Chapter 14: Advanced Features and Extension Development

Haiyue

2025年9月1日

33min

Chapter 14: Advanced Features and Extension Development

Learning Objectives

Master advanced features and extension mechanisms of the MCP protocol
Develop custom protocol extensions and plugins
Implement multi-language MCP Server support
Learn integration with other AI frameworks
Explore MCP practices in enterprise applications

1. Protocol Extension Mechanism

1.1 Custom Protocol Extensions

// MCP protocol extension infrastructure
interface ProtocolExtension {
  name: string;
  version: string;
  capabilities: ExtensionCapability[];
  handlers: ExtensionHandler[];
  metadata: ExtensionMetadata;
}

interface ExtensionCapability {
  name: string;
  description: string;
  parameters?: Record<string, any>;
  optional?: boolean;
}

interface ExtensionHandler {
  method: string;
  handler: (request: any) => Promise<any>;
  schema?: any;
}

interface ExtensionMetadata {
  author: string;
  description: string;
  homepage?: string;
  license: string;
  tags: string[];
}

// Protocol extension manager
class ProtocolExtensionManager {
  private extensions: Map<string, ProtocolExtension> = new Map();
  private server: Server;

  constructor(server: Server) {
    this.server = server;
  }

  registerExtension(extension: ProtocolExtension): void {
    // Validate extension
    this.validateExtension(extension);

    // Register capabilities
    this.registerCapabilities(extension);

    // Register handlers
    this.registerHandlers(extension);

    // Store extension
    this.extensions.set(extension.name, extension);

    console.log(`Extension registered: ${extension.name} v${extension.version}`);
  }

  private validateExtension(extension: ProtocolExtension): void {
    if (!extension.name || !extension.version) {
      throw new Error("Extension must have name and version");
    }

    if (this.extensions.has(extension.name)) {
      throw new Error(`Extension already registered: ${extension.name}`);
    }

    // Validate handler method names don't conflict
    for (const handler of extension.handlers) {
      if (this.server.hasHandler(handler.method)) {
        throw new Error(`Handler method already exists: ${handler.method}`);
      }
    }
  }

  private registerCapabilities(extension: ProtocolExtension): void {
    // Extend server capability declaration
    const currentCapabilities = this.server.getCapabilities();

    extension.capabilities.forEach(capability => {
      currentCapabilities.extensions = currentCapabilities.extensions || {};
      currentCapabilities.extensions[extension.name] = {
        version: extension.version,
        capabilities: extension.capabilities.map(c => c.name)
      };
    });
  }

  private registerHandlers(extension: ProtocolExtension): void {
    extension.handlers.forEach(handlerDef => {
      this.server.setRequestHandler(handlerDef.method, async (request) => {
        try {
          // Validate request schema (if defined)
          if (handlerDef.schema) {
            this.validateRequest(request, handlerDef.schema);
          }

          // Call extension handler
          return await handlerDef.handler(request);
        } catch (error) {
          throw new Error(`Extension ${extension.name} handler failed: ${error.message}`);
        }
      });
    });
  }

  unregisterExtension(extensionName: string): boolean {
    const extension = this.extensions.get(extensionName);
    if (!extension) {
      return false;
    }

    // Remove handlers
    extension.handlers.forEach(handler => {
      this.server.removeHandler(handler.method);
    });

    // Remove extension
    this.extensions.delete(extensionName);

    console.log(`Extension unregistered: ${extensionName}`);
    return true;
  }

  getExtension(name: string): ProtocolExtension | undefined {
    return this.extensions.get(name);
  }

  listExtensions(): ProtocolExtension[] {
    return Array.from(this.extensions.values());
  }
}

1.2 Streaming Processing Extension

// Streaming processing extension implementation
interface StreamingExtension extends ProtocolExtension {
  streamingCapabilities: StreamingCapability[];
}

interface StreamingCapability {
  name: string;
  chunkSize: number;
  timeout: number;
  compression?: boolean;
}

class StreamingProtocolExtension implements StreamingExtension {
  name = "streaming";
  version = "1.0.0";

  capabilities: ExtensionCapability[] = [
    {
      name: "streaming_tools",
      description: "Support for streaming tool execution",
      parameters: {
        maxChunkSize: 8192,
        timeout: 30000
      }
    },
    {
      name: "streaming_resources",
      description: "Support for streaming resource content",
      parameters: {
        maxChunkSize: 16384,
        compression: true
      }
    }
  ];

