const data = {
  content: 'hello world', 
};

async function handleRequest(request) {
  // JSONを文字列に変換します。
  const result = JSON.stringify(data, null, 2);

  return new Response(result, {
    headers: {
      'content-type': 'application/json; charset=UTF-8',
    },
  });
}

addEventListener('fetch', event => {
  return event.respondWith(handleRequest(event.request));
});