Reference implementations, with the limits written down

Known limits

Pagination

The catalog is served in fixed pages, and the channel must be configured with one fetch URL per page.

Derivation

Attributes are derived by ordered literal phrase matching over product text, so the first matching rule wins.

Truncation

A template cannot detect or report a response that was cut short, so a partial fetch reads as a complete catalog.

Currency

One rendered feed carries the one market and currency the storefront rendered it in.

Zero prices

Variants priced at or below zero are dropped from the feed with no record that they were dropped.

Known limits

Carrier variant

Every price tier needs a real carrier variant; the Function cannot create or select that cart line.

Allocation

Equal component allocation misstates line value when selected items have different economic weights.

Selling plans

Selling plan lines cannot be expanded, so this contract cannot price subscription kits.

Stale IDs

Stale component IDs are detected only when Shopify applies the expansion.

Currency

The money model supports only presentment currencies with two decimal places.

Known limits

Repair

The Validation Function can block an invalid kit but cannot remove, repair, or change the parent relationships of its lines.

Error detail

Multiple invalid kits produce one generic cart error instead of repair instructions for each instance.

Nesting depth

The contract relies on parent relationships limited to one level and cannot represent modules nested beneath other modules.

Catalog IDs

Carrier policies authorize current variant IDs, so catalog replacements require policy migration before old IDs are retired.

Known limits

Tree size

The whole option tree is serialised into the page, so its weight scales with the catalog rather than with what the shopper selects.

Price range

Price ranges shown before a configuration is complete are authored alongside the tree, not read from the products behind it.

Stale leaves

Nothing verifies that a leaf still points at a product that exists.

Inventory

Availability is not part of the tree, so an unbuildable configuration is offered like any other.

Authoring

A theme cannot run validation when a merchant saves the tree, so a malformed branch is only detected when it is rendered.

Known limits

Data access

The search template can expose only catalog data available to the storefront.

Route caching

Cache behavior for alternate search views still needs a two request check on each deployed theme.

Projection size

Each response returns at most 120 option rows, so larger families need narrower requests.

Variant access

Products whose complete variant arrays are unavailable return an error and need a different data path.

Known limits

Selection state

Protected sets reopen as a clean configurator and never restore their historical selections.

Account surface

The order action is available only in Shopify's new customer accounts, not classic account templates.

Handoff trust

The URL fragment handoff is validated but not authenticated, so it cannot carry privileged variants, prices, or discounts.

Availability

Catalog availability checked on the order page is not an inventory reservation and can change before Cart Ajax runs.

Storefront origin

Configurator destinations must share the primary storefront origin.

Known limits

Gift insertion

The Discount Function cannot add a missing gift line; the shopper or storefront must put an eligible sample in the cart.

Shopper intent

When several samples qualify, the Function discounts the cheapest one rather than preserving shopper intent.

Nested lines

Nested merchandise can neither qualify nor receive the manual gift discount.

Product lists

The lists of allowed qualifier and gift products are capped at 50 product IDs each.

Combinations

Discount combinations remain an administrative policy outside this evaluator.