vi mode for shell?

On zsh and bash you can configure the shell to work like VIM (i.e. switch between insert and normal mode, use key combos like `dw` in normal mode etc). I wondered if thats possible for a-Shell as well? If I do `echo $SHELL` I see that the used shell is `/bin/sh` which doesn't support VI mode out of the box afaik.

Thanks for the attention,
Normen Hansen