Add Language and Translations to the REST API (WPML)
Adds wpml_language and wpml_translations fields to posts and pages in the REST API, so headless front ends and apps know each item's language and the IDs of its translations.
Snippet Library
Multilingual snippets for WordPress
Snippets for multilingual sites: language switchers, translated strings and per-language behavior with WPML, Polylang and similar plugins. For sites that serve readers in more than one language.
Assign a Language to Posts Created by Importers and Code
Gives posts created outside the editor, for example by importers, cron jobs, forms or the REST API, the default Polylang language when they have none, so they do not vanish from language-filtered lists.
Polylang Language Fields in the REST API
Adds pll_language and pll_translations fields to posts and pages in the REST API, which Polylang's free version does not provide, so headless sites and apps can link translations.