🖋️ InkDrop

Universal Handwritten Signature Insertion for Any Document

Draw it once. Drop it anywhere.

---

InkDrop takes a handwritten signature — drawn, scanned, or photographed — cleans it, and drops it into any PDF, Word document, or PowerPoint presentation. Just add the SKILL.md file, and drop it into any Model. Designed for Claude, Repurposed for everyone.

Drop it in Claude > artifacts : Other LLMs > Webpage Socket = Index.html

---

Screenshots

Draw Tab — draw your signature directly in the browser

Signature Library — manage and download all your saved signatures

---

The Problem

You've got a contract, letter, or form that needs your signature. You could print it, sign it, scan it back. Or you could just InkDrop it.

InkDrop is a complete signature pipeline:

  Raw Signature          Clean PNG            Signed Document
  ┌─────────┐     ┌──────────────┐     ┌──────────────────┐
  │ 📷 Photo │     │              │     │  Dear Client,    │
  │ ✏️ iPad  │ ──▶ │  ✍️ Clean    │ ──▶ │  ...             │
  │ 🖊️ Scan  │     │  Transparent │     │  Signature: ✍️   │
  └─────────┘     └──────────────┘     └──────────────────┘
     INGEST          PROCESS              INSERT

---

Quick Start

Install

git clone https://github.com/BlackhatShiftey/inkdrop.git
cd inkdrop
pip install Pillow numpy pypdf reportlab python-docx python-pptx

Use

# Step 1: Process your raw signature
python scripts/process_signature.py my_signature.png clean.png

# Step 2: Drop it into a document
python scripts/insert_pdf.py  contract.pdf clean.png signed.pdf  --find "Signature:"
python scripts/insert_docx.py letter.docx  clean.png signed.docx --find "Sign here"
python scripts/insert_pptx.py deck.pptx    clean.png signed.pptx --slide 5

That's it. Three lines, signed document.

---

How It Works

Stage 1 — Process

Takes any raw signature input and produces a clean, transparent PNG:

What it does	Why
Removes white/light background	Transparent overlay on any document
Crops to ink bounding box	No wasted space
Smooths jagged edges	Professional appearance
Normalizes to standard size	Consistent placement (2" × 0.75" at 300dpi)
Optional ink recoloring	Match document style

python scripts/process_signature.py raw.png clean.png \
    --width 600 --height 225 --threshold 200 --ink-color "#1a3c6e"

Stage 2 — Locate

InkDrop finds where to place the signature using three strategies:

Strategy	How	Example
Keyword	Searches document text	--find "Signature:"
Coordinates	Explicit position	--x 100 --y 200 --page 0
Auto-detect	Finds _____ or ----- patterns	Automatic fallback
Default	Bottom of last page/slide	No flags needed

Stage 3 — Insert

Merges the signature into the document as an embedded image. The output is a complete, self-contained file — no external references, no broken links.

---

Supported Formats

Format	Engine	Keyword Search	Coordinates	Auto-detect
PDF	pypdf + reportlab	✓	✓ (points)	✓
DOCX	python-docx	✓	✓ (paragraph index)	✓
PPTX	python-pptx	✓	✓ (inches)	✓

---

LLM Support

InkDrop is model-agnostic. The Python engines work with any AI that can execute code. We ship dedicated integration guides:

Model	Guide	Format
Claude (Anthropic)	SKILL.md	Claude Skills format — auto-triggers in Claude.ai and Claude Code
Gemini (Google)	docs/GUIDE.md	General-purpose — works with Gemini's code execution
GPT (OpenAI)	docs/GUIDE.md	General-purpose — works with Code Interpreter
Grok (xAI)	docs/GUIDE.md	General-purpose — works with Grok's code runner
LLaMA / Mistral / Cohere	docs/GUIDE.md	General-purpose — any agent with shell access

For Claude Users

InkDrop ships as a Claude Skill. Install it and Claude will automatically recognize signature requests:

"Hey Claude, sign this contract with my signature" "InkDrop the NDA" "Add my sig to the last page"

Claude reads SKILL.md and knows exactly which scripts to run.

