Add JsonSerializerOptions property to McpServerOptions and update builder extensions

Copilot · eiriktsarpalis · Copilot · commit 2f84c3ea8cc1 · 2025-10-30T13:50:06.000Z
Co-authored-by: eiriktsarpalis &lt;2813363+eiriktsarpalis@users.noreply.github.com&gt;
diff --git a/src/ModelContextProtocol.Core/Server/McpServerOptions.cs b/src/ModelContextProtocol.Core/Server/McpServerOptions.cs
@@ -1,4 +1,5 @@
 using ModelContextProtocol.Protocol;
+using System.Text.Json;
 
 namespace ModelContextProtocol.Server;
 
@@ -60,6 +61,26 @@ public sealed class McpServerOptions
     /// </remarks>
     public string? ServerInstructions { get; set; }
 
+    /// <summary>
+    /// Gets or sets the default JSON serializer options to use for tools, prompts, and resources.
+    /// </summary>
+    /// <remarks>
+    /// <para>
+    /// This property provides server-wide default serialization settings that will be used
+    /// by all tools, prompts, and resources unless they explicitly specify their own
+    /// <see cref="JsonSerializerOptions"/> during registration.
+    /// </para>
+    /// <para>
+    /// If not set, defaults to <see cref="McpJsonUtilities.DefaultOptions"/>.
+    /// </para>
+    /// <para>
+    /// This is useful for configuring settings like <c>JsonNumberHandling.AllowNamedFloatingPointLiterals</c>
+    /// to handle special floating-point values like <see cref="double.PositiveInfinity"/>, <see cref="double.NegativeInfinity"/>,
+    /// and <see cref="double.NaN"/>.
+    /// </para>
+    /// </remarks>
+    public JsonSerializerOptions? JsonSerializerOptions { get; set; }
+
     /// <summary>
     /// Gets or sets whether to create a new service provider scope for each handled request.
     /// </summary>
diff --git a/src/ModelContextProtocol/McpServerBuilderExtensions.cs b/src/ModelContextProtocol/McpServerBuilderExtensions.cs
@@ -45,8 +45,8 @@ public static partial class McpServerBuilderExtensions
             if (toolMethod.GetCustomAttribute<McpServerToolAttribute>() is not null)
             {
                 builder.Services.AddSingleton((Func<IServiceProvider, McpServerTool>)(toolMethod.IsStatic ?
-                    services => McpServerTool.Create(toolMethod, options: new() { Services = services, SerializerOptions = serializerOptions }) :
-                    services => McpServerTool.Create(toolMethod, static r => CreateTarget(r.Services, typeof(TToolType)), new() { Services = services, SerializerOptions = serializerOptions })));
+                    services => McpServerTool.Create(toolMethod, options: new() { Services = services, SerializerOptions = serializerOptions ?? services.GetRequiredService<IOptions<McpServerOptions>>().Value.JsonSerializerOptions }) :
+                    services => McpServerTool.Create(toolMethod, static r => CreateTarget(r.Services, typeof(TToolType)), new() { Services = services, SerializerOptions = serializerOptions ?? services.GetRequiredService<IOptions<McpServerOptions>>().Value.JsonSerializerOptions })));
             }
         }
 
@@ -93,7 +93,7 @@ public static partial class McpServerBuilderExtensions
                 builder.Services.AddSingleton(services => McpServerTool.Create(
                     toolMethod,
                     toolMethod.IsStatic ? null : target,
-                    new() { Services = services, SerializerOptions = serializerOptions }));
+                    new() { Services = services, SerializerOptions = serializerOptions ?? services.GetRequiredService<IOptions<McpServerOptions>>().Value.JsonSerializerOptions }));
             }
         }
 
@@ -149,8 +149,8 @@ public static IMcpServerBuilder WithTools(this IMcpServerBuilder builder, IEnume
                     if (toolMethod.GetCustomAttribute<McpServerToolAttribute>() is not null)
                     {
                         builder.Services.AddSingleton((Func<IServiceProvider, McpServerTool>)(toolMethod.IsStatic ?
-                            services => McpServerTool.Create(toolMethod, options: new() { Services = services , SerializerOptions = serializerOptions }) :
-                            services => McpServerTool.Create(toolMethod, r => CreateTarget(r.Services, toolType), new() { Services = services , SerializerOptions = serializerOptions })));
+                            services => McpServerTool.Create(toolMethod, options: new() { Services = services , SerializerOptions = serializerOptions ?? services.GetRequiredService<IOptions<McpServerOptions>>().Value.JsonSerializerOptions }) :
+                            services => McpServerTool.Create(toolMethod, r => CreateTarget(r.Services, toolType), new() { Services = services , SerializerOptions = serializerOptions ?? services.GetRequiredService<IOptions<McpServerOptions>>().Value.JsonSerializerOptions })));
                     }
                 }
             }
@@ -232,8 +232,8 @@ where t.GetCustomAttribute<McpServerToolTypeAttribute>() is not null
             if (promptMethod.GetCustomAttribute<McpServerPromptAttribute>() is not null)
             {
                 builder.Services.AddSingleton((Func<IServiceProvider, McpServerPrompt>)(promptMethod.IsStatic ?
