Shopify's Market.metafields will match keys in any case from API 2027-01

Shopify has changed how the Market.metafields field matches keys. Starting with Storefront API version 2027-01, the field returns a metafield when the requested key matches the stored key in any letter case. Market.metafield already works this way. Shopify published the change on November 13, 2026.

Until now, Market.metafields returned a metafield only when the requested key and the stored key had the same case. For example, if a market stores a metafield with the namespace custom and the key colour, a request for { namespace: "custom", key: "Colour" } returns null in version 2026-10 and earlier. In version 2027-01, the same request returns the stored metafield. Versions 2026-10 and earlier do not change.

The change is breaking for apps and custom storefronts that query metafields on a Market object, whether through Localization.market or Country.market, when they use version 2027-01 or later. It affects apps that request a key in a different case from the one the market stores, or that read keys that a buyer’s markets store with differing letter case. Apps that request each key in its stored case, or that use only Market.metafield, are not affected.

Why it matters

Before this change, Market.metafield and Market.metafields could return different results for the same key. Market.metafield found the metafield, while Market.metafields returned null. In 2027-01, both fields return the same metafield, so a storefront shows the same value no matter which field it queries.

What to do

Review your Market.metafields queries before moving an app or storefront to 2027-01, especially if any keys are requested in mixed case. Market.metafield already matches keys case-insensitively and returns the metafield from the buyer’s most specific market, so on your current version it returns the result that Market.metafields will return in 2027-01. Compare the two fields to see whether the change affects you, and confirm details on Shopify’s developer site before you upgrade.