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

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

const fee = await client.orders.fees.create('or_abc123', {
  label: 'Gift wrap',
  amount: 4,
  kind: 'gift_wrap',
})

spree api post /orders/{order_id}/fees -d '{"label":"Gift wrap","amount":4,"kind":"gift_wrap"}'

{
  "id": "fee_UkLWZg9DAJ",
  "label": "Gift wrap",
  "kind": "gift_wrap",
  "line_item_id": null,
  "fulfillment_id": null,
  "amount": "4.0",
  "display_amount": "$4.00",
  "metadata": {},
  "created_at": "2026-01-15T12:00:00.000Z",
  "updated_at": "2026-01-15T12:00:00.000Z"
}

{
  "error": {
    "code": "validation_error",
    "message": "Kind is not included in the list",
    "details": {
      "kind": [
        {
          "value": "nonsense",
          "code": "inclusion",
          "message": "is not included in the list",
          "specific": false
        }
      ]
    }
  }
}