billing-kit

Billing primitives on top of decimal-money.

• Re-exports Currency, CurrencyAmount, MoneyError
• Price — net + tax_rate% (VAT), with gross(), tax_amount(), discount_of_gross(), gross_minus_discount()

Quick start

use billing_kit::{Price, Currency};
use rust_decimal_macros::dec;

let p = Price::new(dec!(100), Currency::GBP, dec!(20)).unwrap();
assert_eq!(p.gross().amount, dec!(120));

Assessment vs ecom-engine

ecom-core::Money now wraps CurrencyAmount (GBP) internally; billing-kit is not required for the GBP migration (which preserved Money(Decimal) storage + sqlx(transparent)). Scaffold this crate when extracting promo/insurance/VAT math from ecom-http into a shared billing crate.