Improve tool handling (#28)

* Improve tool handling

* Rework stuff with new hosting options

* Update readme

* Fix build

* Try run client tests

* Fix build

* Fix issues on linux

* Try to run testserver on linux

* Fix test issue

* Fix code smells

.github/workflows/ci.yml

@@ -3,10 +3,8 @@ name: .NET Build, Test and publish
 on:
   push:
     branches: [ "main", "master" ]
-    paths: [ 'src/**' ]
   pull_request:
     branches: [ "main", "master" ]
-    paths: [ 'src/**' ]
   release:    
     types: [published,edited]
 
@@ -24,7 +22,12 @@ jobs:
           fetch-depth: 0  # Shallow clones should be disabled for a better relevancy of analysis
 
     - name: Fetch all history for all tags and branches
-      run: git fetch --prune --unshallow     
+      run: |
+        if [ -f "$(git rev-parse --git-dir)/shallow" ]; then
+          git fetch --prune --unshallow
+        else
+          echo "Repository is already complete."
+        fi 
       
     - name: Setup .NET
       uses: actions/setup-dotnet@v2
@@ -33,6 +36,17 @@ jobs:
           8.0.x
           9.0.x
     
+    - name: Set up Node.js
+      uses: actions/setup-node@v3
+      with:
+        node-version: '20' 
+    
+    - name: Install dependencies for tests
+      run: npm install @modelcontextprotocol/server-everything
+
+    - name: Install dependencies for tests
+      run: npm install @modelcontextprotocol/server-memory
+    
     - name: Run Cake script
       uses: cake-build/cake-action@v1
       with:

.gitignore

@@ -62,4 +62,5 @@ ehthumbs.db
 Desktop.ini
 
 # Recycle Bin used on file shares
-$RECYCLE.BIN/
+$RECYCLE.BIN/
+/mcpdotnet.v3.ncrunchsolution

README.MD

@@ -106,7 +106,33 @@ Remember you can connect to any MCP server, not just ones created using mcpdotne
 
 ## Getting Started (Server)
 
-Here is an example of how to create an MCP server with a single tool. You can also refer to the TestServer in the tests folder, which implements a wider range of capabilities.
+Here is an example of how to create an MCP server and register all tools from the current application.
+
+```csharp
+var builder = Host.CreateApplicationBuilder(args);
+builder.Services.AddMcpServer()
+    .WithStdioServerTransport()
+    .WithTools()
+
+var app = builder.Build();
+
+await app.RunAsync();
+```
+
+The `EchoTool` class is a simple example of a tool implementation:
+```csharp
+[McpToolType]
+public static class EchoTool
+{
+    [McpTool(Description = "Echoes the input back to the client.")]
+    public static string Echo([McpParameter(true)] string message)
+    {
+        return "hello " + message;
+    }
+}
+```
+
+Here is an example of how to create an MCP server manually with a single tool. You can also refer to the TestServer in the tests folder, which implements a wider range of capabilities.
 
 ```csharp
 McpServerOptions options = new McpServerOptions()
@@ -171,6 +197,7 @@ while (true)
 }
 ```
 
+
 ## Roadmap
 
 - Expand documentation with detailed guides for:

samples/TestServerWithHosting/Program.cs

@@ -19,6 +19,7 @@ try
     builder.Services.AddSerilog();
     builder.Services.AddMcpServer()
         .WithStdioServerTransport()
+        .WithTools()
         .WithCallToolHandler((r, ct) => Task.FromResult(new McpDotNet.Protocol.Types.CallToolResponse()));
 
     var app = builder.Build();

samples/TestServerWithHosting/Tools/EchoTool.cs

@@ -0,0 +1,13 @@
+using McpDotNet.Server;
+
+namespace TestServerWithHosting.Tools;
+
+[McpToolType]
+public static class EchoTool
+{
+    [McpTool(Description = "Echoes the input back to the client.")]
+    public static string Echo([McpParameter(true)] string message)
+    {
+        return "hello " + message;
+    }
+}

samples/TestServerWithHosting/Tools/SampleLlmTool.cs

@@ -0,0 +1,47 @@
+using McpDotNet.Protocol.Types;
+using McpDotNet.Server;
+
+namespace TestServerWithHosting.Tools;
+
+/// <summary>
+/// This tool uses depenency injection and async method
+/// </summary>
+[McpToolType]
+public class SampleLlmTool
+{
+    private readonly IMcpServer _server;
+
+    public SampleLlmTool(IMcpServer server)
+    {
+        _server = server ?? throw new ArgumentNullException(nameof(server));
+    }
+
+    [McpTool(Name = "sampleLLM", Description = "Samples from an LLM using MCP's sampling feature")]
+    public async Task<string> SampleLLM([McpParameter(true, Description = "The prompt to send to the LLM")] string prompt, [McpParameter(true, Description = "Maximum number of tokens to generate")] int maxTokens, CancellationToken cancellationToken)
+    {
+        var samplingParams = CreateRequestSamplingParams(prompt ?? string.Empty, "sampleLLM", maxTokens);
+        var sampleResult = await _server.RequestSamplingAsync(samplingParams, cancellationToken);
+
+        return $"LLM sampling result: {sampleResult.Content.Text}";
+    }
+
+    private static CreateMessageRequestParams CreateRequestSamplingParams(string context, string uri, int maxTokens = 100)
+    {
+        return new CreateMessageRequestParams()
+        {
+            Messages = [new SamplingMessage()
+                {
+                    Role = Role.User,
+                    Content = new Content()
+                    {
+                        Type = "text",
+                        Text = $"Resource {uri} context: {context}"
+                    }
+                }],
+            SystemPrompt = "You are a helpful test server.",
+            MaxTokens = maxTokens,
+            Temperature = 0.7f,
+            IncludeContext = ContextInclusion.ThisServer
+        };
+    }
+}

