{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "AI Extraction Checkup response shape — synthetic-invoice-000147",
  "type": "object",
  "additionalProperties": false,
  "required": [
    "invoice_id",
    "invoice_date",
    "currency",
    "seller",
    "buyer",
    "line_items",
    "subtotal",
    "discount_rate",
    "discount_amount",
    "taxable_amount",
    "tax_rate",
    "tax_amount",
    "shipping",
    "total"
  ],
  "properties": {
    "invoice_id": {
      "type": [
        "string",
        "null"
      ],
      "description": "A string when known; null if unreadable. See the versioned comparison contract."
    },
    "invoice_date": {
      "type": [
        "string",
        "null"
      ],
      "description": "A real calendar date in YYYY-MM-DD; null if unreadable."
    },
    "currency": {
      "type": [
        "string",
        "null"
      ],
      "description": "A string when known; null if unreadable. See the versioned comparison contract."
    },
    "seller": {
      "type": [
        "string",
        "null"
      ],
      "description": "A string when known; null if unreadable. See the versioned comparison contract."
    },
    "buyer": {
      "type": [
        "string",
        "null"
      ],
      "description": "A string when known; null if unreadable. See the versioned comparison contract."
    },
    "subtotal": {
      "type": [
        "string",
        "null"
      ],
      "description": "A string when known; null if unreadable. See the versioned comparison contract."
    },
    "discount_rate": {
      "type": [
        "string",
        "null"
      ],
      "description": "Unsigned decimal fraction, such as 0.05 for 5%, expressed as a JSON string; null if unreadable."
    },
    "discount_amount": {
      "type": [
        "string",
        "null"
      ],
      "description": "Positive magnitude to subtract from subtotal, despite the negative adjustment printed on the invoice. Use two decimal places; null if unreadable."
    },
    "taxable_amount": {
      "type": [
        "string",
        "null"
      ],
      "description": "A string when known; null if unreadable. See the versioned comparison contract."
    },
    "tax_rate": {
      "type": [
        "string",
        "null"
      ],
      "description": "Unsigned decimal fraction, such as 0.05 for 5%, expressed as a JSON string; null if unreadable."
    },
    "tax_amount": {
      "type": [
        "string",
        "null"
      ],
      "description": "A string when known; null if unreadable. See the versioned comparison contract."
    },
    "shipping": {
      "type": [
        "string",
        "null"
      ],
      "description": "A string when known; null if unreadable. See the versioned comparison contract."
    },
    "total": {
      "type": [
        "string",
        "null"
      ],
      "description": "A string when known; null if unreadable. See the versioned comparison contract."
    },
    "line_items": {
      "type": "array",
      "items": {
        "type": "object",
        "additionalProperties": false,
        "required": [
          "line_id",
          "item_id",
          "description",
          "quantity",
          "unit_price",
          "line_total"
        ],
        "properties": {
          "line_id": {
            "type": [
              "string",
              "null"
            ],
            "description": "Preserve the printed line ID and leading zeroes. A missing/null or duplicated ID cannot be aligned by guessing."
          },
          "item_id": {
            "type": [
              "string",
              "null"
            ],
            "description": "A string when known; null if unreadable. See the versioned comparison contract."
          },
          "description": {
            "type": [
              "string",
              "null"
            ],
            "description": "A string when known; null if unreadable. See the versioned comparison contract."
          },
          "quantity": {
            "type": [
              "string",
              "null"
            ],
            "description": "A string when known; null if unreadable. See the versioned comparison contract."
          },
          "unit_price": {
            "type": [
              "string",
              "null"
            ],
            "description": "A string when known; null if unreadable. See the versioned comparison contract."
          },
          "line_total": {
            "type": [
              "string",
              "null"
            ],
            "description": "A string when known; null if unreadable. See the versioned comparison contract."
          }
        }
      },
      "maxItems": 20,
      "description": "Rows are matched by unique printed line_id, not by array position. Null row fields disclose uncertainty. The fixed answer has four rows."
    }
  },
  "description": "Fixed exercise response shape. Null discloses uncertainty and does not pass a field check. Value, decimal/date format and row-identity checks are performed by the comparator."
}