{
  "type": "object",
  "additionalProperties": false,
  "properties": {
    "interchangeControlNumber": {
      "type": "string",
      "description": "ISA13 interchange control number"
    },
    "interchangeSenderId": {
      "type": "string",
      "description": "ISA06 sender id"
    },
    "interchangeReceiverId": {
      "type": "string",
      "description": "ISA08 receiver id"
    },
    "groupControlNumber": {
      "type": "string",
      "description": "GS06 functional group control number"
    },
    "functionalIdentifierCode": {
      "type": "string",
      "description": "GS01 functional identifier code, e.g. PO"
    },
    "transactionSetControlNumber": {
      "type": "string",
      "description": "ST02 transaction set control number"
    },
    "transactionSetCode": {
      "type": "string",
      "description": "ST01 transaction set code, e.g. 850"
    },
    "purchaseOrderNumber": {
      "type": "string",
      "description": "BEG03 purchase order number"
    },
    "purchaseOrderTypeCode": {
      "type": "string",
      "description": "BEG02 purchase order type code, e.g. SA"
    },
    "purchaseOrderDate": {
      "type": "string",
      "format": "date",
      "description": "BEG05 purchase order date in YYYY-MM-DD"
    },
    "requestedDeliveryDate": {
      "type": "string",
      "format": "date",
      "description": "DTM date qualifier 001 requested date in YYYY-MM-DD"
    },
    "shipToName": {
      "type": "string",
      "description": "N1 name for ship-to (entity code ST)"
    },
    "shipToIdCode": {
      "type": "string",
      "description": "N1 identification code for ship-to"
    },
    "shipToStreet": {
      "type": "string",
      "description": "N3 ship-to street address"
    },
    "shipToCity": {
      "type": "string",
      "description": "N4 ship-to city"
    },
    "shipToState": {
      "type": "string",
      "description": "N4 ship-to state"
    },
    "shipToZip": {
      "type": "string",
      "description": "N4 ship-to postal code"
    },
    "lineItems": {
      "type": "array",
      "description": "one entry per PO1 segment",
      "items": {
        "type": "object",
        "additionalProperties": false,
        "properties": {
          "lineNumber": {
            "type": "integer",
            "description": "PO1 assigned line item number"
          },
          "quantity": {
            "type": "number",
            "description": "PO1 quantity ordered"
          },
          "unitOfMeasure": {
            "type": "string",
            "description": "PO1 unit of measure code, e.g. EA"
          },
          "unitPrice": {
            "type": "number",
            "description": "PO1 unit price"
          },
          "buyerItemId": {
            "type": "string",
            "description": "buyer item identifier following the CB qualifier"
          },
          "vendorItemId": {
            "type": "string",
            "description": "vendor item identifier following the VN qualifier"
          }
        },
        "required": [
          "lineNumber",
          "quantity",
          "unitOfMeasure",
          "unitPrice"
        ]
      }
    },
    "lineItemCount": {
      "type": "integer",
      "description": "CTT total number of line items"
    }
  },
  "required": [
    "transactionSetCode",
    "purchaseOrderNumber",
    "lineItems",
    "lineItemCount"
  ]
}