MCP Client Manager

A client manager for the Model Context Protocol (MCP) that provides a simple way to manage multiple MCP clients connected to different servers.

Features

• Multiple Server Management: Connect to multiple MCP servers and manage them through a single interface
• Server Discovery: Automatically find which server provides the resources or tools you need
• Error Handling: Robust error handling with detailed error information
• Reconnection Support: Automatic reconnection capabilities for transient failures
• Event System: Event-based architecture for monitoring connections and operations
• Typed API: Fully TypeScript-compatible with comprehensive type definitions

Installation

npm install @modelcontextprotocol/client-manager

Basic Usage

import { MCPClientManager } from '@modelcontextprotocol/client-manager';
import { WebSocketTransport } from '@modelcontextprotocol/sdk/client/websocket.js';

// Create a manager with auto-reconnect enabled
const manager = new MCPClientManager({
  autoReconnect: true,
  defaultTimeout: 10000
});

// Connect to a server
const transport = new WebSocketTransport('ws://localhost:3000');
const clientId = await manager.addServer(transport, 'local-server');

// List available tools from all connected servers
const tools = await manager.listTools();
console.log('Available tools:', tools);

// Call a tool on any server that provides it
const result = await manager.callTool('my-tool', { param: 'value' });
console.log('Tool result:', result);

Advanced Usage

Connecting to Multiple Servers

// Connect to multiple servers
const server1Id = await manager.addServer(
  new WebSocketTransport('ws://server1:3000'), 
  'server-1'
);

const server2Id = await manager.addServer(
  new WebSocketTransport('ws://server2:3000'), 
  'server-2'
);

// You can work with specific servers using their IDs
const server1Tools = await manager.getClient(server1Id).listTools();

// Or use the unified API to work with all servers
const allTools = await manager.listTools();

Handling Events

// Listen for connection errors
manager.on('connectionError', ({ serverName, error }) => {
  console.error(`Failed to connect to ${serverName}:`, error);
});

// Listen for transport closures
manager.on('transportClosed', ({ clientId, serverName }) => {
  console.warn(`Connection to ${serverName} closed`);
});

// Listen for operation errors
manager.on('operationError', ({ operation, clientId, serverName, error }) => {
  console.error(`Error during ${operation} on ${serverName}:`, error);
});

Configuration Options

The MCPClientManager constructor accepts a configuration object with these options:

| Option | Type | Default | Description | |--------|------|---------|-------------| | defaultTimeout | number | 30000 | Default timeout in milliseconds for operations | | autoReconnect | boolean | false | Whether to automatically attempt to reconnect disconnected clients | | maxReconnectAttempts | number | 3 | Maximum number of reconnection attempts | | reconnectDelay | number | 5000 | Delay between reconnection attempts in milliseconds | | debug | boolean | false | Whether to emit verbose debug logs |

API Reference

Class: MCPClientManager

Constructor

constructor(config: Partial<MCPClientManagerConfig> = {})

Creates a new MCPClientManager instance with the given configuration.

Server Management Methods

• async addServer(transport: ClientTransport, serverName: string, clientConfig?: Partial<ClientConfig>): Promise<ClientIdentifier>
• async reconnectClient(clientId: ClientIdentifier): Promise<boolean>
• removeClient(id: ClientIdentifier): boolean
• isClientHealthy(clientId: ClientIdentifier): boolean
• listServerNames(): string[]
• hasServer(serverName: string): boolean
• getClientInfo(id: ClientIdentifier): Omit<ClientInfo, 'client'> | undefined
• getClientIdByServerName(serverName: string): ClientIdentifier | undefined
• listClientIds(): ClientIdentifier[]

MCP Operation Methods

• async listPrompts(timeout?: number): Promise<unknown[]>
• async getPrompt(promptName: string, args?: PromptParams, timeout?: number): Promise<unknown>
• async listResources(timeout?: number): Promise<unknown[]>
• async readResource(resourceUri: string, timeout?: number): Promise<unknown>
• async listTools(timeout?: number): Promise<unknown[]>
• async callTool(toolName: string, args?: Record<string, unknown>, timeout?: number): Promise<ToolResponse>

Events

• serverAdded: Emitted when a server is successfully added
• connectionError: Emitted when there's an error connecting to a server
• transportError: Emitted when there's an error with a transport
• transportClosed: Emitted when a transport is closed
• clientReconnected: Emitted when a client is successfully reconnected
• reconnectionError: Emitted when there's an error reconnecting a client
• closeError: Emitted when there's an error closing a transport
• clientRemoved: Emitted when a client is removed
• operationError: Emitted when there's an error during an operation

License

MIT