Add this snippet at the end of your .zshrc to show your current username from gh CLI in the prompt (right side)

.zshrc

# 1) Function to update the cached GitHub username:
function refresh_github_user() {
  GITHUB_USER_CACHED="$(
    gh auth status --active 2>/dev/null \
    | sed -nE 's/.* account ([^ ]+).*/\1/p'
  )"
}

# 2) Function to display the cached GitHub user if in a Git repo:
function _gh_user_prompt() {
  if git rev-parse --is-inside-work-tree &>/dev/null; then
    if [[ -n "$GITHUB_USER_CACHED" ]]; then
      echo "($GITHUB_USER_CACHED)"
    fi
  fi
}

# 3) Initialize the cache once at shell startup:
refresh_github_user

# 4) Right prompt (RPROMPT): show cached user in yellow:
RPROMPT='%{$fg[yellow]%}$(_gh_user_prompt)%{$reset_color%}'

# 5) Track last command in preexec(), and refresh in precmd() if it was "gh auth switch" or "gh auth login".
autoload -Uz add-zsh-hook

# This variable will hold the last command entered.
LAST_COMMAND=""

function _gh_preexec_capture() {
  LAST_COMMAND="$1"
}

function _gh_precmd_refresh() {
  # If the last command was "gh auth switch" or "gh auth login", refresh now.
  if [[ "$LAST_COMMAND" == gh\ auth\ switch* || "$LAST_COMMAND" == gh\ auth\ login* ]]; then
    refresh_github_user
  fi
}

add-zsh-hook preexec _gh_preexec_capture
add-zsh-hook precmd _gh_precmd_refresh