Branded invoice and receipt PDFs from your billing system.

import Stripe from 'stripe'

const stripe = new Stripe(process.env.STRIPE_SECRET_KEY)
const apiKey = process.env.SIMPLYFILL_API_KEY

export async function POST(req) {
  const sig = req.headers.get('stripe-signature')
  const event = stripe.webhooks.constructEvent(
    await req.text(),
    sig,
    process.env.STRIPE_WEBHOOK_SECRET,
  )

  if (event.type !== 'invoice.finalized') return new Response('ok')
  const invoice = event.data.object

  const pdf = await fetch('https://api.simplyfill.app/v1/generate/pdf', {
    method: 'POST',
    headers: {
      Authorization: `Bearer ${apiKey}`,
      'Content-Type': 'application/json',
    },
    body: JSON.stringify({
      template_id: 'invoice_acme_v1',
      mapping_id:  'stripe_invoice_default',
      data: {
        invoice_number: invoice.number,
        issue_date:     new Date(invoice.created * 1000).toISOString(),
        due_date:       new Date(invoice.due_date * 1000).toISOString(),
        currency:       invoice.currency.toUpperCase(),
        customer_name:  invoice.customer_name,
        customer_email: invoice.customer_email,
        line_items: invoice.lines.data.map((l) => ({
          description: l.description,
          quantity:    l.quantity,
          unit_amount: l.price.unit_amount / 100,
          line_total:  l.amount / 100,
        })),
        subtotal: invoice.subtotal / 100,
        tax:      (invoice.tax ?? 0) / 100,
        total:    invoice.total / 100,
      },
    }),
  }).then((r) => r.json())

  await emailService.send({
    to:          invoice.customer_email,
    subject:     `Invoice ${invoice.number}`,
    attachments: [{ url: pdf.download_url, filename: `${invoice.number}.pdf` }],
  })

  return new Response('ok')
}