PDF Watermark — OpenClaw Plugin
Add watermarks to PDFs and images using the PDFAPIHub API. This OpenClaw plugin gives your AI agent the ability to stamp text watermarks, overlay logos, and apply quick presets for CONFIDENTIAL, DRAFT, and APPROVED documents.
What It Does
Protect and mark your documents with text or image watermarks — tiled across every page or placed at specific positions. Includes one-command presets for the most common watermark needs.
Features
- Text Watermarks — Custom text with color, opacity, angle, and font size
- Image/Logo Watermarks — Overlay PNG/JPG logos with transparency support
- Tiled Mode — Repeat watermark diagonally across the entire page
- Single Placement — Place watermark at a specific position preset
- Position Presets — center, top-left, top-right, bottom-left, bottom-right, top-center, bottom-center
- Quick Presets — One-command CONFIDENTIAL, DRAFT, and APPROVED stamps
- Custom Styling — Hex color, opacity (0-1), rotation angle, font size
- PDF & Image Support — Works with both PDF documents and image files
- Auto-Detection — Automatically detects whether input is a PDF or image
- Multiple Output Formats — Download URL, base64 string, or raw file
Tools
| Tool | Description |
|---|---|
watermark_document | Full-featured: custom text/image, color, opacity, angle, position, tiled mode |
stamp_confidential | Quick preset: tiled "CONFIDENTIAL" watermark across every page |
stamp_draft | Quick preset: tiled "DRAFT" watermark across every page |
stamp_approved | Quick preset: bold green "APPROVED" stamp at center |
add_logo_watermark | Overlay a logo/stamp image with opacity and position control |
Installation
openclaw plugins install clawhub:pdf-add-watermark
Configuration
Add your API key in ~/.openclaw/openclaw.json:
{
"plugins": {
"entries": {
"pdf-add-watermark": {
"enabled": true,
"env": {
"PDFAPIHUB_API_KEY": "your-api-key-here"
}
}
}
}
}
Get your free API key at https://pdfapihub.com.
Usage Examples
Just ask your OpenClaw agent:
- "Add a CONFIDENTIAL watermark to this PDF"
- "Mark this report as DRAFT"
- "Stamp APPROVED on this contract"
- "Add 'FOR INTERNAL USE ONLY' in red at 20% opacity across every page"
- "Overlay our company logo at bottom-right with 15% opacity"
- "Add © 2026 Acme Corp watermark to all pages"
Use Cases
- Confidential Marking — Stamp internal documents before circulation
- Draft Management — Mark documents as DRAFT during review cycles
- Approval Workflows — Stamp APPROVED or REJECTED on reviewed documents
- Brand Protection — Overlay company logos on photos and PDFs
- Copyright Protection — Add © watermarks before public sharing
- Legal Documents — Mark as COPY, ORIGINAL, or VOID
- Photography Proofs — Watermark photo proofs before client purchase
API Documentation
Full API docs: https://pdfapihub.com/docs
License
MIT