SvelteKit + pdf-lib

pdf.pdf.js

import pkg from 'pdf-lib/cjs/index.js';
const { PDFDocument } = pkg;
export const get = async (req, context) => {
  const pdfDoc = await PDFDocument.create();
  const page = pdfDoc.addPage();
  page.drawText('You can create PDFs!');
  const pdfBytes = await pdfDoc.save();

  return {
    body: Buffer.from(pdfBytes, 'binary'),
    status: 200,
    headers: {
      'Content-Type': 'application/pdf',
      'Content-Disposition': `filename=hello-world.pdf`,
      'Content-Length': pdfBytes.length
    }
  }
}