Merge, Split and Compress PDFs from Your Code with One API Key

01Introduction

Most PDF jobs in a product are small and repetitive: join two invoices, pull pages 3 to 5 out of a report, shrink a scan before emailing it, stamp page numbers on a contract. They should not need a PDF library, a worker queue and a week of edge cases.

This post walks through the FreeDailyPro PDF APIs on ApyHub: a set of PDF manipulation APIs that merge, split, compress and edit files in a single request, all with one API key.

02What the PDF APIs do

The FreeDailyPro PDF APIs take a file and return the finished result in a single request. The endpoints cover:

Merge several PDFs into one, in the order you send them, with the Merge PDF API.
Split and extract pages by range, such as 1-3 and 7, with the Split PDF API and Export Selected PDF Pages.
Rotate and organize pages with Rotate PDF Pages and Reorder, Rotate, Remove or Insert Pages.
Compress files with the Compress PDF API.
Add page numbers, watermarks and redactions.
Flatten forms and repair damaged files.

03One request, one result

Every call uses the same pattern: send the file and a few options, receive the processed file. Authentication is one header, apy-token. There is no job to poll and no storage bucket to clean up.

· bash

curl -X POST "https://api.eu.apyhub.com/freedailypro/compress-pdf-file/compress" \
  -H "apy-token: $APY_TOKEN" \
  -F "[email protected]" \
  -o smaller.pdf

The response is the compressed PDF itself, written straight to smaller.pdf. Files up to 20 MB are accepted.

04Nothing is kept

Files are processed in memory and discarded when the response is sent. We do not store the documents you send, which makes the APIs easy to use for contracts, invoices and forms that you would rather not park on someone else's disk.

05For AI agents too

The same tools are available to AI agents through ApyHub MCP, so an assistant in Claude, ChatGPT, Cursor or any MCP client can merge or compress a file as one step of a longer task without you writing glue code.

Connect ApyHub MCP to your agent →

06Where to start

Pick one endpoint, call it from a script with a sample file, and check the result before wiring it into your product. Each API page on ApyHub has the documentation and a playground, and one ApyHub API key covers all of them. If your workload is mostly text, calculators or QR codes, the same key works across those APIs as well.

Try the Merge PDF API for free →

07FAQ

Is there an API to merge PDF files? Yes. The Merge PDF API joins several PDFs into one, in the order you send them, and returns the merged file in the same request.

How do I compress a PDF with an API? POST the file to the Compress PDF API, as in the curl example above. You get the smaller PDF back directly. Files up to 20 MB are supported.

Can I split a PDF by page range? Yes. Send ranges such as 1-3,7 to the Split PDF API, or use Export Selected PDF Pages to pull specific pages into a new file.

Are my files stored? No. FreeDailyPro processes files in memory and discards them when the response is sent.

Can I fill or lock PDF forms? Yes. Fill PDF Form Fields writes values into a form, Extract PDF Form Fields reads them, and Convert Fillable PDF to Locked PDF flattens the result.

How do I test the PDF APIs before writing code? Use the playground on any API page, run the curl command above, or save the request in Voiden, an open-source API client that stores requests as Markdown files next to your code.

Is there a free plan? Yes. The ApyHub Starter plan includes 5 API calls a day and 3,000 atoms a month, with no credit card.

08About FreeDailyPro

FreeDailyPro builds everyday document, text, media and calculator tools for developers and AI agents. Besides the PDF APIs, their 44 services on ApyHub include:

Audio editing: remove silence, reduce background noise and normalize loudness
Video: compress video, video to GIF and generate subtitles
Images: resize, crop and convert to PNG or JPEG
Developer tools: QR codes as SVG, Markdown to HTML and code and data formatting

See all of them on the FreeDailyPro provider page.

09About ApyHub

ApyHub runs a catalog of ready-made APIs for developers and AI agents. The catalog has over 1,500 endpoints and capabilities and keeps growing, all under one subscription billed in atoms. Every service carries machine-readable certification (GDPR, SOC 2, ISO 27001), is MCP-ready by default and runs in dedicated EU and US regions. More than 65,000 developer workspaces use ApyHub every month, and the free tier needs no credit card. Have an API of your own? Publish it on ApyHub.