  streamingCapabilities: StreamingCapability[] = [
    {
      name: "tool_execution_stream",
      chunkSize: 8192,
      timeout: 30000,
      compression: false
    },
    {
      name: "resource_content_stream",
      chunkSize: 16384,
      timeout: 60000,
      compression: true
    }
  ];

  handlers: ExtensionHandler[] = [
    {
      method: "streaming/tools/call",
      handler: this.handleStreamingToolCall.bind(this)
    },
    {
      method: "streaming/resources/read",
      handler: this.handleStreamingResourceRead.bind(this)
    }
  ];

  metadata: ExtensionMetadata = {
    author: "MCP Team",
    description: "Streaming support for tools and resources",
    license: "MIT",
    tags: ["streaming", "performance", "tools", "resources"]
  };

  private async handleStreamingToolCall(request: any): Promise<any> {
    const { name, arguments: args, streamId } = request.params;

    // Create streaming response
    const stream = new ToolExecutionStream(streamId);

    try {
      // Start tool execution
      stream.start();

      // Simulate long-running tool
      const result = await this.executeToolWithStreaming(name, args, stream);

      // Complete stream
      stream.complete(result);

      return {
        streamId,
        status: "completed",
        finalResult: result
      };

    } catch (error) {
      stream.error(error);
      throw error;
    }
  }

  private async executeToolWithStreaming(
    toolName: string,
    args: any,
    stream: ToolExecutionStream
  ): Promise<any> {
    // Simulate step-by-step execution
    const steps = [
      "Initializing tool execution",
      "Processing input parameters",
      "Executing main logic",
      "Generating output",
      "Finalizing results"
    ];

    for (let i = 0; i < steps.length; i++) {
      const step = steps[i];

      // Send progress update
      stream.sendProgress({
        step: i + 1,
        totalSteps: steps.length,
        description: step,
        timestamp: new Date()
      });

      // Simulate work
      await new Promise(resolve => setTimeout(resolve, 1000));
    }

    return { result: "Tool execution completed successfully" };
  }
}

2. Plugin System Architecture

2.1 Plugin Framework Design

// Plugin system core architecture
interface Plugin {
  name: string;
  version: string;
  description: string;
  author: string;
  dependencies?: PluginDependency[];

  // Lifecycle methods
  onLoad?(context: PluginContext): Promise<void>;
  onUnload?(context: PluginContext): Promise<void>;
  onEnable?(context: PluginContext): Promise<void>;
  onDisable?(context: PluginContext): Promise<void>;

  // Plugin provided functionality
  tools?: PluginTool[];
  resources?: PluginResource[];
  prompts?: PluginPrompt[];
  extensions?: ProtocolExtension[];
}

interface PluginDependency {
  name: string;
  version: string;
  optional?: boolean;
}

interface PluginContext {
  server: Server;
  config: any;
  logger: Logger;
  storage: PluginStorage;
  eventBus: EventBus;
}

// Plugin manager
class PluginManager {
  private plugins: Map<string, LoadedPlugin> = new Map();
  private server: Server;
  private config: PluginManagerConfig;
  private eventBus: EventBus;

  constructor(server: Server, config: PluginManagerConfig) {
    this.server = server;
    this.config = config;
    this.eventBus = new EventBus();
    this.setupEventHandlers();
  }

  async loadPlugin(pluginPath: string): Promise<void> {
    try {
      // Load plugin module
      const pluginModule = await import(pluginPath);
      const plugin: Plugin = pluginModule.default || pluginModule;

      // Validate plugin
      this.validatePlugin(plugin);

      // Check dependencies
      await this.checkDependencies(plugin);

      // Create plugin context
      const context = this.createPluginContext(plugin);

      // Load plugin
      if (plugin.onLoad) {
        await plugin.onLoad(context);
      }

      // Register plugin features
      await this.registerPluginFeatures(plugin, context);

      // Enable plugin
      if (plugin.onEnable) {
        await plugin.onEnable(context);
      }

      // Store loaded plugin
      const loadedPlugin: LoadedPlugin = {
        plugin,
        context,
        path: pluginPath,
        loadTime: new Date(),
        enabled: true
      };

      this.plugins.set(plugin.name, loadedPlugin);

      this.eventBus.emit('plugin:loaded', { plugin: plugin.name });

      console.log(`Plugin loaded: ${plugin.name} v${plugin.version}`);

