> ## Documentation Index
> Fetch the complete documentation index at: https://docs.mercurjs.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Create an attribute

> Create a typed catalog attribute with createProductAttributesWorkflow.

In this guide, you'll learn how to create a global catalog attribute from your
own server code, for example in a seed script, a custom API route, or a catalog
import.

Mercur exposes a `createProductAttributesWorkflow` that creates one or more
`ProductAttribute` records along with their values. Run it from any place that
has access to the Medusa container.

## Run the workflow

```ts title="src/api/custom/attributes/route.ts" theme={null}
import type { MedusaRequest, MedusaResponse } from "@medusajs/framework/http"
import { createProductAttributesWorkflow } from "@mercurjs/core/workflows"

export async function POST(req: MedusaRequest, res: MedusaResponse) {
  const { result } = await createProductAttributesWorkflow(req.scope).run({
    input: {
      attributes: [
        {
          name: "Material",
          type: "single_select",
          is_filterable: true,
          values: [{ name: "Cotton" }, { name: "Wool" }, { name: "Linen" }],
        },
      ],
    },
  })

  res.status(201).json({ attribute: result[0] })
}
```

The workflow creates the attribute, its `ProductAttributeValue` records, and,
for a `multi_select` axis, the mirror `ProductOption`. It also emits the
`product-attribute.created` event.

<Note>
  Leaving `product_id` unset creates a **global** attribute reusable across the
  catalog. Passing a `product_id` creates an **inline** attribute scoped to a
  single product. See [Global vs inline](/platform/attribute/concepts/global-vs-inline).
</Note>

## Associate categories

Pass `category_ids` on an attribute to associate it with product categories
through the category link in the same call:

```ts theme={null}
await createProductAttributesWorkflow(req.scope).run({
  input: {
    attributes: [
      {
        name: "Thread count",
        type: "unit",
        category_ids: ["pcat_bedding"],
      },
    ],
  },
})
```

## Attach custom data

The workflow accepts an `additional_data` payload passed to its
`productAttributesCreated` hook, letting you persist marketplace-specific data
alongside the attribute without forking the workflow.

```ts theme={null}
await createProductAttributesWorkflow(req.scope).run({
  input: {
    attributes: [{ name: "Material", type: "single_select" }],
    additional_data: { imported_from: "legacy-pim" },
  },
})
```