Agent skill · software engineering · aradotso
md-preview-app-macos
Native macOS Markdown viewer app with Quick Look extension, Mermaid diagrams, KaTeX math, document outline, and editor integration
Why this skill is useful
Provides specific implementation details and architecture for a macOS Markdown viewer app that the AI wouldn't reliably generate on its own.
What it needs
Requires xcode installed locally. About 6k tokens when loaded. Last updated 2026-07-09. 70 stars on the source repository.
What this skill does
MD Preview App — macOS Markdown Viewer Skill by ara.so — Daily 2026 Skills collection. A fast, native macOS app (AppKit + WKWebView) for reading .md files. No Electron, no browser tab. Features include a document outline sidebar, Mermaid diagram rendering, KaTeX math, Quick Look extension, in-document search, and one-click "Open With" for popular editors. --- Installation Pre-built (recommended) Download the signed and notarized DMG from the Releases page and drag to /Applications. Build from source Requirements: macOS 15+, Xcode with Swift 6.0, Apple Silicon or Intel. --- Project Layout --- Key Dependencies (Swift Package Manager) Package Purpose --- --- swift-markdown (Apple) Markdown parsing via cmark-gfm Sparkle Auto-update framework Mermaid (bundled JS) Fenced mermaid block rendering KaTeX (bundled JS) LaTeX math rendering --- Core Architecture Markdown → HTML Pipeline Loading HTML into WKWebView Document Outline (TOC) Sidebar --- Quick Look Extension The extension lives in quick-look/ and is a separate .appex target. It reuses the same HTML rendering pipeline so Mermaid diagrams and math work offline in Finder spacebar previews. --- Mermaid Diagrams Fenced mermaid blocks are detected during parsing and emitted as <div class="mermaid"> elements. The bundled mermaid.min.js initializes on page load — no CDN required. …
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills aradotso/md-preview-app-macos