@core / money

1.0.1 ▾

1.0.1

verifiziertMIT

GitHub

Geld als Ganzzahlen (Cent): ISO-Währungen, sicheres Parsen, Rundung, verlustfreie Aufteilung, .99-Preise, Format

Code4 DateienKontext~423 TokensPrüfung bestanden

~423 Tokens→ src/lib/money/AGENTS.md→ .cursor/rules/genpm-core-money.mdc

Genau das liest deine KI, wenn sie in src/lib/money arbeitet. Sonst wird ihrem Kontext nichts hinzugefügt.

@core/money — rules for AI agents

Purpose

Money as { amount, currency } with amount an integer of minor units (cents) and an ISO 4217 code, so commerce modules never use floats. Parsing from decimal strings, safe arithmetic that refuses mixed currencies, rounding, percentages, lossless allocation (splitting a discount across lines), charm prices (.99, never below the input; …9 in zero-decimal currencies), formatting with Intl and conversion with a rates table. Pure functions: no tables, no network.

Map

index.ts — public API: money, parseMoney, add, sub, sum, multiply, percent, allocate, charmPrice, format, toDecimalString, convert, currencyDecimals.
money.ts — implementation. The Money type comes from @core/contracts.

Integration

Nothing to configure. Store money in two columns: amount integer (minor units) and currency text.
User input: parseMoney('19,99', 'EUR') (never Number(input) * 100).
Display: format(price, locale); APIs/JSON-LD: toDecimalString(price).
Split amounts: allocate(discount, lines.map((l) => l.subtotal.amount)).
Verify: add(money(1, 'EUR'), money(1, 'USD')) throws.

Conventions

All arithmetic through these helpers; JPY has 0 decimals and KWD 3, so never assume 100.
Percentages round half-up by default; pass 'half-even' where your accounting requires it.
Exchange rates are inputs (store the rate used with each order); this module does not fetch them.

Don't

Don't use floats for prices, totals or taxes, and don't add amounts of different currencies.
Don't round intermediate results before the final step unless the business rule says so.

# @core/money — rules for AI agents

## Purpose
Money as `{ amount, currency }` with `amount` an integer of minor units (cents) and an ISO 4217 code, so commerce
modules never use floats. Parsing from decimal strings, safe arithmetic that refuses mixed currencies, rounding,
percentages, lossless allocation (splitting a discount across lines), charm prices (`.99`, never below the input; `…9` in zero-decimal currencies), formatting with `Intl`
and conversion with a rates table. Pure functions: no tables, no network.

## Map
- `index.ts` — public API: `money`, `parseMoney`, `add`, `sub`, `sum`, `multiply`, `percent`, `allocate`, `charmPrice`, `format`, `toDecimalString`, `convert`, `currencyDecimals`.
- `money.ts` — implementation. The `Money` type comes from @core/contracts.

## Integration
1. Nothing to configure. Store money in two columns: `amount integer` (minor units) and `currency text`.
2. User input: `parseMoney('19,99', 'EUR')` (never `Number(input) * 100`).
3. Display: `format(price, locale)`; APIs/JSON-LD: `toDecimalString(price)`.
4. Split amounts: `allocate(discount, lines.map((l) => l.subtotal.amount))`.
5. Verify: `add(money(1, 'EUR'), money(1, 'USD'))` throws.

## Conventions
- All arithmetic through these helpers; JPY has 0 decimals and KWD 3, so never assume 100.
- Percentages round half-up by default; pass `'half-even'` where your accounting requires it.
- Exchange rates are inputs (store the rate used with each order); this module does not fetch them.

## Don't
- Don't use floats for prices, totals or taxes, and don't add amounts of different currencies.
- Don't round intermediate results before the final step unless the business rule says so.

Der genaue Baum, der nach .genpmignore eingebunden wird. Gepinnt an

src/lib/money/LICENSEschreibgeschützt · e980a84

MIT License

Copyright (c) 2026 GenPM

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.