src/mcpdotnet/Configuration/McpServerBuilderExtensions.Handler.cs

@@ -0,0 +1,111 @@
+using McpDotNet.Configuration;
+using McpDotNet.Protocol.Types;
+using McpDotNet.Server;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace McpDotNet;
+
+/// <summary>
+/// Extension to configure the MCP server with handlers
+/// </summary>
+public static partial class McpServerBuilderExtensions
+{
+    /// <summary>
+    /// Sets the handler for list tools requests.
+    /// </summary>
+    /// <param name="builder">The builder instance.</param>
+    /// <param name="handler">The handler.</param>
+    public static IMcpServerBuilder WithListToolsHandler(this IMcpServerBuilder builder, Func<RequestContext<ListToolsRequestParams>, CancellationToken, Task<ListToolsResult>> handler)
+    {
+        builder.Services.Configure<McpServerDelegates>(s => s.ListToolsHandler = handler);
+        return builder;
+    }
+
+    /// <summary>
+    /// Sets the handler for call tool requests.
+    /// </summary>
+    /// <param name="builder">The builder instance.</param>
+    /// <param name="handler">The handler.</param>
+    public static IMcpServerBuilder WithCallToolHandler(this IMcpServerBuilder builder, Func<RequestContext<CallToolRequestParams>, CancellationToken, Task<CallToolResponse>> handler)
+    {
+        builder.Services.Configure<McpServerDelegates>(s => s.CallToolHandler = handler);
+        return builder;
+    }
+
+    /// <summary>
+    /// Sets the handler for list prompts requests.
+    /// </summary>
+    /// <param name="builder">The builder instance.</param>
+    /// <param name="handler">The handler.</param>
+    public static IMcpServerBuilder WithListPromptsHandler(this IMcpServerBuilder builder, Func<RequestContext<ListPromptsRequestParams>, CancellationToken, Task<ListPromptsResult>> handler)
+    {
+        builder.Services.Configure<McpServerDelegates>(s => s.ListPromptsHandler = handler);
+        return builder;
+    }
+
+    /// <summary>
+    /// Sets the handler for get prompt requests.
+    /// </summary>
+    /// <param name="builder">The builder instance.</param>
+    /// <param name="handler">The handler.</param>
+    public static IMcpServerBuilder WithGetPromptHandler(this IMcpServerBuilder builder, Func<RequestContext<GetPromptRequestParams>, CancellationToken, Task<GetPromptResult>> handler)
+    {
+        builder.Services.Configure<McpServerDelegates>(s => s.GetPromptHandler = handler);
+        return builder;
+    }
+
+    /// <summary>
+    /// Sets the handler for list resources requests.
+    /// </summary>
+    /// <param name="builder">The builder instance.</param>
+    /// <param name="handler">The handler.</param>
+    public static IMcpServerBuilder WithListResourcesHandler(this IMcpServerBuilder builder, Func<RequestContext<ListResourcesRequestParams>, CancellationToken, Task<ListResourcesResult>> handler)
+    {
+        builder.Services.Configure<McpServerDelegates>(s => s.ListResourcesHandler = handler);
+        return builder;
+    }
+
+    /// <summary>
+    /// Sets the handler for read resources requests.
+    /// </summary>
+    /// <param name="builder">The builder instance.</param>
+    /// <param name="handler">The handler.</param>
+    public static IMcpServerBuilder WithReadResourceHandler(this IMcpServerBuilder builder, Func<RequestContext<ReadResourceRequestParams>, CancellationToken, Task<ReadResourceResult>> handler)
+    {
+        builder.Services.Configure<McpServerDelegates>(s => s.ReadResourceHandler = handler);
+        return builder;
+    }
+
+    /// <summary>
+    /// Sets the handler for get resources requests.
+    /// </summary>
+    /// <param name="builder">The builder instance.</param>
+    /// <param name="handler">The handler.</param>
+    public static IMcpServerBuilder WithGetCompletionHandler(this IMcpServerBuilder builder, Func<RequestContext<CompleteRequestParams>, CancellationToken, Task<CompleteResult>> handler)
+    {
+        builder.Services.Configure<McpServerDelegates>(s => s.GetCompletionHandler = handler);
+        return builder;
+    }
+
+    /// <summary>
+    /// Sets the handler for subscribe to resources messages.
+    /// </summary>
+    /// <param name="builder">The builder instance.</param>
+    /// <param name="handler">The handler.</param>
+    public static IMcpServerBuilder WithSubscribeToResourcesHandler(this IMcpServerBuilder builder, Func<RequestContext<string>, CancellationToken, Task> handler)
+    {
+        builder.Services.Configure<McpServerDelegates>(s => s.SubscribeToResourcesHandler = handler);
+        return builder;
+    }
+
+    /// <summary>
+    /// Sets or sets the handler for subscribe to resources messages.
+    /// </summary>
+    /// <param name="builder">The builder instance.</param>
+    /// <param name="handler">The handler.</param>
+    public static IMcpServerBuilder WithUnsubscribeFromResourcesHandler(this IMcpServerBuilder builder, Func<RequestContext<string>, CancellationToken, Task> handler)
+    {
+        builder.Services.Configure<McpServerDelegates>(s => s.UnsubscribeFromResourcesHandler = handler);
+        return builder;
+    }
+}