-                    services => McpServerPrompt.Create(promptMethod, options: new() { Services = services, SerializerOptions = serializerOptions }) :
-                    services => McpServerPrompt.Create(promptMethod, static r => CreateTarget(r.Services, typeof(TPromptType)), new() { Services = services, SerializerOptions = serializerOptions })));
+                    services => McpServerPrompt.Create(promptMethod, options: new() { Services = services, SerializerOptions = serializerOptions ?? services.GetRequiredService<IOptions<McpServerOptions>>().Value.JsonSerializerOptions }) :
+                    services => McpServerPrompt.Create(promptMethod, static r => CreateTarget(r.Services, typeof(TPromptType)), new() { Services = services, SerializerOptions = serializerOptions ?? services.GetRequiredService<IOptions<McpServerOptions>>().Value.JsonSerializerOptions })));
             }
         }
 
@@ -277,7 +277,7 @@ where t.GetCustomAttribute<McpServerToolTypeAttribute>() is not null
         {
             if (promptMethod.GetCustomAttribute<McpServerPromptAttribute>() is not null)
             {
-                builder.Services.AddSingleton(services => McpServerPrompt.Create(promptMethod, target, new() { Services = services, SerializerOptions = serializerOptions }));
+                builder.Services.AddSingleton(services => McpServerPrompt.Create(promptMethod, target, new() { Services = services, SerializerOptions = serializerOptions ?? services.GetRequiredService<IOptions<McpServerOptions>>().Value.JsonSerializerOptions }));
             }
         }
 
@@ -333,8 +333,8 @@ public static IMcpServerBuilder WithPrompts(this IMcpServerBuilder builder, IEnu
                     if (promptMethod.GetCustomAttribute<McpServerPromptAttribute>() is not null)
                     {
                         builder.Services.AddSingleton((Func<IServiceProvider, McpServerPrompt>)(promptMethod.IsStatic ?
-                            services => McpServerPrompt.Create(promptMethod, options: new() { Services = services, SerializerOptions = serializerOptions }) :
-                            services => McpServerPrompt.Create(promptMethod, r => CreateTarget(r.Services, promptType), new() { Services = services, SerializerOptions = serializerOptions })));
+                            services => McpServerPrompt.Create(promptMethod, options: new() { Services = services, SerializerOptions = serializerOptions ?? services.GetRequiredService<IOptions<McpServerOptions>>().Value.JsonSerializerOptions }) :
+                            services => McpServerPrompt.Create(promptMethod, r => CreateTarget(r.Services, promptType), new() { Services = services, SerializerOptions = serializerOptions ?? services.GetRequiredService<IOptions<McpServerOptions>>().Value.JsonSerializerOptions })));
                     }
                 }
             }
@@ -394,6 +394,7 @@ where t.GetCustomAttribute<McpServerPromptTypeAttribute>() is not null
     /// <summary>Adds <see cref="McpServerResource"/> instances to the service collection backing <paramref name="builder"/>.</summary>
     /// <typeparam name="TResourceType">The resource type.</typeparam>
     /// <param name="builder">The builder instance.</param>
+    /// <param name="serializerOptions">The serializer options governing resource parameter marshalling.</param>
     /// <returns>The builder provided in <paramref name="builder"/>.</returns>
     /// <exception cref="ArgumentNullException"><paramref name="builder"/> is <see langword="null"/>.</exception>
     /// <remarks>
@@ -405,7 +406,8 @@ where t.GetCustomAttribute<McpServerPromptTypeAttribute>() is not null
         DynamicallyAccessedMemberTypes.PublicMethods |
         DynamicallyAccessedMemberTypes.NonPublicMethods |
         DynamicallyAccessedMemberTypes.PublicConstructors)] TResourceType>(
-        this IMcpServerBuilder builder)
+        this IMcpServerBuilder builder,
+        JsonSerializerOptions? serializerOptions = null)
     {
         Throw.IfNull(builder);
 
@@ -414,8 +416,8 @@ where t.GetCustomAttribute<McpServerPromptTypeAttribute>() is not null
             if (resourceTemplateMethod.GetCustomAttribute<McpServerResourceAttribute>() is not null)
             {
                 builder.Services.AddSingleton((Func<IServiceProvider, McpServerResource>)(resourceTemplateMethod.IsStatic ?
