List custom field definitions

import { createAdminClient } from '@spree/admin-sdk'

const client = createAdminClient({
  baseUrl: 'https://your-store.com',
  secretKey: 'sk_xxx',
})

const { data: definitions } = await client.customFieldDefinitions.list({
  q: { resource_type_eq: 'Spree::Product' },
})

{
  "data": [
    {
      "id": "cfdef_UkLWZg9DAJ",
      "namespace": "specs",
      "key": "fabric",
      "label": "Title",
      "field_type": "short_text",
      "resource_type": "Spree::Product",
      "storefront_visible": true,
      "created_at": "2026-05-24T17:36:36.857Z",
      "updated_at": "2026-05-24T17:36:36.857Z"
    },
    {
      "id": "cfdef_gbHJdmfrXB",
      "namespace": "custom",
      "key": "order_notes",
      "label": "Order Notes",
      "field_type": "short_text",
      "resource_type": "Spree::Order",
      "storefront_visible": true,
      "created_at": "2026-05-24T17:36:36.857Z",
      "updated_at": "2026-05-24T17:36:36.857Z"
    }
  ],
  "meta": {
    "page": 1,
    "limit": 25,
    "count": 2,
    "pages": 1,
    "from": 1,
    "to": 2,
    "in": 2,
    "previous": null,
    "next": null
  }
}