Shopify Catalog Monitor — Price & Stock Change Alerts

Track price drops, stock-outs, restocks, and new or removed products across any public Shopify store. Schedule it daily or hourly and get only the diffs — not a giant dump you have to compare yourself.

Who uses this

• Competitor price monitoring — watch rivals' Shopify stores and react to every price move.
• Dropshipping & product research — catch new product launches and bestseller restocks early.
• Brand / MAP enforcement — detect when a reseller breaks minimum-advertised-price.
• Deal & restock alerts — know the moment a sold-out item is back in stock.

How it works

The Actor reads each store's public /products.json endpoint (no login, no scraping of rendered pages), stores a snapshot, and on every subsequent run reports what changed since last time:

Change type	Meaning
price_changed	A variant's price moved (includes from / to)
out_of_stock	A variant went unavailable
back_in_stock	A variant became available again
product_added	A new product appeared in the catalog
product_removed	A product disappeared from the catalog
variant_added	A new variant (size/color) was added

Input

Field	Type	Description
stores	array of strings	Store domains or URLs, e.g. gymshark.com
maxProductsPerStore	integer	Cap on products fetched per store per run (default 5000)
onlyReportChanges	boolean	Output only diffs (default true)

Output

Each detected change is one dataset record:

{ "store": "https://gymshark.com", "detectedAt": "2026-06-01T12:00:00.000Z",
  "type": "price_changed", "productId": "123", "handle": "training-shorts",
  "variant": "M / Black", "from": "38.00", "to": "30.00" }

The first run of a store captures a baseline (no diffs); changes start on the second run — so schedule it and let it work.

Notes

• Only works on stores that keep /products.json public (most do; some large brands disable it — those are skipped with a notice).
• Priced pay-per-event: you pay for stores checked and changes detected. No subscription.