Following is the data specification for a invoice that is extracted from accounting OSPs.
invoices endpoint for a connection returns an array of invoices. The
data is the key for an invoice.
Individual line items can be found for each invoice under the `line_items`` key.
|Field||Data Type||Data Type|
|transaction_outstanding_amount||number||Total outstanding invoice amount|
|currency_rate||number||Currency rate between the currency of the invoice and the base currency of the business|
|transaction_date||date||Date on which the invoice was issued|
|transaction_due_date||date||Date on which the invoice is due|
|transaction_status||string||Status of the invoice (Paid, Unpaid)|
|transaction_reference||string||Unique identifier of the invoice on OSP's end|
|transaction_currency||string||Currency in which the invoice was issued|
|transaction_gross_value||number||Total invoice amount|
|line_items||LineItem||An array of line items as defined below|
|product_name||string||Name of the product or service being sold|
|system_id||system_id||Unique identifier of the line item on 9Spokes' end|
|item_identifier||string||Unique identifier of the line item on the app's end|
|item_category||string||Account category under which the transaction item was originally listed|
|item_type||string||'invoice' when the osp is an accounting app and 'good-service' when the osp is a point of sale app|
|item_net_unit_sale_value||number||Net sale value per item|
|item_net_unit_discount_value||number||Net discount value per item|
|item_unit_tax_value||number||Tax value per item|
|item_price_list_reference||string||Reference to any pre-set discounting based upon specific price lists (specials, happy hour, etc.)|
|item_total_gross_value||number||Total gross value of the item (before tax)|