import type { CallToolResult, McpServer } from '@modelcontextprotocol/server';
import * as z from 'zod/v4';
const inputSchema = z.object({
text: z.string().min(1).describe('Text to echo back.'),
});
const outputSchema = z.object({
echoed: z.string(),
length: z.number().int().nonnegative(),
});
export function register(server: McpServer): void {
server.registerTool(
'echo',
{
title: 'Echo',
description: 'Return the provided text and its length.',
inputSchema,
outputSchema,
annotations: {
readOnlyHint: true,
},
},
async ({ text }, ctx): Promise<CallToolResult> => {
await ctx.mcpReq.log('info', `echo called with ${text.length} characters`);
const structuredContent = {
echoed: text,
length: text.length,
};
return {
content: [
{
type: 'text',
text,
},
],
structuredContent,
};
},
);
}
