curl --request GET \
  --url https://{defaultHost}/v1/auto_fees/rule_schema/{fee_target} \
  --header 'Authorization: Bearer <token>'

{
  "object": "rule_schema",
  "schema_id": "auto_fee__line_item",
  "attributes": [
    {
      "key": "quantity",
      "metadata": false,
      "supported_values": [],
      "type": "numeric",
      "operators": [
        "is",
        "is_not",
        "is_more_than",
        "is_less_than",
        "is_at_least",
        "is_at_most"
      ]
    },
    {
      "key": "subtotal_amount",
      "metadata": false,
      "supported_values": [],
      "type": "numeric",
      "operators": [
        "is",
        "is_not",
        "is_more_than",
        "is_less_than",
        "is_at_least",
        "is_at_most"
      ]
    },
    {
      "key": "note",
      "metadata": false,
      "supported_values": [],
      "type": "string",
      "operators": [
        "is",
        "is_not",
        "contains",
        "not_contains",
        "start_with",
        "end_with"
      ]
    },
    {
      "key": "customer_prior_product_purchase_quantity",
      "metadata": false,
      "supported_values": [],
      "type": "numeric",
      "operators": [
        "is",
        "is_not",
        "is_more_than",
        "is_less_than",
        "is_at_least",
        "is_at_most"
      ]
    },
    {
      "key": "sku",
      "metadata": false,
      "supported_values": [],
      "type": "string",
      "operators": [
        "is",
        "is_not",
        "contains",
        "not_contains",
        "start_with",
        "end_with"
      ]
    },
    {
      "key": "checkout.metadata",
      "metadata": true,
      "supported_values": [],
      "type": "string",
      "operators": [
        "is",
        "is_not",
        "contains",
        "not_contains",
        "start_with",
        "end_with"
      ]
    },
    {
      "key": "checkout.subtotal_amount",
      "metadata": false,
      "supported_values": [],
      "type": "numeric",
      "operators": [
        "is",
        "is_not",
        "is_more_than",
        "is_less_than",
        "is_at_least",
        "is_at_most"
      ]
    },
    {
      "key": "checkout.email",
      "metadata": false,
      "supported_values": [],
      "type": "string",
      "operators": [
        "is",
        "is_not",
        "contains",
        "not_contains",
        "start_with",
        "end_with"
      ]
    },
    {
      "key": "checkout.email_domain",
      "metadata": false,
      "supported_values": [],
      "type": "string",
      "operators": [
        "is",
        "is_not",
        "contains",
        "not_contains",
        "start_with",
        "end_with"
      ]
    },
    {
      "key": "checkout.first_name",
      "metadata": false,
      "supported_values": [],
      "type": "string",
      "operators": [
        "is",
        "is_not",
        "contains",
        "not_contains",
        "start_with",
        "end_with"
      ]
    },
    {
      "key": "checkout.last_name",
      "metadata": false,
      "supported_values": [],
      "type": "string",
      "operators": [
        "is",
        "is_not",
        "contains",
        "not_contains",
        "start_with",
        "end_with"
      ]
    },
    {
      "key": "checkout.order_type",
      "metadata": false,
      "supported_values": [
        "checkout",
        "subscription"
      ],
      "type": "string",
      "operators": [
        "is",
        "is_not",
        "contains",
        "not_contains",
        "start_with",
        "end_with"
      ]
    },
    {
      "key": "customer.created_at",
      "metadata": false,
      "supported_values": [],
      "type": "date",
      "operators": [
        "is",
        "is_not",
        "is_after",
        "is_before",
        "is_on_or_after",
        "is_on_or_before"
      ]
    },
    {
      "key": "customer.order_count",
      "metadata": false,
      "supported_values": [],
      "type": "numeric",
      "operators": [
        "is",
        "is_not",
        "is_more_than",
        "is_less_than",
        "is_at_least",
        "is_at_most"
      ]
    },
    {
      "key": "price.created_at",
      "metadata": false,
      "supported_values": [],
