Nuxt (Nitro server route) TypeScript

// server/routes/pixel.gif.ts  (auto-imported h3 helpers, no imports needed)
const GIF = Buffer.from('R0lGODlhAQABAIAAAP///wAAACH5BAEAAAAALAAAAAABAAEAAAICRAEAOw==', 'base64');

export default defineEventHandler((event) => {
  setResponseHeaders(event, {
    'Content-Type': 'image/gif',
    'Cache-Control': 'no-store',
  });
  return GIF;
});