Shopify Price Change Monitor

Run it on a schedule. Get back only what changed since last time — price drops, price rises, sold out, back in stock, new products, removed products.

Not a catalogue export. A change report.

The difference, in one line

A 4,000-row spreadsheet every Monday is work you hand your team. "22 of the products you track dropped price, the deepest by 23%" is something they act on before lunch.

What people use it for

Competitive pricing. Know the morning a competitor discounts, not three weeks later when someone happens to notice.

Promotion intelligence. price_dropped and price_change_pct show how deep a discount really is against the price it is discounted from — not against the banner.

Stock signals. stock_change flags both directions. A product that sells out every week and comes back is a product the store keeps under-buying.

Watching your own catalogue. Price typos, variants that quietly went out of stock, products that disappeared during a theme migration.

What you get back

change_type	changed_fields	product_title	variant_title	previous_price	price	price_change_pct	stock_change
changed	price	Merino Runner	US 9 / Grey	128.00	99.00	-22.7
changed	available	Trail Cap	Default Title	32.00	32.00		went_out_of_stock
changed	price, available	Alpine Shell	S / Storm	245.00	199.00	-18.8	back_in_stock
new		Wool Beanie	One Size		38.00
removed		Old Tee	M / Black	24.00	24.00

Every row also carries the full product record — store, SKU, product URL, compare-at price, vendor, image — plus source_url, collected_at and record_hash.

change_type is one of new, changed, removed — or baseline on the very first run.

Read this before your first run

The first run has nothing to compare against. It reads the full catalogue, saves it, and returns every row marked baseline. RUN_SUMMARY says "baseline": true.

The second run is where the product starts. From then on you get only the differences.

This is not a limitation to work around — it is how any change feed works. Schedule it weekly and by run two you are getting exactly what you came for.

Settings

Setting	Default	What it does
Shopify stores to watch	—	Paste each store's homepage. Keep the list stable between runs.
Tracker name	default	How the actor remembers what it saw. One name per group you follow. Changing it starts over.
Max products per store	0 (whole catalogue)	Leave at 0. A partial read makes unread products look removed.
Requests per second	1	Polite by default.

Tip: use a separate tracker name per group of stores — shoes-competitors, my-own-store. They keep independent memory and never interfere.

What it costs

Event	Price
Run started	$0.01
Store checked	$0.03
Change detected	$0.001

Five stores in a quiet week (about 60 changes) costs roughly $0.22. The same five in a Black Friday week with 900 changes costs about $1.06. The cost follows the value: a week where nothing moved costs almost nothing, and the baseline run is never charged for changes.

Good to know

• A failed run never overwrites the memory. If a store blocks us or robots.txt closes mid-run, the previous snapshot is kept. Otherwise the next run would report as removed everything that was merely unread — and you would act on a report that is wrong.
• Public data only. It reads the same public product endpoint your browser hits when it loads a collection page. No login, no customer data, no orders.
• robots.txt respected. A store that asks crawlers to stay out is skipped and named.
• Sites that are not on Shopify are reported, not silently dropped — check the SKIPPED record in the key-value store.
• Currency is not published by Shopify's public catalogue, so prices come back as plain numbers in each store's own currency. Set it per store on your side if you compare across countries.

Questions?

Open an issue and I answer within 12 hours. Want the change report delivered as a file to your inbox or a Google Sheet every Monday morning instead of pulling it yourself? That is what I do — rowcrate.com.