diff --git a/install.sh b/install.sh
index 36c0ad1..09b73be 100644
--- a/install.sh
+++ b/install.sh
@@ -21,47 +21,212 @@ PORT_PROVIDED=0
 SECRET_PROVIDED=0
 AD_TAG_PROVIDED=0
 DOMAIN_PROVIDED=0
+LANG_PROVIDED=0
 
 ACTION="install"
 TARGET_VERSION="${VERSION:-latest}"
+LANG_CHOICE="en"
+
+set_language() {
+    case "$1" in
+        ru)
+            L_ERR_DOMAIN_REQ="требует аргумент (домен)."
+            L_ERR_PORT_REQ="требует аргумент (порт)."
+            L_ERR_PORT_NUM="Порт должен быть числом."
+            L_ERR_PORT_RANGE="Порт должен быть от 1 до 65535."
+            L_ERR_SECRET_REQ="требует аргумент (секрет)."
+            L_ERR_SECRET_HEX="Секрет должен содержать только HEX символы."
+            L_ERR_SECRET_LEN="Секрет должен состоять ровно из 32 символов."
+            L_ERR_ADTAG_REQ="требует аргумент (ad_tag)."
+            L_ERR_UNKNOWN_OPT="Неизвестная опция:"
+            L_WARN_EXTRA_ARG="Игнорируется лишний аргумент:"
+            L_ERR_REQ_ARG="требует аргумент (1, 2, en или ru)."
+            L_ERR_EMPTY_VAR="не может быть пустым."
+            L_ERR_INV_VER="Недопустимые символы в версии."
+            L_ERR_INV_BIN="Недопустимые символы в BIN_NAME."
+            L_ERR_ROOT="Для работы скрипта требуются права root или sudo."
+            L_ERR_SUDO_TTY="sudo требует пароль, но терминал (TTY) не обнаружен."
+            L_ERR_DIR_CHECK="Ошибка: конфиг является директорией."
+            L_ERR_CMD_NOT_FOUND="Необходимая команда не найдена:"
+            L_ERR_NO_DL_TOOL="Не установлен curl или wget."
+            L_ERR_NO_CP_TOOL="Необходима утилита cp или install."
+            L_WARN_NO_NET_TOOL="Утилиты сети не найдены. Проверка порта пропущена."
+            L_INFO_PORT_IGNORE="Порт занят текущим процессом телеметрии. Игнорируем."
+            L_ERR_PORT_IN_USE="Порт уже занят другим процессом:"
+            L_ERR_PORT_FREE="Освободите порт или укажите другой и попробуйте снова."
+            L_ERR_UNSUP_ARCH="Неподдерживаемая архитектура:"
+            L_ERR_CREATE_GRP="Не удалось создать группу"
+            L_ERR_CREATE_USR="Не удалось создать пользователя"
+            L_ERR_MKDIR="Не удалось создать директории"
+            L_ERR_INSTALL_DIR="не является директорией."
+            L_ERR_BIN_INSTALL="Не удалось установить бинарный файл"
+            L_ERR_BIN_COPY="Не удалось скопировать бинарный файл"
+            L_ERR_BIN_EXEC="Бинарный файл не исполняемый."
+            L_ERR_GEN_SEC="Не удалось сгенерировать секрет."
+            L_INFO_CONF_EXISTS="Конфиг уже существует. Обновление параметров..."
+            L_INFO_UPD_PORT="Обновлен порт:"
+            L_INFO_UPD_SEC="Обновлен секрет для пользователя 'hello'"
+            L_INFO_UPD_DOM="Обновлен tls_domain:"
+            L_INFO_UPD_TAG="Обновлен ad_tag"
+            L_ERR_CONF_INST="Не удалось установить конфиг"
+            L_INFO_CONF_OK="Конфиг успешно создан."
+            L_INFO_CONF_SEC="Настроен секрет для пользователя 'hello':"
+            L_WARN_SVC_FAIL="Не удалось запустить службу"
+            L_INFO_MANUAL_START="Менеджер служб не найден. Запустите вручную:"
+            L_INFO_UNINST_START="Начинается удаление"
+            L_U_STAGE_1=">>> Этап 1: Остановка служб"
+            L_U_STAGE_2=">>> Этап 2: Удаление конфигурации службы"
