PDFCraft
Cloudflare Workers

PDF generation in Cloudflare Workers

Workers cannot run a browser at all — no Chromium, no native binaries. An HTTP call is the only option, and the streaming Response makes it a clean one.

The code

export default {
  async fetch(request: Request, env: { PDFCRAFT_API_KEY: string }): Promise<Response> {
    const { html } = await request.json<{ html: string }>();

    const upstream = await fetch('https://api.pdfcraft.dev/v1/render', {
      method: 'POST',
      headers: {
        authorization: `Bearer ${env.PDFCRAFT_API_KEY}`,
        'content-type': 'application/json',
      },
      body: JSON.stringify({ html, options: { printBackground: true } }),
    });

    if (!upstream.ok) return new Response(upstream.body, { status: upstream.status });

    // Straight through — the Worker never holds the PDF.
    return new Response(upstream.body, {
      headers: {
        'content-type': 'application/pdf',
        'content-disposition': 'attachment; filename="document.pdf"',
      },
    });
  },
};

What to watch for

Why not run the browser yourself

You can. Puppeteer and Playwright both work, and for a script you run by hand they are the right answer. The cost arrives at the point it becomes a service someone depends on: one long-lived browser per process rather than one per request, a semaphore so four renders do not become forty, a hard timeout that force-closes a hung page before it holds a slot forever, a scheduled restart because Chromium leaks, and a Chromium version you are now responsible for patching.

None of that is hard. All of it is work that has nothing to do with your product, and it fails under concurrency rather than in testing — which is the worst time to discover it.

Other frameworks

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