.NewtonsoftJson" VersionOverride="3.0.0" />
-  </ItemGroup>
-
-  <ItemGroup Condition=" '$(TargetFramework)' == 'net5.0' ">
-    <PackageReference Include="Microsoft.AspNetCore.Mvc.NewtonsoftJson" VersionOverride="5.0.0" />
-  </ItemGroup>
-
   <ItemGroup Condition=" '$(TargetFramework)' == 'net6.0' ">
     <PackageReference Include="Microsoft.AspNetCore.Mvc.NewtonsoftJson" VersionOverride="6.0.0" />
   </ItemGroup>
 
-   <ItemGroup Condition=" '$(TargetFramework)' == 'net7.0' ">
-    <PackageReference Include="Microsoft.AspNetCore.Mvc.NewtonsoftJson" VersionOverride="7.0.0" />
-  </ItemGroup>
-
   <ItemGroup Condition=" '$(TargetFramework)' == 'net8.0' ">
     <PackageReference Include="Microsoft.AspNetCore.Mvc.NewtonsoftJson" VersionOverride="8.0.0" />
   </ItemGroup>
 
+  <ItemGroup Condition=" '$(TargetFramework)' == 'net9.0' ">
+    <PackageReference Include="Microsoft.AspNetCore.Mvc.NewtonsoftJson" VersionOverride="9.0.0-rc.2.24474.3" />
+  </ItemGroup>
+
   <ItemGroup>
     <PackageReference Include="Microsoft.CodeAnalysis.PublicApiAnalyzers" PrivateAssets="All" />
     <AdditionalFiles Include="PublicAPI\PublicAPI.Shipped.txt" />

src/Swashbuckle.AspNetCore.ReDoc/PublicAPI/PublicAPI.Shipped.txt

@@ -47,8 +47,6 @@ Swashbuckle.AspNetCore.ReDoc.ConfigObject.SortPropsAlphabetically.get -> bool
 Swashbuckle.AspNetCore.ReDoc.ConfigObject.SortPropsAlphabetically.set -> void
 Swashbuckle.AspNetCore.ReDoc.ConfigObject.UntrustedSpec.get -> bool
 Swashbuckle.AspNetCore.ReDoc.ConfigObject.UntrustedSpec.set -> void
-Swashbuckle.AspNetCore.ReDoc.ReDocMiddleware
-Swashbuckle.AspNetCore.ReDoc.ReDocMiddleware.Invoke(Microsoft.AspNetCore.Http.HttpContext httpContext) -> System.Threading.Tasks.Task
 Swashbuckle.AspNetCore.ReDoc.ReDocOptions
 Swashbuckle.AspNetCore.ReDoc.ReDocOptions.ConfigObject.get -> Swashbuckle.AspNetCore.ReDoc.ConfigObject
 Swashbuckle.AspNetCore.ReDoc.ReDocOptions.ConfigObject.set -> void

src/Swashbuckle.AspNetCore.ReDoc/ReDocMiddleware.cs

@@ -22,7 +22,7 @@
 
 namespace Swashbuckle.AspNetCore.ReDoc
 {
-    public class ReDocMiddleware
+    internal sealed class ReDocMiddleware
     {
         private const string EmbeddedFileNamespace = "Swashbuckle.AspNetCore.ReDoc.node_modules.redoc.bundles";
 

src/Swashbuckle.AspNetCore.ReDoc/Swashbuckle.AspNetCore.ReDoc.csproj

@@ -8,7 +8,7 @@
     <NoWarn>$(NoWarn);1591</NoWarn>
     <PackageTags>swagger;documentation;discovery;help;webapi;aspnet;aspnetcore;redoc</PackageTags>
     <SignAssembly>true</SignAssembly>
-    <TargetFrameworks>netstandard2.0;netcoreapp3.0;net5.0;net6.0;net7.0;net8.0</TargetFrameworks>
+    <TargetFrameworks>net9.0;net8.0;net6.0;netstandard2.0</TargetFrameworks>
   </PropertyGroup>
   <PropertyGroup Condition="$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net8.0'))">
     <EnableAotAnalyzer>true</EnableAotAnalyzer>