+            L_U_STAGE_3=">>> Этап 3: Завершение процессов пользователя"
+            L_U_STAGE_4=">>> Этап 4: Удаление бинарного файла"
+            L_U_STAGE_5=">>> Этап 5: Полная очистка (конфиг, данные, пользователь)"
+            L_INFO_KEEP_CONF="Примечание: Конфигурация сохранена. Используйте 'purge' для очистки."
+            L_INFO_I_START="Начинается установка"
+            L_I_STAGE_1=">>> Этап 1: Проверка окружения и зависимостей"
+            L_I_STAGE_1_5=">>> Этап 1.5: Интерактивная настройка"
+            L_I_PROMPT_DOM="\nПожалуйста, укажите домен TLS\nНажмите Enter, чтобы оставить по умолчанию [%s]: "
+            L_WARN_NO_TTY="Интерактивный режим недоступен (нет TTY). Используется:"
+            L_I_STAGE_2=">>> Этап 2: Загрузка архива"
+            L_ERR_TMP_DIR="Не удалось создать временную директорию"
+            L_ERR_TMP_INV="Временная директория недействительна"
+            L_INFO_FALLBACK="Сборка x86_64-v3 не найдена, откат к стандартной x86_64..."
+            L_ERR_DL_FAIL="Ошибка загрузки архива"
+            L_I_STAGE_3=">>> Этап 3: Распаковка архива"
+            L_ERR_EXTRACT="Ошибка распаковки архива."
+            L_ERR_BIN_NOT_FOUND="Бинарный файл не найден в архиве"
+            L_I_STAGE_4=">>> Этап 4: Настройка окружения (Юзер, Группа, Папки)"
+            L_I_STAGE_5=">>> Этап 5: Установка бинарного файла"
+            L_I_STAGE_6=">>> Этап 6: Генерация/Обновление конфигурации"
+            L_I_STAGE_7=">>> Этап 7: Установка и запуск службы"
+            L_OUT_WARN_H="УСТАНОВКА ЗАВЕРШЕНА С ПРЕДУПРЕЖДЕНИЯМИ"
+            L_OUT_WARN_D="Служба установлена, но не запустилась.\nПожалуйста, проверьте логи.\n"
+            L_OUT_SUCC_H="УСТАНОВКА УСПЕШНО ЗАВЕРШЕНА"
+            L_OUT_UNINST_H="УДАЛЕНИЕ ЗАВЕРШЕНО"
+            L_OUT_LINK="Ваша ссылка для подключения к Telegram Proxy:\n"
+            ;;
+        *)
+            L_ERR_DOMAIN_REQ="requires a domain argument."
+            L_ERR_PORT_REQ="requires a port argument."
+            L_ERR_PORT_NUM="Port must be a valid number."
+            L_ERR_PORT_RANGE="Port must be between 1 and 65535."
+            L_ERR_SECRET_REQ="requires a secret argument."
+            L_ERR_SECRET_HEX="Secret must contain only hex characters."
+            L_ERR_SECRET_LEN="Secret must be exactly 32 chars."
+            L_ERR_ADTAG_REQ="requires an ad_tag argument."
+            L_ERR_UNKNOWN_OPT="Unknown option:"
+            L_WARN_EXTRA_ARG="Ignoring extra argument:"
+            L_ERR_REQ_ARG="requires an argument (1, 2, en, ru)."
+            L_ERR_EMPTY_VAR="cannot be empty."
+            L_ERR_INV_VER="Invalid characters in version."
+            L_ERR_INV_BIN="Invalid characters in BIN_NAME."
+            L_ERR_ROOT="This script requires root or sudo."
+            L_ERR_SUDO_TTY="sudo requires a password, but no TTY detected."
+            L_ERR_DIR_CHECK="Safety check failed: Config is a directory."
+            L_ERR_CMD_NOT_FOUND="Required command not found:"
+            L_ERR_NO_DL_TOOL="Neither curl nor wget is installed."
+            L_ERR_NO_CP_TOOL="Need cp or install."
+            L_WARN_NO_NET_TOOL="Network tools not found. Skipping port check."
+            L_INFO_PORT_IGNORE="Port is in use by telemt. Ignoring as it will be restarted."
