Custom Field Mapping · API2Cart
Custom Field Mapping Across eCommerce Platforms
Every store has custom fields — Shopify metafields, WooCommerce custom attributes, Magento EAV attributes. API2Cart provides access to all of them.
Beyond standard fields, merchants heavily customize their stores — and this is often where the real business logic lives.
API2Cart exposes platform-specific custom fields through the additional_fields mechanism, giving your application full access across every platform.
How Custom Field Mapping Works in API2Cart
- response_fields parameter: request exactly the custom fields you need
- Shopify metafields: namespace, key, value, and type via product.info
- Magento 2 EAV: custom attributes returned as part of the product response
- Writable: product.update accepts additional_fields to write custom data back
Example request
?id=123&response_fields={result{product{*}}}
# Response includes:
# "additional_fields": {
# "metafield_color": "Red",
# "custom_brand": "Nike"
# }
Use Cases for Custom Field Mapping
Product Feed Enrichment
Pull custom fields (brand, material, color) into shopping feeds.
B2B Commerce
Access minimum order qty, wholesale price, company name.
Industry-Specific Data
Wine: region, vintage. Apparel: size chart. Electronics: specs.
Analytics & Segmentation
Use custom customer fields for advanced segmentation.
Frequently asked questions
The things people ask before using Custom Field Mapping.
How do I get custom fields in a product response?
Add response_fields={result{product{*}}} to your request.
Can I write custom fields back?
Yes — product.update accepts additional_fields.
Is additional_fields structured the same across platforms?
Normalized where possible; native format otherwise — nothing is lost.
Are Shopify metafield namespaces supported?
Yes — filter by namespace and key.
Access every custom field from every platform — all through one API.
Explore the full API2Cart API reference.
How do I get custom fields in a product response?
Add response_fields={result{product{*}}} to your request.
Can I write custom fields back?
Yes — product.update accepts additional_fields.
Is additional_fields structured the same across platforms?
Normalized where possible; native format otherwise — nothing is lost.
Are Shopify metafield namespaces supported?
Yes — filter by namespace and key.