src/Swashbuckle.AspNetCore.Swagger/PublicAPI/.NETCoreApp/PublicAPI.Shipped.txt

@@ -1,2 +1 @@
 static Microsoft.AspNetCore.Builder.SwaggerBuilderExtensions.MapSwagger(this Microsoft.AspNetCore.Routing.IEndpointRouteBuilder endpoints, string pattern = "/swagger/{documentName}/swagger.{extension:regex(^(json|ya?ml)$)}", System.Action<Swashbuckle.AspNetCore.Swagger.SwaggerEndpointOptions> setupAction = null) -> Microsoft.AspNetCore.Builder.IEndpointConventionBuilder
-Swashbuckle.AspNetCore.Swagger.SwaggerMiddleware.SwaggerMiddleware(Microsoft.AspNetCore.Http.RequestDelegate next, Swashbuckle.AspNetCore.Swagger.SwaggerOptions options, Microsoft.AspNetCore.Routing.Template.TemplateBinderFactory templateBinderFactory) -> void

src/Swashbuckle.AspNetCore.Swagger/PublicAPI/PublicAPI.Shipped.txt

@@ -16,9 +16,6 @@ Swashbuckle.AspNetCore.Swagger.SwaggerEndpointOptions.PreSerializeFilters.get ->
 Swashbuckle.AspNetCore.Swagger.SwaggerEndpointOptions.SerializeAsV2.get -> bool
 Swashbuckle.AspNetCore.Swagger.SwaggerEndpointOptions.SerializeAsV2.set -> void
 Swashbuckle.AspNetCore.Swagger.SwaggerEndpointOptions.SwaggerEndpointOptions() -> void
-Swashbuckle.AspNetCore.Swagger.SwaggerMiddleware
-Swashbuckle.AspNetCore.Swagger.SwaggerMiddleware.Invoke(Microsoft.AspNetCore.Http.HttpContext httpContext, Swashbuckle.AspNetCore.Swagger.ISwaggerProvider swaggerProvider) -> System.Threading.Tasks.Task
-Swashbuckle.AspNetCore.Swagger.SwaggerMiddleware.SwaggerMiddleware(Microsoft.AspNetCore.Http.RequestDelegate next, Swashbuckle.AspNetCore.Swagger.SwaggerOptions options) -> void
 Swashbuckle.AspNetCore.Swagger.SwaggerOptions
 Swashbuckle.AspNetCore.Swagger.SwaggerOptions.CustomDocumentSerializer.get -> Swashbuckle.AspNetCore.Swagger.ISwaggerDocumentSerializer
 Swashbuckle.AspNetCore.Swagger.SwaggerOptions.CustomDocumentSerializer.set -> void

src/Swashbuckle.AspNetCore.Swagger/SwaggerMiddleware.cs

@@ -14,7 +14,7 @@
 
 namespace Swashbuckle.AspNetCore.Swagger
 {
-    public class SwaggerMiddleware
+    internal sealed class SwaggerMiddleware
     {
         private readonly RequestDelegate _next;
         private readonly SwaggerOptions _options;

src/Swashbuckle.AspNetCore.Swagger/Swashbuckle.AspNetCore.Swagger.csproj

@@ -8,7 +8,7 @@
     <NoWarn>$(NoWarn);1591</NoWarn>
     <PackageTags>swagger;documentation;discovery;help;webapi;aspnet;aspnetcore</PackageTags>
     <SignAssembly>true</SignAssembly>
-    <TargetFrameworks>netstandard2.0;netcoreapp3.0;net5.0;net6.0;net7.0;net8.0</TargetFrameworks>
+    <TargetFrameworks>net9.0;net8.0;net6.0;netstandard2.0</TargetFrameworks>
   </PropertyGroup>
   <PropertyGroup Condition="$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net8.0'))">
     <EnableAotAnalyzer>true</EnableAotAnalyzer>

src/Swashbuckle.AspNetCore.SwaggerGen/DependencyInjection/ConfigureSwaggerGeneratorOptions.cs

