# Sample This is a JavaScript sample for an MCP Server Here's what the calculator portion of it looks like: ```javascript // 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: ```bash npm install ``` ## Run ```bash npm start ```