Header field values of the ACTIVE purchase order template version, as an array of {field_key, value} pairs. Only custom (non-predefined, non-computed) field keys are accepted; predefined fields (vendor, order_date, currency, due_date, payment_method, legal_entity) are populated from the corresponding top-level parameters. Reference fields (employee, cost_center, project, tax_rate, team) take the referenced internal id as the value. If a field_key appears more than once, the last occurrence wins.

Line items of the purchase order, each carrying its values as an array of {field_key, value} pairs addressed by the line-item field keys of the ACTIVE template version (e.g. concept, quantity, unit_price, tax_rate). Computed keys (subtotal, tax_amount, total, discount_amount) are derived server-side and rejected as input.