+            L_ERR_PORT_IN_USE="Port is already in use by another process:"
+            L_ERR_PORT_FREE="Please free the port or change it and try again."
+            L_ERR_UNSUP_ARCH="Unsupported architecture:"
+            L_ERR_CREATE_GRP="Cannot create group"
+            L_ERR_CREATE_USR="Cannot create user"
+            L_ERR_MKDIR="Failed to create directories"
+            L_ERR_INSTALL_DIR="is not a directory."
+            L_ERR_BIN_INSTALL="Failed to install binary"
+            L_ERR_BIN_COPY="Failed to copy binary"
+            L_ERR_BIN_EXEC="Binary not executable."
+            L_ERR_GEN_SEC="Failed to generate secret."
+            L_INFO_CONF_EXISTS="Config already exists. Updating parameters..."
+            L_INFO_UPD_PORT="Updated port:"
+            L_INFO_UPD_SEC="Updated secret for user 'hello'"
+            L_INFO_UPD_DOM="Updated tls_domain:"
+            L_INFO_UPD_TAG="Updated ad_tag"
+            L_ERR_CONF_INST="Failed to install config"
+            L_INFO_CONF_OK="Config created successfully."
+            L_INFO_CONF_SEC="Configured secret for user 'hello':"
+            L_WARN_SVC_FAIL="Failed to start service"
+            L_INFO_MANUAL_START="Service manager not found. Start manually:"
+            L_INFO_UNINST_START="Starting uninstallation of"
+            L_U_STAGE_1=">>> Stage 1: Stopping services"
+            L_U_STAGE_2=">>> Stage 2: Removing service configuration"
+            L_U_STAGE_3=">>> Stage 3: Terminating user processes"
+            L_U_STAGE_4=">>> Stage 4: Removing binary"
+            L_U_STAGE_5=">>> Stage 5: Purging configuration, data, and user"
+            L_INFO_KEEP_CONF="Note: Configuration kept. Run with 'purge' to remove completely."
+            L_INFO_I_START="Starting installation of"
+            L_I_STAGE_1=">>> Stage 1: Verifying environment and dependencies"
+            L_I_STAGE_1_5=">>> Stage 1.5: Interactive Setup"
+            L_I_PROMPT_DOM="\nPlease specify the TLS Domain\nPress Enter to keep default [%s]: "
+            L_WARN_NO_TTY="Interactive mode unavailable (no TTY). Using:"
+            L_I_STAGE_2=">>> Stage 2: Downloading archive"
+            L_ERR_TMP_DIR="Temp directory creation failed"
+            L_ERR_TMP_INV="Temp directory is invalid or was not created"
+            L_INFO_FALLBACK="x86_64-v3 build not found, falling back to standard x86_64..."
+            L_ERR_DL_FAIL="Download failed"
+            L_I_STAGE_3=">>> Stage 3: Extracting archive"
+            L_ERR_EXTRACT="Extraction failed."
+            L_ERR_BIN_NOT_FOUND="Binary not found in archive"
+            L_I_STAGE_4=">>> Stage 4: Setting up environment (User, Group, Directories)"
+            L_I_STAGE_5=">>> Stage 5: Installing binary"
+            L_I_STAGE_6=">>> Stage 6: Generating/Updating configuration"
+            L_I_STAGE_7=">>> Stage 7: Installing and starting service"
+            L_OUT_WARN_H="INSTALLATION COMPLETED WITH WARNINGS"
+            L_OUT_WARN_D="The service was installed but failed to start.\nPlease check the logs to determine the issue.\n"
+            L_OUT_SUCC_H="INSTALLATION SUCCESS"
+            L_OUT_UNINST_H="UNINSTALLATION COMPLETE"
+            L_OUT_LINK="Your Telegram Proxy connection link:\n"
+            ;;
+    esac
+}
+
+set_language "$LANG_CHOICE"
 
