The translate2 app provides machine translation functionality in Nextcloud and acts as a translation backend for the Nextcloud Assistant app. It runs only open weights models and does so entirely on-premises.
The app currently supports 400+ languages. See the complete list here: https://huggingface.co/datasets/allenai/MADLAD-400
Requires AppAPI to work.
For installation steps and other details, see https://docs.nextcloud.com/server/latest/admin_manual/ai/app_translate2.html