Refactor MCP to use SuperSocket Commands for shared HTTP/TCP handling (#810)

* Initial plan

* Initial analysis and planning for MCP command refactoring

Co-authored-by: kerryjiang <[email protected]>

* Implement MCP command infrastructure with handler registry and base commands

Co-authored-by: kerryjiang <[email protected]>

* Refactor MCP servers to use shared handler registry and simplify command service extensions

Co-authored-by: kerryjiang <[email protected]>

* Complete MCP command refactoring implementation with documentation

Co-authored-by: kerryjiang <[email protected]>

* Refactor HTTP server to use command dispatcher, removing switch/case statements

Co-authored-by: kerryjiang <[email protected]>

* Refactor McpServer to also use command dispatcher, removing all remaining switch statements

Co-authored-by: kerryjiang <[email protected]>

* Refactor MCP to use SuperSocket native command system

Co-authored-by: kerryjiang <[email protected]>

* tried to fix the build

---------

Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: kerryjiang <[email protected]>
Co-authored-by: Kerry Jiang <[email protected]>

Author: Copilot

dotnet-install.sh

@@ -0,0 +1,70 @@
+using System.Collections.Generic;
+
+namespace SuperSocket.MCP.Abstractions
+{
+    /// <summary>
+    /// Registry for MCP handlers that can be shared across different transports
+    /// </summary>
+    public interface IMcpHandlerRegistry
+    {
+        /// <summary>
+        /// Registers a tool handler
+        /// </summary>
+        /// <param name="name">Tool name</param>
+        /// <param name="handler">Tool handler</param>
+        void RegisterTool(string name, IMcpToolHandler handler);
+
+        /// <summary>
+        /// Registers a resource handler
+        /// </summary>
+        /// <param name="uri">Resource URI</param>
+        /// <param name="handler">Resource handler</param>
+        void RegisterResource(string uri, IMcpResourceHandler handler);
+
+        /// <summary>
+        /// Registers a prompt handler
+        /// </summary>
+        /// <param name="name">Prompt name</param>
+        /// <param name="handler">Prompt handler</param>
+        void RegisterPrompt(string name, IMcpPromptHandler handler);
+
+        /// <summary>
+        /// Gets all registered tool handlers
+        /// </summary>
+        /// <returns>Dictionary of tool handlers</returns>
+        IReadOnlyDictionary<string, IMcpToolHandler> GetToolHandlers();
+
+        /// <summary>
+        /// Gets all registered resource handlers
+        /// </summary>
+        /// <returns>Dictionary of resource handlers</returns>
+        IReadOnlyDictionary<string, IMcpResourceHandler> GetResourceHandlers();
+
+        /// <summary>
+        /// Gets all registered prompt handlers
+        /// </summary>
+        /// <returns>Dictionary of prompt handlers</returns>
+        IReadOnlyDictionary<string, IMcpPromptHandler> GetPromptHandlers();
+
+        /// <summary>
+        /// Gets a specific tool handler
+        /// </summary>
+        /// <param name="name">Tool name</param>
+        /// <returns>Tool handler if found, null otherwise</returns>
+        IMcpToolHandler? GetToolHandler(string name);
+
+        /// <summary>
+        /// Gets a specific resource handler
+        /// </summary>
+        /// <param name="uri">Resource URI</param>
+        /// <returns>Resource handler if found, null otherwise</returns>
+        IMcpResourceHandler? GetResourceHandler(string uri);
+
+        /// <summary>
+        /// Gets a specific prompt handler
+        /// </summary>
+        /// <param name="name">Prompt name</param>
+        /// <returns>Prompt handler if found, null otherwise</returns>
+        IMcpPromptHandler? GetPromptHandler(string name);
+    }
+}

