Every time the app reads something from Amazon, it has to put that information somewhere your store can use. It uses Shopify metafields. A metafield is simply a labelled piece of extra data attached to a Shopify object, in this case to your product variants.
This matters to you for two reasons. First, it is what makes the storefront features work: the Amazon Price block and the Buy on Amazon button read these metafields rather than calling Amazon on every page load, which is why your product pages stay fast. Second, it means the data is genuinely yours and sits inside your own Shopify store, where any other app, theme or export can read it.
Metafields are grouped into namespaces, which are just prefixes that keep one app's data from colliding with another's. The app uses two, and the difference is about who is allowed to read them.
The app namespace ($app:amazon) is private to the app and to your Shopify admin. It is where the app keeps its own working data. Your theme cannot read it, and that is deliberate: it keeps internal state out of your public storefront.
The storefront namespace (latasys_amazon) is readable by your theme. This is the copy your product page templates and the app's theme blocks actually use to render an Amazon price or a Buy on Amazon link to a shopper. If you want to build something custom in Liquid, this is the namespace to reach for.
You do not have to choose between them or configure anything. The app writes both and keeps them consistent.
These are written by price sync, which runs on every plan including Free.
| Metafield | What it holds |
|---|---|
amazon_asin |
The Amazon ASIN this Shopify variant is linked to. This is the anchor for everything else. It is written when you map a variant, and written back automatically when Product Sync publishes a product and Amazon assigns it an ASIN. |
amazon_price |
The current lowest New offer price on Amazon in your home marketplace. |
amazon_url |
The Amazon product URL for the home marketplace. |
amazon_buybox |
Whether you currently hold the Buy Box for this ASIN. The Buy Box is the "Add to Cart" panel on an Amazon listing, and only one seller wins it at a time. |
amazon_market_prices |
The price for every marketplace you have mapped, each in its own currency, so a German shopper can be shown the Amazon.de price. |
amazon_market_urls |
The Amazon link for each mapped marketplace, so the Buy on Amazon button sends shoppers to the right country's Amazon. |
amazon_price_synced_at |
The timestamp of the last successful sync for this variant. This is what the app uses to tell you a price is fresh or stale. |
amazon_price_history |
A rolling series of price points, capped at 60 entries. Each price sync appends one point and the oldest falls off the end. |
Alongside these, the app also tracks listing status for products you have published through Product Sync, including whether Amazon accepted the listing and whether it currently has issues, and FBA availability for SKUs that Amazon fulfils.
amazon_price_history is what draws the price sparkline on the Product Mapping rows, and it feeds the Buy Box report in Analytics. Because it keeps 60 points and one point is added per sync, the window it covers depends on your plan. On the Free plan, syncing every 24 hours, 60 points is roughly two months of daily history. On a paid plan syncing every 6 hours, 60 points is roughly fifteen days at a finer resolution.
This also explains a common surprise: a brand new install has an empty chart. History has to build up, one sync at a time. Nothing is wrong.
A metafield definition is the schema that tells Shopify what a metafield is called, what type it holds, and who is allowed to read it. If a definition goes missing, the value may still be stored but your theme can no longer see it.
Ensure definitions, in Settings > Metafields, re-creates any definition that is missing or has been altered. It is safe. It does not delete or overwrite the values already stored against your variants, and it does not touch anything on Amazon.
Run it when:
It is quick, it is idempotent, and running it when nothing is broken does no harm.
Remove definitions + data is the opposite, and it is destructive. It deletes the app's metafield definitions from your store and the Amazon data stored under them.
After you run it:
Warning
This cannot be undone. If you only want to fix a theme block that has stopped working, use Ensure definitions instead. Reach for Remove definitions + data only when you genuinely want the Amazon data out of your Shopify store.
The main legitimate reason to use it is housekeeping before you uninstall. Once the app has been removed from your store it can no longer reach in to tidy up, so anything left behind stays behind. Clear it first if you want a clean store. See Uninstalling.