[zarzavat]

Copilot X is just their name for their project to bring AI to more areas of VSCode. I don’t believe they can use GPT-4 for completions because it’s a chat-optimized model. It seems that they are using something else, that blog post seems to imply it’s a custom-trained model.

[cosmojg]

I use GPT-4 for code completion all the time! There are many Neovim extensions[1][2][3] (and I'm sure there are many VSCode extensions) which call the GPT-4 API directly for code completion. I'm pretty sure the only reason that Microsoft might avoid using GPT-4 for Copilot is cost.

[1] https://github.com/cosmojg/nvim-magic

[2] https://github.com/dpayne/CodeGPT.nvim

[3] https://github.com/aduros/ai.vim