src/SuperSocket.MCP/Abstractions/IMcpHandlerRegistry.cs

@@ -0,0 +1,71 @@
+using System;
+using System.Collections.Generic;
+using System.Text.Json;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.Extensions.Logging;
+using SuperSocket.Command;
+using SuperSocket.MCP.Abstractions;
+using SuperSocket.MCP.Models;
+using SuperSocket.Server.Abstractions.Session;
+
+namespace SuperSocket.MCP.Commands
+{
+    /// <summary>
+    /// Command to handle MCP tools/call requests
+    /// </summary>
+    [Command("tools/call")]
+    public class CallToolCommand : McpCommandBase
+    {
+        /// <summary>
+        /// Initializes a new instance of the CallToolCommand class
+        /// </summary>
+        /// <param name="logger">Logger instance</param>
+        /// <param name="handlerRegistry">Handler registry</param>
+        public CallToolCommand(ILogger<CallToolCommand> logger, IMcpHandlerRegistry handlerRegistry)
+            : base(logger, handlerRegistry)
+        {
+        }
+
+        /// <inheritdoc />
+        protected override async Task<McpMessage?> HandleAsync(IAppSession session, McpMessage message, CancellationToken cancellationToken)
+        {
+            try
+            {
+                var callParams = JsonSerializer.Deserialize<McpCallToolParams>(
+                    JsonSerializer.Serialize(message.Params),
+                    new JsonSerializerOptions { PropertyNameCaseInsensitive = true });
+
+                if (callParams == null || string.IsNullOrEmpty(callParams.Name))
+                {
+                    return CreateErrorResponse(message.Id, McpErrorCodes.InvalidParams, "Invalid tool call parameters");
+                }
+
+                var handler = _handlerRegistry.GetToolHandler(callParams.Name);
+                if (handler == null)
+                {
+                    return CreateErrorResponse(message.Id, McpErrorCodes.MethodNotFound, $"Tool '{callParams.Name}' not found");
+                }
+
+                _logger.LogInformation("Executing tool: {ToolName}", callParams.Name);
+
+                var toolResult = await handler.ExecuteAsync(callParams.Arguments ?? new Dictionary<string, object>());
+
+                var result = new McpCallToolResult
+                {
+                    Content = toolResult.Content,
+                    IsError = toolResult.IsError
+                };
+
+                _logger.LogInformation("Tool {ToolName} executed successfully", callParams.Name);
+
+                return CreateSuccessResponse(message.Id, result);
+            }
+            catch (Exception ex)
+            {
+                _logger.LogError(ex, "Error executing tool");
+                return CreateErrorResponse(message.Id, McpErrorCodes.InternalError, "Tool execution failed");
+            }
+        }
+    }
+}

src/SuperSocket.MCP/Commands/CallToolCommand.cs

@@ -0,0 +1,75 @@
+using System;
+using System.Collections.Generic;
+using System.Text.Json;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.Extensions.Logging;
+using SuperSocket.Command;
+using SuperSocket.MCP.Abstractions;
+using SuperSocket.MCP.Models;
+using SuperSocket.Server.Abstractions.Session;
+
+namespace SuperSocket.MCP.Commands
+{
+    /// <summary>
+    /// Command to handle MCP prompts/get requests
+    /// </summary>
+    [Command("prompts/get")]
+    public class GetPromptCommand : McpCommandBase
+    {
+        /// <summary>
+        /// Initializes a new instance of the GetPromptCommand class
+        /// </summary>
+        /// <param name="logger">Logger instance</param>
+        /// <param name="handlerRegistry">Handler registry</param>
+        public GetPromptCommand(ILogger<GetPromptCommand> logger, IMcpHandlerRegistry handlerRegistry)
+            : base(logger, handlerRegistry)
+        {
+        }
+
+        /// <inheritdoc />
+        protected override async Task<McpMessage?> HandleAsync(IAppSession session, McpMessage message, CancellationToken cancellationToken)
+        {
+            try
+            {
+                var promptParams = JsonSerializer.Deserialize<Dictionary<string, object>>(
+                    JsonSerializer.Serialize(message.Params),
+                    new JsonSerializerOptions { PropertyNameCaseInsensitive = true });
+
+                if (promptParams == null || !promptParams.TryGetValue("name", out var nameObj))
+                {
+                    return CreateErrorResponse(message.Id, McpErrorCodes.InvalidParams, "Prompt name required");
+                }
+
+                var name = nameObj?.ToString();
+                if (string.IsNullOrEmpty(name))
+                {
+                    return CreateErrorResponse(message.Id, McpErrorCodes.InvalidParams, "Prompt name cannot be empty");
+                }
+
+                var handler = _handlerRegistry.GetPromptHandler(name);
+                if (handler == null)
+                {
+                    return CreateErrorResponse(message.Id, McpErrorCodes.MethodNotFound, $"Prompt '{name}' not found");
+                }
+
+                _logger.LogInformation("Getting prompt: {PromptName}", name);
+
+                var args = promptParams.ContainsKey("arguments") ?
+                    JsonSerializer.Deserialize<Dictionary<string, object>>(
+                        JsonSerializer.Serialize(promptParams["arguments"])) : null;
+
+                var promptResult = await handler.GetAsync(name, args);
+
+                _logger.LogInformation("Prompt {PromptName} retrieved successfully", name);
+
+                return CreateSuccessResponse(message.Id, promptResult);
+            }
+            catch (Exception ex)
+            {
+                _logger.LogError(ex, "Error getting prompt");
+                return CreateErrorResponse(message.Id, McpErrorCodes.InternalError, "Prompt retrieval failed");
+            }
+        }
+    }
+}

