Harper

QOwnNotes can use Harper for optional offline grammar and style checking in the note editor.

It complements the existing spellchecking support instead of replacing it.

harper-demo

Features

  • Colored underlines for detected grammar, style, punctuation, and wording issues
  • Context-menu suggestions for replacements
  • Ignore this rule and Ignore word actions in the context menu
  • A quick toggle in the Edit menu with Check grammar with Harper
  • Local checking with the harper-ls language server over Stdio or TCP

Setup

Open Settings and select Editor -> Harper.

  • Turn on Enable offline grammar and style checking with Harper
  • Choose the Transport
    • Stdio (recommended) starts a local harper-ls process directly
    • TCP connects to an already running harper-ls server
  • For Stdio, set the Command / binary path
    • The default command is harper-ls
    • Auto-detect searches for it in your PATH
  • For TCP, set the Server address and Port
    • The defaults are 127.0.0.1 and 4000
  • Choose the Dialect
    • American
    • British
    • Australian
    • Canadian
    • Indian
  • Adjust the Check delay to control how long QOwnNotes waits after typing before sending a request
  • Select which linters should be enabled
    • Spell Check
    • Sentence Capitalization
    • Repeated Words
    • Long Sentences
    • An vs A
    • Unclosed Quotes
    • Correct Number Suffix
    • Spaces
    • Quote Spacing
    • No French Spaces
    • Wrong Apostrophe
    • Spelled Numbers

Use Test Connection to verify that QOwnNotes can either start harper-ls in Stdio mode or reach the configured server in TCP mode.

How It Works

  • QOwnNotes checks visible editor blocks instead of the whole document at once
  • Empty lines, headings, and code blocks are skipped
  • Requests are debounced so Harper is not queried on every keystroke
  • Results are shown inline in the Markdown editor
  • Harper and LanguageTool can be enabled at the same time

Notes

  • Harper support is optional and depends on the feature being enabled in your build
  • Stdio mode is the simplest setup for local offline checking
  • If Harper cannot be reached, QOwnNotes shows a warning and stops checking until it is available again