cart/add README example uses variant.id, which returns the Craft element ID instead of the Shopify variant ID (v7)

[rjgux]

Summary

The README's "add products to the cart" example posts variant.id to the cart/add endpoint:

<form action="{{ craft.shopify.store.getUrl('cart/add') }}" method="post">
  <select name="id">
    {% for variant in product.getVariants() %}
      <option value="{{ variant.id }}">{{ variant.title }}</option>
    {% endfor %}
  </select>
  {{ hiddenInput('qty', 1) }}
  <button>Add to Cart</button>
</form>

In v7, variant.id is the Craft element/row ID, not a Shopify identifier. Submitting this form sends e.g. id=7271 to the store, and Shopify responds:

Cart Error: Cannot find variant

Root cause

In v7 a variant is a craft\shopify\models\Variant (@since 7.0.0), where:

public ?int $id = null;           // Craft row/element ID, e.g. 7271
public ?string $shopifyId = null; // Shopify GID, e.g. gid://shopify/ProductVariant/55602221973830

So variant.id is never a Shopify identifier. The Shopify ID is on variant.shopifyId, but it's a GID (gid://shopify/ProductVariant/<numeric>), whereas the cart/add endpoint expects the bare numeric variant ID. The plugin itself strips this prefix elsewhere — see src/fieldlayoutelements/VariantsField.php:

str_replace('gid://shopify/ProductVariant/', '', $variant->shopifyId)

This confirms shopifyId is a GID and there is no first-class numeric accessor on Variant.

Product vs. Variant inconsistency (related)

Products and variants are stored differently, and expose shopifyId differently:

	Storage	Numeric ID exposed?	GID exposed?
Product	shopify_products table	✅ shopifyId (numeric)	✅ shopifyGid
Variant	shopify_data (type = ProductVariant)	❌ none	✅ shopifyId (the GID)

So product.shopifyId is a clean numeric, but variant.shopifyId is a GID — same property name, different shape — and variants have no numeric equivalent.

Suggested fixes (either/both)

1. Docs: update the README cart/add example to use the numeric portion of the variant's Shopify ID:

   <option value="{{ variant.shopifyId|split('/')|last }}">{{ variant.title }}</option>

2. API (preferred): make Variant consistent with the Product element — expose a numeric shopifyId (and a shopifyGid for the GID) — so consumers don't have to string-split a GID for a documented, common workflow.

Environment

• craftcms/shopify 7.1.2
• Craft CMS 5.10.x
• PHP 8.3

[linear-code]

PT-3147

[nfourtythree]

Hi @rjgux

Thank you for reporting this. We have just released a new major version of the plugin, version 8.0. This takes a significant step to aligning all of the Shopify properties so there is complete consistency between ID and GID across the elements and models.

Please take care when upgrading to this version as a number of things have changed. Please consult the CHANGELOG and README to see if any of the changes affect your development/project.

Thanks!