Detector

Karen Alvarez · 2026-08-13T00:00:00.000Z

We watch price and lead time on five supplier catalogues. The pages change all day for reasons that have nothing to do with us, so a page-level alert is a page-level alert we have learned to ignore.

In progress

On track. Field picking already works on all five pages.

I need this too · 57 Follow

How it gets built

AskedAug 13, 2026
R&D
Built
Shipped

Good to know

Old → newevery alert shows both values

Thresholdnumeric fields ignore tiny moves

Alert me when one value on the page changes, not when the page changes

We buy parts. Five suppliers publish a catalogue, and on every product page there are two numbers that decide what we do: the unit price and the quoted lead time.

Those pages change constantly. Promotional banners, a stock badge that flickers between "in stock" and "low", a session id written into the footer on every load. A tool that tells us the page changed is telling us something true and useless, and after two weeks of that nobody reads the alerts.

What we actually need

Pick the field, not the page. Point at the price on the page and say: this, on this page, is what I am watching.
Alert only when that value changes, with the old value and the new one in the message.
A threshold on numbers, so a rounding change is not an alert.
Tell us when the field breaks. If the supplier redesigns and the value is no longer where it was, we need to hear that. Silence has to mean "unchanged", never "we stopped looking".

Why it matters

A lead time that moves from two weeks to four is a production schedule that is now wrong, and we would rather find out the day it moves than the week the parts do not arrive. A price that moves is a quote we have out to a customer that no longer holds. Both are decisions with a deadline, and both are currently found by someone remembering to check.

What we do today

A spreadsheet with 62 rows and a column for "last checked", filled in by whoever has time on a Tuesday. In practice that is once a fortnight, in practice that is not everything, and the rows nobody checked are exactly the ones that turn into a phone call from a customer.

The conversation

Karen AlvarezPurchasing ManagerAug 13, 2026
To be precise about the shape: 62 part numbers across five supplier catalogues, and on each product page there are exactly two things we care about — the unit price and the quoted lead time. Everything else on those pages is banners, stock badges and a session id in the footer. We saw the monitoring request that shipped this month and this is the same idea one level down.
DetectorAug 14, 2026
It is the same engine, pointed at a field instead of a page, and that is exactly why we are timeboxing it to a week rather than assuming. The unknown is not the watching, it is the addressing — a selector picked today has to still mean "unit price" after the supplier reskins the site in March. Two of your five are server-rendered tables, which is easy; the other three build the price in the browser, which is the week.
Karen AlvarezPurchasing ManagerAug 18, 2026
One thing worth more to us than the alert itself: send the old value and the new one in the message. "Lead time changed" makes someone open a browser. "14 days becomes 28 days" makes someone move an order.
DetectorAug 19, 2026
In progress, on track for the 24th. Field picking works on all five now — you click the value on a rendered snapshot and we resolve it to something more durable than a CSS path, then re-verify it on every run and tell you when a field stops resolving instead of silently reporting "no change". Alerts carry old and new, and numeric fields take a threshold so a three-lira move does not wake anybody.