#!/usr/bin/env node
import { spawn } from "child_process";
import { fileURLToPath } from 'url';
import { resolve } from 'path';
class CalculatorDemo {
private serverProcess: any;
private messageId: number = 1;
async startServer(): Promise<void> {
console.log("š Starting MCP Server for Calculator Demo...");
this.serverProcess = spawn("node", ["dist/server.js"], {
stdio: ["pipe", "pipe", "pipe"],
cwd: process.cwd()
});
this.serverProcess.stderr?.on("data", (data: Buffer) => {
console.log("š§ Server:", data.toString().trim());
});
// Wait a moment for server to start
await new Promise(resolve => setTimeout(resolve, 1000));
}
async sendMessage(message: any): Promise<any> {
return new Promise((resolve, reject) => {
let responseData = "";
const onData = (data: Buffer) => {
responseData += data.toString();
// Check if we have a complete JSON response
const lines = responseData.split('\n');
for (const line of lines) {
if (line.trim()) {
try {
const response = JSON.parse(line.trim());
if (response.id === message.id) {
this.serverProcess.stdout?.off("data", onData);
resolve(response);
return;
}
} catch (e) {
// Not a complete JSON yet, continue reading
}
}
}
};
this.serverProcess.stdout?.on("data", onData);
this.serverProcess.stdin?.write(JSON.stringify(message) + "\n");
// Timeout after 5 seconds
setTimeout(() => {
this.serverProcess.stdout?.off("data", onData);
reject(new Error("Timeout waiting for response"));
}, 5000);
});
}
async initialize(): Promise<void> {
console.log("š” Initializing connection...");
const initMessage = {
jsonrpc: "2.0",
id: this.messageId++,
method: "initialize",
params: {
protocolVersion: "2024-11-05",
capabilities: {},
clientInfo: {
name: "calculator-demo-client",
version: "1.0.0"
}
}
};
try {
const response = await this.sendMessage(initMessage);
console.log("ā
Initialization successful");
console.log("š§ Server capabilities:", JSON.stringify(response.result?.capabilities, null, 2));
} catch (error) {
console.error("ā Initialization failed:", error);
throw error;
}
}
async listTools(): Promise<void> {
console.log("\nš Listing available tools...");
const message = {
jsonrpc: "2.0",
id: this.messageId++,
method: "tools/list",
params: {}
};
try {
const response = await this.sendMessage(message);
console.log("š ļø Available tools:");
response.result?.tools?.forEach((tool: any) => {
console.log(` ā¢ ${tool.name}: ${tool.description}`);
});
} catch (error) {
console.error("ā Failed to list tools:", error);
}
}
async calculate(expression: string): Promise<void> {
console.log(`\nš§® Calculating: ${expression}`);
const message = {
jsonrpc: "2.0",
id: this.messageId++,
method: "tools/call",
params: {
name: "calculate",
arguments: {
expression: expression
}
}
};
try {
const response = await this.sendMessage(message);
if (response.result?.content) {
response.result.content.forEach((content: any) => {
if (content.type === "text") {
console.log("š Result:", content.text);
}
});
} else if (response.error) {
console.error("ā Calculation error:", response.error.message);
}
} catch (error) {
console.error("ā Failed to calculate:", error);
}
}
async runDemo(): Promise<void> {
try {
await this.startServer();
await this.initialize();
await this.listTools();
// Demo calculations
const expressions = [
"2 + 3",
"10 * 5",
"(15 + 5) / 4",
"2.5 * 3.14159",
"100 - 25 + 10",
"Math.sqrt(16)", // This might not work due to sanitization
"2**8" // This might not work due to sanitization
];
for (const expr of expressions) {
await this.calculate(expr);
await new Promise(resolve => setTimeout(resolve, 500)); // Small delay between calculations
}
} catch (error) {
console.error("ā Demo failed:", error);
} finally {
console.log("\nš Stopping server...");
this.serverProcess?.kill();
console.log("ā
Demo completed");
}
}
}
const currentFile = fileURLToPath(import.meta.url);
const mainFile = resolve(process.argv[1]);
if (currentFile === mainFile) {
const demo = new CalculatorDemo();
demo.runDemo().catch(console.error);
}
export { CalculatorDemo };