-                    services => McpServerResource.Create(resourceTemplateMethod, options: new() { Services = services }) :
-                    services => McpServerResource.Create(resourceTemplateMethod, static r => CreateTarget(r.Services, typeof(TResourceType)), new() { Services = services })));
+                    services => McpServerResource.Create(resourceTemplateMethod, options: new() { Services = services, SerializerOptions = serializerOptions ?? services.GetRequiredService<IOptions<McpServerOptions>>().Value.JsonSerializerOptions }) :
+                    services => McpServerResource.Create(resourceTemplateMethod, static r => CreateTarget(r.Services, typeof(TResourceType)), new() { Services = services, SerializerOptions = serializerOptions ?? services.GetRequiredService<IOptions<McpServerOptions>>().Value.JsonSerializerOptions })));
             }
         }
 
@@ -426,6 +428,7 @@ where t.GetCustomAttribute<McpServerPromptTypeAttribute>() is not null
     /// <typeparam name="TResourceType">The resource type.</typeparam>
     /// <param name="builder">The builder instance.</param>
     /// <param name="target">The target instance from which the prompts should be sourced.</param>
+    /// <param name="serializerOptions">The serializer options governing resource parameter marshalling.</param>
     /// <returns>The builder provided in <paramref name="builder"/>.</returns>
     /// <exception cref="ArgumentNullException"><paramref name="builder"/> is <see langword="null"/>.</exception>
     /// <remarks>
@@ -443,7 +446,8 @@ where t.GetCustomAttribute<McpServerPromptTypeAttribute>() is not null
         DynamicallyAccessedMemberTypes.PublicMethods |
         DynamicallyAccessedMemberTypes.NonPublicMethods)] TResourceType>(
         this IMcpServerBuilder builder,
-        TResourceType target)
+        TResourceType target,
+        JsonSerializerOptions? serializerOptions = null)
     {
         Throw.IfNull(builder);
         Throw.IfNull(target);
@@ -457,7 +461,7 @@ where t.GetCustomAttribute<McpServerPromptTypeAttribute>() is not null
         {
             if (resourceTemplateMethod.GetCustomAttribute<McpServerResourceAttribute>() is not null)
             {
-                builder.Services.AddSingleton(services => McpServerResource.Create(resourceTemplateMethod, target, new() { Services = services }));
+                builder.Services.AddSingleton(services => McpServerResource.Create(resourceTemplateMethod, target, new() { Services = services, SerializerOptions = serializerOptions ?? services.GetRequiredService<IOptions<McpServerOptions>>().Value.JsonSerializerOptions }));
             }
         }
 
@@ -489,6 +493,7 @@ public static IMcpServerBuilder WithResources(this IMcpServerBuilder builder, IE
     /// <summary>Adds <see cref="McpServerResource"/> instances to the service collection backing <paramref name="builder"/>.</summary>
     /// <param name="builder">The builder instance.</param>
     /// <param name="resourceTemplateTypes">Types with marked methods to add as resources to the server.</param>
+    /// <param name="serializerOptions">The serializer options governing resource parameter marshalling.</param>
     /// <returns>The builder provided in <paramref name="builder"/>.</returns>
     /// <exception cref="ArgumentNullException"><paramref name="builder"/> is <see langword="null"/>.</exception>
     /// <exception cref="ArgumentNullException"><paramref name="resourceTemplateTypes"/> is <see langword="null"/>.</exception>
@@ -498,7 +503,7 @@ public static IMcpServerBuilder WithResources(this IMcpServerBuilder builder, IE
     /// instance for each. For instance methods, an instance will be constructed for each invocation of the resource.
     /// </remarks>
     [RequiresUnreferencedCode(WithResourcesRequiresUnreferencedCodeMessage)]
-    public static IMcpServerBuilder WithResources(this IMcpServerBuilder builder, IEnumerable<Type> resourceTemplateTypes)
+    public static IMcpServerBuilder WithResources(this IMcpServerBuilder builder, IEnumerable<Type> resourceTemplateTypes, JsonSerializerOptions? serializerOptions = null)
     {
         Throw.IfNull(builder);
         Throw.IfNull(resourceTemplateTypes);
@@ -512,8 +517,8 @@ public static IMcpServerBuilder WithResources(this IMcpServerBuilder builder, IE
                     if (resourceTemplateMethod.GetCustomAttribute<McpServerResourceAttribute>() is not null)
                     {
                         builder.Services.AddSingleton((Func<IServiceProvider, McpServerResource>)(resourceTemplateMethod.IsStatic ?
