Cloudflare で MCP サーバーを構築する

npm create cloudflare@latest my-mcp-server

╭ Create an application with Cloudflare Step 1 of 3
│
├ In which directory do you want to create your application?
│ dir ./my-mcp-server
│
├ What would you like to start with?
│ category Hello World example
│
├ Which template would you like to use?
│ type Worker + Durable Objects
│
├ Which language do you want to use?
│ lang TypeScript
│
├ Copying template files
│ files copied to project directory
│
├ Updating name in `package.json`
│ updated `package.json`
│
┴ Installing dependencies  

npm install agents @modelcontextprotocol/sdk zod

import { McpAgent } from 'agents/mcp';
import { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js';
import { z } from 'zod';
 
export class MyMCP extends McpAgent {
	server = new McpServer({
		name: 'MyMCP Server',
		version: '0.1.0',
	});
 
	async init() {
		this.server.tool(
			// ツールの名前
			'dice_roll',
			// ツールの説明
			'サイコロを降った結果を返します',
			// ツールの引数のスキーマ
			{ sides: z.number().min(1).max(100).default(6).describe('サイコロの面の数') },
			// ツールの実行関数
			async ({ sides }) => {
				// サイコロを振る
				const result = Math.floor(Math.random() * sides) + 1;
				// 結果を返す
				return {
					content: [{ type: 'text', text: result.toString() }],
				};
			}
		);
	}
}

import { MyMCP } from './MyMcp.js';
 
// Durable Objects のエクスポート
export { MyMCP };
 
export default {
	fetch(request: Request, env: Env, ctx: ExecutionContext) {
		const url = new URL(request.url);
 
		// /sse エンドポイントの場合は SSE で応答する
		if (url.pathname === '/sse' || url.pathname === '/sse/message') {
			// @ts-ignore
			return MyMCP.serveSSE('/sse').fetch(request, env, ctx);
		}
 
		// /mcp エンドポイントの場合は Streamable HTTP で応答する
		if (url.pathname === '/mcp') {
			// @ts-ignore
			return MyMCP.serve('/mcp').fetch(request, env, ctx);
		}
 
		return new Response('Not found', { status: 404 });
	},
};

{
  "migrations": [
		{
			"new_sqlite_classes": [
				"MyMCP"
			],
			"tag": "v1"
		}
	],
	"durable_objects": {
		"bindings": [
			{
				"class_name": "MyMCP",
				"name": "MCP_OBJECT"
			}
		]
	},
}

npm run dev

npx @modelcontextprotocol/inspector

npm run deploy

npm run deploy
 
> [email protected] deploy
> wrangler deploy
 
 
 ⛅️ wrangler 4.14.4
-------------------
 
Attempting to login via OAuth...
Opening a link in your default browser: https://dash.cloudflare.com/oauth2/auth...
Successfully logged in.
Total Upload: 477.30 KiB / gzip: 89.85 KiB
Worker Startup Time: 23 ms
Your Worker has access to the following bindings:
- Durable Objects:
  - MCP_OBJECT: MyMCP
Uploaded my-mcp-server (2.04 sec)
Deployed my-mcp-server triggers (0.91 sec)
  https://my-mcp-server.azukiazusa.workers.dev