Add middleware and authz support for server-side handlers (#733)

src/ModelContextProtocol/McpServerBuilderExtensions.cs

@@ -91,7 +91,7 @@ public static partial class McpServerBuilderExtensions
             if (toolMethod.GetCustomAttribute<McpServerToolAttribute>() is not null)
             {
                 builder.Services.AddSingleton(services => McpServerTool.Create(
-                    toolMethod, 
+                    toolMethod,
                     toolMethod.IsStatic ? null : target,
                     new() { Services = services, SerializerOptions = serializerOptions }));
             }
@@ -585,7 +585,7 @@ public static partial class McpServerBuilderExtensions
     /// resource system where templates define the URI patterns and the read handler provides the actual content.
     /// </para>
     /// </remarks>
-    public static IMcpServerBuilder WithListResourceTemplatesHandler(this IMcpServerBuilder builder, Func<RequestContext<ListResourceTemplatesRequestParams>, CancellationToken, ValueTask<ListResourceTemplatesResult>> handler)
+    public static IMcpServerBuilder WithListResourceTemplatesHandler(this IMcpServerBuilder builder, McpRequestHandler<ListResourceTemplatesRequestParams, ListResourceTemplatesResult> handler)
     {
         Throw.IfNull(builder);
 
@@ -618,7 +618,7 @@ public static partial class McpServerBuilderExtensions
     /// executes them when invoked by clients.
     /// </para>
     /// </remarks>
-    public static IMcpServerBuilder WithListToolsHandler(this IMcpServerBuilder builder, Func<RequestContext<ListToolsRequestParams>, CancellationToken, ValueTask<ListToolsResult>> handler)
+    public static IMcpServerBuilder WithListToolsHandler(this IMcpServerBuilder builder, McpRequestHandler<ListToolsRequestParams, ListToolsResult> handler)
     {
         Throw.IfNull(builder);
 
@@ -638,7 +638,7 @@ public static partial class McpServerBuilderExtensions
     /// This method is typically paired with <see cref="WithListToolsHandler"/> to provide a complete tools implementation,
     /// where <see cref="WithListToolsHandler"/> advertises available tools and this handler executes them.
     /// </remarks>
-    public static IMcpServerBuilder WithCallToolHandler(this IMcpServerBuilder builder, Func<RequestContext<CallToolRequestParams>, CancellationToken, ValueTask<CallToolResult>> handler)
+    public static IMcpServerBuilder WithCallToolHandler(this IMcpServerBuilder builder, McpRequestHandler<CallToolRequestParams, CallToolResult> handler)
     {
         Throw.IfNull(builder);
 
@@ -671,7 +671,7 @@ public static partial class McpServerBuilderExtensions
     /// produces them when invoked by clients.
     /// </para>
     /// </remarks>
-    public static IMcpServerBuilder WithListPromptsHandler(this IMcpServerBuilder builder, Func<RequestContext<ListPromptsRequestParams>, CancellationToken, ValueTask<ListPromptsResult>> handler)
+    public static IMcpServerBuilder WithListPromptsHandler(this IMcpServerBuilder builder, McpRequestHandler<ListPromptsRequestParams, ListPromptsResult> handler)
     {
         Throw.IfNull(builder);
 
@@ -686,7 +686,7 @@ public static partial class McpServerBuilderExtensions
     /// <param name="handler">The handler function that processes prompt requests.</param>
     /// <returns>The builder provided in <paramref name="builder"/>.</returns>
     /// <exception cref="ArgumentNullException"><paramref name="builder"/> is <see langword="null"/>.</exception>
-    public static IMcpServerBuilder WithGetPromptHandler(this IMcpServerBuilder builder, Func<RequestContext<GetPromptRequestParams>, CancellationToken, ValueTask<GetPromptResult>> handler)
+    public static IMcpServerBuilder WithGetPromptHandler(this IMcpServerBuilder builder, McpRequestHandler<GetPromptRequestParams, GetPromptResult> handler)
     {
         Throw.IfNull(builder);
 
