Developing Custom MCP Servers

Install MCP SDK

Choose your preferred language and install the SDK:

# TypeScript/JavaScript
npm install @modelcontextprotocol/sdk

# Python
pip install mcp

Project Structure

Create a basic project structure:

my-mcp-server/
├── src/
│   ├── index.ts
│   └── tools.ts
├── package.json
└── tsconfig.json

Basic Server Implementation

Create a minimal MCP server with a custom tool:

import { Server } from '@modelcontextprotocol/sdk/server/index.js';
import { StdioServerTransport } from '@modelcontextprotocol/sdk/server/stdio.js';

const server = new Server({
  name: 'my-custom-server',
  version: '1.0.0',
});

// Define tools
server.setRequestHandler('tool/list', async () => ({
  tools: [{
    name: 'my_tool',
    description: 'My custom tool',
    inputSchema: {
      type: 'object',
      properties: {
        input: { type: 'string' }
      }
    }
  }]
}));

// Start server
const transport = new StdioServerTransport();
await server.connect(transport);

MCP Inspector

Use the MCP Inspector to test your server:

npx @modelcontextprotocol/inspector node ./dist/index.js

Test with Plugged.in

Add your server to Plugged.in as a local STDIO server for real-world testing.

Package Configuration

Configure your package.json for distribution:

{
  "name": "my-mcp-server",
  "bin": {
    "my-mcp-server": "./dist/index.js"
  }
}

Share on Plugged.in

Create a server configuration on Plugged.in and share it with the community.

Publish to Registry

Consider publishing to npm or PyPI for wider distribution.