    } catch (error) {
      console.error(`Failed to load plugin from ${pluginPath}:`, error);
      throw error;
    }
  }

  async unloadPlugin(pluginName: string): Promise<void> {
    const loadedPlugin = this.plugins.get(pluginName);
    if (!loadedPlugin) {
      throw new Error(`Plugin not found: ${pluginName}`);
    }

    try {
      // Disable plugin
      if (loadedPlugin.plugin.onDisable) {
        await loadedPlugin.plugin.onDisable(loadedPlugin.context);
      }

      // Unregister plugin features
      await this.unregisterPluginFeatures(loadedPlugin.plugin);

      // Unload plugin
      if (loadedPlugin.plugin.onUnload) {
        await loadedPlugin.plugin.onUnload(loadedPlugin.context);
      }

      // Remove plugin
      this.plugins.delete(pluginName);

      this.eventBus.emit('plugin:unloaded', { plugin: pluginName });

      console.log(`Plugin unloaded: ${pluginName}`);

    } catch (error) {
      console.error(`Failed to unload plugin ${pluginName}:`, error);
      throw error;
    }
  }

  private validatePlugin(plugin: Plugin): void {
    if (!plugin.name || !plugin.version) {
      throw new Error("Plugin must have name and version");
    }

    if (this.plugins.has(plugin.name)) {
      throw new Error(`Plugin already loaded: ${plugin.name}`);
    }

    // Validate version format
    if (!/^\d+\.\d+\.\d+$/.test(plugin.version)) {
      throw new Error("Plugin version must follow semver format");
    }
  }

  private async checkDependencies(plugin: Plugin): Promise<void> {
    if (!plugin.dependencies) return;

    for (const dep of plugin.dependencies) {
      const loadedDep = this.plugins.get(dep.name);

      if (!loadedDep) {
        if (dep.optional) {
          console.warn(`Optional dependency not found: ${dep.name}`);
          continue;
        } else {
          throw new Error(`Required dependency not found: ${dep.name}`);
        }
      }

      // Check version compatibility
      if (!this.isVersionCompatible(loadedDep.plugin.version, dep.version)) {
        throw new Error(`Incompatible dependency version: ${dep.name}`);
      }
    }
  }

  private createPluginContext(plugin: Plugin): PluginContext {
    return {
      server: this.server,
      config: this.config.pluginConfigs?.[plugin.name] || {},
      logger: this.createPluginLogger(plugin.name),
      storage: this.createPluginStorage(plugin.name),
      eventBus: this.eventBus
    };
  }
}

interface LoadedPlugin {
  plugin: Plugin;
  context: PluginContext;
  path: string;
  loadTime: Date;
  enabled: boolean;
}

2.2 Example Plugin Implementation

// Example plugin: Weather Service
class WeatherServicePlugin implements Plugin {
  name = "weather-service";
  version = "1.0.0";
  description = "Weather information service plugin";
  author = "Weather Team";

  private apiKey: string;
  private cache: Map<string, any> = new Map();

  dependencies: PluginDependency[] = [
    {
      name: "http-client",
      version: "1.0.0",
      optional: false
    }
  ];

  tools: PluginTool[] = [
    {
      name: "get_weather",
      description: "Get current weather for a location",
      inputSchema: {
        type: "object",
        properties: {
          location: { type: "string", description: "City name or coordinates" },
          units: { type: "string", enum: ["metric", "imperial"], default: "metric" }
        },
        required: ["location"]
      },
      handler: this.getWeather.bind(this)
    },
    {
      name: "get_forecast",
      description: "Get weather forecast for a location",
      inputSchema: {
        type: "object",
        properties: {
          location: { type: "string", description: "City name or coordinates" },
          days: { type: "number", minimum: 1, maximum: 7, default: 5 }
        },
        required: ["location"]
      },
      handler: this.getForecast.bind(this)
    }
  ];

  async onLoad(context: PluginContext): Promise<void> {
    this.apiKey = context.config.apiKey;
    if (!this.apiKey) {
      throw new Error("Weather API key not configured");
    }

    context.logger.info("Weather service plugin loaded");
  }

  async onUnload(context: PluginContext): Promise<void> {
    this.cache.clear();
    context.logger.info("Weather service plugin unloaded");
  }

  private async getWeather(args: any, context: PluginContext): Promise<any> {
    const { location, units = "metric" } = args;