@@ -6,7 +6,7 @@
 using Microsoft.Extensions.Options;
 using Microsoft.OpenApi.Models;
 
-#if NETSTANDARD2_0
+#if NETSTANDARD
 using IWebHostEnvironment = Microsoft.AspNetCore.Hosting.IHostingEnvironment;
 #endif
 

src/Swashbuckle.AspNetCore.SwaggerGen/SchemaGenerator/SchemaGenerator.cs

@@ -228,7 +228,7 @@ private OpenApiSchema GeneratePolymorphicSchema(
             typeof(IFormFile),
             typeof(FileResult),
             typeof(System.IO.Stream),
-#if NETCOREAPP3_0_OR_GREATER
+#if !NETSTANDARD
             typeof(System.IO.Pipelines.PipeReader),
 #endif
         ];

src/Swashbuckle.AspNetCore.SwaggerGen/SwaggerGenerator/ApiParameterDescriptionExtensions.cs

@@ -49,7 +49,7 @@ public static bool IsRequiredParameter(this ApiParameterDescription apiParameter
 
             // For non-controllers, prefer the IsRequired flag if we're not on netstandard 2.0, otherwise fallback to the default logic.
             return
-#if !NETSTANDARD2_0
+#if !NETSTANDARD
             apiParameter.IsRequired;
 #else
             IsRequired();
@@ -59,7 +59,7 @@ public static bool IsRequiredParameter(this ApiParameterDescription apiParameter
         public static ParameterInfo ParameterInfo(this ApiParameterDescription apiParameter)
         {
             var parameterDescriptor = apiParameter.ParameterDescriptor as
-#if NETCOREAPP2_2_OR_GREATER
+#if !NETSTANDARD
                 Microsoft.AspNetCore.Mvc.Infrastructure.IParameterInfoParameterDescriptor;
 #else
                 ControllerParameterDescriptor;

src/Swashbuckle.AspNetCore.SwaggerGen/Swashbuckle.AspNetCore.SwaggerGen.csproj

@@ -8,7 +8,7 @@
     <NoWarn>$(NoWarn);1591</NoWarn>
     <PackageTags>swagger;documentation;discovery;help;webapi;aspnet;aspnetcore</PackageTags>
     <SignAssembly>true</SignAssembly>
-    <TargetFrameworks>netstandard2.0;netcoreapp3.0;net5.0;net6.0;net7.0;net8.0</TargetFrameworks>
+    <TargetFrameworks>net9.0;net8.0;net6.0;netstandard2.0</TargetFrameworks>
   </PropertyGroup>
 
   <ItemGroup>

src/Swashbuckle.AspNetCore.SwaggerUI/PublicAPI/PublicAPI.Shipped.txt

@@ -116,8 +116,6 @@ Swashbuckle.AspNetCore.SwaggerUI.SubmitMethod.Patch = 6 -> Swashbuckle.AspNetCor
 Swashbuckle.AspNetCore.SwaggerUI.SubmitMethod.Post = 2 -> Swashbuckle.AspNetCore.SwaggerUI.SubmitMethod
 Swashbuckle.AspNetCore.SwaggerUI.SubmitMethod.Put = 1 -> Swashbuckle.AspNetCore.SwaggerUI.SubmitMethod
 Swashbuckle.AspNetCore.SwaggerUI.SubmitMethod.Trace = 7 -> Swashbuckle.AspNetCore.SwaggerUI.SubmitMethod
-Swashbuckle.AspNetCore.SwaggerUI.SwaggerUIMiddleware
-Swashbuckle.AspNetCore.SwaggerUI.SwaggerUIMiddleware.Invoke(Microsoft.AspNetCore.Http.HttpContext httpContext) -> System.Threading.Tasks.Task
 Swashbuckle.AspNetCore.SwaggerUI.SwaggerUIOptions
 Swashbuckle.AspNetCore.SwaggerUI.SwaggerUIOptions.ConfigObject.get -> Swashbuckle.AspNetCore.SwaggerUI.ConfigObject
 Swashbuckle.AspNetCore.SwaggerUI.SwaggerUIOptions.ConfigObject.set -> void