-                            services => McpServerResource.Create(resourceTemplateMethod, options: new() { Services = services }) :
-                            services => McpServerResource.Create(resourceTemplateMethod, r => CreateTarget(r.Services, resourceTemplateType), new() { Services = services })));
+                            services => McpServerResource.Create(resourceTemplateMethod, options: new() { Services = services, SerializerOptions = serializerOptions ?? services.GetRequiredService<IOptions<McpServerOptions>>().Value.JsonSerializerOptions }) :
+                            services => McpServerResource.Create(resourceTemplateMethod, r => CreateTarget(r.Services, resourceTemplateType), new() { Services = services, SerializerOptions = serializerOptions ?? services.GetRequiredService<IOptions<McpServerOptions>>().Value.JsonSerializerOptions })));
                     }
                 }
             }
@@ -526,6 +531,7 @@ public static IMcpServerBuilder WithResources(this IMcpServerBuilder builder, IE
     /// Adds types marked with the <see cref="McpServerResourceTypeAttribute"/> attribute from the given assembly as resources to the server.
     /// </summary>
     /// <param name="builder">The builder instance.</param>
+    /// <param name="serializerOptions">The serializer options governing resource parameter marshalling.</param>
     /// <param name="resourceAssembly">The assembly to load the types from. If <see langword="null"/>, the calling assembly will be used.</param>
     /// <returns>The builder provided in <paramref name="builder"/>.</returns>
     /// <exception cref="ArgumentNullException"><paramref name="builder"/> is <see langword="null"/>.</exception>
@@ -550,7 +556,7 @@ public static IMcpServerBuilder WithResources(this IMcpServerBuilder builder, IE
     /// </para>
     /// </remarks>
     [RequiresUnreferencedCode(WithResourcesRequiresUnreferencedCodeMessage)]
-    public static IMcpServerBuilder WithResourcesFromAssembly(this IMcpServerBuilder builder, Assembly? resourceAssembly = null)
+    public static IMcpServerBuilder WithResourcesFromAssembly(this IMcpServerBuilder builder, Assembly? resourceAssembly = null, JsonSerializerOptions? serializerOptions = null)
     {
         Throw.IfNull(builder);
 
@@ -559,7 +565,8 @@ public static IMcpServerBuilder WithResourcesFromAssembly(this IMcpServerBuilder
         return builder.WithResources(
             from t in resourceAssembly.GetTypes()
             where t.GetCustomAttribute<McpServerResourceTypeAttribute>() is not null
-            select t);
+            select t,
+            serializerOptions);
     }
     #endregion
 
diff --git a/tests/ModelContextProtocol.Tests/Configuration/McpServerJsonSerializerOptionsTests.cs b/tests/ModelContextProtocol.Tests/Configuration/McpServerJsonSerializerOptionsTests.cs
@@ -0,0 +1,94 @@
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Options;
+using ModelContextProtocol.Client;
+using ModelContextProtocol.Protocol;
+using ModelContextProtocol.Server;
+using ModelContextProtocol.Tests.Utils;
+using System.ComponentModel;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+
+namespace ModelContextProtocol.Tests.Configuration;
+
+public class McpServerJsonSerializerOptionsTests : ClientServerTestBase
+{
+    public McpServerJsonSerializerOptionsTests(ITestOutputHelper testOutputHelper)
+        : base(testOutputHelper)
+    {
+    }
+
+    private class SpecialNumbers
+    {
+        public double PositiveInfinity { get; set; }
+        public double NegativeInfinity { get; set; }
+        public double NotANumber { get; set; }
+    }
+
+    protected override void ConfigureServices(ServiceCollection services, IMcpServerBuilder mcpServerBuilder)
+    {
+        // Configure server-wide JsonSerializerOptions to allow named floating point literals
+        var customOptions = new JsonSerializerOptions(McpJsonUtilities.DefaultOptions)
+        {
+            NumberHandling = JsonNumberHandling.AllowNamedFloatingPointLiterals
+        };
+
+        services.Configure<McpServerOptions>(options =>
+        {
+            options.JsonSerializerOptions = customOptions;
+        });
+
+        // Register a tool that will use the server-wide JsonSerializerOptions
+        // The null serializerOptions parameter should cause it to use McpServerOptions.JsonSerializerOptions