 while [ $# -gt 0 ]; do
     case "$1" in
         -h|--help) ACTION="help"; shift ;;
+        -l|--lang)
+            if [ "$#" -lt 2 ] || [ -z "$2" ]; then
+                printf '[ERROR] %s %s\n' "$1" "$L_ERR_REQ_ARG" >&2; exit 1
+            fi
+            case "$2" in
+                ru|2) LANG_CHOICE="ru"; set_language "$LANG_CHOICE"; LANG_PROVIDED=1 ;;
+                en|1) LANG_CHOICE="en"; set_language "$LANG_CHOICE"; LANG_PROVIDED=1 ;;
+                *) printf '[ERROR] %s %s\n' "$1" "$L_ERR_REQ_ARG" >&2; exit 1 ;;
+            esac
+            shift 2 ;;
         -d|--domain)
             if [ "$#" -lt 2 ] || [ -z "$2" ]; then
-                printf '[ERROR] %s requires a domain argument.\n' "$1" >&2
-                exit 1
+                printf '[ERROR] %s %s\n' "$1" "$L_ERR_DOMAIN_REQ" >&2; exit 1
             fi
             TLS_DOMAIN="$2"; DOMAIN_PROVIDED=1; shift 2 ;;
         -p|--port)
             if [ "$#" -lt 2 ] || [ -z "$2" ]; then
-                printf '[ERROR] %s requires a port argument.\n' "$1" >&2; exit 1
+                printf '[ERROR] %s %s\n' "$1" "$L_ERR_PORT_REQ" >&2; exit 1
             fi
             case "$2" in
-                *[!0-9]*) printf '[ERROR] Port must be a valid number.\n' >&2; exit 1 ;;
+                *[!0-9]*) printf '[ERROR] %s\n' "$L_ERR_PORT_NUM" >&2; exit 1 ;;
             esac
             port_num="$(printf '%s\n' "$2" | sed 's/^0*//')"
             [ -z "$port_num" ] && port_num="0"
             if [ "${#port_num}" -gt 5 ] || [ "$port_num" -lt 1 ] || [ "$port_num" -gt 65535 ]; then
-                printf '[ERROR] Port must be between 1 and 65535.\n' >&2; exit 1
+                printf '[ERROR] %s\n' "$L_ERR_PORT_RANGE" >&2; exit 1
             fi
             SERVER_PORT="$port_num"; PORT_PROVIDED=1; shift 2 ;;
         -s|--secret)
             if [ "$#" -lt 2 ] || [ -z "$2" ]; then
-                printf '[ERROR] %s requires a secret argument.\n' "$1" >&2; exit 1
+                printf '[ERROR] %s %s\n' "$1" "$L_ERR_SECRET_REQ" >&2; exit 1
             fi
             case "$2" in
-                *[!0-9a-fA-F]*)
-                    printf '[ERROR] Secret must contain only hex characters.\n' >&2; exit 1 ;;
+                *[!0-9a-fA-F]*) printf '[ERROR] %s\n' "$L_ERR_SECRET_HEX" >&2; exit 1 ;;
             esac
             if [ "${#2}" -ne 32 ]; then
-                printf '[ERROR] Secret must be exactly 32 chars.\n' >&2; exit 1
+                printf '[ERROR] %s\n' "$L_ERR_SECRET_LEN" >&2; exit 1
             fi
             USER_SECRET="$2"; SECRET_PROVIDED=1; shift 2 ;;
         -a|--ad-tag|--ad_tag)
             if [ "$#" -lt 2 ] || [ -z "$2" ]; then
-                printf '[ERROR] %s requires an ad_tag argument.\n' "$1" >&2; exit 1
+                printf '[ERROR] %s %s\n' "$1" "$L_ERR_ADTAG_REQ" >&2; exit 1
             fi
             AD_TAG="$2"; AD_TAG_PROVIDED=1; shift 2 ;;
         uninstall|--uninstall)
@@ -69,14 +234,31 @@ while [ $# -gt 0 ]; do
             shift ;;
         purge|--purge) ACTION="purge"; shift ;;
         install|--install) ACTION="install"; shift ;;
-        -*) printf '[ERROR] Unknown option: %s\n' "$1" >&2; exit 1 ;;
+        -*) printf '[ERROR] %s %s\n' "$L_ERR_UNKNOWN_OPT" "$1" >&2; exit 1 ;;
         *)
             if [ "$ACTION" = "install" ]; then TARGET_VERSION="$1"
-            else printf '[WARNING] Ignoring extra argument: %s\n' "$1" >&2; fi
+            else printf '[WARNING] %s %s\n' "$L_WARN_EXTRA_ARG" "$1" >&2; fi
             shift ;;
     esac
 done
 