src/mcpdotnet/Configuration/McpServerBuilderExtensions.Tools.cs

@@ -0,0 +1,249 @@
+using System.Reflection;
+using System.Text.Json;
+using McpDotNet.Configuration;
+using McpDotNet.Protocol.Types;
+using McpDotNet.Server;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace McpDotNet;
+
+/// <summary>
+/// Extension to configure the MCP server with tools
+/// </summary>
+public static partial class McpServerBuilderExtensions
+{
+    /// <summary>
+    /// Adds a tool to the server.
+    /// </summary>
+    /// <typeparam name="TTool">The tool type.</typeparam>
+    /// <param name="builder">The builder instance.</param>
+    public static IMcpServerBuilder WithTool<TTool>(this IMcpServerBuilder builder)
+    {
+        return WithTools(builder, typeof(TTool));
+    }
+    /// <summary>
+    /// Adds all tools marked with <see cref="McpToolTypeAttribute"/> from the current assembly to the server.
+    /// </summary>
+    /// <param name="builder">The builder instance.</param>
+    public static IMcpServerBuilder WithTools(this IMcpServerBuilder builder)
+    {
+        return WithToolsFromAssembly(builder, Assembly.GetCallingAssembly());
+    }
+
+    /// <summary>
+    /// Adds tools to the server.
+    /// </summary>
+    /// <param name="builder">The builder instance.</param>
+    /// <param name="toolTypes">Types with marked methods to add as tools to the server.</param>
+    public static IMcpServerBuilder WithTools(this IMcpServerBuilder builder, params Type[] toolTypes)
+    {
+        ArgumentNullException.ThrowIfNull(toolTypes);
+        if (toolTypes.Length == 0)
+            throw new ArgumentException("At least one tool type must be provided.", nameof(toolTypes));
+
+        var tools = new List<Tool>();
+        Dictionary<string, Func<RequestContext<CallToolRequestParams>, CancellationToken, Task<CallToolResponse>>> callbacks = [];
+
+        foreach (var type in toolTypes)
+        {
+            var methods = type.GetMethods(BindingFlags.Public | BindingFlags.Instance | BindingFlags.Static);
+            foreach (var method in methods)
+            {
+                var attribute = method.GetCustomAttribute<McpToolAttribute>();
+                if (attribute != null)
+                {
+                    var tool = CreateTool(method, attribute);
+                    tools.Add(tool);
+
+                    callbacks.Add(tool.Name, async (request, cancellationToken) => await CallTool(request, method, cancellationToken));
+
+                    // register type because method is not static and so we need an instance
+                    if (!method.IsStatic)
+                        builder.Services.AddScoped(type);
+                }
+            }
+        }
+
+        builder.WithListToolsHandler((_, _) => Task.FromResult(new ListToolsResult() { Tools = tools }));
+
+        builder.WithCallToolHandler(async (request, cancellationToken) =>
+        {
+            if (request.Params != null && callbacks.TryGetValue(request.Params.Name, out var callback))
+                return await callback(request, cancellationToken);
+
+            throw new McpServerException($"Unknown tool: {request.Params?.Name}");
+        });
+
+        return builder;
+    }
+
+    /// <summary>
+    /// Adds types marked with the <see cref="McpToolTypeAttribute"/> attribute from the given assembly as tools to the server.
+    /// </summary>
+    /// <param name="builder">The builder instance.</param>
+    /// <param name="assembly">The assembly to load the types from. Null to get the current assembly</param>
+    public static IMcpServerBuilder WithToolsFromAssembly(this IMcpServerBuilder builder, Assembly? assembly = null)
+    {
+        assembly ??= Assembly.GetCallingAssembly();
+
+        List<Type> toolTypes = [];
+
+        foreach (var type in assembly.GetTypes())
+        {
+            bool hasToolTypeAttribute = type.GetCustomAttribute<McpToolTypeAttribute>() != null;
+            if (!hasToolTypeAttribute)
+                continue;
+
+            var methods = type.GetMethods(BindingFlags.Public | BindingFlags.Instance | BindingFlags.Static);
+            foreach (var method in methods)
+            {
+                var attribute = method.GetCustomAttribute<McpToolAttribute>();
+                if (attribute != null)
+                {
+                    toolTypes.Add(type);
+                    break;
+                }
+            }
+        }
+
+        if (toolTypes.Count == 0)
+            throw new ArgumentException("No types with marked methods found in the assembly.", nameof(assembly));
+
+        return WithTools(builder, toolTypes.ToArray());
+    }
+
+    private static Tool CreateTool(MethodInfo method, McpToolAttribute attribute)
+    {
+        Dictionary<string, JsonSchemaProperty> properties = [];
+        List<string>? requiredProperties = null;
+
+        foreach (var parameter in method.GetParameters())
+        {
+            if (parameter.ParameterType == typeof(CancellationToken))
+                continue;
+
+            var parameterAttribute = parameter.GetCustomAttribute<McpParameterAttribute>();
+
+            properties.Add(parameter.Name ?? "NoName", new JsonSchemaProperty()
+            {
+                Type = GetParameterType(parameter.ParameterType),
+                Description = parameterAttribute?.Description
+            });
+
+            if (parameterAttribute?.Required == true)
+            {
+                requiredProperties ??= [];
+                requiredProperties.Add(parameter.Name ?? "NoName");
+            }
+        }
+
+        return new Tool()
+        {
+            Name = attribute.Name ?? method.Name,
+            Description = attribute.Description,
+            InputSchema = new JsonSchema()
+            {
+                Type = "object",
+                Properties = properties,
+                Required = requiredProperties
+            },
+        };
+    }
+
+    private static string GetParameterType(Type parameterType)
+    {
+        return parameterType switch
+        {
+            Type t when t == typeof(string) => "string",
+            Type t when t == typeof(int) || t == typeof(double) || t == typeof(float) => "number",
+            Type t when t == typeof(bool) => "boolean",
+            Type t when t.IsArray => "array",
+            Type t when t == typeof(DateTime) => "string",
+            _ => "object"
+        };
+    }
+
+    private static async Task<CallToolResponse> CallTool(RequestContext<CallToolRequestParams> request, MethodInfo method, CancellationToken cancellationToken)
+    {
+        var methodParameters = method.GetParameters();
+        List<object?> parameters = ResolveParameters(request, methodParameters, cancellationToken);
+
+        if (cancellationToken.IsCancellationRequested)
+            return new CallToolResponse { Content = [new Content { Text = "Operation was cancelled" }] };
+
+        try
+        {
+            using var scope = request.Server.ServiceProvider?.CreateScope();
+            var objectInstance = CreateObjectInstance(method, scope?.ServiceProvider);
+            var result = method.Invoke(objectInstance, parameters.ToArray());
+
+
+            if (result is Task task)
+            {
+                await task.ConfigureAwait(false);
+                var resultProperty = task.GetType().GetProperty("Result");
+                result = resultProperty?.GetValue(task);
+            }
+
+            if (result is string resultString)
+                return new CallToolResponse { Content = [new Content() { Text = resultString, Type = "text" }] };
+
+            if (result is string[] resultStringArray)
+                return new CallToolResponse { Content = resultStringArray.Select(s => new Content() { Text = s, Type = "text" }).ToList() };
+
+            if (result is null)
+                return new CallToolResponse { Content = [new Content() { Text = "null" }] };
+
+            if (result is JsonElement jsonElement)
+                return new CallToolResponse { Content = [new Content() { Text = jsonElement.GetRawText(), Type = "text" }] };
+
+            return new CallToolResponse { Content = [new Content() { Text = result.ToString(), Type = "text" }] };
+        }
+        catch (TargetInvocationException e)
+        {
+            throw new McpServerException(e.Message, e);
+        }
+    }
+
+    private static List<object?> ResolveParameters(RequestContext<CallToolRequestParams> request, ParameterInfo[] methodParameters, CancellationToken cancellationToken)
+    {
+        var parameters = new List<object?>(methodParameters.Length);
+
+        foreach (var parameter in methodParameters)
+        {
+            if (parameter.ParameterType == typeof(CancellationToken))
+            {
+                parameters.Add(cancellationToken);
+            }
+            else if (request.Params?.Arguments != null && request.Params.Arguments.TryGetValue(parameter.Name ?? "NoName", out var value))
+            {
+                if (value is JsonElement element)
+                    value = JsonSerializer.Deserialize(element.GetRawText(), parameter.ParameterType);
+
+                parameters.Add(Convert.ChangeType(value, parameter.ParameterType));
+            }
+            else
+            {
+                var parameterAttribute = parameter.GetCustomAttribute<McpParameterAttribute>();
+
+                if (parameterAttribute?.Required == true)
+                    throw new McpServerException($"Missing required argument '{parameter.Name}'.");
+
+                parameters.Add(parameter.HasDefaultValue ? parameter.DefaultValue : null);
+            }
+        }
+
+        return parameters;
+    }
+
+    private static object? CreateObjectInstance(MethodInfo method, IServiceProvider? serviceProvider)
+    {
+        if (method.IsStatic)
+            return null;
+
+        if (serviceProvider != null)
+            return ActivatorUtilities.CreateInstance(serviceProvider, method.DeclaringType!);
+
+        return Activator.CreateInstance(method.DeclaringType!);
+    }
+}

