GUI Hub
GUI Hub Essentials / pdfcpu

PDF Toolkit

The pdfcpu app and MCP server

Merge, split, compress, rotate, watermark and password-protect PDFs. Works offline; your files never leave your computer.

Free · no account · 3 free uses of every tool · also for Mac (Intel), Windows, Linux

PDF Toolkit in GUI Hub
In the app

What it can do

Merge

Combine several PDFs into one, in the order listed.

Split

Split a PDF into smaller files.

Compress

Shrink a PDF by removing duplicate and unused data. Text and images stay the same quality.

Rotate

Rotate all pages or a range of pages.

Watermark

Stamp text such as DRAFT or CONFIDENTIAL across every page.

Add password

Protect a PDF with AES-256 encryption.

Remove password

Remove the password from a PDF you have the password for.

Extract pages

Save selected pages as separate PDF files.

Step-by-step guides

For your AI

Ask Claude, Cursor or VS Code to do it

GUI Hub gives your assistant these 8 tools. Install it once (below) and ask in plain words.

MCP toolWhat it doesInputs
pdfcpu_mergeCombine several PDFs into one, in the order listed.inputs* array
out* string
pdfcpu_splitSplit a PDF into smaller files.input* string
outDir* string
mode string
span number
pdfcpu_optimizeShrink a PDF by removing duplicate and unused data. Text and images stay the same quality.input* string
out* string
pdfcpu_rotateRotate all pages or a range of pages.input* string
rotation string
pages string
out* string
pdfcpu_watermarkStamp text such as DRAFT or CONFIDENTIAL across every page.input* string
text* string
style string
out* string
pdfcpu_encryptProtect a PDF with AES-256 encryption.input* string
upw* string
opw* string
out* string
pdfcpu_decryptRemove the password from a PDF you have the password for.input* string
upw string
out* string
pdfcpu_extract_pagesSave selected pages as separate PDF files.input* string
pages* string
outDir* string

* required

Install

Ready in two minutes

Free to try — 3 full uses of every tool.

1Claude Desktop

Download the one-file extension, double-click it, press Install. Done — ask Claude for a file job.

Download gui-hub.mcpb

2Cursor, VS Code, Claude Code, Windsurf

Add an MCP server with this command (needs Node.js 18+):

npx -y github:MuttyRab/MuttyRab.github.io

Claude Code:

claude mcp add gui-hub -- npx -y github:MuttyRab/MuttyRab.github.io

3The desktop app

Point-and-click forms for every tool, plus a Use with AI button that connects Claude Desktop or Cursor for you.

Download for Windows
Windows or macOS shows a warning when I open the app
  1. Windows “protected your PC”: click More info → Run anyway.
  2. macOS “can’t be verified”: click Done, then System Settings → Privacy & Security → Open Anyway.
  3. Linux: allow executing the AppImage (Properties → Permissions), then run it.

New independent apps get this one-time caution. The full source is public on GitHub.

Under the hood

The real pdfcpu, not an imitation.

“Merge” runs the official pdfcpu 0.16.4 program with arguments passed directly — never through a shell.

pdfcpu merge /Users/you/out.pdf /Users/you/a.pdf /Users/you/b.pdf

Simple, honest pricing

Use PDF Toolkit 3 times free. $9 once unlocks all of GUI Hub Essentials.

GUI Hub Essentials

$9
once — not a subscription
  • Every Essentials tool, unlimited
  • Caesium, croc, F2, FFmpeg, immich-go, Pandoc, pdfcpu, Typst
  • Future tools in this product
  • Up to 3 computers
Get Essentials for $9

GUI Hub All-Access

$19
once — not a subscription
  • Every product, unlimited
  • Essentials + Data — and every future product
  • Up to 3 computers
  • 30-day money-back guarantee
Get All-Access for $19

Every tool works 3 times free first. Secure checkout by Polar; your license key arrives by email — paste it into the app, or just give it to your AI. 30-day refunds.

Other tools

Powered by pdfcpu 0.16.4 (Apache-2.0), downloaded from its official release and verified by SHA-256. GUI Hub is independent and not affiliated with pdfcpu.