I think it's very useful cause i also had these types of miss fortunes in the past and i don't want to experiance these again at all
Show HN: I built a tool that watches webpages and exposes changes as RSS
61–70 of 86 posts
Re: Show HN: I built a tool that watches webpages and exposes changes as RSS
#62Earlier quoted context omitted.
Yep, changedetection.io is a good project. With Site Spy, I wanted to make the browser-first workflow much easier: install the extension, connect it to the dashboard, click the exact part of the page you care about, and then follow changes as diffs, history, or RSS with very little setup. I can definitely see why the open-source / self-hosted route is appealing too.
Does your project use changedetection.io behind the scenes? When I look at the _All Watches Feed_ the contents of the rss file include; https://changedetection.io Feed description http://www.rssboard.org/rss-specification python-feedgen Thu, 12 Mar 2026 10:10:10 +0000
Re: Show HN: I built a tool that watches webpages and exposes changes as RSS
#63I got claude to reverse engineer the extension and compare to changedetection and here's what it came up with. Apologies for clanker slop but I think its in poor taste to not attribute the opensource tool that the service is built on (one that's also funded by their SaaS plan)
---
Summary: What Is Objectively Provable
- The extension stores its config under the key changedetection_config
- 16 API endpoints in the extension are 1:1 matches with changedetection.io's documented API
- 16 data model field names are exact matches with changedetection.io's Watch model (including obscure ones like time_between_check_use_default, history_n, notification_muted, fetch_backend)
- The authentication mechanism (x-api-key header) is identical
- The default port (5000) matches changedetection.io's default
- Custom endpoints (/auth/, /feature-flags, /email/, /generate_key, /pregate) do NOT exist in changedetection.io — these are proprietary additions
- The watch limit error format is completely different from changedetection.io's, adding billing-specific fields (current_plan, upgrade_required)
- The extension ships with error tracking that sends telemetry (including user emails on login) to the developer's GlitchTip server at 100% sample rate
The extension is provably a client for a modified/extended changedetection.io backend. The open question is only the degree of modification - whether it's a fork, a proxy wrapper, or a plugin system. But the underlying engine is unambiguously changedetection.io.
Re: Show HN: I built a tool that watches webpages and exposes changes as RSS
#64I got claude to reverse engineer the extension and compare to changedetection and here's what it came up with. Apologies for clanker slop but I think its in poor taste to not attribute the opensource tool that the service is built on (one that's also funded by their SaaS plan) --- Summary: What Is Objectively Provable - The extension stores its config under the key changedetection_config - 16 API endpoints in the ext…
Fair point, and I should have been upfront about this earlier. The backend is a fork of changedetection.io. I've built on top of it — added the browser extension workflow, element picker, billing, auth, notifications, and other things — but the core detection engine comes from their project. That should have been clearly attributed from the start, and I'll add it to the docs and about page.
changedetection.io is a genuinely great project. What I'm trying to build on top of it is the browser-first UX layer and hosted product that makes it easier for non-technical users to get value from it without self-hosting and AI focus approach
P.S -> I've also added an acknowledgements page to the docs: https://docs.sitespy.app/docs/acknowledgements
Re: Show HN: I built a tool that watches webpages and exposes changes as RSS
#65Earlier quoted context omitted.
Yep, changedetection.io is a good project. With Site Spy, I wanted to make the browser-first workflow much easier: install the extension, connect it to the dashboard, click the exact part of the page you care about, and then follow changes as diffs, history, or RSS with very little setup. I can definitely see why the open-source / self-hosted route is appealing too.
Does your project use changedetection.io behind the scenes? When I look at the _All Watches Feed_ the contents of the rss file include; https://changedetection.io Feed description http://www.rssboard.org/rss-specification python-feedgen Thu, 12 Mar 2026 10:10:10 +0000
Yes — it's a fork of changedetection.io. I went into more detail here: https://news.ycombinator.com/item?id=47349141. The RSS link you spotted was a leftover, already fixed
Re: Show HN: I built a tool that watches webpages and exposes changes as RSS
#66I use RSS to get updates from a ll the stuff I read online at once, and thought this would be nice for those websites that don't already have an RSS feed, but... Perhaps I'm stupid, but I can't actually find the RSS output? And searching for RSS on https://docs.sitespy.app/docs returns no hits.
Re: Show HN: I built a tool that watches webpages and exposes changes as RSS
#67RSS is a useful interface, but: "Do most people just want direct alerts?" Yes, of course. RSS is beloved but niche. Depends who your target audience is. I personally would want an email, because that's how I get alerts about other things. RSS to me is for long form reading, not notifications I must notice. The answer to any product question like this totally depends on your audience and their normal routines.
[flagged]
Re: Show HN: I built a tool that watches webpages and exposes changes as RSS
#68[flagged]
Re: Show HN: I built a tool that watches webpages and exposes changes as RSS
#69I use RSS to get updates from a ll the stuff I read online at once, and thought this would be nice for those websites that don't already have an RSS feed, but... Perhaps I'm stupid, but I can't actually find the RSS output? And searching for RSS on https://docs.sitespy.app/docs returns no hits.
Not stupid at all — the docs were missing an RSS page, which is on me. I've just added one: https://docs.sitespy.app/docs/dashboard/rss. RSS feeds are available per watch, per tag, or across all watches from the dashboard. Thanks for flagging it, this is exactly the kind of feedback that helps
Re: Show HN: I built a tool that watches webpages and exposes changes as RSS
#70[flagged]
The selector is stored as a CSS path and matched against the fetched HTML on each check — so as long as the element's structure and nesting stay roughly the same, minor layout changes don't usually break it.
The fragile cases are sites that generate class names on every build (React/webpack/vite apps often do this) — those selectors will just stop working.
For semantic elements like price tags, availability text, or content blocks, they tend to be stable enough that it's not a real problem day-to-day. And if a filter stops matching entirely, the watch flags with error message it rather than silently giving you empty diffs.