+if [ "$ACTION" != "help" ] && [ "$LANG_PROVIDED" -eq 0 ]; then
+    if [ -t 0 ] || [ -c /dev/tty ]; then
+        printf "\nSelect language / Выберите язык:\n"
+        printf "  1) English (default)\n"
+        printf "  2) Русский\n"
+        printf "Your choice / Ваш выбор [1/2]: "
+        read -r input_lang </dev/tty || input_lang=""
+        case "$input_lang" in
+            2) LANG_CHOICE="ru" ;;
+            *) LANG_CHOICE="en" ;;
+        esac
+    else
+        LANG_CHOICE="en"
+    fi
+    set_language "$LANG_CHOICE"
+fi
+
 say() {
     if [ "$#" -eq 0 ] || [ -z "${1:-}" ]; then
         printf '\n'
@@ -96,17 +278,33 @@ cleanup() {
 trap cleanup EXIT INT TERM
 
 show_help() {
-    say "Usage: $0 [ <version> | install | uninstall | purge ] [ options ]"
-    say "  <version>    Install specific version (e.g. 3.3.15, default: latest)"
-    say "  install      Install the latest version"
-    say "  uninstall    Remove the binary and service"
-    say "  purge        Remove everything including configuration, data, and user"
-    say ""
-    say "Options:"
-    say "  -d, --domain Set TLS domain (default: petrovich.ru)"
-    say "  -p, --port   Set server port (default: 443)"
-    say "  -s, --secret Set specific user secret (32 hex characters)"
-    say "  -a, --ad-tag Set ad_tag"
+    if [ "$LANG_CHOICE" = "ru" ]; then
+        say "Использование: $0 [ <версия> | install | uninstall | purge ] [ опции ]"
+        say "  <версия>     Установить конкретную версию (например, 3.3.15, по умолчанию: latest)"
+        say "  install      Установить последнюю версию"
+        say "  uninstall    Удалить бинарный файл и службу"
+        say "  purge        Полностью удалить вместе с конфигурацией, данными и пользователем"
+        say ""
+        say "Опции:"
+        say "  -d, --domain Указать домен TLS (по умолчанию: petrovich.ru)"
+        say "  -p, --port   Указать порт сервера (по умолчанию: 443)"
+        say "  -s, --secret Указать секрет пользователя (32 hex символа)"
+        say "  -a, --ad-tag Указать ad_tag"
+        say "  -l, --lang   Выбрать язык вывода (1/en или 2/ru)"
+    else
+        say "Usage: $0 [ <version> | install | uninstall | purge ] [ options ]"
+        say "  <version>    Install specific version (e.g. 3.3.15, default: latest)"
+        say "  install      Install the latest version"
+        say "  uninstall    Remove the binary and service"
+        say "  purge        Remove everything including configuration, data, and user"
+        say ""
+        say "Options:"
+        say "  -d, --domain Set TLS domain (default: petrovich.ru)"
+        say "  -p, --port   Set server port (default: 443)"
+        say "  -s, --secret Set specific user secret (32 hex characters)"
+        say "  -a, --ad-tag Set ad_tag"
+        say "  -l, --lang   Set output language (1/en or 2/ru)"
+    fi
     exit 0
 }
 
@@ -171,17 +369,13 @@ is_config_exists() {
 }
 
 verify_common() {
-    [ -n "$BIN_NAME" ] || die "BIN_NAME cannot be empty."
-    [ -n "$INSTALL_DIR" ] || die "INSTALL_DIR cannot be empty."
-    [ -n "$CONFIG_DIR" ] || die "CONFIG_DIR cannot be empty."
-    [ -n "$CONFIG_FILE" ] || die "CONFIG_FILE cannot be empty."
+    [ -n "$BIN_NAME" ] || die "BIN_NAME $L_ERR_EMPTY_VAR"
+    [ -n "$INSTALL_DIR" ] || die "INSTALL_DIR $L_ERR_EMPTY_VAR"
+    [ -n "$CONFIG_DIR" ] || die "CONFIG_DIR $L_ERR_EMPTY_VAR"
+    [ -n "$CONFIG_FILE" ] || die "CONFIG_FILE $L_ERR_EMPTY_VAR"
 
