How to use the ```t``` function in an API call on Vercel?

Hey,

I use next-i18next to translate my app and it works really great, but I can’t figure out how to use it properly in the API calls. I don’t want to use the locale detection because I send the locale in the request body.

I have an API endpoint like pages/api/image/[id].js. In this file I’m trying to use the t function like #1437 solution:

import { i18n } from 'next-i18next';
const createImage = async ( req, res ) => {
  i18n?.init() // Initialize i18n
  i18n?.changeLanguage('en')
  
  const translated = i18n?.t('key')
  // ...
}

This code works well on my local machine, but after deployment on Vercel the “translated” variable always equals “undefined”. I also didn’t find an answer in the #918 issue.

A few notes:

1. Of course, I use the appWithTranslation HOC.
2. This API endpoint can be called directly (outside of my app) like site.com/api/image/12345_en.
3. I use this code for image generation (open graph and others).

[isaachinman]

Please note that you can use createClient from next-i18next and instantiate an i18next instance yourselves.

[rolznz]

Do you seriously expect people to have to include from the dist file?

I managed to get it working locally using https://github.com/i18next/i18next-fs-backend

import i18next from "i18next";
import Backend from "i18next-fs-backend";
const i18n = await i18next.use(Backend).init({
    lng: locale,
    ns: "common",
    backend: {
      loadPath: path.join(process.cwd(), "/public/locales/{{lng}}/{{ns}}.json"),
      addPath: path.join(
        process.cwd(),
        "/public/locales/{{lng}}/{{ns}}.missing.json"
      ),
    },
  });