custom-tool.ts•1.67 kB
/**
* @example Custom Tool Implementation
*
* This example demonstrates how to create a custom tool
* that can be auto-discovered by the MCP server.
*/
import { z } from "zod";
import type { RegisterableModule } from "../src/registry/types.js";
import type { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
/**
* Example: Calculator tool that performs basic arithmetic operations
*/
const calculatorModule: RegisterableModule = {
type: "tool",
name: "calculator",
description: "Perform basic arithmetic operations",
register(server: McpServer) {
server.tool(
"calculator",
"Perform basic arithmetic operations",
{
operation: z.enum(["add", "subtract", "multiply", "divide"])
.describe("The operation to perform"),
a: z.number().describe("First operand"),
b: z.number().describe("Second operand"),
},
async (args) => {
const { operation, a, b } = args;
let result: number;
switch (operation) {
case "add":
result = a + b;
break;
case "subtract":
result = a - b;
break;
case "multiply":
result = a * b;
break;
case "divide":
if (b === 0) {
throw new Error("Division by zero is not allowed");
}
result = a / b;
break;
}
return {
content: [
{
type: "text",
text: `${a} ${operation} ${b} = ${result}`,
},
],
};
}
);
}
};
export default calculatorModule;