The spelling cue is OpenCues' built-in spell-checker, and it's implemented with a deliberately elegant idiom: it's just a regular word cue whose match: is .* (everything) at priority 10 (lower than every other shipped source). It claims exactly the words no more specific cue wanted, which makes it the catch-all safety net.
How the routing idiom works
Word routing walks sources by priority, and each word is claimed by the highest-priority source that matches it. The domain cues (legal, medical, financial) sit at higher priorities with narrow claims; spelling sits at the bottom with an everything-regex. So attorney goes to the legal cue and gets terminology alternatives, while recieve falls through to spelling and gets receive. There's no special-case spell-check flag anywhere in the system; the spec is explicit that spelling is a regular word-cue source gated by word-cues-mode like any other, and the routing layer requires every source to declare a claim, so the catch-all has to say match: .* out loud.
What the prompt asks for
The shipped prompt is a compact spec: identify misspelled words, output up to three corrections per word with the most likely first, and output nothing at all when nothing is wrong. It carries an explicit skip list, and the entries are the difference between a spell-checker you keep and one you disable:
- Proper nouns, place names, brands, and acronyms are assumed intentional.
- Numbers, codes, hex, URLs, and file paths are never flagged.
- The literal
_is never a word (it's the blank placeholder). - Single-letter words are left alone.
One nice detail from its examples: homophone errors get the plausible set, so their going to the store offers they're first and there second, and you pick by cycling.
What it looks like in use
A misspelled word dims as you type. Ctrl+Alt+←/→ navigates to it, Ctrl+Alt+↑/↓ cycles the corrections into place, and ignoring it costs nothing. There's no squiggle, no popup, no interruption; the dim is the whole signal. And when your text is clean, the prompt's contract is to output nothing at all, so a well-spelled draft generates zero visual noise rather than a stream of "looks fine" confirmations.
Tuning or removing it
Jargon and identifiers a spell-checker keeps flagging belong on the ignore: list in CUES.md. The whole source can be muted with disable: [spelling], per project or globally, and because it's just a folder (cues/spelling/CUE.md) you can also edit the prompt itself: the skip list is plain text, and adding your own rule is a one-line edit that hot-reloads in seconds. It also makes a good template for a catch-all cue of your own design at a different priority.
Related: What is a cue? · Better cue prompts · How to disable a cue · The more-formal cue · GitHub repo