src/SuperSocket.MCP/Commands/GetPromptCommand.cs

@@ -0,0 +1,82 @@
+using System;
+using System.Linq;
+using System.Text.Json;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.Extensions.Logging;
+using SuperSocket.Command;
+using SuperSocket.MCP.Abstractions;
+using SuperSocket.MCP.Models;
+using SuperSocket.Server.Abstractions.Session;
+
+namespace SuperSocket.MCP.Commands
+{
+    /// <summary>
+    /// Command to handle MCP initialize requests
+    /// </summary>
+    [Command("initialize")]
+    public class InitializeCommand : McpCommandBase
+    {
+        private readonly McpServerInfo _serverInfo;
+
+        /// <summary>
+        /// Initializes a new instance of the InitializeCommand class
+        /// </summary>
+        /// <param name="logger">Logger instance</param>
+        /// <param name="handlerRegistry">Handler registry</param>
+        /// <param name="serverInfo">Server information</param>
+        public InitializeCommand(ILogger<InitializeCommand> logger, IMcpHandlerRegistry handlerRegistry, McpServerInfo serverInfo)
+            : base(logger, handlerRegistry)
+        {
+            _serverInfo = serverInfo ?? throw new ArgumentNullException(nameof(serverInfo));
+        }
+
+        /// <inheritdoc />
+        protected override async Task<McpMessage?> HandleAsync(IAppSession session, McpMessage message, CancellationToken cancellationToken)
+        {
+            try
+            {
+                var initParams = JsonSerializer.Deserialize<McpInitializeParams>(
+                    JsonSerializer.Serialize(message.Params),
+                    new JsonSerializerOptions { PropertyNameCaseInsensitive = true });
+
+                if (initParams == null)
+                {
+                    return CreateErrorResponse(message.Id, McpErrorCodes.InvalidParams, "Invalid initialize parameters");
+                }
+
+                _logger.LogInformation("Initializing MCP server for client: {ClientName} {ClientVersion}",
+                    initParams.ClientInfo.Name, initParams.ClientInfo.Version);
+
+                // Create server capabilities based on registered handlers
+                var toolHandlers = _handlerRegistry.GetToolHandlers();
+                var resourceHandlers = _handlerRegistry.GetResourceHandlers();
+                var promptHandlers = _handlerRegistry.GetPromptHandlers();
+
+                var capabilities = new McpServerCapabilities
+                {
+                    Tools = toolHandlers.Any() ? new McpToolsCapabilities { ListChanged = true } : null,
+                    Resources = resourceHandlers.Any() ? new McpResourcesCapabilities { ListChanged = true, Subscribe = true } : null,
+                    Prompts = promptHandlers.Any() ? new McpPromptsCapabilities { ListChanged = true } : null,
+                    Logging = new McpLoggingCapabilities()
+                };
+
+                var result = new McpInitializeResult
+                {
+                    ProtocolVersion = _serverInfo.ProtocolVersion,
+                    ServerInfo = _serverInfo,
+                    Capabilities = capabilities
+                };
+
+                _logger.LogInformation("MCP server initialized successfully");
+
+                return CreateSuccessResponse(message.Id, result);
+            }
+            catch (Exception ex)
+            {
+                _logger.LogError(ex, "Error during MCP initialization");
+                return CreateErrorResponse(message.Id, McpErrorCodes.InternalError, "Initialization failed");
+            }
+        }
+    }
+}

src/SuperSocket.MCP/Commands/InitializeCommand.cs

@@ -0,0 +1,38 @@
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.Extensions.Logging;
+using SuperSocket.Command;
+using SuperSocket.MCP.Abstractions;
+using SuperSocket.MCP.Models;
+using SuperSocket.Server.Abstractions.Session;
+
+namespace SuperSocket.MCP.Commands
+{
+    /// <summary>
+    /// Command to handle MCP initialized notifications
+    /// </summary>
+    [Command("initialized")]
+    public class InitializedCommand : McpCommandBase
+    {
+        /// <summary>
+        /// Initializes a new instance of the InitializedCommand class
+        /// </summary>
+        /// <param name="logger">Logger instance</param>
+        /// <param name="handlerRegistry">Handler registry</param>
+        public InitializedCommand(ILogger<InitializedCommand> logger, IMcpHandlerRegistry handlerRegistry)
+            : base(logger, handlerRegistry)
+        {
+        }
+
+        /// <inheritdoc />
+        protected override async Task<McpMessage?> HandleAsync(IAppSession session, McpMessage message, CancellationToken cancellationToken)
+        {
+            await Task.Yield(); // Simulate async operation
+            
+            _logger.LogInformation("MCP server initialization completed");
+            
+            // Notifications don't send responses
+            return null;
+        }
+    }
+}