SinceWhenBot

If you found this page in your server logs: hello. SinceWhenBot/1.0 is the change-monitoring crawler for sincewhen.dev. Someone asked us to tell them when a page on your site changes.

How it behaves

• One page per request — it fetches exactly the URLs users registered, never crawls outward from them.
• At most hourly per page (daily on the free tier), no matter how many users watch it — watches of the same URL share one fetch.
• Sends If-None-Match / If-Modified-Since; a 304 costs you almost nothing.
• Reads at most 2.5 MB per fetch, follows redirects, times out at 20 seconds.
• Backs off exponentially (up to a week) when your site errors.

Blocking it

Return 403 for the SinceWhenBot user-agent and the target stops being checkable; monitoring of your page then fails visibly for the user who requested it, which is what we want — no stealth, no UA rotation.