+        services.AddSingleton(sp =>
+        {
+            var serverOptions = sp.GetRequiredService<IOptions<McpServerOptions>>().Value;
+            return McpServerTool.Create(
+                () => new SpecialNumbers
+                {
+                    PositiveInfinity = double.PositiveInfinity,
+                    NegativeInfinity = double.NegativeInfinity,
+                    NotANumber = double.NaN
+                },
+                new McpServerToolCreateOptions
+                {
+                    Name = "GetSpecialNumbers",
+                    Description = "Returns special floating point values",
+                    UseStructuredContent = true,
+                    SerializerOptions = serverOptions.JsonSerializerOptions,
+                    Services = sp
+                });
+        });
+    }
+
+    [Fact]
+    public async Task ServerWide_JsonSerializerOptions_Applied_To_Tools()
+    {
+        // Arrange
+        McpClient client = await CreateMcpClientForServer();
+
+        // Act
+        IList<McpClientTool> tools = await client.ListToolsAsync(cancellationToken: TestContext.Current.CancellationToken);
+        CallToolResult result = await client.CallToolAsync("GetSpecialNumbers", cancellationToken: TestContext.Current.CancellationToken);
+
+        // Assert
+        Assert.NotNull(tools);
+        Assert.Single(tools);
+        Assert.Equal("GetSpecialNumbers", tools[0].Name);
+
+        // Verify the result contains structured content with special numbers
+        Assert.NotNull(result);
+        Assert.NotNull(result.StructuredContent);
+        
+        var structuredContent = JsonSerializer.Deserialize<SpecialNumbers>(
+            result.StructuredContent.ToString(),
+            new JsonSerializerOptions(McpJsonUtilities.DefaultOptions)
+            {
+                NumberHandling = JsonNumberHandling.AllowNamedFloatingPointLiterals
+            });
+
+        Assert.NotNull(structuredContent);
+        Assert.True(double.IsPositiveInfinity(structuredContent.PositiveInfinity));
+        Assert.True(double.IsNegativeInfinity(structuredContent.NegativeInfinity));
+        Assert.True(double.IsNaN(structuredContent.NotANumber));
+    }
+}

Original file line number	Diff line number	Diff line change
`@@ -45,8 +45,8 @@ public static partial class McpServerBuilderExtensions`
`45`	`45`	`if (toolMethod.GetCustomAttribute<McpServerToolAttribute>() is not null)`
`46`	`46`	`{`
`47`	`47`	`builder.Services.AddSingleton((Func<IServiceProvider, McpServerTool>)(toolMethod.IsStatic ?`
`48`		`- services => McpServerTool.Create(toolMethod, options: new() { Services = services, SerializerOptions = serializerOptions }) :`
`49`		`- services => McpServerTool.Create(toolMethod, static r => CreateTarget(r.Services, typeof(TToolType)), new() { Services = services, SerializerOptions = serializerOptions })));`
	`48`	`+ services => McpServerTool.Create(toolMethod, options: new() { Services = services, SerializerOptions = serializerOptions ?? services.GetRequiredService<IOptions<McpServerOptions>>().Value.JsonSerializerOptions }) :`
	`49`	`+ services => McpServerTool.Create(toolMethod, static r => CreateTarget(r.Services, typeof(TToolType)), new() { Services = services, SerializerOptions = serializerOptions ?? services.GetRequiredService<IOptions<McpServerOptions>>().Value.JsonSerializerOptions })));`
`50`	`50`	`}`
`51`	`51`	`}`
`52`	`52`
`@@ -93,7 +93,7 @@ public static partial class McpServerBuilderExtensions`
`93`	`93`	`builder.Services.AddSingleton(services => McpServerTool.Create(`
`94`	`94`	`toolMethod,`
`95`	`95`	`toolMethod.IsStatic ? null : target,`
`96`		`- new() { Services = services, SerializerOptions = serializerOptions }));`
	`96`	`+ new() { Services = services, SerializerOptions = serializerOptions ?? services.GetRequiredService<IOptions<McpServerOptions>>().Value.JsonSerializerOptions }));`
`97`	`97`	`}`
`98`	`98`	`}`
`99`	`99`
`@@ -149,8 +149,8 @@ public static IMcpServerBuilder WithTools(this IMcpServerBuilder builder, IEnume`
`149`	`149`	`if (toolMethod.GetCustomAttribute<McpServerToolAttribute>() is not null)`
`150`	`150`	`{`
`151`	`151`	`builder.Services.AddSingleton((Func<IServiceProvider, McpServerTool>)(toolMethod.IsStatic ?`
