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POST /api/pdf/page/overlay

PDF Overlay (Watermark) API

Send your PDF and a stamp PDF, and get the stamp drawn on top of the pages you pick. Made for CONFIDENTIAL marks, DRAFT labels, logos and approval stamps.

  • Free plan
  • No credit card

Request

curl -X POST https://apdf.io/api/pdf/page/overlay \
  -H "Authorization: Bearer TOKEN" \
  -d file="FILE_URL" \
  -d overlay="OVERLAY_FILE_URL" \
  -d from="1,3" \
  -d to="2-z" \
  -d repeat="1"

Drawn on top.
Page by page.

The stamp is drawn over your page content, not behind it. You choose which pages get it and which stamp goes where.

report.pdf
stamp.pdf
POST /api/pdf/page/overlay
stamped.pdf to=2-z repeat=1
cover
CONFIDENTIAL
p2
CONFIDENTIAL
p3
CONFIDENTIAL
p4
Stamp, on top Your content, below
The page parameters
to
Pages of your PDF that get a stamp
from
Stamp pages to place, one per page, in order
repeat
Stamp pages reused once from runs out
repeat=1
A one-page stamp on every target page
(none set)
Stamp page 1 on page 1, 2 on 2, and so on

Marked before it leaves.

A stamp tells the reader what a document is before they read a word of it. Add it on the way out.

Confidential documents

Mark board packs, HR files and due diligence documents as confidential before they are shared beyond the core team.

Draft versus final

Put a DRAFT label on every page while a document is in review, and send the final version without it from the same source.

Approval stamps

Stamp approved invoices, signed-off drawings and checked reports with a mark everyone on your team spots at a glance.

Samples and copies

Label specimen certificates, sample contracts and demo exports, so nobody mistakes them for the real document.

Stamp from anywhere.

Watermark each file right where your workflow makes it. One account and one monthly allowance behind every route.

Your code

One authenticated POST from any language. Copy-paste samples in cURL, Node.js, Python and more.

POST /api/pdf/page/overlay
Open the endpoint docs
Zapier

Pick the action in any Zap and map files from earlier steps. No code and no servers to run.

Overlay PDF
Use it in Zapier
n8n

Add the Apdf node to any workflow, on n8n Cloud or self-hosted, and chain it with your automation.

Overlay PDF pages
Use it in n8n
AI agents

Let Claude, ChatGPT, Gemini or your own agent run it through the MCP server, on any paid plan.

overlay-pdf-pages
See what agents can do

1,000 watermarks
a month. Free.

Start on the free plan and move up only when your volume does — up to 1,000,000 operations a month on Business.

  • One call is one operation, however many pages.
  • Only calls that do the work are counted.
  • Hard limits, so no surprise overage charges.
Plan PDF operations / month
Hobby Free
$0 / month
1,000
Pro
$39–$99 / month
20,000 – 60,000
Business
$149–$899 / month
100,000 – 1,000,000

Watermarking PDFs, answered

A page with only your mark on it. Everything on the stamp page is drawn over your content, so leave its background empty rather than filling it with white.
A stamp page that is larger than your page is scaled down to fit and centered. For exact placement, give the stamp the same page size as your document.
Someone with a PDF editor can, as with any watermark. It marks a document, it doesn't lock it. To control who opens a file, add a password with the PDF Password API.
As URLs, one for your PDF and one for the stamp: Apdf downloads both, up to 100 MB per file. In Zapier and n8n you can map the files from earlier steps instead.
The response contains a download URL that stays valid for 60 minutes. Store the file on your side if you need it longer.
After the API call

Your code made the PDF.
Then it went dark.

Opened, read, re-read, dropped on page 4 — you never see any of it. Share the PDFs you generate through Apdf recipient links, and every signal becomes something you can act on: ping Slack, update the CRM, let an agent follow up. Same account, same API token, one more call.

Your PDF, after sending Live
document:loaded CFO
page:read p4 · 38s
link:clicked pricing

API · Webhook · MCP

Put your stamp
on the next PDF.