curl https://invoice.horizonpay.co/api/v1/invoices/in_Pb2Xk7Mv4Qs9Lr1Wd6Tn3Fh8/pdf \
  -H "Authorization: Bearer $INVOICE_AI_API_KEY" \
  -o invoice.pdf

import { writeFile } from 'node:fs/promises'
import InvoiceAI from '@horizonpay/invoice-ai'

const invoiceai = new InvoiceAI() // reads INVOICE_AI_API_KEY

const pdf = await invoiceai.invoices.pdf('in_Pb2Xk7Mv4Qs9Lr1Wd6Tn3Fh8')
await writeFile('invoice.pdf', Buffer.from(pdf))

from invoice_ai import InvoiceAI

client = InvoiceAI()  # reads INVOICE_AI_API_KEY

pdf = client.invoices.pdf("in_Pb2Xk7Mv4Qs9Lr1Wd6Tn3Fh8")
with open("invoice.pdf", "wb") as f:
    f.write(pdf)

"<string>"

{
  "type": "https://invoice.horizonpay.co/problems/unauthorized",
  "title": "Unauthorized",
  "status": 401,
  "detail": "Send your API key as `Authorization: Bearer inv_live_…`.",
  "instance": "req_7f3c9a1e2b4d4e8a9c6f2d1b0a3e5f71",
  "code": "unauthorized"
}

{
  "type": "https://invoice.horizonpay.co/problems/forbidden",
  "title": "Insufficient scope",
  "status": 403,
  "detail": "This credential is missing the invoices:write scope.",
  "instance": "req_7f3c9a1e2b4d4e8a9c6f2d1b0a3e5f71",
  "code": "forbidden"
}

{
  "type": "https://invoice.horizonpay.co/problems/not-found",
  "title": "Not found",
  "status": 404,
  "detail": "Invoice not found.",
  "instance": "req_7f3c9a1e2b4d4e8a9c6f2d1b0a3e5f71",
  "code": "not_found"
}

{
  "type": "https://invoice.horizonpay.co/problems/rate-limited",
  "title": "Too many requests",
  "status": 429,
  "detail": "Rate limit of 120 per 60s exceeded.",
  "instance": "req_7f3c9a1e2b4d4e8a9c6f2d1b0a3e5f71",
  "code": "rate_limited"
}