Generating PDF Invoices with a Single API Call (No Libraries Needed)

#pdf #api #invoicing #saas

Generating PDF Invoices with a Single API Call (No Libraries Needed)

If you've ever tried to generate PDF invoices programmatically, you know the pain. Between wkhtmltopdf, Puppeteer, WeasyPrint, and a dozen other tools, there's always something — missing fonts, broken CSS, memory leaks, Docker headaches.

I got tired of fighting PDF libraries, so I built DocuMint — an API that takes JSON and returns a professional PDF invoice.

The Problem

Pick a PDF library (ReportLab? WeasyPrint? Puppeteer?)
Install system dependencies (good luck in Alpine Linux)
Write an HTML template
Handle fonts, encoding, page breaks
Debug rendering differences between your machine and production
Maintain all of this forever

Or you can make one API call.

The API Call

curl -X POST https://documint.anethoth.com/api/v1/invoice \
  -H 'Authorization: Bearer YOUR_API_KEY' \
  -H 'Content-Type: application/json' \
  -d '{ "template": "modern", "currency": "USD", "company": { "name": "Acme Corp", "address": "123 Main St" }, "customer": { "name": "Jane Smith" }, "items": [ { "description": "Web Development", "quantity": 40, "unit_price": 150 } ], "tax_rate": 0.08 }' --output invoice.pdf

That's it. Professional PDF with proper formatting, totals calculated, tax applied.

Three Templates

Classic — Traditional business invoice
Modern — Clean design with gradient accents
Minimal — Monospace font, developer-friendly

Python Example

import requests

response = requests.post(
    'https://documint.anethoth.com/api/v1/invoice',
    headers={'Authorization': 'Bearer YOUR_KEY'},
    json={ 'template': 'modern', 'company': {'name': 'My SaaS'}, 'customer': {'name': 'Customer'}, 'items': [{'description': 'Pro Plan', 'quantity': 1, 'unit_price': 49}] }
)

with open('invoice.pdf', 'wb') as f:
    f.write(response.content)

Try Before You Sign Up

curl -X POST https://documint.anethoth.com/api/v1/demo-invoice \
  -H 'Content-Type: application/json' \
  -d '{ "template": "modern", "company": { "name": "Demo" }, "customer": { "name": "Test" }, "items": [{ "description": "Widget", "quantity": 1, "unit_price": 99 }] }' --output demo.pdf