Transport Overview

MCP Framework supports multiple transport mechanisms for communication between the client and server. Each transport type has its own characteristics, advantages, and use cases.

Available Transports

The framework currently supports the following transport types:

• STDIO Transport: The default transport that uses standard input/output streams
• HTTP Stream Transport: Streamable HTTP transport that implements the MCP 2025-03-26 specification
• SSE Transport: ⚠️ DEPRECATED - Server-Sent Events based transport that has been replaced by HTTP Stream Transport

Comparison

Feature	STDIO Transport	HTTP Stream Transport	SSE Transport (Deprecated)
Protocol	Standard I/O streams	HTTP/SSE	HTTP/SSE
Connection	Direct process communication	Network-based	Network-based
Authentication	Not applicable	Supports JWT and API Key	Supports JWT and API Key
Session Management	Not applicable	Built-in	Limited
Resumability	Not applicable	Supported	No
Use Case	CLI tools, local integrations	Web applications, distributed systems	Legacy systems
Configuration	Minimal	Highly configurable	Configurable
Scalability	Single process	Multiple clients	Multiple clients
MCP Specification	Compliant	2025-03-26 compliant	Legacy (2024-11-05)

Choosing a Transport

Choose your transport based on your application's needs:

• Use STDIO Transport when:

  • Building CLI tools
  • Need direct process communication
  • Working with local integrations
  • Want minimal configuration

• Use HTTP Stream Transport when:

  • Building web applications
  • Need network-based communication
  • Require authentication or session management
  • Want to support multiple clients
  • Need resumable connections
  • Need to scale horizontally
  • Require compliance with latest MCP specification

• Use SSE Transport only for:

  • Legacy applications that depend on the older transport

Configuration

STDIO Transport (Default)

const server = new MCPServer();
// or explicitly:
const server = new MCPServer({
  transport: { type: "stdio" }
});

HTTP Stream Transport

const server = new MCPServer({
  transport: {
    type: "http-stream",
    options: {
      port: 8080,            // Optional (default: 8080)
      endpoint: "/mcp",      // Optional (default: "/mcp")
      responseMode: "batch", // Optional (default: "batch")
      cors: {
        allowOrigin: "*"     // Optional CORS configuration
      },
      auth: {
        // Optional authentication configuration
      }
    }
  }
});

SSE Transport (Deprecated)

const server = new MCPServer({
  transport: {
    type: "sse",
    options: {
      port: 8080,            // Optional (default: 8080)
      endpoint: "/sse",      // Optional (default: "/sse")
      messageEndpoint: "/messages", // Optional (default: "/messages")
      auth: {
        // Optional authentication configuration
      }
    }
  }
});

For detailed information about each transport type, see:

• STDIO Transport
• HTTP Stream Transport
• SSE Transport (Deprecated)