PDF Blocks documentation

Where to start for each integration, the action catalog, the concepts that cut across every action, and the security and legal documentation.

Every action follows one model: send a document, name what to do with it, and get the finished document straight back. There is no SDK to install and no state to manage, and nothing is kept once the response is sent.

Start with the way you plan to call it, or search every page from the header (⌘K, or Ctrl K on Windows).

Choose your integration

API

For writing code, in any language.

One authenticated HTTPS call per action: multipart/form-data in, a PDF back. Every action is available, and each output is a valid input to the next.

Quickstart Actions

Power Automate

For building a flow in Power Automate.

Our certified connector, with all eighteen actions as flow steps. Documents move between steps as file content, so no intermediate storage is needed.

Getting started Templates

Zapier

For wiring apps together without code.

The most common actions as Zap steps, taking files from the apps you already connect. Start here for the file-field rules that trip up most Zaps.

Getting started File fields

Try one request

Put a PDF named input.pdf in your working directory, swap in your key, and run this. It stamps a watermark across the document and writes the result to watermarked.pdf.

Add a text watermarkbash

curl https://api.pdfblocks.com/v1/add_text_watermark \
  -H 'X-API-Key: your_api_key' \
  -F file=@input.pdf \
  -F line_1='CONFIDENTIAL' \
  -o watermarked.pdf

The answer is 200 OK with application/pdf and the finished document as the body. Every single-output action follows that same shape, so swapping the action name is most of the work of adopting the next one. The Quickstart has the same call in Python, Node.js, PHP, Ruby, and more, plus how to get a key.

What you can do

Seventeen actions, grouped by capability. Each group links into the full catalog, where every action has its own reference page.

Merge & split

Combine an ordered list of documents, or break one apart by page count, at a page, by file size, or into groups you define.

Watermarks

Stamp text or an image across the pages, with control over placement, rotation, opacity, and which pages are covered.

Passwords & security

Add or remove a password, apply or lift permission restrictions, and strip existing signatures.

Pages

Extract, remove, rotate, reverse, and reorder pages, all sharing one range syntax.

Core concepts

These cut across every action, and they are where most integration questions are actually answered.

Authentication: how API keys work, what to send on each request, and how to keep a key safe.
Working with files: how to send documents, the size limits, and what comes back.
Selecting pages: the pages range syntax shared by every page-level action.
Chaining actions: feeding one action’s output into the next without ever touching disk.
Response formats: content negotiation, and how actions that produce several documents answer.
Errors: the error body, and what each status code means.
Rate limits and usage: what counts as a request, and what happens when you reach a limit.
Regions and data residency: the regional endpoints, and where each one processes documents.
Versioning and stability: what can change under a running integration, and what cannot.

Security and compliance

Two structural facts shape most review questions: documents are never stored, and no LLM ever reads them. Each file is processed in memory and returned in the same response.

The Trust section has the detail: the security overview with a SOC 2 control mapping, HIPAA and BAA terms, the subprocessor list, and the legal set (Terms, Privacy Policy, and DPA).