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PDF Tools API

Page Numbers API

Add predictable page numbering to generated packets, review bundles, or archive PDFs.

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/pdf-tools/page-numbers

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

Use case

Use it when merged or generated documents need stable references for approvals, reviews, and audit trails.

cURL example

curl -X POST https://itextmaster.com/api/external/pdf-tools/page-numbers \
  -H 'x-api-key: YOUR_API_KEY' \
  -F 'file=@input.pdf;type=application/pdf' \
  -F 'options={"position":"bottom-center","startNumber":1}' \
  --output numbered.pdf

Multipart example

curl -X POST https://itextmaster.com/api/external/pdf-tools/page-numbers \
  -H 'x-api-key: YOUR_API_KEY' \
  -F 'file=@input.pdf;type=application/pdf' \
  -F 'options={"position":"bottom-center","startNumber":1}' \
  --output numbered.pdf

JSON base64 example

curl -X POST https://itextmaster.com/api/external/pdf-tools/page-numbers \
  -H 'Content-Type: application/json' \
  -H 'x-api-key: YOUR_API_KEY' \
  -d '{
    "file": { "name": "input.pdf", "dataBase64": "JVBERi0xLjcK..." },
    "options": {"position":"bottom-center","startNumber":1}
  }' \
  --output numbered.pdf

Node.js example

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

const response = await fetch('https://itextmaster.com/api/external/pdf-tools/page-numbers', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
    'x-api-key': process.env.ITEXTMASTER_API_KEY
  },
  body: JSON.stringify({
  file: { name: 'input.pdf', dataBase64: 'JVBERi0xLjcK...' },
  options: {"position":"bottom-center","startNumber":1}
})
});

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

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

Python example

import os
import requests

response = requests.post(
    'https://itextmaster.com/api/external/pdf-tools/page-numbers',
    headers={
        'Content-Type': 'application/json',
        'x-api-key': os.environ['ITEXTMASTER_API_KEY'],
    },
    json={
        'file': {'name': 'input.pdf', 'dataBase64': 'JVBERi0xLjcK...'},
        'options': {'position': 'bottom-center', 'startNumber': 1}
    },
)
response.raise_for_status()

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

Error codes

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.

422pdf_tool_processing_failed

The file, options, or PDF structure could not be processed. Failed processing attempts are refunded automatically.

Limits

  • Requires one valid PDF file.
  • Start numbers should be positive integers.
  • Choose a position that does not collide with existing content.

Response headers

numbered.pdf with X-Credits-Charged: 1 and X-Credit-Balance 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 Page Numbers API cost?

Each successful Page Numbers 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 page numbers.

Start with 100 free API Credits

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

Get API KeyView full API docs