Is CF-Predictor safe?

CF-Predictor reads every contestant handle from a Codeforces standings page and sends them to its own server to compute rating predictions.

On any Codeforces contest standings page, the extension scrapes all visible contestant handles and the contest ID, then forwards them to cf-predictor.wasylf.xyz to fetch predicted rating deltas, which it overlays on the page. The data is public Codeforces handles, not credentials or personal information. The background service worker also runs a fetch relay that retrieves any URL passed to it and returns the response body, so any script running on a standings page can use the extension to make cross-origin requests.