Try a Hono API locally

Give a Hono API consistent HTTP behavior: a health response with a weak ETag and a predictable JSON response for missing routes. You will see both without opening a port or creating a Cloudflare account.

1. Create a small project

Use Node.js 24 and npm for this exercise. The commands pin the documented kit release. npm installs its required peers; package managers configured to omit peers must follow the installation requirements.

mkdir hono-kit-demo
cd hono-kit-demo
npm init -y
npm pkg set type=module
npm install @rdlabo/workers-hono-kit@0.12.2 hono@4
npm install --save-dev tsx@4

2. Send two requests

Save this as demo.ts. app.request() exercises the Hono app in the current process.

import { Hono } from 'hono';
import { createAppErrorHandler, finalizeResponse, notFoundHandler } from '@rdlabo/workers-hono-kit';

const app = new Hono();
app.use('*', finalizeResponse());
app.onError(createAppErrorHandler());
app.notFound(notFoundHandler);
app.get('/health', (c) => c.json({ ok: true }));

const healthy = await app.request('/health');
console.log(healthy.status, await healthy.text());
console.log('weak etag:', healthy.headers.get('etag')?.startsWith('W/'));

const missing = await app.request('/missing');
console.log(missing.status, await missing.text());

npx tsx demo.ts

Expected output (JSON property order does not matter):

200 {"ok":true}
weak etag: true
404 {"message":"Cannot GET /missing","error":"Not Found","statusCode":404}

You have checked the HTTP behavior added by the kit. This exercise does not provision Workers bindings, authenticate users, or test a deployed service.

3. Move into your application

Keep the middleware and route registrations, remove the demonstration requests, and export app as your Worker handler. Continue with HTTP and authentication. Add the MySQL adapter only when the application needs a database.

Existing kit users should check the 0.12 import migration before upgrading. The old /db and /business-time paths are compatibility exports; new integrations use the standalone packages.

Next steps

The kit supplies reusable infrastructure. Your routes, domain rules, credentials, and database schema remain in your application. Adopt one helper first; you do not need to adopt every entry point.