@@ -707,7 +707,7 @@ public static partial class McpServerBuilderExtensions
     /// where this handler advertises available resources and the read handler provides their content when requested.
     /// </para>
     /// </remarks>
-    public static IMcpServerBuilder WithListResourcesHandler(this IMcpServerBuilder builder, Func<RequestContext<ListResourcesRequestParams>, CancellationToken, ValueTask<ListResourcesResult>> handler)
+    public static IMcpServerBuilder WithListResourcesHandler(this IMcpServerBuilder builder, McpRequestHandler<ListResourcesRequestParams, ListResourcesResult> handler)
     {
         Throw.IfNull(builder);
 
@@ -726,7 +726,7 @@ public static partial class McpServerBuilderExtensions
     /// This handler is typically paired with <see cref="WithListResourcesHandler"/> to provide a complete resources implementation,
     /// where the list handler advertises available resources and the read handler provides their content when requested.
     /// </remarks>
-    public static IMcpServerBuilder WithReadResourceHandler(this IMcpServerBuilder builder, Func<RequestContext<ReadResourceRequestParams>, CancellationToken, ValueTask<ReadResourceResult>> handler)
+    public static IMcpServerBuilder WithReadResourceHandler(this IMcpServerBuilder builder, McpRequestHandler<ReadResourceRequestParams, ReadResourceResult> handler)
     {
         Throw.IfNull(builder);
 
@@ -745,7 +745,7 @@ public static partial class McpServerBuilderExtensions
     /// The completion handler is invoked when clients request suggestions for argument values.
     /// This enables auto-complete functionality for both prompt arguments and resource references.
     /// </remarks>
-    public static IMcpServerBuilder WithCompleteHandler(this IMcpServerBuilder builder, Func<RequestContext<CompleteRequestParams>, CancellationToken, ValueTask<CompleteResult>> handler)
+    public static IMcpServerBuilder WithCompleteHandler(this IMcpServerBuilder builder, McpRequestHandler<CompleteRequestParams, CompleteResult> handler)
     {
         Throw.IfNull(builder);
 
@@ -775,7 +775,7 @@ public static partial class McpServerBuilderExtensions
     /// resources and to send appropriate notifications through the connection when resources change.
     /// </para>
     /// </remarks>
-    public static IMcpServerBuilder WithSubscribeToResourcesHandler(this IMcpServerBuilder builder, Func<RequestContext<SubscribeRequestParams>, CancellationToken, ValueTask<EmptyResult>> handler)
+    public static IMcpServerBuilder WithSubscribeToResourcesHandler(this IMcpServerBuilder builder, McpRequestHandler<SubscribeRequestParams, EmptyResult> handler)
     {
         Throw.IfNull(builder);
 
@@ -805,7 +805,7 @@ public static partial class McpServerBuilderExtensions
     /// to the specified resource.
     /// </para>
     /// </remarks>
-    public static IMcpServerBuilder WithUnsubscribeFromResourcesHandler(this IMcpServerBuilder builder, Func<RequestContext<UnsubscribeRequestParams>, CancellationToken, ValueTask<EmptyResult>> handler)
+    public static IMcpServerBuilder WithUnsubscribeFromResourcesHandler(this IMcpServerBuilder builder, McpRequestHandler<UnsubscribeRequestParams, EmptyResult> handler)
     {
         Throw.IfNull(builder);
 
@@ -832,7 +832,7 @@ public static partial class McpServerBuilderExtensions
     /// most recently set level.
     /// </para>
     /// </remarks>
-    public static IMcpServerBuilder WithSetLoggingLevelHandler(this IMcpServerBuilder builder, Func<RequestContext<SetLevelRequestParams>, CancellationToken, ValueTask<EmptyResult>> handler)
+    public static IMcpServerBuilder WithSetLoggingLevelHandler(this IMcpServerBuilder builder, McpRequestHandler<SetLevelRequestParams, EmptyResult> handler)
     {
         Throw.IfNull(builder);
 
@@ -841,6 +841,278 @@ public static partial class McpServerBuilderExtensions
     }
     #endregion
 