-    case "${INSTALL_DIR}${CONFIG_DIR}${WORK_DIR}${CONFIG_FILE}" in
-        *[!a-zA-Z0-9_./-]*) die "Invalid characters in paths." ;;
-    esac
-
-    case "$TARGET_VERSION" in *[!a-zA-Z0-9_.-]*) die "Invalid characters in version." ;; esac
-    case "$BIN_NAME" in *[!a-zA-Z0-9_-]*) die "Invalid characters in BIN_NAME." ;; esac
+    case "$TARGET_VERSION" in *[!a-zA-Z0-9_.-]*) die "$L_ERR_INV_VER" ;; esac
+    case "$BIN_NAME" in *[!a-zA-Z0-9_-]*) die "$L_ERR_INV_BIN" ;; esac
 
     INSTALL_DIR="$(get_realpath "$INSTALL_DIR")"
     CONFIG_DIR="$(get_realpath "$CONFIG_DIR")"
@@ -195,42 +389,42 @@ verify_common() {
     if [ "$(id -u)" -eq 0 ]; then
         SUDO=""
     else
-        command -v sudo >/dev/null 2>&1 || die "This script requires root or sudo."
+        command -v sudo >/dev/null 2>&1 || die "$L_ERR_ROOT"
         SUDO="sudo"
         if ! sudo -n true 2>/dev/null; then
             if ! [ -t 0 ]; then
-                die "sudo requires a password, but no TTY detected."
+                die "$L_ERR_SUDO_TTY"
             fi
         fi
     fi
 
     if [ -n "$SUDO" ]; then
         if $SUDO sh -c '[ -d "$1" ]' _ "$CONFIG_FILE"; then
-            die "Safety check failed: CONFIG_FILE '$CONFIG_FILE' is a directory."
+            die "$L_ERR_DIR_CHECK"
         fi
     elif [ -d "$CONFIG_FILE" ]; then
-        die "Safety check failed: CONFIG_FILE '$CONFIG_FILE' is a directory."
+        die "$L_ERR_DIR_CHECK"
     fi
 
     for cmd in id uname awk grep find rm chown chmod mv mktemp mkdir tr dd sed ps head sleep cat tar gzip; do
-        command -v "$cmd" >/dev/null 2>&1 || die "Required command not found: $cmd"
+        command -v "$cmd" >/dev/null 2>&1 || die "$L_ERR_CMD_NOT_FOUND $cmd"
     done
 }
 
 verify_install_deps() {
-    command -v curl >/dev/null 2>&1 || command -v wget >/dev/null 2>&1 || die "Neither curl nor wget is installed."
-    command -v cp >/dev/null 2>&1 || command -v install >/dev/null 2>&1 || die "Need cp or install"
+    command -v curl >/dev/null 2>&1 || command -v wget >/dev/null 2>&1 || die "$L_ERR_NO_DL_TOOL"
+    command -v cp >/dev/null 2>&1 || command -v install >/dev/null 2>&1 || die "$L_ERR_NO_CP_TOOL"
 
