Agnoster is one of the simplest and cleaner theme for your oh-my-zsh mod for your ZSH. However, having the entire pwd shown in your prompt would make the terminal less efficient.
To begin with, add these lines in your .zshrc:
prompt_dir() {
prompt_segment blue black "${PWD##*/}"
}
And do $ source .zshrc and you’re good to go! VOILA!