src/mcpdotnet/Configuration/McpServerBuilderExtensions.Transports.cs

@@ -0,0 +1,21 @@
+using McpDotNet.Configuration;
+using McpDotNet.Protocol.Transport;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace McpDotNet;
+
+/// <summary>
+/// Extension to configure the MCP server with transports
+/// </summary>
+public static partial class McpServerBuilderExtensions
+{
+    /// <summary>
+    /// Adds a server transport that uses stdin/stdout for communication.
+    /// </summary>
+    /// <param name="builder">The builder instance.</param>
+    public static IMcpServerBuilder WithStdioServerTransport(this IMcpServerBuilder builder)
+    {
+        builder.Services.AddSingleton<IServerTransport, StdioServerTransport>();
+        return builder;
+    }
+}

src/mcpdotnet/Server/IMcpServer.cs

@@ -23,6 +23,11 @@ public interface IMcpServer : IAsyncDisposable
     /// </summary>
     Implementation? ClientInfo { get; }
 
+    /// <summary>
+    /// Gets the service provider for the server.
+    /// </summary>
+    IServiceProvider? ServiceProvider { get; }
+
     /// <summary>
     /// Starts the server and begins listening for client requests.
     /// </summary>
@@ -31,47 +36,47 @@ public interface IMcpServer : IAsyncDisposable
     /// <summary>
     /// Gets or sets the handler for list tools requests.
     /// </summary>
-    Func<ListToolsRequestParams?, CancellationToken, Task<ListToolsResult>>? ListToolsHandler { get; set; }
+    Func<RequestContext<ListToolsRequestParams>, CancellationToken, Task<ListToolsResult>>? ListToolsHandler { get; set; }
 
     /// <summary>
     /// Gets or sets the handler for call tool requests.
     /// </summary>
-    Func<CallToolRequestParams?, CancellationToken, Task<CallToolResponse>>? CallToolHandler { get; set; }
+    Func<RequestContext<CallToolRequestParams>, CancellationToken, Task<CallToolResponse>>? CallToolHandler { get; set; }
 
     /// <summary>
     /// Gets or sets the handler for list prompts requests.
     /// </summary>
-    Func<ListPromptsRequestParams?, CancellationToken, Task<ListPromptsResult>>? ListPromptsHandler { get; set; }
+    Func<RequestContext<ListPromptsRequestParams>, CancellationToken, Task<ListPromptsResult>>? ListPromptsHandler { get; set; }
 
     /// <summary>
     /// Gets or sets the handler for get prompt requests.
     /// </summary>
-    Func<GetPromptRequestParams?, CancellationToken, Task<GetPromptResult>>? GetPromptHandler { get; set; }
+    Func<RequestContext<GetPromptRequestParams>, CancellationToken, Task<GetPromptResult>>? GetPromptHandler { get; set; }
 
     /// <summary>
     /// Gets or sets the handler for list resources requests.
     /// </summary>
-    Func<ListResourcesRequestParams?, CancellationToken, Task<ListResourcesResult>>? ListResourcesHandler { get; set; }
+    Func<RequestContext<ListResourcesRequestParams>, CancellationToken, Task<ListResourcesResult>>? ListResourcesHandler { get; set; }
 
     /// <summary>
     /// Gets or sets the handler for read resources requests.
     /// </summary>
-    Func<ReadResourceRequestParams?, CancellationToken, Task<ReadResourceResult>>? ReadResourceHandler { get; set; }
+    Func<RequestContext<ReadResourceRequestParams>, CancellationToken, Task<ReadResourceResult>>? ReadResourceHandler { get; set; }
 
     /// <summary>
     /// Gets or sets the handler for get resources requests.
     /// </summary>
-    Func<CompleteRequestParams?, CancellationToken, Task<CompleteResult>>? GetCompletionHandler { get; set; }
+    Func<RequestContext<CompleteRequestParams>, CancellationToken, Task<CompleteResult>>? GetCompletionHandler { get; set; }
 
     /// <summary>
     /// Gets or sets the handler for subscribe to resources messages.
     /// </summary>
-    Func<string, CancellationToken, Task>? SubscribeToResourcesHandler { get; set; }
+    Func<RequestContext<string>, CancellationToken, Task>? SubscribeToResourcesHandler { get; set; }
 
     /// <summary>
     /// Gets or sets the handler for subscribe to resources messages.
     /// </summary>
-    Func<string, CancellationToken, Task>? UnsubscribeFromResourcesHandler { get; set; }
+    Func<RequestContext<string>, CancellationToken, Task>? UnsubscribeFromResourcesHandler { get; set; }
 
