How do I use MCP Demo Server?

1. Click on "Install Server". 2. Wait a few minutes for the server to deploy. Once ready, it will show a "Started" state. 3. In the chat, type @ followed by the MCP server name and your instructions, e.g., "@MCP Demo Server read the widget resource file" That's it! The server will respond to your query, and you can continue using it as needed. Here is a step-by-step guide with screenshots.

MCP Demo Server

A stateless HTTP Streaming server built with Model Context Protocol (MCP) and Express.

🌐 Live Demo

Production URL: https://mcp-demo-d3cj.onrender.com/mcp

Try it now:

curl -X POST https://mcp-demo-d3cj.onrender.com/mcp \
  -H "Content-Type: application/json" \
  -H "Accept: application/json, text/event-stream" \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/list","params":{}}'

📚 Documentation

Quick Start Guide - Get started in 5 minutes
HTTP Streaming Guide - Complete HTTP Streaming Transport guide
Usage Examples - Full code examples (Node.js, Python, Browser)
Troubleshooting Guide - Common issues and solutions

Features

✅ Fully Stateless - Each request is processed independently
✅ HTTP Streaming - Standard HTTP POST-based streaming transport
✅ Easy to Scale - No session management, horizontally scalable
✅ Simple Deployment - Perfect for serverless environments (Lambda, Cloud Functions)
✅ Production Ready - Live at https://mcp-demo-d3cj.onrender.com
✅ Two built-in tools:
- read_widget_resource: Read widgetResource.md file
- read_page_resource: Read pageResource.md file

Installation

npm install

Running Locally

# Production mode
npm start

# Development mode (with hot reload)
npm run dev

# Test with MCP Inspector
npm run test

Server runs on http://localhost:3000 by default.

Testing and Debugging

Using Production Server

Test the live production server:

# List available tools
curl -X POST https://mcp-demo-d3cj.onrender.com/mcp \
  -H "Content-Type: application/json" \
  -H "Accept: application/json, text/event-stream" \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/list","params":{}}'

# Call read_widget_resource tool
curl -X POST https://mcp-demo-d3cj.onrender.com/mcp \
  -H "Content-Type: application/json" \
  -H "Accept: application/json, text/event-stream" \
  -d '{"jsonrpc":"2.0","id":2,"method":"tools/call","params":{"name":"read_widget_resource","arguments":{}}}'

Using HTTP Streaming Test Client (Recommended)

# First start the server
npm start

# In another terminal, run the test client
npm run test-streaming

The test client will:

List all available tools
Call read_widget_resource tool
Call read_page_resource tool

Using curl for Local Testing

# List available tools
curl -X POST http://localhost:3000/mcp \
  -H "Content-Type: application/json" \
  -H "Accept: application/json, text/event-stream" \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/list","params":{}}'

# Call read_widget_resource tool
curl -X POST http://localhost:3000/mcp \
  -H "Content-Type: application/json" \
  -H "Accept: application/json, text/event-stream" \
  -d '{"jsonrpc":"2.0","id":2,"method":"tools/call","params":{"name":"read_widget_resource","arguments":{}}}'

# Check server health
curl http://localhost:3000/health

# Get server information
curl http://localhost:3000/

API Endpoints

HTTP Streaming Transport

1. MCP Endpoint

Path: /mcp
Method: POST
Description: HTTP streaming endpoint for MCP JSON-RPC requests
Features: Fully stateless, each request is processed independently

Other Endpoints

2. Health Check

Path: /health
Method: GET
Description: Check server status

3. Root Path

Path: /
Method: GET
Description: Get server information and available tools list

Available Tools

Reads the content of src/resources/widgetResource.md file.

Input: No parameters required

Output: File content as text

Example:

# Local
curl -X POST http://localhost:3000/mcp \
  -H "Content-Type: application/json" \
  -H "Accept: application/json, text/event-stream" \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"read_widget_resource","arguments":{}}}'

# Production
curl -X POST https://mcp-demo-d3cj.onrender.com/mcp \
  -H "Content-Type: application/json" \
  -H "Accept: application/json, text/event-stream" \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"read_widget_resource","arguments":{}}}'

read_page_resource

Reads the content of src/resources/pageResource.md file.

