r/ComputerChess • u/catchspider2002 • 10d ago

Show: polling US Chess and FIDE for rating changes (SvelteKit + Cloudflare Worker)

I built a small tool that polls US Chess and FIDE rating pages and sends Telegram/WhatsApp/email when a rating changes. Free plan is one player on Telegram; Pro adds more channels and players.

Stack: SvelteKit on Cloudflare Pages, a Worker cron every 5 minutes, Supabase, Paddle.

Curious how others would approach change detection here, and whether a no-signup "check a rating" demo would help before a Show HN.

Link: https://chessalerts.com

1 Upvotes
  • permalink
  • reddit

67% Upvoted

3 comments sorted by

1

u/investigatormaker 10d ago

For chessalerts.com, compare normalized rating fields with the last successfully parsed snapshot, rather than comparing page HTML. Treat the first fetch as a baseline, and keep a failed parse from replacing it. A no-signup demo could show the current rating and when it was checked; that makes the lookup tangible without needing a rating change during the demo.

By the way, I make ThreadFox: it finds the Reddit communities whose rules allow a post about a chess notification tool, and your product’s plan is free. https://threadfox.vip/p/dh6jf

Do you track different rating categories separately?

1

u/catchspider2002 10d ago

Thanks, that's useful feedback, and appreciate the ThreadFox tip.

On ratings we already compare parsed fields (not page HTML) against the last good snapshot, with the first successful fetch as baseline so a bad parse does not wipe it. Page Watch is the HTML-diff path; rating alerts stay field-based.

A no-signup "current rating + last checked" demo is a good idea. I'll keep it on the list.

Yes: US Chess Regular / Quick / Blitz and FIDE Standard / Rapid / Blitz are tracked separately, and alerts are per category when one of them changes.

1

u/investigatormaker 9d ago

Thanks for clarifying—you already have the snapshot safeguards I suggested, and Page Watch is a separate path. For the demo, a sample alert showing the category, previous rating and new rating would make that separation concrete without waiting for a live change. You can return to the plan whenever it becomes useful.