+    #region Filters
+    /// <summary>
+    /// Adds a filter to the list resource templates handler pipeline.
+    /// </summary>
+    /// <param name="builder">The builder instance.</param>
+    /// <param name="filter">The filter function that wraps the handler.</param>
+    /// <returns>The builder provided in <paramref name="builder"/>.</returns>
+    /// <exception cref="ArgumentNullException"><paramref name="builder"/> is <see langword="null"/>.</exception>
+    /// <remarks>
+    /// <para>
+    /// This filter wraps handlers that return a list of available resource templates when requested by a client.
+    /// The filter can modify, log, or perform additional operations on requests and responses for
+    /// <see cref="RequestMethods.ResourcesTemplatesList"/> requests. It supports pagination through the cursor mechanism,
+    /// where the client can make repeated calls with the cursor returned by the previous call to retrieve more resource templates.
+    /// </para>
+    /// </remarks>
+    public static IMcpServerBuilder AddListResourceTemplatesFilter(this IMcpServerBuilder builder, McpRequestFilter<ListResourceTemplatesRequestParams, ListResourceTemplatesResult> filter)
+    {
+        Throw.IfNull(builder);
+
+        builder.Services.Configure<McpServerOptions>(options => options.Filters.ListResourceTemplatesFilters.Add(filter));
+        return builder;
+    }
+
+    /// <summary>
+    /// Adds a filter to the list tools handler pipeline.
+    /// </summary>
+    /// <param name="builder">The builder instance.</param>
+    /// <param name="filter">The filter function that wraps the handler.</param>
+    /// <returns>The builder provided in <paramref name="builder"/>.</returns>
+    /// <exception cref="ArgumentNullException"><paramref name="builder"/> is <see langword="null"/>.</exception>
+    /// <remarks>
+    /// <para>
+    /// This filter wraps handlers that return a list of available tools when requested by a client.
+    /// The filter can modify, log, or perform additional operations on requests and responses for
+    /// <see cref="RequestMethods.ToolsList"/> requests. It supports pagination through the cursor mechanism,
+    /// where the client can make repeated calls with the cursor returned by the previous call to retrieve more tools.
+    /// </para>
+    /// <para>
+    /// This filter works alongside any tools defined in the <see cref="McpServerTool"/> collection.
+    /// Tools from both sources will be combined when returning results to clients.
+    /// </para>
+    /// </remarks>
+    public static IMcpServerBuilder AddListToolsFilter(this IMcpServerBuilder builder, McpRequestFilter<ListToolsRequestParams, ListToolsResult> filter)
+    {
+        Throw.IfNull(builder);
+
+        builder.Services.Configure<McpServerOptions>(options => options.Filters.ListToolsFilters.Add(filter));
+        return builder;
+    }
+
+    /// <summary>
+    /// Adds a filter to the call tool handler pipeline.
+    /// </summary>
+    /// <param name="builder">The builder instance.</param>
+    /// <param name="filter">The filter function that wraps the handler.</param>
+    /// <returns>The builder provided in <paramref name="builder"/>.</returns>
+    /// <exception cref="ArgumentNullException"><paramref name="builder"/> is <see langword="null"/>.</exception>
+    /// <remarks>
+    /// <para>
+    /// This filter wraps handlers that are invoked when a client makes a call to a tool that isn't found in the <see cref="McpServerTool"/> collection.
+    /// The filter can modify, log, or perform additional operations on requests and responses for
+    /// <see cref="RequestMethods.ToolsCall"/> requests. The handler should implement logic to execute the requested tool and return appropriate results.
+    /// </para>
+    /// </remarks>
+    public static IMcpServerBuilder AddCallToolFilter(this IMcpServerBuilder builder, McpRequestFilter<CallToolRequestParams, CallToolResult> filter)
+    {
+        Throw.IfNull(builder);
+
+        builder.Services.Configure<McpServerOptions>(options => options.Filters.CallToolFilters.Add(filter));
+        return builder;
+    }
+
+    /// <summary>
+    /// Adds a filter to the list prompts handler pipeline.
+    /// </summary>
+    /// <param name="builder">The builder instance.</param>
+    /// <param name="filter">The filter function that wraps the handler.</param>
+    /// <returns>The builder provided in <paramref name="builder"/>.</returns>
+    /// <exception cref="ArgumentNullException"><paramref name="builder"/> is <see langword="null"/>.</exception>
+    /// <remarks>
+    /// <para>
+    /// This filter wraps handlers that return a list of available prompts when requested by a client.
+    /// The filter can modify, log, or perform additional operations on requests and responses for
+    /// <see cref="RequestMethods.PromptsList"/> requests. It supports pagination through the cursor mechanism,
+    /// where the client can make repeated calls with the cursor returned by the previous call to retrieve more prompts.
+    /// </para>
+    /// <para>
+    /// This filter works alongside any prompts defined in the <see cref="McpServerPrompt"/> collection.