 
     /// <summary>

src/mcpdotnet/Server/McpParameterAttribute.cs

@@ -0,0 +1,29 @@
+namespace McpDotNet.Server;
+
+/// <summary>
+/// Attribute to mark a method parameter
+/// </summary>
+[AttributeUsage(AttributeTargets.Parameter)]
+public class McpParameterAttribute : Attribute
+{
+    /// <summary>
+    /// Defines if the parameter is required.
+    /// </summary>
+    public bool Required { get; set; }
+
+    /// <summary>
+    /// A description of the parameter.
+    /// </summary>
+    public string? Description { get; set; }
+
+    /// <summary>
+    /// Attribute to mark a method as an MCP tool.
+    /// </summary>
+    /// <param name="required">True if the parameter is mandatory.</param>
+    /// <param name="description">A description of the tool.</param>
+    public McpParameterAttribute(bool required = false, string? description = null)
+    {
+        Required = required;
+        Description = description;
+    }
+}

src/mcpdotnet/Server/McpServer.cs

@@ -12,8 +12,8 @@ namespace McpDotNet.Server;
 /// <inheritdoc />
 internal class McpServer : McpJsonRpcEndpoint, IMcpServer
 {
-    private IServerTransport _serverTransport;
-    private McpServerOptions _options;
+    private readonly IServerTransport _serverTransport;
+    private readonly McpServerOptions _options;
     private volatile bool _isInitializing;
     private readonly ILogger<McpServer> _logger;
 
@@ -24,142 +24,24 @@ internal class McpServer : McpJsonRpcEndpoint, IMcpServer
     /// <param name="options">Configuration options for this server, including capabilities. 
     /// Make sure to accurately reflect exactly what capabilities the server supports and does not support.</param>    
     /// <param name="loggerFactory">Logger factory to use for logging</param>
+    /// <param name="serviceProvider">Optional service provider to use for dependency injection</param>
     /// <exception cref="McpServerException"></exception>
-    public McpServer(IServerTransport transport, McpServerOptions options, ILoggerFactory loggerFactory)
+    public McpServer(IServerTransport transport, McpServerOptions options, ILoggerFactory loggerFactory, IServiceProvider? serviceProvider)
         : base(transport, loggerFactory)
     {
         _serverTransport = transport;
         _options = options;
         _logger = loggerFactory.CreateLogger<McpServer>();
         ServerInstructions = options.ServerInstructions;
+        ServiceProvider = serviceProvider;
 
-        if (options.Capabilities?.Tools != null)
-        {
-            SetRequestHandler<ListToolsRequestParams, ListToolsResult>("tools/list",
-                async (request) =>
-                {
-                    if (ListToolsHandler == null)
-                    {
-                        // Setting the capability, but not a handler means we have nothing to return to the server
-                        _logger.ListToolsHandlerNotConfigured(EndpointName);
-                        throw new McpServerException("ListTools handler not configured");
-                    }
-
-                    return await ListToolsHandler(request, CancellationTokenSource?.Token ?? CancellationToken.None);
-                });
-
-            SetRequestHandler<CallToolRequestParams, CallToolResponse>("tools/call",
-                async (request) =>
-                {
-                    if (CallToolHandler == null)
-                    {
-                        // Setting the capability, but not a handler means we have nothing to return to the server
-                        _logger.CallToolHandlerNotConfigured(EndpointName);
-                        throw new McpServerException("CallTool handler not configured");
-                    }
-
-                    return await CallToolHandler(request, CancellationTokenSource?.Token ?? CancellationToken.None);
-                });
-        }
-        if (options.Capabilities?.Prompts != null)
-        {
-            SetRequestHandler<ListPromptsRequestParams, ListPromptsResult>("prompts/list",
-                async (request) =>
-                {
-                    if (ListPromptsHandler == null)
-                    {
-                        // Setting the capability, but not a handler means we have nothing to return to the server
-                        _logger.ListPromptsHandlerNotConfigured(EndpointName);
-                        throw new McpServerException("ListPrompts handler not configured");
-                    }
-
-                    return await ListPromptsHandler(request, CancellationTokenSource?.Token ?? CancellationToken.None);
-                });
-
-            SetRequestHandler<GetPromptRequestParams, GetPromptResult>("prompts/get",
-                async (request) =>
-                {
-                    if (GetPromptHandler == null)
-                    {
-                        // Setting the capability, but not a handler means we have nothing to return to the server
-                        _logger.GetPromptHandlerNotConfigured(EndpointName);
-                        throw new McpServerException("GetPrompt handler not configured");
-                    }
-
-                    return await GetPromptHandler(request, CancellationTokenSource?.Token ?? CancellationToken.None);
-                });
-        }
-        if (options.Capabilities?.Resources != null)
-        {
-            SetRequestHandler<ListResourcesRequestParams, ListResourcesResult>("resources/list",
-                async (request) =>
-                {
-                    if (ListResourcesHandler == null)
-                    {
-                        // Setting the capability, but not a handler means we have nothing to return to the server
-                        _logger.ListResourcesHandlerNotConfigured(EndpointName);
-                        throw new McpServerException("ListResources handler not configured");
-                    }
-
-                    return await ListResourcesHandler(request, CancellationTokenSource?.Token ?? CancellationToken.None);
-                });
-
-            SetRequestHandler<ReadResourceRequestParams, ReadResourceResult>("resources/read",
-                async (request) =>
-                {
-                    if (ReadResourceHandler == null)
-                    {
-                        // Setting the capability, but not a handler means we have nothing to return to the server
-                        _logger.ReadResourceHandlerNotConfigured(EndpointName);
-                        throw new McpServerException("ReadResource handler not configured");
-                    }
-
-                    return await ReadResourceHandler(request, CancellationTokenSource?.Token ?? CancellationToken.None);
-                });
-        }
-        SetRequestHandler<CompleteRequestParams, CompleteResult>("completion/complete",
-                async (request) =>
-                {
-                    if (GetCompletionHandler == null)
-                    {
-                        // This capability is not optional, so return an empty result if there is no handler
-                        return new CompleteResult()
-                        {
-                            Completion = new()
-                            {
-                                Values = [],
-                                Total = 0,
-                                HasMore = false
-                            }
-                        };
-                    }
-
-                    return await GetCompletionHandler(request, CancellationTokenSource?.Token ?? CancellationToken.None);
-                });
-        SetRequestHandler<InitializeRequestParams, InitializeResult>("initialize",
-            (request) =>
-            {
-                ClientCapabilities = request?.Capabilities ?? new();
-                ClientInfo = request?.ClientInfo;
-                return Task.FromResult(new InitializeResult()
-                {
-                    ProtocolVersion = options.ProtocolVersion,
-                    Instructions = ServerInstructions,
-                    ServerInfo = _options.ServerInfo,
-                    Capabilities = options.Capabilities ?? new ServerCapabilities(),
-                });
-            });
-        SetRequestHandler<JsonNode, PingResult>("ping",
-            (request) =>
-            {
-                return Task.FromResult(new PingResult());
-            });
-
-        OnNotification("notifications/initialized", (notification) =>
-        {
-            IsInitialized = true;
-            return Task.CompletedTask;
-        });
+        SetToolsHandler(options);
+        SetPromptsHandler(options);
+        SetResourcesHandler(options);
+        SetCompletionHandler();
+        SetInitializeHandler(options);
+        SetPingHandler();
+        SetNotificationHandler();
     }
 
     public ClientCapabilities? ClientCapabilities { get; set; }
@@ -171,31 +53,34 @@ internal class McpServer : McpJsonRpcEndpoint, IMcpServer
     public string? ServerInstructions { get; set; }
 
