I know duckduckgo has an implementation but as a service not as a download?
If there isn't any how much would it cost say for the English version? How about maybe just a subset?
I did do some searches but couldn't find any project like this.
If you want a completely offline version you'd be running one of the open source LLMs locally. Otherwise put the embeddings in a VectorDB, query it for the context and send it to one of the completion APIs available (OpenAI, etc)