+    /// Prompts from both sources will be combined when returning results to clients.
+    /// </para>
+    /// </remarks>
+    public static IMcpServerBuilder AddListPromptsFilter(this IMcpServerBuilder builder, McpRequestFilter<ListPromptsRequestParams, ListPromptsResult> filter)
+    {
+        Throw.IfNull(builder);
+
+        builder.Services.Configure<McpServerOptions>(options => options.Filters.ListPromptsFilters.Add(filter));
+        return builder;
+    }
+
+    /// <summary>
+    /// Adds a filter to the get prompt handler pipeline.
+    /// </summary>
+    /// <param name="builder">The builder instance.</param>
+    /// <param name="filter">The filter function that wraps the handler.</param>
+    /// <returns>The builder provided in <paramref name="builder"/>.</returns>
+    /// <exception cref="ArgumentNullException"><paramref name="builder"/> is <see langword="null"/>.</exception>
+    /// <remarks>
+    /// <para>
+    /// This filter wraps handlers that are invoked when a client requests details for a specific prompt that isn't found in the <see cref="McpServerPrompt"/> collection.
+    /// The filter can modify, log, or perform additional operations on requests and responses for
+    /// <see cref="RequestMethods.PromptsGet"/> requests. The handler should implement logic to fetch or generate the requested prompt and return appropriate results.
+    /// </para>
+    /// </remarks>
+    public static IMcpServerBuilder AddGetPromptFilter(this IMcpServerBuilder builder, McpRequestFilter<GetPromptRequestParams, GetPromptResult> filter)
+    {
+        Throw.IfNull(builder);
+
+        builder.Services.Configure<McpServerOptions>(options => options.Filters.GetPromptFilters.Add(filter));
+        return builder;
+    }
+
+    /// <summary>
+    /// Adds a filter to the list resources handler pipeline.
+    /// </summary>
+    /// <param name="builder">The builder instance.</param>
+    /// <param name="filter">The filter function that wraps the handler.</param>
+    /// <returns>The builder provided in <paramref name="builder"/>.</returns>
+    /// <exception cref="ArgumentNullException"><paramref name="builder"/> is <see langword="null"/>.</exception>
+    /// <remarks>
+    /// <para>
+    /// This filter wraps handlers that return a list of available resources when requested by a client.
+    /// The filter can modify, log, or perform additional operations on requests and responses for
+    /// <see cref="RequestMethods.ResourcesList"/> requests. It supports pagination through the cursor mechanism,
+    /// where the client can make repeated calls with the cursor returned by the previous call to retrieve more resources.
+    /// </para>
+    /// </remarks>
+    public static IMcpServerBuilder AddListResourcesFilter(this IMcpServerBuilder builder, McpRequestFilter<ListResourcesRequestParams, ListResourcesResult> filter)
+    {
+        Throw.IfNull(builder);
+
+        builder.Services.Configure<McpServerOptions>(options => options.Filters.ListResourcesFilters.Add(filter));
+        return builder;
+    }
+
+    /// <summary>
+    /// Adds a filter to the read resource handler pipeline.
+    /// </summary>
+    /// <param name="builder">The builder instance.</param>
+    /// <param name="filter">The filter function that wraps the handler.</param>
+    /// <returns>The builder provided in <paramref name="builder"/>.</returns>
+    /// <exception cref="ArgumentNullException"><paramref name="builder"/> is <see langword="null"/>.</exception>
+    /// <remarks>
+    /// <para>
+    /// This filter wraps handlers that are invoked when a client requests the content of a specific resource identified by its URI.
+    /// The filter can modify, log, or perform additional operations on requests and responses for
+    /// <see cref="RequestMethods.ResourcesRead"/> requests. The handler should implement logic to locate and retrieve the requested resource.
+    /// </para>
+    /// </remarks>
+    public static IMcpServerBuilder AddReadResourceFilter(this IMcpServerBuilder builder, McpRequestFilter<ReadResourceRequestParams, ReadResourceResult> filter)
+    {
+        Throw.IfNull(builder);
+
+        builder.Services.Configure<McpServerOptions>(options => options.Filters.ReadResourceFilters.Add(filter));
+        return builder;
+    }
+
+    /// <summary>
+    /// Adds a filter to the complete handler pipeline.
+    /// </summary>
+    /// <param name="builder">The builder instance.</param>
+    /// <param name="filter">The filter function that wraps the handler.</param>
+    /// <returns>The builder provided in <paramref name="builder"/>.</returns>
+    /// <exception cref="ArgumentNullException"><paramref name="builder"/> is <see langword="null"/>.</exception>
+    /// <remarks>
+    /// <para>
+    /// This filter wraps handlers that provide auto-completion suggestions for prompt arguments or resource references in the Model Context Protocol.
+    /// The filter can modify, log, or perform additional operations on requests and responses for
+    /// <see cref="RequestMethods.CompletionComplete"/> requests. The handler processes auto-completion requests, returning a list of suggestions based on the
+    /// reference type and current argument value.