     /// <inheritdoc />
-    public Func<ListToolsRequestParams?, CancellationToken, Task<ListToolsResult>>? ListToolsHandler { get; set; }
+    public IServiceProvider? ServiceProvider { get; }
 
     /// <inheritdoc />
-    public Func<CallToolRequestParams?, CancellationToken, Task<CallToolResponse>>? CallToolHandler { get; set; }
+    public Func<RequestContext<ListToolsRequestParams>, CancellationToken, Task<ListToolsResult>>? ListToolsHandler { get; set; }
 
     /// <inheritdoc />
-    public Func<ListPromptsRequestParams?, CancellationToken, Task<ListPromptsResult>>? ListPromptsHandler { get; set; }
+    public Func<RequestContext<CallToolRequestParams>, CancellationToken, Task<CallToolResponse>>? CallToolHandler { get; set; }
 
     /// <inheritdoc />
-    public Func<GetPromptRequestParams?, CancellationToken, Task<GetPromptResult>>? GetPromptHandler { get; set; }
+    public Func<RequestContext<ListPromptsRequestParams>, CancellationToken, Task<ListPromptsResult>>? ListPromptsHandler { get; set; }
 
     /// <inheritdoc />
-    public Func<ListResourcesRequestParams?, CancellationToken, Task<ListResourcesResult>>? ListResourcesHandler { get; set; }
+    public Func<RequestContext<GetPromptRequestParams>, CancellationToken, Task<GetPromptResult>>? GetPromptHandler { get; set; }
 
     /// <inheritdoc />
-    public Func<ReadResourceRequestParams?, CancellationToken, Task<ReadResourceResult>>? ReadResourceHandler { get; set; }
+    public Func<RequestContext<ListResourcesRequestParams>, CancellationToken, Task<ListResourcesResult>>? ListResourcesHandler { get; set; }
 
     /// <inheritdoc />
-    public Func<CompleteRequestParams?, CancellationToken, Task<CompleteResult>>? GetCompletionHandler { get; set; }
+    public Func<RequestContext<ReadResourceRequestParams>, CancellationToken, Task<ReadResourceResult>>? ReadResourceHandler { get; set; }
 
     /// <inheritdoc />
-    public Func<string, CancellationToken, Task>? SubscribeToResourcesHandler { get; set; }
+    public Func<RequestContext<CompleteRequestParams>, CancellationToken, Task<CompleteResult>>? GetCompletionHandler { get; set; }
 
     /// <inheritdoc />
-    public Func<string, CancellationToken, Task>? UnsubscribeFromResourcesHandler { get; set; }
+    public Func<RequestContext<string>, CancellationToken, Task>? SubscribeToResourcesHandler { get; set; }
+
+    /// <inheritdoc />
+    public Func<RequestContext<string>, CancellationToken, Task>? UnsubscribeFromResourcesHandler { get; set; }
 
