Is it possible to have an LLM always give a consistent output?

Is there any LLM who's focus is this? EG:

1. Given the same exact tokens, 2. Always return the same tokens.

EG: I give the LLM the following tokens:

"What color is the sky?"

it always would return a message like:

"It's Purple!"

and never change. I understand this not a normal usecase or in many cases desired for an LLM, but I am curious if anyone is working on this in an academic paper, or if there is a private organization which is doing something along these lines.