A self-hosted LanguageTool (dev: docker/docker-compose.yml, started by
`make up`) checks what the user writes in the compose window, through
POST /api/spellcheck — the browser never talks to the engine directly.
- Marks are CSS highlights over the text, never written into the message: red
wavy for spelling, blue for grammar/style. Clicking one shows the message,
up to five suggestions (applied as typed, so Ctrl+Z undoes them) and Ignore.
The popup, like the link popup, opens above its anchor when there is no
room below.
- Checked after a pause in typing; the signature and quoted original are
skipped; marks on words just edited drop at once; a check overtaken by a
newer one, by turning checking off, or by closing the window is discarded.
- With "auto", text is checked in chunks of lines, each in its own detected
language — LanguageTool settles on one language per request, so a mixed
Polish/English message had every English word flagged as a Polish typo.
- Settings > Appearance: on/off and language (Auto-detect or any of the
engine's languages); the compose window's More menu overrides it for one
message. The browser's own spellcheck steps aside while ours runs, and comes
back when it is off or the server has no engine (503 from the endpoint).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
