microsoft--mcp-for-beginners/translations/en/03-GettingStarted/samples/javascript/README.md

Sample

This is a JavaScript sample for an MCP Server

Here's what the calculator part looks like:

// Define calculator tools for each operation
server.tool(
  "add",
  {
    a: z.number(),
    b: z.number()
  },
  async ({ a, b }) => ({
    content: [{ type: "text", text: String(a + b) }]
  })
);

server.tool(
  "subtract",
  {
    a: z.number(),
    b: z.number()
  },
  async ({ a, b }) => ({
    content: [{ type: "text", text: String(a - b) }]
  })
);

server.tool(
  "multiply",
  {
    a: z.number(),
    b: z.number()
  },
  async ({ a, b }) => ({
    content: [{ type: "text", text: String(a * b) }]
  })
);

server.tool(
  "divide",
  {
    a: z.number(),
    b: z.number()
  },
  async ({ a, b }) => {
    if (b === 0) {
      return {
        content: [{ type: "text", text: "Error: Cannot divide by zero" }],
        isError: true
      };
    }
    return {
      content: [{ type: "text", text: String(a / b) }]
    };
  }
);

Install

Run the following command:

npm install

Run

npm start

Disclaimer:
This document has been translated using the AI translation service Co-op Translator. While we strive for accuracy, please be aware that automated translations may contain errors or inaccuracies. The original document in its native language should be considered the authoritative source. For critical information, professional human translation is recommended. We are not liable for any misunderstandings or misinterpretations arising from the use of this translation.