🗣️ fix: Prevent @librechat/client useLocalize from Overwriting Host App Language State

[shtayeb]

Summary

langAtom is hardcoded to en in packages/client/src/store.ts
in comparison with the main app's client/src/hooks/useLocalize.ts which reads from real sources in client/src/store/language.ts

Both hooks call i18n.changeLanguage() on the same i18next singleton. When the packages/client hook fires first with 'en', it overwrites the language before the main app hook can correct it.

---

(look at value of i18nextLng in localstorage)

Screen.Recording.2026-04-02.at.0.16.31.PM.mov

Change Type

• Bug fix (non-breaking change which fixes an issue)

How the bug plays out

1. User visits /d/new with language set to e.g., fr
2. Opens settings dialog, which imports components from @librechat/client (e.g., Button, Input, Select)
3. Some of these components use useLocalize from packages/client/src/hooks/useLocalize.ts
4. That hook reads langAtom → 'en' (hardcoded default)
5. Since i18n.language (detected as fr) !== 'en', it calls i18n.changeLanguage('en')
6. This writes i18nextLng = 'en' to localStorage. the user sees the flicker to English(not very visible in the dialog case but can be worse when you are fetching data and have to wait for the result)
7. The main app's(client/) useLocalize (from client/src/hooks/useLocalize.ts) reads the Recoil atom (fr) and calls i18n.changeLanguage('fr') fixing it back since no data is fetched it happens fast.
8. On second visit, i18nextLng is already fr from step 7, so i18n.language matches langAtom... wait, no, langAtom is still 'en'

Checklist

• My code adheres to this project's style guidelines
• I have performed a self-review of my own code

Proposed fix

It removes the language overwrite from packages/client/src/hooks/useLocalize.ts hook and only read it.

Alt fix: initialize langAtom from actual language sources.

Note: If there is any reason for keeping it as it is, please let me know.