Message format

One small syntax, powered by native Intl underneath: plurals, gender and formatting without learning full ICU.

Interpolation

"Hola {name}"          → t('saludo', { name: 'Aron' })

Values format themselves by type: numbers via Intl.NumberFormat, dates via Intl.DateTimeFormat, strings as-is. A missing param shows the placeholder literally, so it's easy to spot and never a crash.

Formatters

Append :formatter (with optional /arg) to a param:

Custom formatters plug in at instance creation. The full signature is (value, locale, arg?) => string, where locale is the active locale and arg is whatever follows the / in the placeholder:

createVerbaly({
  formatters: { upper: (v) => String(v).toUpperCase() },
});
// "{word:upper}" → HOLA

Relative time, lists & units

Since 0.11.0 the format surface covers the rest of modern Intl, still with zero dependencies:

"Updated {when:relative}"       → Updated 2 hours ago · yesterday
"Ready {n:relative/day}"        → Ready in 3 days
"Works in {langs:list}"         → Works in English, Spanish, and Portuguese
"Pick {opts:list/or}"           → Pick red, green, or blue
"{d:unit/kilometer}"            → 3 km

• relative: pass a Date and the unit picks itself against now (Intl.RelativeTimeFormat with numeric: 'auto', so you get yesterday, not 1 day ago); pass a number with an explicit unit (relative/hour).
• list: arrays localize via Intl.ListFormat, conjunction by default, /or for disjunction, /unit for unit lists. Each item auto-formats per locale.
• unit: any CLDR unit id (kilometer, megabyte, liter…) through Intl.NumberFormat.
• Unknown formats and invalid units warn once and fall back to String(value), so nothing crashes at render time.

Plurals and selects: one syntax

"{count | =0: sin mensajes | one: un mensaje | other: # mensajes}"
"{gender | male: él | female: ella | other: elle}"

• Numbers match =N exact values first, then Intl.PluralRules categories (zero one two few many other).
• Strings match their variant key, falling back to other.
• # renders the number, locale-formatted. Variants nest placeholders freely.

ICU escape-hatch

Have existing ICU MessageFormat strings, or need its exact syntax? Write ICU and Verbaly detects it automatically and parses it into the same engine, with zero extra dependencies.

"{count, plural, one {# item} other {# items}}"
"{gender, select, male {he} female {she} other {they}}"
"{n, selectordinal, one {#st} two {#nd} few {#rd} other {#th}}"

• Auto-detected per message: no config, no marker. Native and ICU messages coexist in the same catalog.
• Supports plural, select, selectordinal (real ordinal rules), {n, number/date/time, style}, #, =N, nesting and '…' quoting.
• Prefer the native syntax by default; reach for ICU only when you need it.

Escapes