Patina

A hyper-efficient macOS app for any text-ish file. Markdown gets a beautiful rendered view; code (json / yaml / .env) gets syntax highlighting; everything else just opens, instantly. Native AppKit, no Xcode project, no web view, zero third-party dependencies — links only system frameworks.

Make it the default for .md, .txt, .env, .json, .yaml, and even unknown file types, and it opens them in a blink. Binary or oversized files are detected and shown a friendly notice instead of a screenful of garbage.

Your files stay plain files. Patina never locks them in a database — it's a fast, beautiful lens over a directory you already own.

Download

Grab the latest .dmg from the Releases page, open it, and drag Patina into Applications. It's a universal build — runs natively on Apple Silicon and Intel.

First launch (important): Patina is a free, unsigned build — it isn't notarized through a paid Apple Developer account, so the first time you open it macOS Gatekeeper blocks it with "Apple could not verify Patina is free of malware." This is expected; don't click Move to Bin. Clear the quarantine flag once, from Terminal:

xattr -dr com.apple.quarantine /Applications/Patina.app

then double-click Patina. No Terminal? Try to open it once, then go to System Settings → Privacy & Security, scroll to "Patina was blocked…" and click Open Anyway. (On macOS Sequoia/Tahoe the old right-click → Open trick no longer works.)

Prefer to compile it yourself? See Build below.

Features

• Opens anything text — Markdown renders beautifully; .json, .yaml/.yml, and .env get live syntax highlighting (keys, strings, numbers, comments); .txt and unknown files open as fast plain text. Binary/oversized files are detected and declined gracefully.
• [[wiki-links]] + backlinks — type [[ for fuzzy autocomplete over your whole library; [[Note]] becomes a clickable link (and is created on click if it doesn't exist yet). Each note shows a "Linked from" strip of the notes that point at it. The links are literal [[…]] text — open the file anywhere and it's still readable. No database, no link table.
• #tags — #tag is styled inline and clickable; clicking filters the sidebar to it. Typing #tag in search already filters by full text. Tags are just words in the file — nothing to set up, nothing to migrate.
• Never lose an edit — if the open file changes on disk (another app, git, sync), Patina reloads it when you have no unsaved edits, or shows a Keep Mine / Reload banner when you do — it never silently overwrites.
• Undo delete — deleting moves to Trash and offers a one-click Undo.
• Word count + reading time — a live footer with words · characters · minutes.
• Command Palette (⌘K) — fuzzy quick-open across every note you've ever opened, in any folder. Patina keeps a self-healing index (JSON in Application Support) that remembers your files and prunes ones that no longer exist.
• Live Markdown styling — headings, bold, italic, code, links, and list/quote markers are styled right in the editor as you type; the syntax markers dim so the prose stands out.
• Classic shortcuts — ⌘B bold, ⌘I italic, ⌘⌥C inline code, ⌘⇧K link, ⌘⌥H heading, ⌘⇧L bullet list — each toggles the selection.
• Folder library + live search — point Patina at a folder; the vibrant sidebar lists every note (title · snippet · date), newest first. Search filters by filename and full text as you type.
• Live folder watching — add, rename, or delete files in Finder and the sidebar updates itself (FSEvents).
• Autosave to disk — edits are written back to the file ~0.6 s after you stop typing, and flushed on note-switch, app-hide, and quit. No save dialogs.
• Beautiful editing — a centered, fixed-width reading column with generous line spacing; the measure stays comfortable at any window size.
• Native Markdown preview — ⌘⇧P renders to a native NSAttributedString (no WebView), so the preview is effectively free.
• Inline rename — double-click a note's title in the sidebar to rename the file on disk.
• Reopens where you left off — last folder, note, and window frame restored.
• Set it as your default — registers UTIs for .txt/.md; double-click a file in Finder and Patina opens its folder with that note selected.

Build

./build.sh        # → build/Patina.app  (swiftc, no Xcode project)
./tests/run.sh    # headless logic tests (store, index, highlighters)

Requires the Swift toolchain (ships with Xcode / Command Line Tools). Every push builds the app and runs the tests in CI.

Install + make it the default app

./install.sh      # copies to /Applications and registers with Launch Services

With duti installed (brew install duti) the script also makes Patina the default opener for .txt and .md. Otherwise: right-click a file → Get Info → Open with → Patina → Change All…

Keys

Action	Shortcut
Quick Open (command palette)	⌘K
New note	⌘N
Open notes folder	⌘⇧O
Move note to Trash	⌘⌫
Search notes	⌘⌥F
Find in note	⌘F
Toggle sidebar	⌃⌘S
Toggle Markdown preview	⌘⇧P
Bold / Italic	⌘B / ⌘I
Inline code / Link	⌘⌥C / ⌘⇧K
Heading / Bullet list	⌘⌥H / ⌘⇧L
Rename note	double-click its title

Markdown supported in preview

Headings, bold, italic, inline code, fenced code blocks, links, unordered/ordered lists, blockquotes, horizontal rules.

Architecture

Sources/
  main.swift                  # entry point
  Theme.swift                 # all visual tuning + centered-column text view
  AppDelegate.swift           # window chrome, toolbar, menu, persistence, open-from-Finder
  WorkspaceController.swift    # split-view hub; wires sidebar ↔ editor ↔ palette over one store
  SidebarViewController.swift  # search + source-list note rows + inline rename
  EditorViewController.swift   # centered editor, autosave, live preview, formatting cmds
  SyntaxHighlighter.swift      # live in-editor Markdown styling + wiki-link/tag links
  CodeHighlighter.swift        # FileKind detection + json/yaml/.env syntax highlighting
  CommandPalette.swift         # ⌘K fuzzy quick-open panel
  WikiLinkCompleter.swift      # [[ autocomplete panel
  EditorAccessories.swift      # conflict/undo banner, backlinks bar
  NotesStore.swift            # folder scan, search, backlinks, mutations
  LibraryIndex.swift          # persistent index of all opened notes (+ auto-prune)
  FolderWatcher.swift         # FSEvents wrapper for live updates
  Markdown.swift              # dependency-free Markdown → NSAttributedString
  Persistence.swift           # last folder / note / frame
Resources/Info.plist          # bundle id + document-type / UTI declarations
Resources/AppIcon.icns        # generated by tools/build_icon.sh
build.sh / install.sh

Notes stay plain files; Patina is a thin, fast, native layer over a folder.

License

MIT © 2026 David Borgenvik