Attribute links

The Product Attribute module never references Medusa’s Product module directly. Five module links in packages/core/src/links connect them: two that store data in pivot tables and three read-only links resolved from a foreign key on one side. Resolve query from the container to read across them.

import { ContainerRegistrationKeys } from "@medusajs/framework/utils"

const query = container.resolve(ContainerRegistrationKeys.QUERY)

Product to attribute value

The values a product holds, for every attribute type. This is the link the attachment workflows write.

Property	Value
Sides	`Product` ↔ `ProductAttributeValue`
Cardinality	Many-to-many
Storage	Pivot table `product_attribute_value_link`
Aliases	`product_attribute_values` on product, `products` on value
Defined in	`product-attribute-value-pivot-link.ts`

const { data: [product] } = await query.graph({
  entity: "product",
  fields: [
    "product_attribute_values.name",
    "product_attribute_values.attribute.name",
  ],
  filters: { id: "prod_01JD8Q1234567" },
})

The query returns each linked value with its parent attribute, which is how you read a product’s full attribute selection.

Product to scoped attributes

The inline attributes created on a product. The link is read-only and resolves ProductAttribute.product_id against product.id.

Property	Value
Sides	`Product` → `ProductAttribute`
Cardinality	One-to-many
Storage	None, read-only
Alias	`scoped_attributes` on product
Defined in	`product-attribute-product-link.ts`

const { data: [product] } = await query.graph({
  entity: "product",
  fields: ["scoped_attributes.name", "scoped_attributes.values.name"],
  filters: { id: "prod_01JD8Q1234567" },
})

Attribute to category

The product categories a global attribute is offered for. An attribute with no category links is offered for every product.

Property	Value
Sides	`ProductAttribute` ↔ `ProductCategory`
Cardinality	Many-to-many
Storage	Pivot table `product_category_attribute`
Aliases	`categories` on attribute, `product_attributes` on category
Defined in	`product-attribute-category-link.ts`

const { data: attributes } = await query.graph({
  entity: "product_attribute",
  fields: ["id", "name", "categories.id", "categories.name"],
  filters: { product_id: null },
})

createProductAttributesWorkflow writes these links from category_ids. Write more yourself with the link service, using the keys product_attribute_id and product_category_id.

Attribute to product option

The Medusa ProductOption that backs a variant axis. The link is read-only and keyed on ProductAttribute.product_option_id.

Property	Value
Sides	`ProductAttribute` → `ProductOption`
Cardinality	One-to-one
Storage	None, read-only
Defined in	`product-attribute-option-mirror-link.ts`

Attribute value to option value

The Medusa ProductOptionValue that backs one value of a variant axis. The link is read-only and keyed on ProductAttributeValue.product_option_value_id.

Property	Value
Sides	`ProductAttributeValue` → `ProductOptionValue`
Cardinality	One-to-one
Storage	None, read-only
Defined in	`product-attribute-value-option-value-mirror-link.ts`

Core code reads the mirror through the foreign keys, not through these links. Do the same: read the ids from the attribute, then query the option.

const { data: [option] } = await query.graph({
  entity: "product_option",
  fields: ["id", "title", "is_exclusive", "values.id", "values.value"],
  filters: { id: attribute.product_option_id },
})

The workflows keep the mirror in step. Never write product_option_id or product_option_value_id yourself, or the attribute and its option will drift apart.

Store

Catalog

Offer

Attribute

Product Edit

Order Group

Commission

Payout

Review

Product to attribute value

Product to scoped attributes

Attribute to category

Attribute to product option

Attribute value to option value

​Product to attribute value

​Product to scoped attributes

​Attribute to category

​Attribute to product option

​Attribute value to option value

Product to attribute value

Product to scoped attributes

Attribute to category

Attribute to product option

Attribute value to option value