Shopify API 2026-10 went stable on 1 October and some of it is the…

Shopify API 2026-10 went stable on 1 October and some of it is the quiet kind of breaking 🙃

Carrier services. Creating one now only registers the service, the rates are NOT added to the General shipping profile anymore. So a shipping app gets installed, everything looks fine, and checkout just doesn't show the carrier rates until someone sets them up in a shipping profile.

Inventory. ITEM_NOT_STOCKED_AT_LOCATION is gone from the adjust / move / set on hand mutations. If your sync code was waiting for that error, it will wait forever.

Metafield filters. Filter products by a metafield that isn't set up for filtering and you get an error now. Before it was silently ignored, so some "working" queries were never really working 😅

The boring but useful version is here: https://shopify.dev/changelog/release-notes/2026-10

Merchants, if a shipping or stock app starts acting weird in the next weeks, it's probably not you. Ask your developer which API version they are on. Devs, you know what to do 🤷‍♂️