import { Hono } from "hono";
import { z } from "zod";
import { mcp, registerTool } from "hono-mcp-server";
const app = new Hono()
.get("/", (c) =>
c.json({
name: "Users API",
endpoints: ["/users", "/users/:id"],
mcp: "/mcp",
}),
)
// With output schema for structured responses
.get(
"/users",
registerTool({
description: "List all users in the system",
outputSchema: {
users: z.array(
z.object({
id: z.number(),
name: z.string(),
email: z.string(),
}),
),
},
}),
(c) =>
c.json({
users: [
{ id: 1, name: "Alice", email: "alice@example.com" },
{ id: 2, name: "Bob", email: "bob@example.com" },
],
}),
)
// Simple description
.get(
"/users/:id",
registerTool("Get a specific user by their ID"),
(c) => {
const id = c.req.param("id");
return c.json({ id: Number(id), name: "Alice", email: "alice@example.com" });
},
)
// With inputSchema - use c.req.valid('json') for typed input
.post(
"/users",
registerTool({
description: "Create a new user",
inputSchema: {
name: z.string().describe("User's full name"),
email: z.string().email().describe("User's email address"),
},
}),
async (c) => {
const { name, email } = c.req.valid("json"); // typed!
return c.json({ id: 3, name, email }, 201);
},
)
// With both inputSchema and outputSchema
.put(
"/users/:id",
registerTool({
description: "Update an existing user",
inputSchema: {
name: z.string().optional().describe("User's full name"),
email: z.string().email().optional().describe("User's email address"),
},
outputSchema: {
id: z.number(),
name: z.string(),
email: z.string(),
},
}),
async (c) => {
const id = c.req.param("id");
const { name, email } = c.req.valid("json"); // typed!
return c.json({ id: Number(id), name: name ?? "", email: email ?? "" });
},
)
.delete(
"/users/:id",
registerTool("Delete a user"),
(c) => {
const id = c.req.param("id");
return c.json({ deleted: true, id: Number(id) });
},
);
export default mcp(app, {
name: "Users API",
version: "1.0.0",
description: "A simple users CRUD API",
});