    // Check cache
    const cacheKey = `weather:${location}:${units}`;
    const cached = this.cache.get(cacheKey);
    if (cached && Date.now() - cached.timestamp < 300000) { // 5 minute cache
      return {
        content: [{
          type: "text",
          text: JSON.stringify(cached.data, null, 2)
        }]
      };
    }

    try {
      // Call weather API
      const weatherData = await this.fetchWeatherData(location, units);

      // Cache result
      this.cache.set(cacheKey, {
        data: weatherData,
        timestamp: Date.now()
      });

      return {
        content: [{
          type: "text",
          text: JSON.stringify(weatherData, null, 2)
        }]
      };
    } catch (error) {
      context.logger.error(`Failed to get weather for ${location}:`, error);
      throw error;
    }
  }

  private async fetchWeatherData(location: string, units: string): Promise<any> {
    // Simulate API call
    const response = await fetch(`https://api.openweathermap.org/data/2.5/weather?q=${location}&units=${units}&appid=${this.apiKey}`);

    if (!response.ok) {
      throw new Error(`Weather API error: ${response.status}`);
    }

    const data = await response.json();

    return {
      location: data.name,
      country: data.sys.country,
      temperature: data.main.temp,
      feelsLike: data.main.feels_like,
      description: data.weather[0].description,
      humidity: data.main.humidity,
      pressure: data.main.pressure,
      windSpeed: data.wind.speed,
      windDirection: data.wind.deg,
      visibility: data.visibility,
      cloudiness: data.clouds.all,
      timestamp: new Date(data.dt * 1000).toISOString()
    };
  }
}

// Export plugin
export default WeatherServicePlugin;

3. Multi-Language Support

3.1 Multi-Language Service Architecture

// Multi-language MCP Server bridge architecture
interface LanguageBridge {
  language: string;
  executable: string;
  args: string[];
  environment?: Record<string, string>;
  workingDirectory?: string;
}

class MultiLanguageServerManager {
  private bridges: Map<string, LanguageBridgeInstance> = new Map();
  private server: Server;

  constructor(server: Server) {
    this.server = server;
  }

  async registerLanguageBridge(config: LanguageBridge): Promise<void> {
    const bridge = new LanguageBridgeInstance(config);
    await bridge.start();

    this.bridges.set(config.language, bridge);

    // Proxy requests from language bridge
    this.setupBridgeProxy(config.language, bridge);

    console.log(`Language bridge registered: ${config.language}`);
  }

  private setupBridgeProxy(language: string, bridge: LanguageBridgeInstance): void {
    // Proxy tool calls
    bridge.on('tools/list', async () => {
      const tools = await bridge.sendRequest('tools/list', {});
      return tools;
    });

    bridge.on('tools/call', async (request: any) => {
      const result = await bridge.sendRequest('tools/call', request.params);
      return result;
    });

    // Proxy resource access
    bridge.on('resources/list', async () => {
      const resources = await bridge.sendRequest('resources/list', {});
      return resources;
    });

    bridge.on('resources/read', async (request: any) => {
      const result = await bridge.sendRequest('resources/read', request.params);
      return result;
    });
  }
}

class LanguageBridgeInstance {
  private config: LanguageBridge;
  private process: ChildProcess | null = null;
  private requestId = 1;
  private pendingRequests = new Map<number, { resolve: Function; reject: Function }>();
  private eventListeners = new Map<string, Function[]>();

  constructor(config: LanguageBridge) {
    this.config = config;
  }

  async start(): Promise<void> {
    const { spawn } = require('child_process');

    this.process = spawn(this.config.executable, this.config.args, {
      cwd: this.config.workingDirectory,
      env: { ...process.env, ...this.config.environment },
      stdio: ['pipe', 'pipe', 'pipe']
    });

    this.process.on('error', (error) => {
      console.error(`Language bridge process error (${this.config.language}):`, error);
    });

    this.process.on('exit', (code) => {
      console.log(`Language bridge process exited (${this.config.language}):`, code);
    });

    // Setup message handling
    this.setupMessageHandling();
  }

  async sendRequest(method: string, params: any): Promise<any> {
    if (!this.process) {
      throw new Error('Language bridge not started');
    }

    const id = this.requestId++;
    const request = {
      jsonrpc: '2.0',
      id,
      method,
      params
    };

    return new Promise((resolve, reject) => {
      this.pendingRequests.set(id, { resolve, reject });

      this.process!.stdin!.write(JSON.stringify(request) + '\n');

