Internationalization

Internationalization ships with @astryxdesign/core. There is nothing to install. Wrap your app in <InternationalizationProvider> and set the active locale; astryx components pick up localized strings from that provider.

tsx
import {InternationalizationProvider} from '@astryxdesign/core/i18n';
​
function App() {
  return (
    <InternationalizationProvider locale="en">
      <YourApp />
    </InternationalizationProvider>
  );
}

The provider always has the built-in English catalog. Pass additional catalogs through messages when you enable another locale.

tsx
import {InternationalizationProvider} from '@astryxdesign/core/i18n';
import fr from '@astryxdesign/core/locales/fr.json';
​
<InternationalizationProvider locale="fr" messages={{fr}}>
  <App />
</InternationalizationProvider>;

Astryx ships English today, with first-party translations for other locales on the roadmap. Until a locale is available from @astryxdesign/core/locales/*, apps can pass a local catalog with the same shape. See @astryxdesign/core/locales/en.json for the current key inventory. Missing keys fall back through the locale chain to English (for example, pt-BR walks to pt, then to shipped en).

Locale catalogs only affect astryx strings. Your app can continue using its own i18n system for product copy.

Re-render <InternationalizationProvider> with a new locale prop and every astryx string updates live. No reload, no separate API call.

tsx
const [locale, setLocale] = useState<'en' | 'fr'>('en');
​
<InternationalizationProvider locale={locale} messages={{fr}}>
  <Button
    label={locale === 'en' ? 'Français' : 'English'}
    onClick={() => setLocale(l => (l === 'en' ? 'fr' : 'en'))}
  />
  <App />
</InternationalizationProvider>;

Persisting the user's choice (localStorage, cookie, URL segment, account setting) is up to the consumer. Astryx reads whatever locale you pass in.

Use overrides to change individual strings without shipping a full catalog. Overrides are keyed by locale and merged on top of the built-in and user-supplied catalogs.

tsx
<InternationalizationProvider
  locale="en"
  overrides={{en: {'@astryx.pagination.next': 'Next →'}}}
>
  <App />
</InternationalizationProvider>

Overrides win over both bundled English and any messages catalog for the same key. Use them for brand voice tweaks or one-off wording changes.

Astryx components render astryx strings through astryx's provider. Consumer components render consumer strings through whatever i18n library you already use: react-intl, i18next, next-intl, LinguiJS, and so on. The two systems coexist and read from the same source of truth for the active locale.

tsx
import {InternationalizationProvider} from '@astryxdesign/core/i18n';
import {Selector} from '@astryxdesign/core/Selector';
import {Button} from '@astryxdesign/core/Button';
import {FormattedMessage, IntlProvider, useIntl} from 'react-intl';
import astryxFr from './locales/astryx/fr.json'; // astryx's UI, in French
import appFr from './locales/app/fr.json';       // your app strings, in French
​
function Pricing() {
  // Consumer strings — resolved by react-intl.
  const intl = useIntl();
​
  return (
    <section>
      <h1><FormattedMessage id="pricing.heading" /></h1>
​
      {/* Astryx Selector — trigger placeholder, search-box placeholder,
          clear-button aria-label all resolved by
          <InternationalizationProvider>. Options come from react-intl. */}
      <Selector
        label={intl.formatMessage({id: 'pricing.region.label'})}
        options={[
          {value: 'na', label: intl.formatMessage({id: 'pricing.region.na'})},
          {value: 'eu', label: intl.formatMessage({id: 'pricing.region.eu'})},
        ]}
        hasSearch
        hasClear
      />
​
      <Button label={intl.formatMessage({id: 'pricing.cta.subscribe'})} />
    </section>
  );
}
​
export default function App() {
  return (
    // Same locale, two providers reading their own catalogs.
    <IntlProvider locale="fr" messages={appFr}>
      <InternationalizationProvider locale="fr" messages={{fr: astryxFr}}>
        <Pricing />
      </InternationalizationProvider>
    </IntlProvider>
  );
}

Keep the two providers in sync on locale, and each library owns its own catalog. Astryx never sees your app strings, and your i18n library never sees astryx internals. Runtime locale swap works the same way: re-render both providers with a new locale prop and the whole tree updates live.

Single-catalog usage (where an external i18n runtime like react-intl or i18next resolves both your app strings AND astryx's strings through one provider) is on the roadmap via a Translator adapter. Track facebook/astryx#4029. For now, run the two providers side by side as shown above.

For production apps with substantial localization needs, we recommend a dedicated i18n library such as react-intl, i18next, next-intl, or LinguiJS. If your app is small or you do not want another runtime, you can resolve your own strings through astryx too. Keep app keys in a separate namespace from @astryx.*, and include your own en catalog because astryx's built-in English fallback only contains astryx component strings.

tsx
import {Button} from '@astryxdesign/core/Button';
import {
  InternationalizationProvider,
  useTranslator,
  type Catalog,
  type MessagesByLocale,
} from '@astryxdesign/core/i18n';
​
const en: Catalog = {
  '@myapp.actions.save': {defaultMessage: 'Save'},
};
​
const fr: Catalog = {
  '@myapp.actions.save': {defaultMessage: 'Enregistrer'},
};
​
const messages: MessagesByLocale = {en, fr};
​
function SaveButton() {
  const t = useTranslator();
  return <Button label={t('@myapp.actions.save')} />;
}
​
export default function App() {
  return (
    <InternationalizationProvider locale="fr" messages={messages}>
      <SaveButton />
    </InternationalizationProvider>
  );
}

Catalog types a single locale file; MessagesByLocale types the map passed to messages. A catalog entry uses the same {defaultMessage, description?} shape as @astryxdesign/core/locales/en.json.

Astryx generates a pseudo locale that wraps every string in ⟦…⟧ and replaces letters with accented look-alikes. Switch to it in development to catch hardcoded astryx strings and layout issues caused by longer text.

tsx
import {InternationalizationProvider} from '@astryxdesign/core/i18n';
import pseudo from '@astryxdesign/core/locales/pseudo.json';
​
<InternationalizationProvider locale="pseudo" messages={{pseudo}}>
  <App />
</InternationalizationProvider>;

Astryx component authors read strings with useTranslator() rather than hardcoding user-facing text.

tsx
import {useTranslator} from '@astryxdesign/core/i18n';
​
function SaveButton() {
  const t = useTranslator();
  return <button>{t('@astryx.actions.save')}</button>;
}

Astryx's own strings live in packages/core/locales/en.json. New user-facing strings must go through useTranslator; this is enforced by the @astryx/no-hardcoded-i18n-string ESLint rule. See the AI contribution guide for the alias-and-resolve pattern used when adding new keys.

Crowdin is the preferred way to contribute — join a language, translate strings in the web UI, and your work syncs back to the repo without opening a PR. Direct PRs against packages/core/locales/*.json also work if you prefer that flow.