{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://ap2-protocol.org/schemas/types/line_item.json",
  "title": "LineItem",
  "description": "UCP line item (dev.ucp.shopping 2026-04-08). Uses nested item object for product details.",
  "type": "object",
  "required": ["id", "item", "quantity", "totals"],
  "properties": {
    "id": {
      "type": "string",
      "description": "Unique line-item identifier."
    },
    "item": {
      "$ref": "item.json"
    },
    "quantity": {
      "type": "integer",
      "description": "Quantity of the item being purchased.",
      "minimum": 1
    },
    "totals": {
      "type": "array",
      "description": "Per-line-item totals breakdown.",
      "items": { "$ref": "total.json" }
    },
    "parent_id": {
      "type": "string",
      "description": "Parent line item identifier for nested structures."
    }
  }
}