Shopify Price & Stock Monitor

Track price changes, stock changes and new or removed products on any Shopify store. Each run compares the store with the previous run and outputs only what changed, with optional Slack alerts.

Schedule it daily or hourly and you'll know when a competitor runs a sale, a product sells out, or a new collection drops.

What you get

Each run outputs one row per change:

changeType	Meaning
PRICE_CHANGE	Variant price went up or down (with old price, new price and % change)
OUT_OF_STOCK	Variant became unavailable
BACK_IN_STOCK	Variant became available again
NEW_VARIANT	New product or variant appeared
REMOVED_VARIANT	Product or variant disappeared
STORE_SUMMARY	One row per store per run: variants checked and number of changes found

The first run for a store saves a baseline and outputs the full catalog (changeType: SNAPSHOT), so you also get a complete product export.

Example output

{
  "changeType": "PRICE_CHANGE",
  "store": "https://www.example-store.com",
  "title": "Classic Runner",
  "variantTitle": "Black / 9",
  "sku": "CR-BLK-9",
  "oldPrice": 120.0,
  "newPrice": 96.0,
  "changePercent": -20.0,
  "compareAtPrice": 120.0,
  "url": "https://www.example-store.com/products/classic-runner?variant=4123",
  "image": "https://cdn.shopify.com/..."
}

Fields: store, productId, variantId, title, variantTitle, vendor, sku, oldPrice, newPrice, changePercent, compareAtPrice, available, url, image.

How to use

1. Add one or more store URLs (any page of the store works).
2. Run once to create the baseline.
3. Add a schedule (Apify Console → Schedules), for example every day at 08:00.
4. Optional: paste a Slack incoming webhook URL to get a summary message whenever something changes.
5. Optional: set Minimum price change (%) to ignore tiny changes.

Export results as JSON, CSV or Excel, or pull them from the API, Make, Zapier or n8n.

How it works

The tool reads the store's public product feed (/products.json), which most Shopify stores expose. It doesn't log in, doesn't use a browser, and sends polite, rate-limited requests through Apify Proxy (on by default, since many stores rate-limit cloud servers), so runs are fast and cheap. If a store can't be reached, you get a STORE_SUMMARY row with the error instead of silent failure. A store with a few thousand variants is checked in seconds.

Snapshots are kept in a named key-value store (shopify-price-monitor-state), so every scheduled run picks up where the last one stopped.

Limitations

• Works only with Shopify stores that keep /products.json enabled (most do). Other stores return a clear error and are skipped.
• Prices are in the store's default currency.
• Stock is available or unavailable only; Shopify doesn't publish exact quantities in this feed.

Use cases

• Competitor price monitoring for e-commerce brands
• Sale and restock alerts for resellers
• Catalog change tracking for market research and price-comparison sites

Need a custom version (other platforms, Google Sheets output, email alerts, historical price charts)? Contact the author.