MarkMyDeck

A .NET library for converting CommonMark/GitHub Flavored Markdown to Microsoft PowerPoint (.pptx) presentations. The library targets .NET Standard 2.1 and .NET 10, and the CLI targets .NET 10.

Features

• Markdown → PowerPoint: Convert CommonMark markdown to PowerPoint (.pptx) presentations using the Open XML SDK

Currently Supported

✅ Slide Generation

• # H1 and ## H2 headings create new slides
• ### H3 through ###### H6 render as styled text on the current slide
• --- (thematic breaks) force a new slide
• Content between headings renders on the current slide

✅ Block Elements

• Headings (ATX: # H1 through ###### H6)
• Paragraphs
• Code blocks (fenced with ```) with syntax highlighting
• Block quotes (>)
• Thematic breaks (---, ***, ___) as slide separators
• Lists (ordered, unordered, nested)
• Tables (with headers, borders, and shading)

✅ Inline Elements

• Bold (**text** or __text__)
• Italic (*text* or _text_)
• Bold + Italic (***text***)
• Inline code (`code`)
• Links ([text](url))
• Images (![alt](url))
• Hard line breaks

✅ Styling

• Customizable fonts and colors
• Configurable heading/title sizes
• Code syntax highlighting for JSON, TypeSpec, and Bash
• Widescreen 16:9 slide format

Installation

dotnet add package SpecWorks.MarkMyDeck

Quick Start

using MarkMyDeck;

// Convert markdown string to .pptx file
string markdown = "# Hello World\n\nThis is **bold** text.\n\n---\n\n# Slide 2\n\n- Item 1\n- Item 2";
MarkdownConverter.ConvertToPptx(markdown, "output.pptx");

Convert to Byte Array

byte[] pptxBytes = MarkdownConverter.ConvertToPptxBytes(markdown);

Stream-based Conversion

using var inputStream = File.OpenRead("input.md");
using var outputStream = File.Create("output.pptx");
MarkdownConverter.ConvertToPptx(inputStream, outputStream);

Async Conversion

await MarkdownConverter.ConvertToPptxAsync(markdown, "output.pptx");

Custom Styling

using MarkMyDeck.Configuration;

var options = new ConversionOptions
{
    Styles = new SlideStyleConfiguration
    {
        DefaultFontName = "Arial",
        DefaultFontSize = 20,
        TitleFontSize = 40,
        TitleColor = "2E74B5",
        CodeFontName = "Fira Code",
        CodeFontSize = 16,
        CodeBackgroundColor = "282C34"
    },
    DocumentTitle = "My Presentation",
    Author = "John Doe"
};

MarkdownConverter.ConvertToPptx(markdown, "styled.pptx", options);

Command-Line Interface

MarkMyDeck includes a CLI for converting markdown files from the command line.

Installation

dotnet tool install --global SpecWorks.MarkMyDeck.CLI

Or run directly from the project:

dotnet run --project src/MarkMyDeck.CLI/MarkMyDeck.CLI.csproj -- convert -i input.md

Usage

# Basic conversion
markmydeck convert -i README.md

# Specify output file
markmydeck convert -i input.md -o output.pptx

# Custom font and size
markmydeck convert -i document.md --font "Arial" --font-size 20

# With title metadata
markmydeck convert -i document.md --title "My Presentation"

# Verbose output
markmydeck convert -i document.md -v

# Force overwrite
markmydeck convert -i document.md --force

# View version
markmydeck version

CLI Options

Option	Alias	Description
--input	-i	Input markdown file path (required)
--output	-o	Output file path (default: same name with .pptx)
--verbose	-v	Enable verbose output
--force	-	Overwrite output file if it exists
--font	-f	Default font name
--font-size	-s	Default font size (6-72 points)
--title	-t	Presentation title metadata

Architecture

MarkMyDeck uses a three-stage conversion pipeline:

1. Parse: Markdown is parsed into an AST using Markdig
2. Render: The AST is traversed and converted to OpenXML Presentation elements
3. Save: The presentation is saved using DocumentFormat.OpenXml

Slide Strategy

• # H1 and ## H2 headings create new slides
• ### H3 through ###### H6 are rendered as styled text within the current slide
• --- thematic breaks force a new slide
• All other content (paragraphs, lists, tables, code blocks) renders on the current slide

Project Structure

MarkMyDeck/
├── src/
│   ├── MarkMyDeck/                    # Core library (netstandard2.1;net10.0)
│   │   ├── MarkdownConverter.cs       # Public API
│   │   ├── Converters/
│   │   │   ├── OpenXmlPresentationRenderer.cs  # Main renderer
│   │   │   ├── BlockRenderers/        # Block element renderers
│   │   │   └── InlineRenderers/       # Inline element renderers
│   │   ├── SyntaxHighlighting/        # Syntax highlighting
│   │   ├── OpenXml/
│   │   │   ├── PresentationBuilder.cs # OpenXML presentation builder
│   │   │   └── SlideManager.cs        # Slide content management
│   │   └── Configuration/             # Configuration classes
│   └── MarkMyDeck.CLI/                # Command-line tool (net10.0)
└── tests/
    └── MarkMyDeck.Tests/              # Unit tests (net10.0)

Requirements

• Library: .NET Standard 2.1 or .NET 10.0
• CLI: .NET 10.0
• Dependencies:
  • Markdig 0.37.0
  • DocumentFormat.OpenXml 3.1.0
  • ColorCode.Core 2.0.15

Building from Source

git clone https://github.com/spec-works/MarkMyDeck.git
cd MarkMyDeck/dotnet
dotnet build
dotnet test

Specifications

This project implements:

• CommonMark 0.31.2 - Markdown parsing
• GitHub Flavored Markdown - Extended Markdown features (tables)
• ECMA-376 5th edition - Office Open XML presentation format
• ISO/IEC 29500 - Office implementation information

License

MIT License

Acknowledgments

• Built with Markdig by Alexandre Mutel
• Uses DocumentFormat.OpenXml by Microsoft
• Implements CommonMark specification
• Inspired by MarkMyWord

API Reference

See the API Reference for detailed documentation of all public types and methods.