For All Other LLMs

The docs/GUIDE.md provides:

• Complete Python API reference
• CLI examples for every format
• Agent tool/function schema (JSON) for framework integration
• Decision tree for automated workflows
• MCP server spec (coming soon)

---

Python API

Every engine is importable:

from scripts.process_signature import process_signature
from scripts.insert_pdf import insert_signature_pdf
from scripts.insert_docx import insert_signature_docx
from scripts.insert_pptx import insert_signature_pptx

# Process
result = process_signature("raw.png", "clean.png", threshold=200)

# Insert into PDF
result = insert_signature_pdf("contract.pdf", "clean.png", "signed.pdf", keyword="Signature:")

# Insert into DOCX with extras
result = insert_signature_docx(
    "letter.docx", "clean.png", "signed.docx",
    keyword="Signature:", add_line=True, add_name="Terra", add_date=True,
)

# Insert into PPTX
result = insert_signature_pptx("deck.pptx", "clean.png", "signed.pptx", slide_num=5)

---

Interactive Dashboard

InkDrop includes a React-based signature management dashboard (assets/signature-manager.jsx) with:

• Draw pad — Dual-canvas system: white strokes for visibility on dark UI, dark ink for document export
• Signature library — Save and manage multiple signatures
• Live preview — See how your signature looks on a document thumbnail
• One-click export — Download clean PNG ready for insertion

Launching the Dashboard

To run the React Dashboard locally without a build system or external artifacts:

1. Open the included index.html file in any modern web browser.
2. Alternatively, serve it via a local web server (e.g., python -m http.server 8080 and navigate to http://localhost:8080).

The index.html file acts as a standalone wrapper that pulls in React via CDN and compiles the assets/signature-manager.jsx component directly in your browser.

---

Project Structure

inkdrop/
├── README.md                    ← You are here
├── SKILL.md                     ← Claude-specific integration (Skills format)
├── LICENSE                      ← MIT
│
├── scripts/
│   ├── process_signature.py     ← Ingest → clean transparent PNG
│   ├── insert_pdf.py            ← PDF insertion engine
│   ├── insert_docx.py           ← DOCX insertion engine
│   └── insert_pptx.py           ← PPTX insertion engine
│
├── assets/
│   ├── signature-manager.jsx    ← Full React dashboard
│   └── signature-pad.jsx        ← Lightweight standalone canvas
│
├── tests/
│   └── test_pipeline.py         ← 5 end-to-end tests
│
└── docs/
    └── GUIDE.md                 ← General LLM integration guide

---

Testing

python tests/test_pipeline.py

╔══════════════════════════════════════╗
║       InkDrop — Test Pipeline        ║
╚══════════════════════════════════════╝

  ✓ Process raw signature → clean PNG
  ✓ Insert signature into PDF (keyword)
  ✓ Insert signature into DOCX (keyword)
  ✓ Insert signature into PPTX (keyword)
  ✓ Recolor ink to custom color

══════════════════════════════════════
  Results: 5/5 passed
  Status:  ALL CLEAR ✓
══════════════════════════════════════

---

Roadmap

• MCP Server — Wrap as Model Context Protocol server for direct tool-use
• Batch signing — Sign 100 documents in one command
• HTML/Markdown — Insert into web documents and markdown files
• Signature verification — Validate signature authenticity via hash
• Multi-signature — Place different signatures on different pages
• Position learning — Remember where signatures go for recurring document types

---

Contributing

1. Fork it
2. Create your feature branch (git checkout -b feature/batch-signing)
3. Commit your changes (git commit -m 'feat: batch signing engine')
4. Push to the branch (git push origin feature/batch-signing)
5. Open a Pull Request

---

License

MIT — Use freely. Commercial use welcome.

---

InkDrop — by BlackhatShiftey

Draw it once. Drop it anywhere.