      // Set timeout
      setTimeout(() => {
        if (this.pendingRequests.has(id)) {
          this.pendingRequests.delete(id);
          reject(new Error('Request timeout'));
        }
      }, 30000);
    });
  }
}

3.2 Python Bridge Example

# Python MCP Server bridge implementation
import json
import sys
import asyncio
from typing import Dict, Any, List, Optional
from abc import ABC, abstractmethod

class MCPHandler(ABC):
    @abstractmethod
    async def handle_tools_list(self) -> List[Dict[str, Any]]:
        pass

    @abstractmethod
    async def handle_tools_call(self, name: str, arguments: Dict[str, Any]) -> Any:
        pass

    @abstractmethod
    async def handle_resources_list(self) -> List[Dict[str, Any]]:
        pass

    @abstractmethod
    async def handle_resources_read(self, uri: str) -> Any:
        pass

class PythonMCPBridge:
    def __init__(self, handler: MCPHandler):
        self.handler = handler
        self.running = True

    async def start(self):
        """Start bridge service"""
        while self.running:
            try:
                line = await self._read_line()
                if line:
                    await self._handle_request(line)
            except EOFError:
                break
            except Exception as e:
                await self._send_error(None, str(e))

    async def _read_line(self) -> str:
        """Read a line from stdin"""
        loop = asyncio.get_event_loop()
        line = await loop.run_in_executor(None, sys.stdin.readline)
        return line.strip()

    async def _handle_request(self, line: str):
        """Handle JSON-RPC request"""
        try:
            request = json.loads(line)
            method = request.get('method')
            params = request.get('params', {})
            request_id = request.get('id')

            if method == 'tools/list':
                result = await self.handler.handle_tools_list()
            elif method == 'tools/call':
                result = await self.handler.handle_tools_call(
                    params.get('name'),
                    params.get('arguments', {})
                )
            elif method == 'resources/list':
                result = await self.handler.handle_resources_list()
            elif method == 'resources/read':
                result = await self.handler.handle_resources_read(params.get('uri'))
            else:
                raise ValueError(f"Unknown method: {method}")

            await self._send_response(request_id, result)

        except Exception as e:
            await self._send_error(request.get('id'), str(e))

    async def _send_response(self, request_id: Any, result: Any):
        """Send success response"""
        response = {
            'jsonrpc': '2.0',
            'id': request_id,
            'result': result
        }
        print(json.dumps(response), flush=True)

    async def _send_error(self, request_id: Any, error_message: str):
        """Send error response"""
        response = {
            'jsonrpc': '2.0',
            'id': request_id,
            'error': {
                'code': -1,
                'message': error_message
            }
        }
        print(json.dumps(response), flush=True)

# Example Python MCP Server implementation
class FileOperationsHandler(MCPHandler):
    def __init__(self, base_directory: str):
        self.base_directory = base_directory

    async def handle_tools_list(self) -> List[Dict[str, Any]]:
        return [
            {
                'name': 'list_files',
                'description': 'List files in a directory',
                'inputSchema': {
                    'type': 'object',
                    'properties': {
                        'path': {'type': 'string', 'description': 'Directory path'}
                    }
                }
            },
            {
                'name': 'read_file',
                'description': 'Read file content',
                'inputSchema': {
                    'type': 'object',
                    'properties': {
                        'path': {'type': 'string', 'description': 'File path'}
                    },
                    'required': ['path']
                }
            }
        ]

    async def handle_tools_call(self, name: str, arguments: Dict[str, Any]) -> Any:
        if name == 'list_files':
            return await self._list_files(arguments.get('path', '.'))
        elif name == 'read_file':
            return await self._read_file(arguments['path'])
        else:
            raise ValueError(f"Unknown tool: {name}")

    async def _list_files(self, path: str) -> Dict[str, Any]:
        import os
        from pathlib import Path

        full_path = Path(self.base_directory) / path
        if not full_path.exists():
            raise FileNotFoundError(f"Directory not found: {path}")

        files = []
        for item in full_path.iterdir():
            stat_info = item.stat()
            files.append({
                'name': item.name,
                'type': 'directory' if item.is_dir() else 'file',
                'size': stat_info.st_size,
                'modified': stat_info.st_mtime
            })

        return {
            'content': [{
                'type': 'text',
                'text': json.dumps(files, indent=2)
            }]
        }

