Well it's published. Wasn't ready to publish and didn't have time to clean it up but I'll get back to it in the coming days, there's also some extra features on the way but disabled currently. Works quite well for me though.

https://github.com/TIAcode/LLMShellAutoComplete

Forgot to add needs tiktoken, openai and fzf. If someone knows how to do that command line query and replace on other than fish/nushell, please let me know.