macOS Autocorrect

Autocorrect as you type — something Electron apps famously can't do — powered by the real macOS autocorrect engine (NSSpellChecker, the same API native Mac apps use).

How it works

When you finish a word (space, punctuation, or Enter), the plugin asks macOS what it would have autocorrected that word to, via a tiny background osascript helper. macOS answers only when it's confident — the same logic as TextEdit/Notes — and the plugin swaps the word in, with a brief highlight so you notice. It respects words you've taught your Mac via "Learn Spelling".

• One Cmd+Z undoes a correction like any edit.
• The command "Revert last correction" (assign it a hotkey!) puts your original word back and stops correcting it for the rest of the session.
• A permanent ignore list lives in the plugin settings.
• It skips code blocks, inline code, math, links, tags, URLs, frontmatter, ALLCAPS/camelCase words, and anything typed during IME composition.
• Works in every pane and pop-out window.

Install

Install from Community plugins in Obsidian, or manually: unzip into YourVault/.obsidian/plugins/mac-autocorrect/ (folder must contain main.js, manifest.json, styles.css), then enable it in Settings → Community plugins (hit the refresh icon first).

Full macOS typing behavior

Mirroring the macOS keyboard settings panel, each with its own toggle:

• Correct spelling automatically — native autocorrect as described above.
• Capitalize words automatically — capitalizes the first word of sentences, new paragraphs, list items, headings, and blockquotes. It will NOT capitalize: soft-wrapped continuation lines (a new line whose previous line doesn't end a sentence), words after abbreviations ("etc.", "e.g.", "Mr.", initials like "J."), after ellipses ("..."), or words with internal capitals ("iPhone").
• Add period with double-space — two spaces after a word become ". ", and the next word then gets capitalized naturally.
• Smart quotes — corrected contractions use a curly apostrophe (don’t), matching native macOS autocorrect. On by default; toggle in settings.

A note on macOS Text Replacements

Unlike autocorrect, your macOS Text Replacements (System Settings → Keyboard) already work natively inside Obsidian — Obsidian applies them for you. So this plugin leaves them alone by default, and its "Use macOS Text Replacements" setting is off. (Earlier versions had it on, which double-expanded shortcuts like "dont" → "don'tt"; 1.3.0 turns it off, once, for everyone.)

The setting is still there for one specific case: the native handling applies replacements everywhere, including inside code and math. If that bothers you, disable Obsidian's own handling (Settings → Editor) and turn this on instead — the plugin's version is context-aware and skips code blocks, inline code, math, and links. Owning replacements in exactly one layer is the rule; using both double-expands them.

When enabled, the plugin reads your replacement list from ~/Library/KeyboardServices/TextReplacements.db (the store behind that Settings panel), reloads it automatically when it changes, and supports shortcuts with digits or symbols. Shortcuts containing spaces are not supported.

Security & privacy disclosures

Per Obsidian's developer policies, this plugin accesses things outside your vault — here is exactly what and why:

• Helper process: on macOS it spawns one small /usr/bin/osascript process (Apple's own scripting runtime, script embedded in this plugin's source — nothing downloaded) to query NSSpellChecker, the system autocorrect engine. It runs only while the plugin is enabled and is terminated on unload.
• File access outside the vault: only if you turn on "Use macOS Text Replacements" (off by default), it reads (never writes) ~/Library/KeyboardServices/TextReplacements.db — the database behind System Settings → Keyboard → Text Replacements — using the system sqlite3 tool. Left off, the plugin never touches it.
• No network use. Nothing leaves your machine; no telemetry of any kind. Words you type are sent only to your Mac's own local spellchecker.

Maintenance

Provided as-is and maintained on a best-effort basis. It's MIT-licensed — forks, fixes, and adoptions are welcome and encouraged.

Notes & limitations

• macOS only for the native engine. On other platforms (or if the helper fails), it falls back to the Electron spellchecker's first suggestion — set the engine to "Electron spellchecker" explicitly if you prefer that behavior.
• Inline predictive text is not possible — Apple's on-device language model has no public API.
• Vim mode: corrections apply to text typed in insert mode; if you find any interaction odd, toggles let you disable individual features. Feedback welcome.
• The abbreviation list for auto-capitalization is English-centric; add your own in settings ("Additional abbreviations").
• If the Text Replacements database can't be read (very old macOS, or none defined yet), the feature quietly does nothing — everything else still works.
• System-wide double-space timing, sentence detection, and capitalization are reimplemented to match macOS behavior as closely as markdown allows; version history lives in CHANGELOG.md.