# Start Python MCP Server
async def main():
    import os

    base_directory = os.environ.get('MCP_BASE_DIR', '.')
    handler = FileOperationsHandler(base_directory)
    bridge = PythonMCPBridge(handler)

    await bridge.start()

if __name__ == '__main__':
    asyncio.run(main())

4. AI Framework Integration

4.1 LangChain Integration

// LangChain and MCP integration
import { Tool } from "langchain/tools";
import { CallbackManagerForToolRun } from "langchain/callbacks";

class MCPTool extends Tool {
  name: string;
  description: string;
  private mcpClient: MCPClient;
  private toolName: string;

  constructor(mcpClient: MCPClient, toolDefinition: any) {
    super();
    this.mcpClient = mcpClient;
    this.toolName = toolDefinition.name;
    this.name = toolDefinition.name;
    this.description = toolDefinition.description;
  }

  async _call(
    input: string,
    runManager?: CallbackManagerForToolRun
  ): Promise<string> {
    try {
      // Parse input parameters
      let args: any = {};
      try {
        args = JSON.parse(input);
      } catch {
        // If not JSON, use as single string parameter
        args = { input };
      }

      // Call MCP tool
      const result = await this.mcpClient.callTool(this.toolName, args);

      // Return result
      if (result.content && result.content[0]) {
        return result.content[0].text;
      }

      return JSON.stringify(result);
    } catch (error) {
      throw new Error(`MCP tool execution failed: ${error.message}`);
    }
  }
}

class MCPLangChainIntegration {
  private mcpClient: MCPClient;
  private tools: MCPTool[] = [];

  constructor(mcpClient: MCPClient) {
    this.mcpClient = mcpClient;
  }

  async loadTools(): Promise<MCPTool[]> {
    const toolDefinitions = await this.mcpClient.listTools();

    this.tools = toolDefinitions.map(toolDef =>
      new MCPTool(this.mcpClient, toolDef)
    );

    return this.tools;
  }

  getTools(): MCPTool[] {
    return this.tools;
  }

  async createAgent(llm: any): Promise<any> {
    const { createReactAgent } = await import("langchain/agents");
    const { pull } = await import("langchain/hub");

    // Load tools
    await this.loadTools();

    // Create prompt
    const prompt = await pull("hwchase17/react");

    // Create agent
    const agent = await createReactAgent({
      llm,
      tools: this.tools,
      prompt
    });

    return agent;
  }
}

5. Enterprise Applications

5.1 Enterprise Integration Architecture

// Enterprise-level MCP integration architecture
interface EnterpriseConfig {
  authentication: {
    provider: "ldap" | "saml" | "oauth2" | "custom";
    config: Record<string, any>;
  };
  authorization: {
    model: "rbac" | "abac" | "custom";
    policies: AuthorizationPolicy[];
  };
  monitoring: {
    enabled: boolean;
    endpoints: string[];
    metrics: string[];
  };
  compliance: {
    dataRetention: number; // days
    auditLogging: boolean;
    encryptionAtRest: boolean;
    encryptionInTransit: boolean;
  };
  scaling: {
    maxInstances: number;
    autoScaling: boolean;
    loadBalancer: string;
  };
}

class EnterpriseMCPServer {
  private server: Server;
  private config: EnterpriseConfig;
  private authProvider: EnterpriseAuthProvider;
  private auditLogger: EnterpriseAuditLogger;
  private metricsCollector: EnterpriseMetricsCollector;
  private complianceManager: ComplianceManager;

  constructor(config: EnterpriseConfig) {
    this.config = config;
    this.initializeComponents();
  }

  private initializeComponents(): void {
    // Initialize authentication provider
    this.authProvider = new EnterpriseAuthProvider(this.config.authentication);

    // Initialize audit logger
    this.auditLogger = new EnterpriseAuditLogger(this.config.compliance);

    // Initialize metrics collector
    this.metricsCollector = new EnterpriseMetricsCollector(this.config.monitoring);

    // Initialize compliance manager
    this.complianceManager = new ComplianceManager(this.config.compliance);

    // Create MCP server
    this.server = new Server(
      {
        name: "enterprise-mcp-server",
        version: "1.0.0"
      },
      {
        capabilities: {
          tools: {},
          resources: {},
          prompts: {},
          enterprise: {
            authentication: true,
            authorization: true,
            auditing: true,
            compliance: true
          }
        }
      }
    );

    this.setupMiddleware();
    this.setupHandlers();
  }

  private setupMiddleware(): void {
    // Authentication middleware
    this.server.use(async (request, next) => {
      const authResult = await this.authProvider.authenticate(request);
      if (!authResult.success) {
        throw new Error("Authentication failed");
      }

      request.user = authResult.user;
      return next();
    });

