Zod and texts outside components

text(translation)

text() turns one text into a function that returns it in the current language. The language is read from current when the function is called, not when it is created. So you can define it once at module level, for example in a Zod schema shared by app and backend.

text() needs current in createLang():

lang/setup.ts

export const { t, group, text, createUseLang } = createLang({
  base: 'en',
  languages: ['en', 'de'],
  current: () => getLocale(), // your store: a variable, Zustand, a Vue ref, ...
})

In the app, current should read the same state you pass to the adapter (LangProvider lang, or the Vue ref), kept outside of React so code outside of components can read it.

Zod error messages

A text function is already a valid Zod error message. Zod calls it with the values of the check (maximum, minimum, input, …). The parameter type is checked against the Zod issue, so a wrong name is a type error in the schema.

lang/validation.ts

export const validation = {
  tooLong: t((p: { maximum: number | bigint }) => `At most ${p.maximum} characters`, {
    de: (p) => `Höchstens ${p.maximum} Zeichen`,
  }),
  invalidEmail: t('Invalid email address', { de: 'Ungültige E-Mail-Adresse' }),
}

schemas.ts

export const signupSchema = z.object({
  name: z.string().max(50, { error: text(validation.tooLong) }), // 'Höchstens 50 Zeichen'
  email: z.email({ error: text(validation.invalidEmail) }),
})

• Zod types maximum and minimum as number | bigint, so declare the parameter that way.
• Texts without parameters become () => string. Zod accepts them too.
• The message is created in the language that is current at parse time. A shown error does not switch language until the field is validated again.
• Zod’s own default messages (“Expected string”) are translated by Zod: z.config(z.locales.de()).

Outside of Zod

Call the function yourself, for example in a toast from an event handler:

text(validation.invalidEmail)()
text(validation.tooLong)({ maximum: 5 })