MCPServer Class API Reference

---

title: "MCPServer Class API Reference" description: "Complete API reference for the MCPServer class in mcp-framework — configure, initialize, and run MCP servers with auto-discovery, transport selection, and authentication." order: 5 keywords: ["MCPServer", "MCP server", "mcp-framework server", "server configuration", "MCP transport", "server API"] date: "2026-04-01"

Overview

Basic Usage

The simplest possible MCP server entry point:

import { MCPServer } from "mcp-framework";

const server = new MCPServer();
server.start();

This uses all defaults: stdio transport, auto-discovery from src/tools/, src/resources/, and src/prompts/.

Constructor

new MCPServer(options?: MCPServerOptions)

MCPServerOptions

interface MCPServerOptions {
  name?: string;
  version?: string;
  transport?: TransportConfig;
  basePath?: string;
}

Configuration Examples

Default stdio Server

import { MCPServer } from "mcp-framework";

const server = new MCPServer();
server.start();

Named Server with Version

import { MCPServer } from "mcp-framework";

const server = new MCPServer({
  name: "my-analytics-server",
  version: "2.1.0",
});

server.start();

SSE Transport

import { MCPServer } from "mcp-framework";

const server = new MCPServer({
  transport: {
    type: "sse",
    options: {
      port: 8080,
      cors: {
        allowOrigins: ["https://myapp.com"],
      },
    },
  },
});

server.start();

SSE with Authentication

import { MCPServer } from "mcp-framework";

const server = new MCPServer({
  transport: {
    type: "sse",
    options: {
      port: 8080,
      auth: {
        type: "jwt",
        options: {
          secret: process.env.JWT_SECRET!,
          algorithms: ["HS256"],
        },
      },
    },
  },
});

server.start();

Methods

start()

Starts the MCP server, initializes the transport, and begins listening for client connections.

async start(): Promise<void>

This method:

1. Scans directories for tools, resources, and prompts
2. Registers all discovered components with the MCP protocol handler
3. Initializes the configured transport (stdio or SSE)
4. Begins accepting client connections

Auto-Discovery

MCPServer automatically discovers and registers components from:

Each .ts file in these directories must have a default export of the appropriate class (MCPTool, MCPResource, or MCPPrompt). The framework:

1. Scans each directory recursively
2. Imports each file dynamically
3. Validates the default export
4. Registers the component with the protocol handler

Lifecycle

new MCPServer(options)
    │
    ▼
server.start()
    │
    ├── Scan src/tools/
    ├── Scan src/resources/
    ├── Scan src/prompts/
    │
    ├── Register all components
    │
    ├── Initialize transport
    │     ├── stdio: Read from stdin, write to stdout
    │     └── SSE: Start HTTP server on configured port
    │
    └── Accept client connections

Entry Point Pattern

The standard entry point (src/index.ts) generated by the CLI:

import { MCPServer } from "mcp-framework";

const server = new MCPServer();

server.start().catch((error) => {
  console.error("Server failed to start:", error);
  process.exit(1);
});

Environment Configuration

Common patterns for configuring the server based on environment:

import { MCPServer } from "mcp-framework";

const isDev = process.env.NODE_ENV === "development";

const server = new MCPServer({
  transport: isDev
    ? { type: "sse", options: { port: 3001 } }
    : { type: "stdio" },
});

server.start();