     /// <inheritdoc />
     public override string EndpointName
@@ -277,4 +162,158 @@ internal class McpServer : McpJsonRpcEndpoint, IMcpServer
             cancellationToken
         ).ConfigureAwait(false);
     }
+
+    private void SetNotificationHandler()
+    {
+        OnNotification("notifications/initialized", (notification) =>
+        {
+            IsInitialized = true;
+            return Task.CompletedTask;
+        });
+    }
+
+    private void SetPingHandler()
+    {
+        SetRequestHandler<JsonNode, PingResult>("ping",
+                    (request) =>
+                    {
+                        return Task.FromResult(new PingResult());
+                    });
+    }
+
+    private void SetInitializeHandler(McpServerOptions options)
+    {
+        SetRequestHandler<InitializeRequestParams, InitializeResult>("initialize",
+                    (request) =>
+                    {
+                        ClientCapabilities = request?.Capabilities ?? new();
+                        ClientInfo = request?.ClientInfo;
+                        return Task.FromResult(new InitializeResult()
+                        {
+                            ProtocolVersion = options.ProtocolVersion,
+                            Instructions = ServerInstructions,
+                            ServerInfo = _options.ServerInfo,
+                            Capabilities = options.Capabilities ?? new ServerCapabilities(),
+                        });
+                    });
+    }
+
+    private void SetCompletionHandler()
+    {
+        SetRequestHandler<CompleteRequestParams, CompleteResult>("completion/complete",
+                        async (request) =>
+                        {
+                            if (GetCompletionHandler == null)
+                            {
+                                // This capability is not optional, so return an empty result if there is no handler
+                                return new CompleteResult()
+                                {
+                                    Completion = new()
+                                    {
+                                        Values = [],
+                                        Total = 0,
+                                        HasMore = false
+                                    }
+                                };
+                            }
+
+                            return await GetCompletionHandler(new(this, request), CancellationTokenSource?.Token ?? CancellationToken.None);
+                        });
+    }
+
+    private void SetResourcesHandler(McpServerOptions options)
+    {
+        if (options.Capabilities?.Resources != null)
+        {
+            SetRequestHandler<ListResourcesRequestParams, ListResourcesResult>("resources/list",
+                async (request) =>
+                {
+                    if (ListResourcesHandler == null)
+                    {
+                        // Setting the capability, but not a handler means we have nothing to return to the server
+                        _logger.ListResourcesHandlerNotConfigured(EndpointName);
+                        throw new McpServerException("ListResources handler not configured");
+                    }
+
+                    return await ListResourcesHandler(new(this, request), CancellationTokenSource?.Token ?? CancellationToken.None);
+                });
+
+            SetRequestHandler<ReadResourceRequestParams, ReadResourceResult>("resources/read",
+                async (request) =>
+                {
+                    if (ReadResourceHandler == null)
+                    {
+                        // Setting the capability, but not a handler means we have nothing to return to the server
+                        _logger.ReadResourceHandlerNotConfigured(EndpointName);
+                        throw new McpServerException("ReadResource handler not configured");
+                    }
+
+                    return await ReadResourceHandler(new(this, request), CancellationTokenSource?.Token ?? CancellationToken.None);
+                });
+        }
+    }
+
+    private void SetPromptsHandler(McpServerOptions options)
+    {
+        if (options.Capabilities?.Prompts != null)
+        {
+            SetRequestHandler<ListPromptsRequestParams, ListPromptsResult>("prompts/list",
+                async (request) =>
+                {
+                    if (ListPromptsHandler == null)
+                    {
+                        // Setting the capability, but not a handler means we have nothing to return to the server
+                        _logger.ListPromptsHandlerNotConfigured(EndpointName);
+                        throw new McpServerException("ListPrompts handler not configured");
+                    }
+
+                    return await ListPromptsHandler(new(this, request), CancellationTokenSource?.Token ?? CancellationToken.None);
+                });
+
+            SetRequestHandler<GetPromptRequestParams, GetPromptResult>("prompts/get",
+                async (request) =>
+                {
+                    if (GetPromptHandler == null)
+                    {
+                        // Setting the capability, but not a handler means we have nothing to return to the server
+                        _logger.GetPromptHandlerNotConfigured(EndpointName);
+                        throw new McpServerException("GetPrompt handler not configured");
+                    }
+
+                    return await GetPromptHandler(new(this, request), CancellationTokenSource?.Token ?? CancellationToken.None);
+                });
+        }
+    }
+
+    private void SetToolsHandler(McpServerOptions options)
+    {
+        if (options.Capabilities?.Tools != null)
+        {
+            SetRequestHandler<ListToolsRequestParams, ListToolsResult>("tools/list",
+                async (request) =>
+                {
+                    if (ListToolsHandler == null)
+                    {
+                        // Setting the capability, but not a handler means we have nothing to return to the server
+                        _logger.ListToolsHandlerNotConfigured(EndpointName);
+                        throw new McpServerException("ListTools handler not configured");
+                    }
+
+                    return await ListToolsHandler(new(this, request), CancellationTokenSource?.Token ?? CancellationToken.None);
+                });
+
+            SetRequestHandler<CallToolRequestParams, CallToolResponse>("tools/call",
+                async (request) =>
+                {
+                    if (CallToolHandler == null)
+                    {
+                        // Setting the capability, but not a handler means we have nothing to return to the server
+                        _logger.CallToolHandlerNotConfigured(EndpointName);
+                        throw new McpServerException("CallTool handler not configured");
+                    }
+
+                    return await CallToolHandler(new(this, request), CancellationTokenSource?.Token ?? CancellationToken.None);
+                });
+        }
+    }
 }

src/mcpdotnet/Server/McpServerDelegates.cs

@@ -10,47 +10,47 @@ public class McpServerDelegates
     /// <summary>
     /// Gets or sets the handler for list tools requests.
     /// </summary>
-    public Func<ListToolsRequestParams?, CancellationToken, Task<ListToolsResult>>? ListToolsHandler { get; set; }
+    public Func<RequestContext<ListToolsRequestParams>, CancellationToken, Task<ListToolsResult>>? ListToolsHandler { get; set; }
 
     /// <summary>
     /// Gets or sets the handler for call tool requests.
     /// </summary>
-    public Func<CallToolRequestParams?, CancellationToken, Task<CallToolResponse>>? CallToolHandler { get; set; }
+    public Func<RequestContext<CallToolRequestParams>, CancellationToken, Task<CallToolResponse>>? CallToolHandler { get; set; }
 
     /// <summary>
     /// Gets or sets the handler for list prompts requests.
     /// </summary>
-    public Func<ListPromptsRequestParams?, CancellationToken, Task<ListPromptsResult>>? ListPromptsHandler { get; set; }
+    public Func<RequestContext<ListPromptsRequestParams>, CancellationToken, Task<ListPromptsResult>>? ListPromptsHandler { get; set; }
 
     /// <summary>
     /// Gets or sets the handler for get prompt requests.
     /// </summary>
-    public Func<GetPromptRequestParams?, CancellationToken, Task<GetPromptResult>>? GetPromptHandler { get; set; }
+    public Func<RequestContext<GetPromptRequestParams>, CancellationToken, Task<GetPromptResult>>? GetPromptHandler { get; set; }
 
     /// <summary>
     /// Gets or sets the handler for list resources requests.
     /// </summary>
-    public Func<ListResourcesRequestParams?, CancellationToken, Task<ListResourcesResult>>? ListResourcesHandler { get; set; }
+    public Func<RequestContext<ListResourcesRequestParams>, CancellationToken, Task<ListResourcesResult>>? ListResourcesHandler { get; set; }
 
     /// <summary>
     /// Gets or sets the handler for read resources requests.
     /// </summary>
-    public Func<ReadResourceRequestParams?, CancellationToken, Task<ReadResourceResult>>? ReadResourceHandler { get; set; }
+    public Func<RequestContext<ReadResourceRequestParams>, CancellationToken, Task<ReadResourceResult>>? ReadResourceHandler { get; set; }
 
     /// <summary>
     /// Gets or sets the handler for get resources requests.
     /// </summary>
-    public Func<CompleteRequestParams?, CancellationToken, Task<CompleteResult>>? GetCompletionHandler { get; set; }
+    public Func<RequestContext<CompleteRequestParams>, CancellationToken, Task<CompleteResult>>? GetCompletionHandler { get; set; }
 
     /// <summary>
     /// Gets or sets the handler for subscribe to resources messages.
     /// </summary>
-    public Func<string, CancellationToken, Task>? SubscribeToResourcesHandler { get; set; }
+    public Func<RequestContext<string>, CancellationToken, Task>? SubscribeToResourcesHandler { get; set; }
 
     /// <summary>
     /// Gets or sets the handler for subscribe to resources messages.
     /// </summary>
-    public Func<string, CancellationToken, Task>? UnsubscribeFromResourcesHandler { get; set; }
+    public Func<RequestContext<string>, CancellationToken, Task>? UnsubscribeFromResourcesHandler { get; set; }
 
