🖨️ print-mark

Convert Markdown to clean, printable HTML with PDF export

Maintained by

---

Features

• Live Preview - See formatted output as you type with real-time rendering
• Multiple Themes - Choose from 9 print-optimized themes with live preview styling
• PDF Export - Generate professional PDFs with customizable page sizes, margins, and page numbers
• Syntax Highlighting - Beautiful code highlighting powered by Shiki
• File Upload - Drag and drop or upload .md, .markdown, or .txt files
• Responsive Design - Works on desktop and tablets with resizable split panes
• No Account Required - Stateless, privacy-focused design

Quick Start

Docker (Recommended)

docker run -p 3000:3000 ghcr.io/jparkerweb/print-mark:latest

Then open http://localhost:3000 in your browser.

Docker Compose

services:
  print-mark:
    image: ghcr.io/jparkerweb/print-mark:latest
    ports:
      - "3000:3000"
    environment:
      - PDF_TIMEOUT=30000
      - PDF_CONCURRENT_LIMIT=3
    restart: unless-stopped

docker-compose up -d

Local Development

Prerequisites:

• Node.js 22 or later
• npm 10 or later

# Clone the repository
git clone https://github.com/jparkerweb/print-mark.git
cd print-mark

# Install dependencies
npm install

# Build the application
npm run build

# Start the server
npm start

Development mode with hot reload:

npm run dev

Testing

Running Tests

# Run all tests once
npm run test

# Run tests in watch mode (re-runs on file changes)
npm run test:watch

# Run tests with coverage report
npm run test:coverage

# Run slow Puppeteer tests (real PDF generation)
npm run test:slow

# Run all tests including slow tests
npm run test:all

Pre-commit Hooks

This project uses Husky and lint-staged to enforce code quality on every commit. When you commit:

1. ESLint runs on staged TypeScript files and auto-fixes issues where possible
2. Vitest runs tests related to your changed files

If either linting or tests fail, the commit is blocked until issues are resolved.

To bypass hooks in emergencies (use sparingly):

git commit --no-verify -m "emergency commit"

Configuration

Environment Variables

Variable	Default	Description
PORT	3000	HTTP server port
HOST	0.0.0.0	Server bind address
NODE_ENV	production	Environment (development, production, test)
MAX_FILE_SIZE	26214400	Maximum upload size in bytes (default: 25MB)
PDF_TIMEOUT	30000	PDF generation timeout in milliseconds
PDF_CONCURRENT_LIMIT	3	Maximum concurrent PDF generations

API Documentation

Health Check

GET /api/health

Returns server health status and version.

Response:

{
  "status": "healthy",
  "version": "1.0.0"
}

Example:

curl http://localhost:3000/api/health

---

List Themes

GET /api/themes

Returns available themes with metadata.

Response:

{
  "themes": [
    { "id": "clean", "name": "Clean", "description": "Minimal, professional styling" },
    { "id": "academic", "name": "Academic", "description": "Scholarly formatting with serifs" },
    { "id": "modern", "name": "Modern", "description": "Contemporary sans-serif design" },
    { "id": "compact", "name": "Compact", "description": "Space-efficient for dense content" },
    { "id": "executive", "name": "Executive", "description": "Bold, corporate look" },
    { "id": "manuscript", "name": "Manuscript", "description": "Classic serif book style" },
    { "id": "technical", "name": "Technical", "description": "Code-optimized high contrast" },
    { "id": "minimalist", "name": "Minimalist", "description": "Ultra-clean with max whitespace" },
    { "id": "newsletter", "name": "Newsletter", "description": "Friendly with decorative elements" }
  ]
}

Example:

curl http://localhost:3000/api/themes

---

Generate PDF

POST /api/pdf
Content-Type: application/json

Converts Markdown to PDF and returns the file.

