import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/streamableHttp.js";
import {
registerAppTool,
registerAppResource,
RESOURCE_MIME_TYPE,
} from "@modelcontextprotocol/ext-apps/server";
import cors from "cors";
import express from "express";
import fs from "node:fs/promises";
import path from "node:path";
import { z } from "zod";
let highScore = 0;
const resourceUri = "ui://flappy-bird/flappy-bird.html";
function createServer() {
const server = new McpServer({
name: "Flappy Bird MCP",
version: "1.0.0",
});
// Main tool: renders the game UI
registerAppTool(
server,
"play-flappy-bird",
{
title: "Play Flappy Bird",
description:
"Launch a game of Flappy Bird! A classic side-scrolling game where you tap to keep the bird flying through gaps in pipes.",
inputSchema: {},
_meta: { ui: { resourceUri } },
},
async () => {
return {
content: [
{
type: "text" as const,
text: JSON.stringify({ highScore }),
},
],
};
},
);
// Tool for submitting scores from the game UI
server.tool(
"submit-score",
"Submit a score from the Flappy Bird game",
{ score: z.number().int().min(0) },
async ({ score }) => {
if (score > highScore) {
highScore = score;
}
return {
content: [
{
type: "text" as const,
text: JSON.stringify({ highScore, submitted: score }),
},
],
};
},
);
// Tool for retrieving the high score
server.tool(
"get-high-score",
"Get the current Flappy Bird high score",
{},
async () => {
return {
content: [
{
type: "text" as const,
text: JSON.stringify({ highScore }),
},
],
};
},
);
// Register the UI resource (bundled HTML)
registerAppResource(
server,
resourceUri,
resourceUri,
{ mimeType: RESOURCE_MIME_TYPE },
async () => {
const html = await fs.readFile(
path.join(import.meta.dirname, "dist", "flappy-bird.html"),
"utf-8",
);
return {
contents: [
{ uri: resourceUri, mimeType: RESOURCE_MIME_TYPE, text: html },
],
};
},
);
return server;
}
// Express HTTP server
const app = express();
app.use(cors());
app.use(express.json());
app.post("/mcp", async (req, res) => {
const server = createServer();
const transport = new StreamableHTTPServerTransport({
sessionIdGenerator: undefined,
enableJsonResponse: true,
});
res.on("close", () => transport.close());
await server.connect(transport);
await transport.handleRequest(req, res, req.body);
});
const PORT = 3001;
app.listen(PORT, () => {
console.log(`Flappy Bird MCP server running at http://localhost:${PORT}/mcp`);
});
