Shopify Functions API metafield missing? Prove the owner, input query, API version, and active Function.

Use this page when the Functions API input never includes the metafield at all: omitted from the query, wrong owner path, unsupported on the Functions API version, or not present on the resource the Function receives. If the field is selected but empty/null, use Functions metafield blank. If the WASM binary fails to load, use Functions WASM failing.

Capture Function handle, Functions API version, input owner, namespace.key, and the Partner / Admin place the Function should consume the value before re-uploading WASM.

Confirm whether the field belongs to cart, cart line, product, variant, customer, company, shop, or another owner the Functions API input query documents for your Function type. A shop metafield will not appear because the Function selects a line-level key. Record one synthetic test resource and its ID.

Copy the exact namespace.key, including case. Do not create a duplicate definition because its label looks identical in Admin Custom data. Distinct from cart transform metafield missing when you are debugging a different Function API type.

Record the definition type, list or reference shape, and whether Admin / Apps access is enabled for the surfaces the Functions API uses. Save one unmistakable, reversible test value on the exact owner, refresh Admin, and confirm it persists. If Admin itself has no value, the Function will correctly see a miss.

Keep customer data, tokens, and passwords out of screenshots. Treat an absent field, null, empty string, and empty list as separate observations from a field the query never selected.

Open the Function's input query (or app TOML) and confirm which namespace.key it selects under the current Functions API version. Separate: query never selects the field, query selects a different owner, type unsupported on this API version, stale deployed version, or Function not activated on the target discount / checkout / delivery customization.

Keep the diagnosis distinct from Theme App Extensions API metafield blank and Functions discount not applying. Those touch theme blocks and discount outcome, not Functions API input selection.

Use one cart or checkout, one Function handle, one Functions API version, and one known owner. Record owner ID, namespace.key, type, saved test value, access flags, input query snippet, API version, active version ID, and Partner Dashboard / Function run evidence. Hard-refresh only after the first trace is captured.

Classify the miss as owner, definition/value, access, input query, API version mismatch, stale activation, or WASM/discount instead. Keep it separate from Scripts-to-Functions migration leftovers.

Stay DIY when one owner, access, input-query, API-version, or active-Function check explains the missing field. Keep the proof packet so future Functions API changes are reversible.

Pay for the $997 one-time install when several Shopify surfaces, apps, and ops alerts need to be wired and documented on one live store. Nico at Latch AI Ops can connect the agreed workflow in a 72-hour window after collaborator access. No earnings claim, conversion guarantee, or theme rebuild is included; owner passwords are not requested.