Add missing strings to an existing next-i18next setup

Most next-i18next projects aren't starting from zero — they have public/locales/en/common.json, namespaced useTranslation() hooks, maybe typed keys. The dangerous failure mode for any automation is writing keys somewhere your app never loads. Polyglot is built to be a guest in your catalog world instead.

The transformation

import { useTranslation } from 'next-i18next';

export default function Home() {
  const { t } = useTranslation();
  return (
    <main>
      <h1>Welcome back</h1>
      <p>{t('title')}</p>
    </main>
  );
}

import { useTranslation } from 'next-i18next';

export default function Home() {
  const { t } = useTranslation();
  return (
    <main>
      <h1>{t('welcome_back')}</h1>
      <p>{t('title')}</p>
    </main>
  );
}

Notice the call is t('welcome_back') — relative, because your component's t is bound to a namespace. Polyglot reads useTranslation('ns') arguments and keyPrefix options and generates keys that resolve through the exact translator each component binds.

Keys merge into YOUR files

{
  "title": "Meine App",
  "welcome_back": "Welcome back"
}

{
  "title": "My App",
  "welcome_back": "Welcome back"
}

• New keys land in the bound namespace file — defaultNS and localePath from next-i18next.config.js are honored.
• Your key order and formatting survive. Merges are textual edits, not a serializer round-trip that alphabetizes your catalog.
• Existing keys get reused. If a string's exact text already exists in the bound namespace, Polyglot calls the existing key instead of minting a duplicate — your German translation for it keeps working untouched.
• Typed-key setups (CustomTypeOptions deriving from your JSON) type-check after wrap, because the key really is in the catalog the types derive from.

Wiring verified

Try it on your repo

$ curl -fsSL https://getpolyglot.ai/install.sh | bash
$ polyglot init --framework nextjs
$ polyglot scan
$ polyglot wrap
$ polyglot translate --languages de   # 50 strings free, no signup

The dry run prints every planned change and writes nothing. If Polyglot can't resolve where a key should live, it flags the string with a recipe instead of guessing.