src/Swashbuckle.AspNetCore.SwaggerUI/SwaggerUIBuilderExtensions.cs

@@ -4,7 +4,7 @@
 using Microsoft.Extensions.Options;
 using Swashbuckle.AspNetCore.SwaggerUI;
 
-#if NETSTANDARD2_0
+#if NETSTANDARD
 using IWebHostEnvironment = Microsoft.AspNetCore.Hosting.IHostingEnvironment;
 #endif
 

src/Swashbuckle.AspNetCore.SwaggerUI/SwaggerUIMiddleware.cs

@@ -16,13 +16,13 @@
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
 
-#if NETSTANDARD2_0
+#if NETSTANDARD
 using IWebHostEnvironment = Microsoft.AspNetCore.Hosting.IHostingEnvironment;
 #endif
 
 namespace Swashbuckle.AspNetCore.SwaggerUI
 {
-    public class SwaggerUIMiddleware
+    internal sealed partial class SwaggerUIMiddleware
     {
         private const string EmbeddedFileNamespace = "Swashbuckle.AspNetCore.SwaggerUI.node_modules.swagger_ui_dist";
 

src/Swashbuckle.AspNetCore.SwaggerUI/Swashbuckle.AspNetCore.SwaggerUI.csproj

@@ -8,7 +8,7 @@
     <NoWarn>$(NoWarn);1591</NoWarn>
     <PackageTags>swagger;documentation;discovery;help;webapi;aspnet;aspnetcore</PackageTags>
     <SignAssembly>true</SignAssembly>
-    <TargetFrameworks>netstandard2.0;netcoreapp3.0;net5.0;net6.0;net7.0;net8.0</TargetFrameworks>
+    <TargetFrameworks>net9.0;net8.0;net6.0;netstandard2.0</TargetFrameworks>
   </PropertyGroup>
   <PropertyGroup Condition="$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net8.0'))">
     <EnableAotAnalyzer>true</EnableAotAnalyzer>

src/Swashbuckle.AspNetCore/Swashbuckle.AspNetCore.csproj

@@ -13,7 +13,15 @@
     <NuspecFile>$(MSBuildProjectName).nuspec</NuspecFile>
     <PackageId>Swashbuckle.AspNetCore</PackageId>
     <PackageTags>swagger;documentation;discovery;help;webapi;aspnet;aspnetcore</PackageTags>
-    <TargetFrameworks>netstandard2.0;netcoreapp3.0;net5.0;net6.0;net7.0;net8.0</TargetFrameworks>
+    <TargetFrameworks>net9.0;net8.0;net6.0;netstandard2.0</TargetFrameworks>
+  </PropertyGroup>
+
+  <PropertyGroup Condition=" '$(TargetFramework)' == 'net8.0' ">
+    <MicrosoftExtensionsApiDescriptionServerPackageVersion>8.0.0</MicrosoftExtensionsApiDescriptionServerPackageVersion>
+  </PropertyGroup>
+
+  <PropertyGroup Condition=" '$(TargetFramework)' == 'net9.0' ">
+    <MicrosoftExtensionsApiDescriptionServerPackageVersion>9.0.0-rc.2.24474.3</MicrosoftExtensionsApiDescriptionServerPackageVersion>
   </PropertyGroup>
 
   <Target Name="PopulateNuspec">