+    /// </para>
+    /// </remarks>
+    public static IMcpServerBuilder AddCompleteFilter(this IMcpServerBuilder builder, McpRequestFilter<CompleteRequestParams, CompleteResult> filter)
+    {
+        Throw.IfNull(builder);
+
+        builder.Services.Configure<McpServerOptions>(options => options.Filters.CompleteFilters.Add(filter));
+        return builder;
+    }
+
+    /// <summary>
+    /// Adds a filter to the subscribe to resources handler pipeline.
+    /// </summary>
+    /// <param name="builder">The builder instance.</param>
+    /// <param name="filter">The filter function that wraps the handler.</param>
+    /// <returns>The builder provided in <paramref name="builder"/>.</returns>
+    /// <exception cref="ArgumentNullException"><paramref name="builder"/> is <see langword="null"/>.</exception>
+    /// <remarks>
+    /// <para>
+    /// This filter wraps handlers that are invoked when a client wants to receive notifications about changes to specific resources or resource patterns.
+    /// The filter can modify, log, or perform additional operations on requests and responses for
+    /// <see cref="RequestMethods.ResourcesSubscribe"/> requests. The handler should implement logic to register the client's interest in the specified resources
+    /// and set up the necessary infrastructure to send notifications when those resources change.
+    /// </para>
+    /// <para>
+    /// After a successful subscription, the server should send resource change notifications to the client
+    /// whenever a relevant resource is created, updated, or deleted.
+    /// </para>
+    /// </remarks>
+    public static IMcpServerBuilder AddSubscribeToResourcesFilter(this IMcpServerBuilder builder, McpRequestFilter<SubscribeRequestParams, EmptyResult> filter)
+    {
+        Throw.IfNull(builder);
+
+        builder.Services.Configure<McpServerOptions>(options => options.Filters.SubscribeToResourcesFilters.Add(filter));
+        return builder;
+    }
+
+    /// <summary>
+    /// Adds a filter to the unsubscribe from resources handler pipeline.
+    /// </summary>
+    /// <param name="builder">The builder instance.</param>
+    /// <param name="filter">The filter function that wraps the handler.</param>
+    /// <returns>The builder provided in <paramref name="builder"/>.</returns>
+    /// <exception cref="ArgumentNullException"><paramref name="builder"/> is <see langword="null"/>.</exception>
+    /// <remarks>
+    /// <para>
+    /// This filter wraps handlers that are invoked when a client wants to stop receiving notifications about previously subscribed resources.
+    /// The filter can modify, log, or perform additional operations on requests and responses for
+    /// <see cref="RequestMethods.ResourcesUnsubscribe"/> requests. The handler should implement logic to remove the client's subscriptions to the specified resources
+    /// and clean up any associated resources.
+    /// </para>
+    /// <para>
+    /// After a successful unsubscription, the server should no longer send resource change notifications
+    /// to the client for the specified resources.
+    /// </para>
+    /// </remarks>
+    public static IMcpServerBuilder AddUnsubscribeFromResourcesFilter(this IMcpServerBuilder builder, McpRequestFilter<UnsubscribeRequestParams, EmptyResult> filter)
+    {
+        Throw.IfNull(builder);
+
+        builder.Services.Configure<McpServerOptions>(options => options.Filters.UnsubscribeFromResourcesFilters.Add(filter));
+        return builder;
+    }
+
+    /// <summary>
+    /// Adds a filter to the set logging level handler pipeline.
+    /// </summary>
+    /// <param name="builder">The builder instance.</param>
+    /// <param name="filter">The filter function that wraps the handler.</param>
+    /// <returns>The builder provided in <paramref name="builder"/>.</returns>
+    /// <exception cref="ArgumentNullException"><paramref name="builder"/> is <see langword="null"/>.</exception>
+    /// <remarks>
+    /// <para>
+    /// This filter wraps handlers that process <see cref="RequestMethods.LoggingSetLevel"/> requests from clients. When set, it enables
+    /// clients to control which log messages they receive by specifying a minimum severity threshold.
+    /// The filter can modify, log, or perform additional operations on requests and responses for
+    /// <see cref="RequestMethods.LoggingSetLevel"/> requests.
+    /// </para>
+    /// <para>
+    /// After handling a level change request, the server typically begins sending log messages
+    /// at or above the specified level to the client as notifications/message notifications.
+    /// </para>
+    /// </remarks>
+    public static IMcpServerBuilder AddSetLoggingLevelFilter(this IMcpServerBuilder builder, McpRequestFilter<SetLevelRequestParams, EmptyResult> filter)
+    {
+        Throw.IfNull(builder);
+
+        builder.Services.Configure<McpServerOptions>(options => options.Filters.SetLoggingLevelFilters.Add(filter));
+        return builder;
+    }
+    #endregion
+
     #region Transports
     /// <summary>
     /// Adds a server transport that uses standard input (stdin) and standard output (stdout) for communication.

