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"

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
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

PDF Watermark