Monify

Small, zero-dependency TypeScript utilities for locale-aware currency and unit formatting. Monify is built on the standard Intl.NumberFormat API, ships its own types, and works in Node.js and modern browsers.

Install

npm install monify-ts

Currency formatting

import { format, formatCurrency } from "monify-ts";

formatCurrency(1_234_567.89, { currency: "USD" });
// "$1,234,567.89"

formatCurrency(1_234_567.89, { currency: "IDR" });
// "Rp 1.234.567,89"

formatCurrency(1_500_000, {
  currency: "USD",
  compact: true,
  decimalDigits: 1,
});
// "$1.5M"

format(1_234.5, {
  currency: "EUR",
  locale: "de-DE",
  decimalDigits: 1,
});
// "1.234,5 €"

formatCurrency(amount, options) is the recommended API. format accepts the same options and continues to support the positional API from Monify 1.0.

Currency options

| Option | Type | Default | Description | | --- | --- | --- | --- | | currency | string | "USD" | ISO 4217 currency code | | locale | string | inferred | BCP 47 locale | | compact | boolean | false | Use compact notation | | decimalDigits | number | currency default | Fraction digits, from 0 to 20 | | useSpacing | boolean | true | Keep spacing around the symbol | | currencyDisplay | Intl option | "symbol" | Symbol, narrow symbol, code, or name | | compactDisplay | Intl option | "short" | Short or long compact notation |

Currency locale inference is provided for 41 common currencies. Any valid currency and locale supported by the runtime can still be passed explicitly.

Unit formatting

import { formatUnit } from "monify-ts";

formatUnit(1_000, "kilometer");
// "1,000 km"

formatUnit(1_234.56, "liter", {
  locale: "en-US",
  thousandSeparator: "_",
  decimalDigits: 1,
  unitDisplay: "long",
});
// "1_234.6 liters"

The legacy formatUnit(value, unit, locale, thousandSeparator) signature is also supported.

Compatibility

• Node.js 18 or newer
• Modern browsers with Intl.NumberFormat
• CommonJS (require) and TypeScript/ES module imports
• No runtime dependencies

Output can differ slightly between runtime versions because locale data is provided by the JavaScript engine.

Development

npm test
npm run build
npm run check

License

MIT