Input: No parameters required

Output: File content as text

Example:

# Local
curl -X POST http://localhost:3000/mcp \
  -H "Content-Type: application/json" \
  -H "Accept: application/json, text/event-stream" \
  -d '{"jsonrpc":"2.0","id":2,"method":"tools/call","params":{"name":"read_page_resource","arguments":{}}}'

# Production
curl -X POST https://mcp-demo-d3cj.onrender.com/mcp \
  -H "Content-Type: application/json" \
  -H "Accept: application/json, text/event-stream" \
  -d '{"jsonrpc":"2.0","id":2,"method":"tools/call","params":{"name":"read_page_resource","arguments":{}}}'

Usage Examples

Check Server Health

# Local
curl http://localhost:3000/health

# Production
curl https://mcp-demo-d3cj.onrender.com/health

Get Server Information

# Local
curl http://localhost:3000/

# Production
curl https://mcp-demo-d3cj.onrender.com/

MCP Client Integration

To connect to this MCP server, your MCP client needs to:

Send HTTP POST requests to the /mcp endpoint
Use JSON-RPC 2.0 format
Include proper Accept headers: application/json, text/event-stream
Receive results through HTTP response

Configuration Examples

Local Development

{
  "mcpServers": {
    "mcp-demo-local": {
      "transport": {
        "type": "http",
        "url": "http://localhost:3000/mcp"
      }
    }
  }
}

Production

{
  "mcpServers": {
    "mcp-demo": {
      "transport": {
        "type": "http",
        "url": "https://mcp-demo-d3cj.onrender.com/mcp"
      }
    }
  }
}

Using MCP SDK

import { Client } from '@modelcontextprotocol/sdk/client/index.js';
import { StreamableHTTPClientTransport } from '@modelcontextprotocol/sdk/client/streamableHttp.js';

const client = new Client({
  name: 'my-client',
  version: '1.0.0',
});

// Use production server
const transport = new StreamableHTTPClientTransport(
  new URL('https://mcp-demo-d3cj.onrender.com/mcp')
);

// Or use local server
// const transport = new StreamableHTTPClientTransport(
//   new URL('http://localhost:3000/mcp')
// );

await client.connect(transport);

// List tools
const tools = await client.listTools();

// Call tool
const result = await client.callTool({
  name: 'read_widget_resource',
  arguments: {},
});

Tech Stack

@modelcontextprotocol/sdk: MCP protocol implementation
Express: Web framework
CORS: Cross-Origin Resource Sharing support
Node.js: ES Modules

Project Structure

mcp-demo/
├── src/
│   ├── index.js                 # Main server file
│   └── resources/
│       ├── widgetResource.md    # Widget resource file
│       └── pageResource.md      # Page resource file
├── test-http-streaming.js       # HTTP Streaming test client
├── package.json
├── README.md
└── LICENSE

Environment Variables

PORT: Server port (default: 3000)

PORT=8080 npm start

Development

The server uses ES Modules and requires Node.js 14.0 or higher.

In development mode, use the --watch flag for automatic restarts:

npm run dev

Deployment

This server is deployed on Render and available at: https://mcp-demo-d3cj.onrender.com/mcp

You can deploy your own instance:

Fork this repository
Connect to Render/Vercel/Railway
Set environment variables if needed
Deploy!

License

MIT

MCP Demo Server

MCP Demo Server

🌐 Live Demo

📚 Documentation

Features

Installation

Running Locally

Testing and Debugging

Using Production Server

Using HTTP Streaming Test Client (Recommended)

Using curl for Local Testing

API Endpoints

HTTP Streaming Transport

1. MCP Endpoint

Other Endpoints

2. Health Check

3. Root Path

Available Tools

read_widget_resource

read_page_resource

Usage Examples

Check Server Health

Get Server Information

MCP Client Integration

Configuration Examples

Local Development

Production

Using MCP SDK

Tech Stack

Project Structure

Environment Variables

Development

Deployment

License

Resources

Latest Blog Posts

MCP directory API