Apply a Ghostty theme to a single surface (split/tab) without affecting others

ghostty-surface-theme.sh

#!/bin/bash
#
# ghostty-surface-theme.sh
# Apply a Ghostty theme to the current surface only, without affecting other
# splits, tabs, or windows. Works by reading Ghostty's built-in theme files
# and sending the equivalent OSC escape sequences to the current terminal.
#
# INSTALL
#   Copy this script somewhere on your PATH and make it executable:
#
#     curl -o ~/.local/bin/ghostty-surface-theme.sh \
#       https://gist.githubusercontent.com/ykessler/517a5c28618e1aaa21307559d6064902/raw/ghostty-surface-theme.sh
#     chmod +x ~/.local/bin/ghostty-surface-theme.sh
#
#   Make sure ~/.local/bin is in your PATH. Add this to your ~/.zshrc or
#   ~/.bashrc if it isn't already:
#
#     export PATH="$HOME/.local/bin:$PATH"
#
# USAGE
#   Apply a theme to the current surface:
#     ghostty-surface-theme.sh "Catppuccin Frappe"
#
#   Reset the current surface back to your config defaults:
#     ghostty-surface-theme.sh --reset
#
#   List available theme names:
#     ghostty +list-themes
#
# SHORTCUT
#   Add an alias to your ~/.zshrc or ~/.bashrc:
#
#     alias gtheme="ghostty-surface-theme.sh"
#
#   Then just:
#     gtheme "Tokyo Night"
#     gtheme --reset
#
# THEME FILE LOCATIONS
#   The script checks for themes in this order:
#     1. macOS app bundle: /Applications/Ghostty.app/Contents/Resources/ghostty/themes/
#     2. Linux system:     /usr/share/ghostty/themes/
#     3. User custom:      ~/.config/ghostty/themes/
#

THEME="$1"

if [[ -z "$THEME" ]]; then
  echo "Usage: ghostty-surface-theme.sh <theme-name>"
  echo "       ghostty-surface-theme.sh --reset"
  echo ""
  echo "Run 'ghostty +list-themes' to see available themes."
  exit 1
fi

# Reset to config defaults
if [[ "$THEME" == "--reset" ]]; then
  printf '\e]110\a'  # reset foreground
  printf '\e]111\a'  # reset background
  printf '\e]112\a'  # reset cursor color
  printf '\e]117\a'  # reset selection background
  printf '\e]119\a'  # reset selection foreground
  printf '\e]104\a'  # reset all palette colors
  exit 0
fi

# Find the theme file
THEME_FILE=""
for dir in \
  "/Applications/Ghostty.app/Contents/Resources/ghostty/themes" \
  "/usr/share/ghostty/themes" \
  "$HOME/.config/ghostty/themes"; do
  if [[ -f "$dir/$THEME" ]]; then
    THEME_FILE="$dir/$THEME"
    break
  fi
done

if [[ -z "$THEME_FILE" ]]; then
  echo "Theme '$THEME' not found"
  exit 1
fi

# Parse theme file and send OSC escape sequences
while IFS='= ' read -r key value; do
  case "$key" in
    foreground)            printf '\e]10;%s\a' "$value" ;;
    background)            printf '\e]11;%s\a' "$value" ;;
    cursor-color)          printf '\e]12;%s\a' "$value" ;;
    selection-background)  printf '\e]17;%s\a' "$value" ;;
    selection-foreground)  printf '\e]19;%s\a' "$value" ;;
    palette)
      IFS='=' read -r idx color <<< "$value"
      printf '\e]4;%s;%s\a' "$idx" "$color"
      ;;
  esac
done < "$THEME_FILE"