mcplex v1.0.14

MCPlex

A lightweight multiplexer for managing multiple Model Context Protocol (MCP) clients.

Features

• Support for multiple MCP clients (both SSE and StdIO transports)
• Easy client initialization and management
• Combined tool management across all clients
• Type-safe configurations
• Enable/disable functionality for clients

Installation

npm install mcplex

Usage

import { Mcplex } from 'mcplex';

// Create a new wrapper instance
const wrapper = new Mcplex();

// Initialize a StdIO client with additional options
await wrapper.initializeClient({
  name: 'linear-bot',
  type: 'stdio',
  command: 'npx',
  args: ['-y', 'linear-mcp-server'],
  env: {
    LINEAR_API_KEY: process.env.LINEAR_API_KEY,
  },
  version: '1.0.0',           // Optional: specify client version
  cwd: process.cwd(),         // Optional: specify working directory
  clientOptions: {},          // Optional: MCP client options
});

// Initialize an SSE client with options
await wrapper.initializeClient({
  name: 'sse-client',
  type: 'sse',
  url: 'http://localhost:3000/sse',
  version: '1.0.0',           // Optional: specify client version
  clientOptions: {},          // Optional: MCP client options
  options: {}                  // Optional: SSE transport options
});

// Check if a client is connected
const isConnected = wrapper.isClientConnected('linear-bot');

// Get tools for a specific client
const linearTools = wrapper.getClientTools('linear-bot');

// Get all tools from all connected clients
const allTools = wrapper.getAllTools();

// Enable/disable a client
await wrapper.setClientEnabled('linear-bot', false);

// Get list of all registered clients
const clients = wrapper.getClients();

API Reference

Mcplex

Methods

• initializeClient(config: ClientConfig): Promise<void>

  • Initializes a new MCP client with the given configuration

• connectClient(clientName: string): Promise<boolean>

  • Connects a specific client by name

• isClientConnected(clientName: string): boolean

  • Returns the connection status of a specific client

• getClientTools(clientName: string): ToolSet | undefined

  • Returns the tools available for a specific client

• getAllTools(): ToolSet

  • Returns all tools from all connected clients combined

• setClientEnabled(clientName: string, enabled: boolean): Promise<void>

  • Enables or disables a specific client

• getClients(): string[]

  • Returns an array of all registered client names

Configuration Types

interface BaseClientConfig {
  name: string;
  type: "stdio" | "sse";
  enabled?: boolean;
  version?: string;
  clientOptions?: ClientOptions;
}

interface StdioClientConfig extends BaseClientConfig {
  type: "stdio";
  command: string;
  args?: string[];
  env?: Record<string, string>;
  cwd?: string;
  stderr?: boolean | "pipe";
}

interface SSEClientConfig extends BaseClientConfig {
  type: "sse";
  url: string;
  options?: {
    headers?: Record<string, string>;
    [key: string]: any;
  };
}

type ClientConfig = StdioClientConfig | SSEClientConfig;

Configuration Options

• name: Unique identifier for the client
• type: Type of client transport ("stdio" or "sse")
• enabled: Whether the client should be automatically connected (optional)
• version: Client version (optional, defaults to package version)
• clientOptions: MCP client configuration options (optional)

For StdIO clients:

• command: Command to execute
• args: Command arguments (optional)
• env: Environment variables (optional)
• cwd: Working directory for the command (optional)
• stderr: How to handle stderr output (optional)

For SSE clients:

• url: SSE endpoint URL
• options: SSE transport options including headers (optional)

License

MIT