      "type": "date",
      "operators": [
        "is",
        "is_not",
        "is_after",
        "is_before",
        "is_on_or_after",
        "is_on_or_before"
      ]
    },
    {
      "key": "price.metadata",
      "metadata": true,
      "supported_values": [],
      "type": "string",
      "operators": [
        "is",
        "is_not",
        "contains",
        "not_contains",
        "start_with",
        "end_with"
      ]
    },
    {
      "key": "price.name",
      "metadata": false,
      "supported_values": [],
      "type": "string",
      "operators": [
        "is",
        "is_not",
        "contains",
        "not_contains",
        "start_with",
        "end_with"
      ]
    },
    {
      "key": "price.recurring_period_count",
      "metadata": false,
      "supported_values": [],
      "type": "numeric",
      "operators": [
        "is",
        "is_not",
        "is_more_than",
        "is_less_than",
        "is_at_least",
        "is_at_most"
      ]
    },
    {
      "key": "price.recurring_interval",
      "metadata": false,
      "supported_values": [
        "day",
        "week",
        "month",
        "year"
      ],
      "type": "string",
      "operators": [
        "is",
        "is_not",
        "contains",
        "not_contains",
        "start_with",
        "end_with"
      ]
    },
    {
      "key": "price.price_type",
      "metadata": false,
      "supported_values": [
        "one_time",
        "finite_recurring",
        "infinite_recurring"
      ],
      "type": "string",
      "operators": [
        "is",
        "is_not",
        "contains",
        "not_contains",
        "start_with",
        "end_with"
      ]
    },
    {
      "key": "product.created_at",
      "metadata": false,
      "supported_values": [],
      "type": "date",
      "operators": [
        "is",
        "is_not",
        "is_after",
        "is_before",
        "is_on_or_after",
        "is_on_or_before"
      ]
    },
    {
      "key": "product.metadata",
      "metadata": true,
      "supported_values": [],
      "type": "string",
      "operators": [
        "is",
        "is_not",
        "contains",
        "not_contains",
        "start_with",
        "end_with"
      ]
    },
    {
      "key": "product.name",
      "metadata": false,
      "supported_values": [],
      "type": "string",
      "operators": [
        "is",
        "is_not",
        "contains",
        "not_contains",
        "start_with",
        "end_with"
      ]
    },
    {
      "key": "product.slug",
      "metadata": false,
      "supported_values": [],
      "type": "string",
      "operators": [
        "is",
        "is_not",
        "contains",
        "not_contains",
        "start_with",
        "end_with"
      ]
    },
    {
      "key": "product.product_collections.metadata",
      "metadata": true,
      "supported_values": [],
      "type": "string",
      "operators": [
        "is",
        "is_not",
        "contains",
        "not_contains",
        "start_with",
        "end_with"
      ]
    },
    {
      "key": "product.product_collections.name",
      "metadata": false,
      "supported_values": [],
      "type": "string",
      "operators": [
        "is",
        "is_not",
        "contains",
        "not_contains",
        "start_with",
        "end_with"
      ]
    },
    {
      "key": "product.product_collections.slug",
      "metadata": false,
      "supported_values": [],
      "type": "string",
      "operators": [
        "is",
        "is_not",
        "contains",
        "not_contains",
        "start_with",
        "end_with"
      ]
    },
    {
      "key": "product.product_group.metadata",
      "metadata": true,
      "supported_values": [],
      "type": "string",
      "operators": [
        "is",
        "is_not",
        "contains",
        "not_contains",
        "start_with",
        "end_with"
      ]
    },
    {
      "key": "product.product_group.name",
      "metadata": false,
      "supported_values": [],
      "type": "string",
      "operators": [
        "is",
        "is_not",
        "contains",
        "not_contains",
        "start_with",
        "end_with"
      ]
    }
  ]
}