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Stirling Pdf

MCP Tools

Complete local PDF toolkit — OCR, merge, split, compress, watermark, convert, and 30+ operations via Stirling-PDF API.

Install

openclaw skills install local-pdf-suite

PDF Toolkit

Local PDF processing suite powered by Stirling-PDF. All operations run on your own hardware — no cloud, no uploads, data stays private.

⚠️ Privacy note: This skill sends PDFs to your Stirling-PDF instance via API. Ensure Stirling-PDF is deployed locally or on a trusted private network — do not point STIRLING_BASE_URL at a public third-party instance. Treat uploaded PDFs, passwords, and signing material as sensitive.

About Stirling-PDF

Stirling-PDF is a powerful, open-source PDF editor that lets you edit, sign, redact, convert, and automate PDFs without sending documents to third-party services. It offers 60+ operations including:

  • OCR — Turn scanned images into searchable PDFs (Chinese + English supported)
  • Merge/Split — Combine or break apart PDFs
  • Compress — Reduce file size without quality loss
  • Convert — PDF ↔ Word/HTML/Markdown/CSV/EPUB/PDF/A
  • Security — Watermark, password protect, encrypt/decrypt, flatten
  • Edit — Rotate, crop, reorder pages, add page numbers
  • Extract — Pull images, bookmarks, metadata from PDFs

Self-hosted means your sensitive documents never leave your machine.

Deploy with Docker

# Create directories for persistent data
mkdir -p /opt/stirling-pdf/data /opt/stirling-pdf/logs

# Run Stirling-PDF
docker run -d \
  --name stirling-pdf \
  -p 3998:8080 \
  -v /opt/stirling-pdf/data:/data \
  -v /opt/stirling-pdf/logs:/logs \
  -e DOCKER_ENABLE=true \
  -e PUID=1000 \
  -e PGID=1000 \
  -e SECURITY_INITIALLOGIN_USERNAME=admin \
  -e SECURITY_INITIALLOGIN_PASSWORD=your-password \
  --restart unless-stopped \
  frooodle/s-pdf:latest

Then access at http://your-server:3998

First-time Setup

  1. Open http://your-server:3998 in your browser
  2. Log in with the username/password set above
  3. Go to Account Settings → API Keys → Generate a new key
  4. Copy the key and set it as an environment variable:
export STIRLING_API_KEY="your-generated-api-key"
export STIRLING_BASE_URL="http://your-server:3998"

Quick Reference

Health check

GET /api/v1/info/health
X-API-KEY: $STIRLING_API_KEY

OCR — Image/Scan to searchable PDF

POST /api/v1/misc/ocr-pdf
X-API-KEY: $STIRLING_API_KEY
Form: fileInput=@file.pdf, languages=chi_sim+eng

Merge — Combine multiple PDFs

POST /api/v1/general/merge-pdfs
X-API-KEY: $STIRLING_API_KEY
Form: fileInput[]=@a.pdf, fileInput[]=@b.pdf, sortType=orderProvided

Compress — Reduce file size

POST /api/v1/misc/compress-pdf
X-API-KEY: $STIRLING_API_KEY
Form: fileInput=@file.pdf, compressionLevel=standard

Remove blank pages

POST /api/v1/misc/remove-blanks
X-API-KEY: $STIRLING_API_KEY
Form: fileInput=@file.pdf
Returns: ZIP containing processed PDF

Convert PDF to other formats

POST /api/v1/convert/pdf/word     → .docx
POST /api/v1/convert/pdf/html     → .html
POST /api/v1/convert/pdf/markdown → .md
POST /api/v1/convert/pdf/csv      → .csv
POST /api/v1/convert/pdf/epub    → .epub
POST /api/v1/convert/pdf/txt     → .txt
POST /api/v1/convert/pdf/pdfa    → PDF/A (archival)

Convert images to PDF

POST /api/v1/convert/img/pdf
X-API-KEY: $STIRLING_API_KEY
Form: fileInput=@image.jpg, colorType=color, fitOption=maintainAspectRatio

Security

POST /api/v1/security/add-watermark  → text/image watermark
POST /api/v1/security/remove-watermark
POST /api/v1/security/encrypt        → password protect
POST /api/v1/security/decrypt        → remove password
POST /api/v1/security/flatten        → flatten annotations
POST /api/v1/security/sign            → digital signature

Page operations

POST /api/v1/general/split-pdf       → split by page range
POST /api/v1/general/rotate-pdf     → rotate pages
POST /api/v1/general/extract-pages   → extract specific pages
POST /api/v1/general/move-pages      → reorder pages

Extract

POST /api/v1/images/extract-images     → pull images from PDF
POST /api/v1/misc/extract-bookmarks   → extract PDF bookmarks
POST /api/v1/misc/extract-metadata    → read PDF metadata

Utilities

POST /api/v1/general/add-page-numbers
POST /api/v1/general/rename
POST /api/v1/general/join-pdfs
POST /api/v1/general/flatten          → flatten PDF form fields

Environment

Set before use:

export STIRLING_API_KEY="your-api-key"
export STIRLING_BASE_URL="http://your-server:3998"  # optional, defaults to localhost

Notes

  • All requests require X-API-KEY header
  • Returns processed file or JSON error
  • remove-blanks returns a ZIP — extract the PDF inside
  • merge requires at least 2 files
  • ocr: use chi_sim+eng for Chinese documents
  • Full endpoint list: /swagger-ui/index.html on your instance
  • OCR requires Tesseract language packs (chi_sim for Chinese)
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