    // Authorization middleware
    this.server.use(async (request, next) => {
      const authorized = await this.authProvider.authorize(request.user, request.method, request.params);
      if (!authorized) {
        this.auditLogger.logUnauthorizedAccess(request.user, request.method, request.params);
        throw new Error("Access denied");
      }

      return next();
    });

    // Audit middleware
    this.server.use(async (request, next) => {
      const startTime = Date.now();

      try {
        const result = await next();

        this.auditLogger.logSuccessfulOperation(
          request.user,
          request.method,
          request.params,
          Date.now() - startTime
        );

        return result;
      } catch (error) {
        this.auditLogger.logFailedOperation(
          request.user,
          request.method,
          request.params,
          error.message,
          Date.now() - startTime
        );

        throw error;
      }
    });
  }
}

6. Best Practices Summary

6.1 Advanced Features Usage Guide

class AdvancedFeatureGuidelines {
  static readonly GUIDELINES = {
    PROTOCOL_EXTENSIONS: {
      principles: [
        "Extension should be backward compatible",
        "Clear versioning and deprecation policy",
        "Comprehensive documentation and examples",
        "Thorough testing across different clients"
      ],
      antipatterns: [
        "Breaking existing functionality",
        "Overly complex extension interfaces",
        "Poor error handling in extensions",
        "Lack of proper validation"
      ]
    },

    PLUGIN_DEVELOPMENT: {
      principles: [
        "Single responsibility per plugin",
        "Clean dependency management",
        "Proper lifecycle management",
        "Configuration externalization"
      ],
      antipatterns: [
        "Tight coupling between plugins",
        "Blocking operations in lifecycle methods",
        "Hardcoded configuration values",
        "Missing error boundaries"
      ]
    },

    MULTI_LANGUAGE_SUPPORT: {
      principles: [
        "Consistent protocol implementation",
        "Proper error propagation",
        "Efficient data serialization",
        "Resource cleanup"
      ],
      antipatterns: [
        "Language-specific protocol deviations",
        "Blocking I/O in bridge processes",
        "Memory leaks in long-running bridges",
        "Inconsistent error formats"
      ]
    }
  };
}

Summary

Through this chapter, we explored advanced MCP features and extension development in depth:

Protocol Extension Mechanism - Learned how to extend the MCP protocol and implement advanced features like streaming
Plugin System Architecture - Mastered complete plugin system design and implementation
Multi-Language Support - Understood how to implement cross-language MCP Server bridges
AI Framework Integration - Learned integration methods with LangChain, LlamaIndex, and other frameworks
Enterprise Application Practice - Explored security, compliance, and monitoring requirements in enterprise environments

These advanced features and extension capabilities enable MCP to adapt to more complex application scenarios and enterprise needs, providing powerful infrastructure support for building next-generation AI applications.

With this, we have completed the comprehensive learning journey of MCP Server development, from basic concepts to advanced features, from hands-on projects to enterprise applications, covering all aspects of MCP development. We hope this complete learning material helps you become an MCP development expert!

Argo Tutorial Series

Chapter 2: Argo CD Getting Started

Chapter 3: Argo CD Advanced Configuration

Chapter 4: Argo Workflows Fundamentals

Chapter 5: Argo Workflows Advanced Features

Argo Tutorial Series

Chapter 2: Argo CD Getting Started

Chapter 3: Argo CD Advanced Configuration

Chapter 4: Argo Workflows Fundamentals

Chapter 5: Argo Workflows Advanced Features

Chapter 14: Advanced Features and Extension Development

Chapter 14: Advanced Features and Extension Development

Learning Objectives

1. Protocol Extension Mechanism

1.1 Custom Protocol Extensions

1.2 Streaming Processing Extension

2. Plugin System Architecture

2.1 Plugin Framework Design

2.2 Example Plugin Implementation

3. Multi-Language Support

3.1 Multi-Language Service Architecture

3.2 Python Bridge Example

4. AI Framework Integration

4.1 LangChain Integration

5. Enterprise Applications

5.1 Enterprise Integration Architecture

6. Best Practices Summary

6.1 Advanced Features Usage Guide

Summary