`152`		`- services => McpServerTool.Create(toolMethod, options: new() { Services = services , SerializerOptions = serializerOptions }) :`
`153`		`- services => McpServerTool.Create(toolMethod, r => CreateTarget(r.Services, toolType), new() { Services = services , SerializerOptions = serializerOptions })));`
	`152`	`+ services => McpServerTool.Create(toolMethod, options: new() { Services = services , SerializerOptions = serializerOptions ?? services.GetRequiredService<IOptions<McpServerOptions>>().Value.JsonSerializerOptions }) :`
	`153`	`+ services => McpServerTool.Create(toolMethod, r => CreateTarget(r.Services, toolType), new() { Services = services , SerializerOptions = serializerOptions ?? services.GetRequiredService<IOptions<McpServerOptions>>().Value.JsonSerializerOptions })));`
`154`	`154`	`}`
`155`	`155`	`}`
`156`	`156`	`}`
`@@ -232,8 +232,8 @@ where t.GetCustomAttribute<McpServerToolTypeAttribute>() is not null`
`232`	`232`	`if (promptMethod.GetCustomAttribute<McpServerPromptAttribute>() is not null)`
`233`	`233`	`{`
`234`	`234`	`builder.Services.AddSingleton((Func<IServiceProvider, McpServerPrompt>)(promptMethod.IsStatic ?`
`235`		`- services => McpServerPrompt.Create(promptMethod, options: new() { Services = services, SerializerOptions = serializerOptions }) :`
`236`		`- services => McpServerPrompt.Create(promptMethod, static r => CreateTarget(r.Services, typeof(TPromptType)), new() { Services = services, SerializerOptions = serializerOptions })));`
	`235`	`+ services => McpServerPrompt.Create(promptMethod, options: new() { Services = services, SerializerOptions = serializerOptions ?? services.GetRequiredService<IOptions<McpServerOptions>>().Value.JsonSerializerOptions }) :`
	`236`	`+ services => McpServerPrompt.Create(promptMethod, static r => CreateTarget(r.Services, typeof(TPromptType)), new() { Services = services, SerializerOptions = serializerOptions ?? services.GetRequiredService<IOptions<McpServerOptions>>().Value.JsonSerializerOptions })));`
`237`	`237`	`}`
`238`	`238`	`}`
`239`	`239`
`@@ -277,7 +277,7 @@ where t.GetCustomAttribute<McpServerToolTypeAttribute>() is not null`
`277`	`277`	`{`
`278`	`278`	`if (promptMethod.GetCustomAttribute<McpServerPromptAttribute>() is not null)`
`279`	`279`	`{`
`280`		`- builder.Services.AddSingleton(services => McpServerPrompt.Create(promptMethod, target, new() { Services = services, SerializerOptions = serializerOptions }));`
	`280`	`+ builder.Services.AddSingleton(services => McpServerPrompt.Create(promptMethod, target, new() { Services = services, SerializerOptions = serializerOptions ?? services.GetRequiredService<IOptions<McpServerOptions>>().Value.JsonSerializerOptions }));`
`281`	`281`	`}`
`282`	`282`	`}`
`283`	`283`
`@@ -333,8 +333,8 @@ public static IMcpServerBuilder WithPrompts(this IMcpServerBuilder builder, IEnu`
`333`	`333`	`if (promptMethod.GetCustomAttribute<McpServerPromptAttribute>() is not null)`
`334`	`334`	`{`
`335`	`335`	`builder.Services.AddSingleton((Func<IServiceProvider, McpServerPrompt>)(promptMethod.IsStatic ?`
`336`		`- services => McpServerPrompt.Create(promptMethod, options: new() { Services = services, SerializerOptions = serializerOptions }) :`
`337`		`- services => McpServerPrompt.Create(promptMethod, r => CreateTarget(r.Services, promptType), new() { Services = services, SerializerOptions = serializerOptions })));`
	`336`	`+ services => McpServerPrompt.Create(promptMethod, options: new() { Services = services, SerializerOptions = serializerOptions ?? services.GetRequiredService<IOptions<McpServerOptions>>().Value.JsonSerializerOptions }) :`
	`337`	`+ services => McpServerPrompt.Create(promptMethod, r => CreateTarget(r.Services, promptType), new() { Services = services, SerializerOptions = serializerOptions ?? services.GetRequiredService<IOptions<McpServerOptions>>().Value.JsonSerializerOptions })));`
`338`	`338`	`}`
`339`	`339`	`}`
`340`	`340`	`}`
`@@ -394,6 +394,7 @@ where t.GetCustomAttribute<McpServerPromptTypeAttribute>() is not null`
`394`	`394`	`/// <summary>Adds <see cref="McpServerResource"/> instances to the service collection backing <paramref name="builder"/>.</summary>`
`395`	`395`	`/// <typeparam name="TResourceType">The resource type.</typeparam>`
`396`	`396`	`/// <param name="builder">The builder instance.</param>`
	`397`	`+ /// <param name="serializerOptions">The serializer options governing resource parameter marshalling.</param>`
