curl "https://www.facture.ar/api/invoices/cmg1a2b3e0002xyz/pdf?download=true" \
  -H "x-api-key: tu_api_key" \
  --output factura.pdf

curl "https://www.facture.ar/api/invoices/cmg1a2b3e0002xyz/pdf" \
  -H "x-api-key: tu_api_key"

{
  "download_url": "https://...",
  "invoice_id": "cmg1a2b3e0002xyz",
  "invoice_number": "0001-00000145",
  "environment": "production"
}

const fs = require('fs');
const path = require('path');

const API = 'https://www.facture.ar/api';
const headers = { 'x-api-key': process.env.FACTUREAR_API_KEY };

async function descargarFacturasMes(cuit, mes, anio) {
  const desde = new Date(anio, mes - 1, 1);
  const hasta = new Date(anio, mes, 1);
  const carpeta = `facturas-${anio}-${String(mes).padStart(2, '0')}`;
  fs.mkdirSync(carpeta, { recursive: true });

  let page = 1;
  let descargadas = 0;

  while (true) {
    const params = new URLSearchParams({ status: 'success', cuit, page, limit: 100 });
    const res = await fetch(`${API}/invoices?${params}`, { headers });
    const { invoices, pagination } = await res.json();

    for (const factura of invoices) {
      const creada = new Date(factura.createdAt);
      if (creada >= hasta) continue;   // más nueva que el período
      if (creada < desde) return descargadas; // ya pasamos el período

      const pdf = await fetch(`${API}/invoices/${factura.id}/pdf?download=true`, { headers });
      if (!pdf.ok) {
        console.error(`No se pudo descargar ${factura.id}: ${pdf.status}`);
        continue;
      }
      const nombre = `${String(factura.ptoVta ?? 0).padStart(4, '0')}-${String(factura.voucherNumber).padStart(8, '0')}.pdf`;
      fs.writeFileSync(path.join(carpeta, nombre), Buffer.from(await pdf.arrayBuffer()));
      descargadas++;
    }

    if (!pagination.hasNextPage) return descargadas;
    page++;
  }
}

facturas-2026-09/
├── 0001-00000001.pdf
├── 0001-00000002.pdf
├── ...
└── 0001-00000145.pdf