Request Body:

{
  "markdown": "# Hello World\n\nThis is **bold** text.",
  "theme": "clean",
  "options": {
    "pageSize": "A4",
    "margins": "normal",
    "includePageNumbers": true
  }
}

Parameter	Type	Required	Description
markdown	string	Yes	Markdown content to convert
theme	string	Yes	Theme ID (clean, academic, modern, compact, executive, manuscript, technical, minimalist, newsletter)
options.pageSize	string	No	Page size: A4, Letter, Legal, B5 (default: A4)
options.margins	string	No	Margins: normal, narrow, wide (default: normal)
options.includePageNumbers	boolean	No	Show page numbers (default: true)

Response: Binary PDF file with headers:

• Content-Type: application/pdf
• Content-Disposition: attachment; filename="document.pdf"

Example:

curl -X POST http://localhost:3000/api/pdf \
  -H "Content-Type: application/json" \
  -d '{
    "markdown": "# Hello World\n\nThis is a test document.",
    "theme": "clean",
    "options": {
      "pageSize": "A4",
      "margins": "normal",
      "includePageNumbers": true
    }
  }' \
  --output document.pdf

Error Responses:

Status	Description
400	Validation failed (missing/invalid parameters)
408	Request timeout (document too large)
503	Service unavailable (server busy)
500	Internal server error

---

Upload File

POST /api/upload
Content-Type: multipart/form-data

Upload a Markdown file and receive its content.

Request: Multipart form with file field

Response:

{
  "filename": "document.md",
  "content": "# File content here...",
  "size": 1234
}

Example:

curl -X POST http://localhost:3000/api/upload \
  -F "file=@document.md"

Supported file types: .md, .markdown, .txt

Error Responses:

Status	Description
400	No file provided or invalid file type
413	File too large (exceeds MAX_FILE_SIZE)
500	Internal server error

Docker Deployment

Building the Image

docker build -t print-mark:latest .

Running with Docker

docker run -d \
  --name print-mark \
  -p 3000:3000 \
  -e PDF_TIMEOUT=60000 \
  -e PDF_CONCURRENT_LIMIT=5 \
  print-mark:latest

Docker Compose (Production)

services:
  print-mark:
    image: ghcr.io/jparkerweb/print-mark:latest
    ports:
      - "3000:3000"
    environment:
      - NODE_ENV=production
      - PDF_TIMEOUT=30000
      - PDF_CONCURRENT_LIMIT=3
      - MAX_FILE_SIZE=26214400
    restart: unless-stopped
    healthcheck:
      test: ["CMD", "wget", "-q", "--spider", "http://localhost:3000/api/health"]
      interval: 30s
      timeout: 10s
      retries: 3

Reverse Proxy (nginx)

Example nginx configuration for running behind a reverse proxy:

server {
    listen 80;
    server_name print-mark.example.com;

    location / {
        proxy_pass http://localhost:3000;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_cache_bypass $http_upgrade;

        # Increase timeout for PDF generation
        proxy_read_timeout 60s;
        proxy_send_timeout 60s;

        # Increase max body size for file uploads
        client_max_body_size 25M;
    }
}

Themes

print-mark includes 9 print-optimized themes:

Theme	Description
Clean	Minimal, professional styling with excellent readability
Academic	Scholarly formatting with serif fonts, ideal for papers
Modern	Contemporary sans-serif design with subtle accents
Compact	Space-efficient layout for dense technical content
Executive	Bold, corporate look with strong visual hierarchy
Manuscript	Traditional book style with classic serif typography
Technical	Optimized for code-heavy documentation with high contrast
Minimalist	Ultra-clean design with maximum whitespace
Newsletter	Friendly layout with subtle decorative elements

All themes are optimized for:

• Print media with proper page breaks
• Syntax-highlighted code blocks
• Tables with clear borders
• Proper heading hierarchy

Tech Stack

• Runtime: Node.js 22 LTS
• Backend: Fastify 5.x
• Markdown: markdown-it 14.x with plugins
• Syntax Highlighting: Shiki 1.x
• PDF Generation: Puppeteer 23.x
• HTML Sanitization: DOMPurify 3.x
• Editor: CodeMirror 6.x
• Build: Vite 6.x
• Language: TypeScript 5.x

Security

• All HTML output is sanitized with DOMPurify to prevent XSS attacks
• File uploads are validated for type and size
• Input validation using Zod schemas
• Runs as non-root user in Docker
• No data persistence - all processing is stateless

Contributing

1. Fork the repository
2. Create a feature branch: git checkout -b feature/my-feature
3. Commit your changes: git commit -am 'Add my feature'
4. Push to the branch: git push origin feature/my-feature
5. Submit a pull request

License

Apache License 2.0 - see LICENSE for details.