`397`	`398`	`/// <returns>The builder provided in <paramref name="builder"/>.</returns>`
`398`	`399`	`/// <exception cref="ArgumentNullException"><paramref name="builder"/> is <see langword="null"/>.</exception>`
`399`	`400`	`/// <remarks>`
`@@ -405,7 +406,8 @@ where t.GetCustomAttribute<McpServerPromptTypeAttribute>() is not null`
`405`	`406`	`DynamicallyAccessedMemberTypes.PublicMethods \|`
`406`	`407`	`DynamicallyAccessedMemberTypes.NonPublicMethods \|`
`407`	`408`	`DynamicallyAccessedMemberTypes.PublicConstructors)] TResourceType>(`
`408`		`- this IMcpServerBuilder builder)`
	`409`	`+ this IMcpServerBuilder builder,`
	`410`	`+ JsonSerializerOptions? serializerOptions = null)`
`409`	`411`	`{`
`410`	`412`	`Throw.IfNull(builder);`
`411`	`413`
`@@ -414,8 +416,8 @@ where t.GetCustomAttribute<McpServerPromptTypeAttribute>() is not null`
`414`	`416`	`if (resourceTemplateMethod.GetCustomAttribute<McpServerResourceAttribute>() is not null)`
`415`	`417`	`{`
`416`	`418`	`builder.Services.AddSingleton((Func<IServiceProvider, McpServerResource>)(resourceTemplateMethod.IsStatic ?`
`417`		`- services => McpServerResource.Create(resourceTemplateMethod, options: new() { Services = services }) :`
`418`		`- services => McpServerResource.Create(resourceTemplateMethod, static r => CreateTarget(r.Services, typeof(TResourceType)), new() { Services = services })));`
	`419`	`+ services => McpServerResource.Create(resourceTemplateMethod, options: new() { Services = services, SerializerOptions = serializerOptions ?? services.GetRequiredService<IOptions<McpServerOptions>>().Value.JsonSerializerOptions }) :`
	`420`	`+ services => McpServerResource.Create(resourceTemplateMethod, static r => CreateTarget(r.Services, typeof(TResourceType)), new() { Services = services, SerializerOptions = serializerOptions ?? services.GetRequiredService<IOptions<McpServerOptions>>().Value.JsonSerializerOptions })));`
`419`	`421`	`}`
`420`	`422`	`}`
`421`	`423`
`@@ -426,6 +428,7 @@ where t.GetCustomAttribute<McpServerPromptTypeAttribute>() is not null`
`426`	`428`	`/// <typeparam name="TResourceType">The resource type.</typeparam>`
`427`	`429`	`/// <param name="builder">The builder instance.</param>`
`428`	`430`	`/// <param name="target">The target instance from which the prompts should be sourced.</param>`
	`431`	`+ /// <param name="serializerOptions">The serializer options governing resource parameter marshalling.</param>`
`429`	`432`	`/// <returns>The builder provided in <paramref name="builder"/>.</returns>`
`430`	`433`	`/// <exception cref="ArgumentNullException"><paramref name="builder"/> is <see langword="null"/>.</exception>`
`431`	`434`	`/// <remarks>`
`@@ -443,7 +446,8 @@ where t.GetCustomAttribute<McpServerPromptTypeAttribute>() is not null`
`443`	`446`	`DynamicallyAccessedMemberTypes.PublicMethods \|`
`444`	`447`	`DynamicallyAccessedMemberTypes.NonPublicMethods)] TResourceType>(`
`445`	`448`	`this IMcpServerBuilder builder,`
`446`		`- TResourceType target)`
	`449`	`+ TResourceType target,`
	`450`	`+ JsonSerializerOptions? serializerOptions = null)`
`447`	`451`	`{`
`448`	`452`	`Throw.IfNull(builder);`
`449`	`453`	`Throw.IfNull(target);`
`@@ -457,7 +461,7 @@ where t.GetCustomAttribute<McpServerPromptTypeAttribute>() is not null`
`457`	`461`	`{`
`458`	`462`	`if (resourceTemplateMethod.GetCustomAttribute<McpServerResourceAttribute>() is not null)`
`459`	`463`	`{`
`460`		`- builder.Services.AddSingleton(services => McpServerResource.Create(resourceTemplateMethod, target, new() { Services = services }));`
	`464`	`+ builder.Services.AddSingleton(services => McpServerResource.Create(resourceTemplateMethod, target, new() { Services = services, SerializerOptions = serializerOptions ?? services.GetRequiredService<IOptions<McpServerOptions>>().Value.JsonSerializerOptions }));`
`461`	`465`	`}`
`462`	`466`	`}`
`463`	`467`
`@@ -489,6 +493,7 @@ public static IMcpServerBuilder WithResources(this IMcpServerBuilder builder, IE`
`489`	`493`	`/// <summary>Adds <see cref="McpServerResource"/> instances to the service collection backing <paramref name="builder"/>.</summary>`
`490`	`494`	`/// <param name="builder">The builder instance.</param>`
`491`	`495`	`/// <param name="resourceTemplateTypes">Types with marked methods to add as resources to the server.</param>`
