quillpdf-mcp

PDF operations for MCP. An MCP server and CLI for local PDF manipulation:

• Merge, split, organize, delete pages
• Rotate, crop
• Watermark, Bates numbering, page numbers
• Flatten forms, images → PDF
• Metadata cleaning, page count
• AES-256 protect / unlock

Built on pdf-lib. MIT licensed. stdio transport. No network calls — files never leave your machine.

Install

npx -p quillpdf-mcp quillpdf --help   # CLI
npx quillpdf-mcp --help               # MCP server (your MCP client launches it over stdio)

Or globally:

npm install -g quillpdf-mcp
quillpdf --help

Requires Node.js 18+.

Scope

quillpdf-mcp implements structural PDF transforms and AES-256 protect/unlock. It does not perform OCR, redaction, or compression — those are available in the browser version (quillpdf.com), where processing also stays client-side. They'll ship here only when they can run fully locally.

Use it from an AI assistant (MCP)

The MCP server speaks stdio and exposes one tool per operation.

Claude Desktop

Add to claude_desktop_config.json:

{
  "mcpServers": {
    "quillpdf": {
      "command": "npx",
      "args": ["-y", "quillpdf-mcp"]
    }
  }
}

Claude Code

claude mcp add quillpdf -- npx -y quillpdf-mcp

Then ask your assistant things like "merge invoice-1.pdf and invoice-2.pdf into combined.pdf" or "Bates-number discovery.pdf with prefix ABC starting at 1." The assistant supplies file paths on your machine; the server reads and writes them locally.

A ready-to-copy config lives in examples/mcp-config.json.

Tools

Use it from the command line

# Merge (order is preserved)
quillpdf merge a.pdf b.pdf c.pdf -o combined.pdf

# Split into one file per range group → out-1.pdf (pages 1-3), out-2.pdf (page 5)
quillpdf split in.pdf --ranges "1-3,5" -o out.pdf

# Extract specific pages into a single file (reordering/duplicates allowed)
quillpdf split in.pdf --pages "5,1,1" -o extract.pdf

# Rotate every page 90°, or just some pages
quillpdf rotate in.pdf --angle 90 -o rotated.pdf
quillpdf rotate in.pdf --angle 180 --pages "2,4" -o rotated.pdf

# Watermark
quillpdf watermark in.pdf --text "DRAFT" --opacity 0.15 --position center -o wm.pdf

# Bates numbering → PLT-000001, PLT-000002, …
quillpdf bates in.pdf --prefix "PLT-" --start 1 --pad 6 -o numbered.pdf

# Strip document metadata
quillpdf clean-metadata in.pdf -o clean.pdf

# Page count (prints a number)
quillpdf page-count in.pdf

Every command has --help.

Existing files are never silently replaced. If the -o path already exists, the command stops with an error instead of clobbering it — add --force (or force: true on the MCP tools) to replace it deliberately.

Privacy & security notes

• Local only. All PDF processing happens in-process via pdf-lib. The server communicates over stdio and never opens a network connection. (The MCP SDK bundles optional HTTP/SSE transports in node_modules, but this server only ever uses stdio, so none of that code runs.)
• Password-protected PDFs are refused, not silently unlocked. Every operation except unlock stops with a clear message rather than stripping the password for you. unlock decrypts only with a password you supply — it does not recover, guess, or brute-force one.
• Encryption engine. protect and unlock run QPDF (Apache-2.0) compiled to WebAssembly, in-process and offline like everything else. pdf-lib cannot encrypt at all, and the community forks that add it are unmaintained — encryption is the one operation where a subtle bug means a document you believe is locked isn't, so this uses the reference implementation instead.
• AES-256 only. protect emits PDF 2.0 encryption revision 6. The 40-bit and 128-bit modes are deliberately not exposed: QPDF classes both as weak crypto, and shipping a "protected" file that isn't meaningfully protected is worse than shipping nothing.
• Permission flags are a request, not a guarantee. --no-print / --no-copy / --no-modify set bits that a well-behaved reader honours; they are not enforced by the encryption. The password is the part that actually protects the file. (Extraction for accessibility stays permitted even with --no-copy, so screen readers keep working.)
• Cropping is not redaction. crop sets the CropBox, so trimmed content is hidden but still present in the file and fully recoverable. Do not use it to remove sensitive material.
• clean-metadata scope. It clears the title, author, subject, keywords, and creator fields plus the CreationDate/ModDate in the document information dictionary, and deletes the document-level XMP metadata stream — the copy Acrobat, Word, InDesign, and LibreOffice write, which is often the authoritative one. Note that pdf-lib rewrites the /Producer field with its own signature on save, so that one field is replaced rather than emptied. It does not scrub page-level annotations, embedded file attachments, or the text/image content of pages.

Not here yet (roadmap)

These need a Node image backend or an OCR engine and are planned for a later release — they are not in this package today:

• compress (image re-encode) — needs an image codec such as sharp
• pdf-to-image (render pages to PNG) — needs a rasterizer (pdfjs-dist + canvas)
• redact (true rasterize-on-redact removal) — needs the same rasterizer
• ocr (searchable-text layer) — needs tesseract.js

Each would roughly quadruple this package's dependency surface, which is the whole reason they're held back: the pitch here is a small, local, no-network tool. They'll ship only when they can run fully locally without giving that up.

Philosophy

Keep the server small, local, and easy to audit. Most "PDF API" tools answer document work with "upload it to us" — for legal discovery, medical records, or financials, the upload is the problem. This runs where you are; the bytes stay on your disk.

Development

npm install
npm run build     # tsc → dist/
npm test          # builds, then runs the unit suite (node:test)

The engine (src/core.ts) is pure: bytes in, bytes out, no I/O. The CLI (src/cli.ts) and MCP server (src/server.ts) are thin front-ends over it.

License

MIT © Purple Directive. See LICENSE.

Learn more at quillpdf.com.