     /// <summary>
     /// Applies the delegates to the server.

src/mcpdotnet/Server/McpServerFactory.cs

@@ -20,6 +20,7 @@ public class McpServerFactory : IMcpServerFactory
     private readonly McpServerOptions _options;
     private readonly ILoggerFactory _loggerFactory;
     private readonly McpServerDelegates? _serverDelegates;
+    private readonly IServiceProvider? _serviceProvider;
 
     /// <summary>
     /// Initializes a new instance of the <see cref="McpServerFactory"/> class.
@@ -27,14 +28,16 @@ public class McpServerFactory : IMcpServerFactory
     /// <param name="serverTransport">Transport to use for the server</param>
     /// <param name="options">Configuration options for this server, including capabilities. 
     /// Make sure to accurately reflect exactly what capabilities the server supports and does not support.</param>
+    /// <param name="serviceProvider">Optional service provider to create new instances.</param>
     /// <param name="loggerFactory">Logger factory to use for logging</param>
     /// <param name="serverDelegates"></param>
-    public McpServerFactory(IServerTransport serverTransport, McpServerOptions options, ILoggerFactory loggerFactory, IOptions<McpServerDelegates>? serverDelegates = null)
+    public McpServerFactory(IServerTransport serverTransport, McpServerOptions options, ILoggerFactory loggerFactory, IOptions<McpServerDelegates>? serverDelegates = null, IServiceProvider? serviceProvider = null)
     {
         _serverTransport = serverTransport ?? throw new ArgumentNullException(nameof(serverTransport));
         _options = options ?? throw new ArgumentNullException(nameof(options));
         _loggerFactory = loggerFactory ?? throw new ArgumentNullException(nameof(loggerFactory));
         _serverDelegates = serverDelegates?.Value;
+        _serviceProvider = serviceProvider;
     }
 
     /// <summary>
@@ -44,7 +47,7 @@ public class McpServerFactory : IMcpServerFactory
     /// </summary>
     public IMcpServer CreateServer()
     {
-        var server = new McpServer(_serverTransport, _options, _loggerFactory);
+        var server = new McpServer(_serverTransport, _options, _loggerFactory, _serviceProvider);
 
         _serverDelegates?.Apply(server);
 

src/mcpdotnet/Server/McpToolAttribute.cs

@@ -0,0 +1,27 @@
+namespace McpDotNet.Server;
+
+/// <summary>
+/// Attribute to mark a method as an MCP tool.
+/// </summary>
+[AttributeUsage(AttributeTargets.Method)]
+public class McpToolAttribute : Attribute
+{
+    /// The name of the tool. If not provided, the class name will be used.  
+    public string? Name { get; set; }
+
+    /// <summary>
+    /// A description of the tool.
+    /// </summary>
+    public string? Description { get; set; }
+
+    /// <summary>
+    /// Attribute to mark a method as an MCP tool.
+    /// </summary>
+    /// <param name="name">The name of the tool. If not provided, the class name will be used.</param>
+    /// <param name="description">A description of the tool.</param>
+    public McpToolAttribute(string? name = null, string? description = null)
+    {
+        Name = name;
+        Description = description;
+    }
+}

src/mcpdotnet/Server/McpToolTypeAttribute.cs

@@ -0,0 +1,9 @@
+namespace McpDotNet.Server;
+
+/// <summary>
+/// Attribute to mark a type as container for MCP tools.
+/// </summary>
+[AttributeUsage(AttributeTargets.Class)]
+public class McpToolTypeAttribute : Attribute
+{
+}

src/mcpdotnet/Server/RequestContext.cs

@@ -0,0 +1,10 @@
+namespace McpDotNet.Server;
+
+/// <summary>
+/// Container for the request context.
+/// </summary>
+/// <typeparam name="TParams">Type of the request parameters</typeparam>
+public record RequestContext<TParams>(IMcpServer Server, TParams? Params)
+{
+
+}

src/mcpdotnet/Shared/McpJsonRpcEndpoint.cs

@@ -21,7 +21,7 @@ internal abstract class McpJsonRpcEndpoint
     private readonly ITransport _transport;
     private readonly ConcurrentDictionary<RequestId, TaskCompletionSource<IJsonRpcMessage>> _pendingRequests;
     private readonly ConcurrentDictionary<string, List<Func<JsonRpcNotification, Task>>> _notificationHandlers;
-    private readonly Dictionary<string, Func<JsonRpcRequest, Task<object>>> _requestHandlers = [];
+    private readonly Dictionary<string, Func<JsonRpcRequest, Task<object?>>> _requestHandlers = [];
     private int _nextRequestId;
     private readonly JsonSerializerOptions _jsonOptions;
     private readonly ILogger<McpClient> _logger;
@@ -349,7 +349,7 @@ internal abstract class McpJsonRpcEndpoint
     /// <typeparam name="TResponse">Type of response payload (not full RPC response</typeparam>
     /// <param name="method">Method identifier to register for</param>
     /// <param name="handler">Handler to be called when a request with specified method identifier is received</param>
-    protected void SetRequestHandler<TRequest, TResponse>(string method, Func<TRequest?, Task<TResponse>> handler) where TResponse : class
+    protected void SetRequestHandler<TRequest, TResponse>(string method, Func<TRequest?, Task<TResponse>> handler)
     {
         ArgumentNullException.ThrowIfNull(handler);
 

tests/McpDotNet.Extensions.AI.Tests/IntegrationTests.cs

@@ -17,7 +17,7 @@ public class IntegrationTests
         {
             Id = "everything",
             Name = "Everything",
-            TransportType = McpDotNet.Protocol.Transport.TransportTypes.StdIo,
+            TransportType = "stdio",
             TransportOptions = new Dictionary<string, string>
             {
                 ["command"] = "npx",

tests/McpDotNet.Extensions.AI.Tests/McpDotNet.Extensions.AI.Tests.csproj

@@ -27,7 +27,6 @@
 
   <ItemGroup>
     <ProjectReference Include="..\..\src\McpDotNet.Extensions.AI\McpDotNet.Extensions.AI.csproj" />
-    <ProjectReference Include="..\..\src\mcpdotnet\mcpdotnet.csproj" />
     <PackageReference Include="Microsoft.Extensions.AI.OpenAI" Version="9.3.0-preview.1.25114.11" />
   </ItemGroup>