	`496`	`+ /// <param name="serializerOptions">The serializer options governing resource parameter marshalling.</param>`
`492`	`497`	`/// <returns>The builder provided in <paramref name="builder"/>.</returns>`
`493`	`498`	`/// <exception cref="ArgumentNullException"><paramref name="builder"/> is <see langword="null"/>.</exception>`
`494`	`499`	`/// <exception cref="ArgumentNullException"><paramref name="resourceTemplateTypes"/> is <see langword="null"/>.</exception>`
`@@ -498,7 +503,7 @@ public static IMcpServerBuilder WithResources(this IMcpServerBuilder builder, IE`
`498`	`503`	`/// instance for each. For instance methods, an instance will be constructed for each invocation of the resource.`
`499`	`504`	`/// </remarks>`
`500`	`505`	`[RequiresUnreferencedCode(WithResourcesRequiresUnreferencedCodeMessage)]`
`501`		`- public static IMcpServerBuilder WithResources(this IMcpServerBuilder builder, IEnumerable<Type> resourceTemplateTypes)`
	`506`	`+ public static IMcpServerBuilder WithResources(this IMcpServerBuilder builder, IEnumerable<Type> resourceTemplateTypes, JsonSerializerOptions? serializerOptions = null)`
`502`	`507`	`{`
`503`	`508`	`Throw.IfNull(builder);`
`504`	`509`	`Throw.IfNull(resourceTemplateTypes);`
`@@ -512,8 +517,8 @@ public static IMcpServerBuilder WithResources(this IMcpServerBuilder builder, IE`
`512`	`517`	`if (resourceTemplateMethod.GetCustomAttribute<McpServerResourceAttribute>() is not null)`
`513`	`518`	`{`
`514`	`519`	`builder.Services.AddSingleton((Func<IServiceProvider, McpServerResource>)(resourceTemplateMethod.IsStatic ?`
`515`		`- services => McpServerResource.Create(resourceTemplateMethod, options: new() { Services = services }) :`
`516`		`- services => McpServerResource.Create(resourceTemplateMethod, r => CreateTarget(r.Services, resourceTemplateType), new() { Services = services })));`
	`520`	`+ services => McpServerResource.Create(resourceTemplateMethod, options: new() { Services = services, SerializerOptions = serializerOptions ?? services.GetRequiredService<IOptions<McpServerOptions>>().Value.JsonSerializerOptions }) :`
	`521`	`+ services => McpServerResource.Create(resourceTemplateMethod, r => CreateTarget(r.Services, resourceTemplateType), new() { Services = services, SerializerOptions = serializerOptions ?? services.GetRequiredService<IOptions<McpServerOptions>>().Value.JsonSerializerOptions })));`
`517`	`522`	`}`
`518`	`523`	`}`
`519`	`524`	`}`
`@@ -526,6 +531,7 @@ public static IMcpServerBuilder WithResources(this IMcpServerBuilder builder, IE`
`526`	`531`	`/// Adds types marked with the <see cref="McpServerResourceTypeAttribute"/> attribute from the given assembly as resources to the server.`
`527`	`532`	`/// </summary>`
`528`	`533`	`/// <param name="builder">The builder instance.</param>`
	`534`	`+ /// <param name="serializerOptions">The serializer options governing resource parameter marshalling.</param>`
`529`	`535`	`/// <param name="resourceAssembly">The assembly to load the types from. If <see langword="null"/>, the calling assembly will be used.</param>`
`530`	`536`	`/// <returns>The builder provided in <paramref name="builder"/>.</returns>`
`531`	`537`	`/// <exception cref="ArgumentNullException"><paramref name="builder"/> is <see langword="null"/>.</exception>`
`@@ -550,7 +556,7 @@ public static IMcpServerBuilder WithResources(this IMcpServerBuilder builder, IE`
`550`	`556`	`/// </para>`
`551`	`557`	`/// </remarks>`
`552`	`558`	`[RequiresUnreferencedCode(WithResourcesRequiresUnreferencedCodeMessage)]`
`553`		`- public static IMcpServerBuilder WithResourcesFromAssembly(this IMcpServerBuilder builder, Assembly? resourceAssembly = null)`
	`559`	`+ public static IMcpServerBuilder WithResourcesFromAssembly(this IMcpServerBuilder builder, Assembly? resourceAssembly = null, JsonSerializerOptions? serializerOptions = null)`
`554`	`560`	`{`
`555`	`561`	`Throw.IfNull(builder);`
`556`	`562`
`@@ -559,7 +565,8 @@ public static IMcpServerBuilder WithResourcesFromAssembly(this IMcpServerBuilder`
`559`	`565`	`return builder.WithResources(`
`560`	`566`	`from t in resourceAssembly.GetTypes()`
`561`	`567`	`where t.GetCustomAttribute<McpServerResourceTypeAttribute>() is not null`
`562`		`- select t);`
	`568`	`+ select t,`
	`569`	`+ serializerOptions);`
`563`	`570`	`}`
`564`	`571`	`#endregion`
`565`	`572`