src/ModelContextProtocol/McpServerHandlers.cs

@@ -40,7 +40,7 @@ public sealed class McpServerHandlers
     /// Tools from both sources will be combined when returning results to clients.
     /// </para>
     /// </remarks>
-    public Func<RequestContext<ListToolsRequestParams>, CancellationToken, ValueTask<ListToolsResult>>? ListToolsHandler { get; set; }
+    public McpRequestHandler<ListToolsRequestParams, ListToolsResult>? ListToolsHandler { get; set; }
 
     /// <summary>
     /// Gets or sets the handler for <see cref="RequestMethods.ToolsCall"/> requests.
@@ -49,7 +49,7 @@ public sealed class McpServerHandlers
     /// This handler is invoked when a client makes a call to a tool that isn't found in the <see cref="McpServerTool"/> collection.
     /// The handler should implement logic to execute the requested tool and return appropriate results.
     /// </remarks>
-    public Func<RequestContext<CallToolRequestParams>, CancellationToken, ValueTask<CallToolResult>>? CallToolHandler { get; set; }
+    public McpRequestHandler<CallToolRequestParams, CallToolResult>? CallToolHandler { get; set; }
 
     /// <summary>
     /// Gets or sets the handler for <see cref="RequestMethods.PromptsList"/> requests.
@@ -65,7 +65,7 @@ public sealed class McpServerHandlers
     /// Prompts from both sources will be combined when returning results to clients.
     /// </para>
     /// </remarks>
-    public Func<RequestContext<ListPromptsRequestParams>, CancellationToken, ValueTask<ListPromptsResult>>? ListPromptsHandler { get; set; }
+    public McpRequestHandler<ListPromptsRequestParams, ListPromptsResult>? ListPromptsHandler { get; set; }
 
     /// <summary>
     /// Gets or sets the handler for <see cref="RequestMethods.PromptsGet"/> requests.
@@ -74,7 +74,7 @@ public sealed class McpServerHandlers
     /// This handler is invoked when a client requests details for a specific prompt that isn't found in the <see cref="McpServerPrompt"/> collection.
     /// The handler should implement logic to fetch or generate the requested prompt and return appropriate results.
     /// </remarks>
-    public Func<RequestContext<GetPromptRequestParams>, CancellationToken, ValueTask<GetPromptResult>>? GetPromptHandler { get; set; }
+    public McpRequestHandler<GetPromptRequestParams, GetPromptResult>? GetPromptHandler { get; set; }
 
     /// <summary>
     /// Gets or sets the handler for <see cref="RequestMethods.ResourcesTemplatesList"/> requests.
@@ -84,7 +84,7 @@ public sealed class McpServerHandlers
     /// It supports pagination through the cursor mechanism, where the client can make
     /// repeated calls with the cursor returned by the previous call to retrieve more resource templates.
     /// </remarks>
-    public Func<RequestContext<ListResourceTemplatesRequestParams>, CancellationToken, ValueTask<ListResourceTemplatesResult>>? ListResourceTemplatesHandler { get; set; }
+    public McpRequestHandler<ListResourceTemplatesRequestParams, ListResourceTemplatesResult>? ListResourceTemplatesHandler { get; set; }
 
