Goal Open individual .md files on macOS in a rendered preview, without a vault (ruling out Obsidian) and without showing the editor pane. Tool: MacDown 3000 MacDown 3000 is an actively maintained MIT-licensed fork of the abandoned MacDown project. Install via Homebrew: bashbrew install --cask macdown-3000 Key features relevant here:
Split editor + live preview pane Editor pane can be hidden with Cmd+Shift+E Quick Look extension for Space-bar previews in Finder Apple Silicon native
Problem MacDown 3000 doesn't persist the "editor hidden" state across new windows, so every file opens with the editor pane visible. Solution: Automator Application Wrapper Create an Automator Application that opens the file in MacDown 3000 and immediately hides the editor pane via keystroke automation. Steps
Open Automator → New Document → Application Add a Run AppleScript action with the following script:
applescripton run {input, parameters}
repeat with f in input
set filePath to POSIX path of f
tell application "MacDown 3000"
activate
open filePath
end tell
delay 0.5
tell application "System Events"
tell process "MacDown 3000"
keystroke "e" using {command down, shift down}
end tell
end tell
end repeat
return input
end runSave as /Applications/Open in MacDown Preview.app Right-click any .md file in Finder → Get Info → Open With → select Open in MacDown Preview → click Change All
Permissions Grant Accessibility access to Automator in System Settings → Privacy & Security → Accessibility for the keystroke automation to work. Notes
The delay 0.5 gives MacDown 3000 time to render before the keystroke fires — increase if needed on slower machines Cmd+Shift+E toggles the editor pane; this assumes it starts visible (the default) Quick Look (Space in Finder) still works as a zero-friction read-only alternative for quick checks