Generate PDF invoices from Python in 20 lines

A complete, working example: invoice data as a dict, a template, one API call, a PDF on disk. Then the same thing for a batch of a hundred.

Updated 31 August 2026

You have invoice data in your database and need PDFs. The options are a PDF library (ReportLab, fpdf2 — you draw every line), an HTML renderer you host (WeasyPrint, Playwright — you run it), or an API. This is the API version, because it is the shortest.

One invoice

import requests

KEY = "pg_…"
invoice = {
    "company": "Northwind Studio Ltd",
    "client": "Acme Corporation",
    "number": "INV-2026-014",
    "issued": "31 August 2026",
    "due": "30 September 2026",
    "item1": "Design retainer, August", "qty1": "1", "price1": "2400.00",
    "item2": "Illustration set", "qty2": "6", "price2": "120.00",
    "subtotal": "3120.00", "tax_label": "VAT 20%", "tax": "624.00", "total": "3744.00",
    "currency": "£",
}

r = requests.post(
    "https://pdfgeny.com/api/v1/render",
    headers={"Authorization": f"Bearer {KEY}"},
    json={"template": "invoice", "data": invoice, "filename": "INV-2026-014.pdf"},
    timeout=60,
)
r.raise_for_status()
open("INV-2026-014.pdf", "wb").write(r.content)

Line amounts are computed for you from quantity and price. Fields you leave out take the template's example values, so start with two fields and grow.

Your own layout

If the built-in invoice does not match your brand, render your own HTML instead — Jinja2 or Django templates on your side, `"html": rendered` in the request. Everything else stays the same.

A hundred invoices

Month-end runs are where synchronous loops hurt: 100 requests in sequence take a couple of minutes and hold a connection open the whole time. Use the batch endpoint and let it run:

docs = [{"template": "invoice", "data": inv, "filename": f"{inv['number']}.pdf"} for inv in invoices]
r = requests.post("https://pdfgeny.com/api/v1/batch", headers={"Authorization": f"Bearer {KEY}"},
                  json={"documents": docs}, timeout=30)
batch_id = r.json()["batch_id"]

# later, or from a webhook:
status = requests.get(f"https://pdfgeny.com/api/v1/batch/{batch_id}", headers={"Authorization": f"Bearer {KEY}"}).json()
for job in status["jobs"]:
    if job["status"] == "done":
        pdf = requests.get(job["document_url"]).content

Each `document_url` is signed and valid for seven days — long enough to email or archive, short enough not to be a liability.

Errors you will see

• `401 invalid_api_key` — the key is revoked or the account email is not confirmed yet.
• `429 quota_exceeded` — free plan is 50 documents a month; the response says how many you used.
• `422 render_failed` — your HTML did something Chromium refused; the message says what.

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