     /// <summary>
     /// Gets or sets the handler for <see cref="RequestMethods.ResourcesList"/> requests.
@@ -94,7 +94,7 @@ public sealed class McpServerHandlers
     /// It supports pagination through the cursor mechanism, where the client can make
     /// repeated calls with the cursor returned by the previous call to retrieve more resources.
     /// </remarks>
-    public Func<RequestContext<ListResourcesRequestParams>, CancellationToken, ValueTask<ListResourcesResult>>? ListResourcesHandler { get; set; }
+    public McpRequestHandler<ListResourcesRequestParams, ListResourcesResult>? ListResourcesHandler { get; set; }
 
     /// <summary>
     /// Gets or sets the handler for <see cref="RequestMethods.ResourcesRead"/> requests.
@@ -103,17 +103,17 @@ public sealed class McpServerHandlers
     /// This handler is invoked when a client requests the content of a specific resource identified by its URI.
     /// The handler should implement logic to locate and retrieve the requested resource.
     /// </remarks>
-    public Func<RequestContext<ReadResourceRequestParams>, CancellationToken, ValueTask<ReadResourceResult>>? ReadResourceHandler { get; set; }
+    public McpRequestHandler<ReadResourceRequestParams, ReadResourceResult>? ReadResourceHandler { get; set; }
 
     /// <summary>
     /// Gets or sets the handler for <see cref="RequestMethods.CompletionComplete"/> requests.
     /// </summary>
     /// <remarks>
     /// This handler provides auto-completion suggestions for prompt arguments or resource references in the Model Context Protocol.
-    /// The handler processes auto-completion requests, returning a list of suggestions based on the 
+    /// The handler processes auto-completion requests, returning a list of suggestions based on the
     /// reference type and current argument value.
     /// </remarks>
-    public Func<RequestContext<CompleteRequestParams>, CancellationToken, ValueTask<CompleteResult>>? CompleteHandler { get; set; }
+    public McpRequestHandler<CompleteRequestParams, CompleteResult>? CompleteHandler { get; set; }
 
     /// <summary>
     /// Gets or sets the handler for <see cref="RequestMethods.ResourcesSubscribe"/> requests.
@@ -129,7 +129,7 @@ public sealed class McpServerHandlers
     /// whenever a relevant resource is created, updated, or deleted.
     /// </para>
     /// </remarks>
-    public Func<RequestContext<SubscribeRequestParams>, CancellationToken, ValueTask<EmptyResult>>? SubscribeToResourcesHandler { get; set; }
+    public McpRequestHandler<SubscribeRequestParams, EmptyResult>? SubscribeToResourcesHandler { get; set; }
 
     /// <summary>
     /// Gets or sets the handler for <see cref="RequestMethods.ResourcesUnsubscribe"/> requests.
@@ -145,7 +145,7 @@ public sealed class McpServerHandlers
     /// to the client for the specified resources.
     /// </para>
     /// </remarks>
-    public Func<RequestContext<UnsubscribeRequestParams>, CancellationToken, ValueTask<EmptyResult>>? UnsubscribeFromResourcesHandler { get; set; }
+    public McpRequestHandler<UnsubscribeRequestParams, EmptyResult>? UnsubscribeFromResourcesHandler { get; set; }
 
     /// <summary>
     /// Gets or sets the handler for <see cref="RequestMethods.LoggingSetLevel"/> requests.
@@ -160,7 +160,7 @@ public sealed class McpServerHandlers
     /// at or above the specified level to the client as notifications/message notifications.
     /// </para>
     /// </remarks>
-    public Func<RequestContext<SetLevelRequestParams>, CancellationToken, ValueTask<EmptyResult>>? SetLoggingLevelHandler { get; set; }
+    public McpRequestHandler<SetLevelRequestParams, EmptyResult>? SetLoggingLevelHandler { get; set; }
 
     /// <summary>
     /// Overwrite any handlers in McpServerOptions with non-null handlers from this instance.