Type safety

Declaring a schema

I18nService.t(), I18nPipe, and I18nCompatService.t() are fully generic once you declare your catalog schema via module augmentation.

Create a declaration file in your app (e.g. src/i18n.d.ts):

import type en from '../public/i18n/en.json';
 
declare module '@ngx-runtime-i18n/core' {
  interface I18nSchema {
    translations: typeof en;
  }
}

What you get

With the schema declared, TypeScript enforces valid keys and narrows param types:

// OK — valid key
this.i18n.t('hello.user', { name: 'Ashwin' });
 
// Error — 'does.not.exist' is not in the catalog
this.i18n.t('does.not.exist');
 
// Error — missing required param 'name'
this.i18n.t('hello.user');

Key types are computed via DeepKeys<T> (dot-notation paths up to 4 levels). Interpolation params are extracted via ExtractParams<S> from the string literal value. Both types are exported from @ngx-runtime-i18n/core for advanced usage — for example, building your own typed wrapper around t().

Without a schema

When no schema is declared (the default), t() accepts plain string, preserving full backward compatibility. You can adopt module augmentation later without changing any call sites that already pass string literals.