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PDF Tools API

Invoice Generator API

Turn invoice JSON into polished PDF invoices from your billing system, admin panel, or automation workflow.

Create API KeyRead full API docs

Credits

1 Credit / call

1 Credit per successful API request. Failed processing attempts are refunded automatically.

Pricing

1,000 Credits = $1

Every signed-in user receives 100 free API Credits each month.

Endpoint

/api/external/invoice-generator/pdf

Use your API Key in the x-api-key header.

Use case

Use it when your app already has invoice data and needs a branded PDF receipt or invoice without maintaining a PDF template service.

cURL example

curl -X POST https://itextmaster.com/api/external/invoice-generator/pdf \
  -H 'x-api-key: YOUR_API_KEY' \
  -F 'invoiceNumber=INV-001' \
  -F 'fromName=Your Company' \
  -F 'billToName=Client Name' \
  -F 'items=[{"description":"Consulting","quantity":10,"rate":150}]' \
  --output invoice.pdf

Multipart example

curl -X POST https://itextmaster.com/api/external/invoice-generator/pdf \
  -H 'x-api-key: YOUR_API_KEY' \
  -F 'invoiceNumber=INV-001' \
  -F 'fromName=Your Company' \
  -F 'billToName=Client Name' \
  -F 'items=[{"description":"Consulting","quantity":10,"rate":150}]' \
  --output invoice.pdf

JSON base64 example

curl -X POST https://itextmaster.com/api/external/invoice-generator/pdf \
  -H 'Content-Type: application/json' \
  -H 'x-api-key: YOUR_API_KEY' \
  -d '{
    "invoiceNumber": "INV-001",
    "from": { "name": "Your Company", "email": "you@example.com" },
    "billTo": { "name": "Client Name", "email": "client@example.com" },
    "items": [{ "description": "Consulting", "quantity": 10, "rate": 150 }]
  }' \
  --output invoice.pdf

Node.js example

import { writeFile } from 'node:fs/promises';

const response = await fetch('https://itextmaster.com/api/external/invoice-generator/pdf', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
    'x-api-key': process.env.ITEXTMASTER_API_KEY
  },
  body: JSON.stringify({
  invoiceNumber: 'INV-001',
  from: { name: 'Your Company', email: 'you@example.com' },
  billTo: { name: 'Client Name', email: 'client@example.com' },
  items: [{ description: 'Consulting', quantity: 10, rate: 150 }]
})
});

if (!response.ok) {
  throw new Error(await response.text());
}

await writeFile('invoice.pdf', Buffer.from(await response.arrayBuffer()));

Python example

import os
import requests

response = requests.post(
    'https://itextmaster.com/api/external/invoice-generator/pdf',
    headers={
        'Content-Type': 'application/json',
        'x-api-key': os.environ['ITEXTMASTER_API_KEY'],
    },
    json={
        'invoiceNumber': 'INV-001',
        'from': {'name': 'Your Company', 'email': 'you@example.com'},
        'billTo': {'name': 'Client Name', 'email': 'client@example.com'},
        'items': [{'description': 'Consulting', 'quantity': 10, 'rate': 150}],
    },
)
response.raise_for_status()

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

Error codes

400invalid_invoice_payload

The invoice JSON payload is malformed or missing required invoice fields.

401invalid_api_key

The x-api-key header is missing, invalid, or has been rotated.

402insufficient_credits

The account does not have enough API Credits for the request.

500invoice_pdf_generation_failed

Invoice rendering failed. Failed processing attempts are refunded automatically.

Limits

  • Requires invoice number, sender, recipient, and at least one line item.
  • Currency defaults to USD when omitted.
  • Use server-side API calls so your API Key is never exposed in the browser.

Response headers

invoice.pdf with Credits response headers.

Content-Type
The MIME type of the generated file, usually application/pdf or application/zip.
Content-Disposition
Attachment filename for the generated output.
X-Credits-Charged
Credits charged for the successful request.
X-Credit-Balance
Remaining API Credit balance after the request.

FAQ

How much does the Invoice Generator API cost?

Each successful Invoice Generator API request uses 1 Credit. 1,000 Credits cost $1, and every signed-in user receives 100 free API Credits each month.

What happens if processing fails?

Failed processing attempts are refunded automatically, and the API returns an error response you can log or retry.

Should I call this API from the browser?

No. Keep API Keys server-side and call the endpoint from your backend, queue, or automation job when you need to generate invoice PDFs.

Start with 100 free API Credits

Create an API Key, test Invoice Generator API, and buy more Credits only when automation volume grows.

Get API KeyView full API docs