-    if ! command -v setcap >/dev/null 2>&1 || ! command -v conntrack >/dev/null 2>&1; then
+    if ! command -v setcap >/dev/null 2>&1; then
         if command -v apk >/dev/null 2>&1; then
-            $SUDO apk add --no-cache libcap-utils libcap conntrack-tools >/dev/null 2>&1 || true
+            $SUDO apk add --no-cache libcap-utils libcap >/dev/null 2>&1 || true
         elif command -v apt-get >/dev/null 2>&1; then
-            $SUDO env DEBIAN_FRONTEND=noninteractive apt-get install -y -q libcap2-bin conntrack >/dev/null 2>&1 || {
+            $SUDO env DEBIAN_FRONTEND=noninteractive apt-get install -y -q libcap2-bin >/dev/null 2>&1 || {
                 $SUDO env DEBIAN_FRONTEND=noninteractive apt-get update -q >/dev/null 2>&1 || true
-                $SUDO env DEBIAN_FRONTEND=noninteractive apt-get install -y -q libcap2-bin conntrack >/dev/null 2>&1 || true
+                $SUDO env DEBIAN_FRONTEND=noninteractive apt-get install -y -q libcap2-bin >/dev/null 2>&1 || true
             }
-        elif command -v dnf >/dev/null 2>&1; then $SUDO dnf install -y -q libcap conntrack-tools >/dev/null 2>&1 || true
-        elif command -v yum >/dev/null 2>&1; then $SUDO yum install -y -q libcap conntrack-tools >/dev/null 2>&1 || true
+        elif command -v dnf >/dev/null 2>&1; then $SUDO dnf install -y -q libcap >/dev/null 2>&1 || true
+        elif command -v yum >/dev/null 2>&1; then $SUDO yum install -y -q libcap >/dev/null 2>&1 || true
         fi
     fi
 }
@@ -245,17 +439,17 @@ check_port_availability() {
     elif command -v lsof >/dev/null 2>&1; then
         port_info=$($SUDO lsof -i :${SERVER_PORT} 2>/dev/null | grep LISTEN || true)
     else
-        say "[WARNING] Network diagnostic tools (ss, netstat, lsof) not found. Skipping port check."
+        say "[WARNING] $L_WARN_NO_NET_TOOL"
         return 0
     fi
 
     if [ -n "$port_info" ]; then
         if printf '%s\n' "$port_info" | grep -q "${BIN_NAME}"; then
-            say "  -> Port ${SERVER_PORT} is in use by ${BIN_NAME}. Ignoring as it will be restarted."
+            say "  -> $L_INFO_PORT_IGNORE"
         else
-            say "[ERROR] Port ${SERVER_PORT} is already in use by another process:"
+            say "[ERROR] $L_ERR_PORT_IN_USE $SERVER_PORT:"
             printf '  %s\n' "$port_info"
-            die "Please free the port ${SERVER_PORT} or change it and try again."
+            die "$L_ERR_PORT_FREE"
         fi
     fi
 }
@@ -271,7 +465,7 @@ detect_arch() {
             fi
             ;;
         aarch64|arm64) echo "aarch64" ;;
-        *) die "Unsupported architecture: $sys_arch" ;;
+        *) die "$L_ERR_UNSUP_ARCH $sys_arch" ;;
     esac
 }
 
@@ -295,7 +489,7 @@ ensure_user_group() {
     if ! check_os_entity group telemt; then
         if command -v groupadd >/dev/null 2>&1; then $SUDO groupadd -r telemt
         elif command -v addgroup >/dev/null 2>&1; then $SUDO addgroup -S telemt
-        else die "Cannot create group"; fi
+        else die "$L_ERR_CREATE_GRP" ; fi
     fi
 
     if ! check_os_entity passwd telemt; then
@@ -307,12 +501,12 @@ ensure_user_group() {
             else
                 $SUDO adduser --system --home "$WORK_DIR" --shell "$nologin_bin" --no-create-home --ingroup telemt --disabled-password telemt
             fi
-        else die "Cannot create user"; fi
+        else die "$L_ERR_CREATE_USR"; fi
     fi
 }
 
 setup_dirs() {
-    $SUDO mkdir -p "$WORK_DIR" "$CONFIG_DIR" "$CONFIG_PARENT_DIR" || die "Failed to create directories"
+    $SUDO mkdir -p "$WORK_DIR" "$CONFIG_DIR" "$CONFIG_PARENT_DIR" || die "$L_ERR_MKDIR"
 
     $SUDO chown telemt:telemt "$WORK_DIR" && $SUDO chmod 750 "$WORK_DIR"
     $SUDO chown telemt:telemt "$CONFIG_DIR" && $SUDO chmod 750 "$CONFIG_DIR"
@@ -334,20 +528,20 @@ stop_service() {
 install_binary() {
     bin_src="$1"; bin_dst="$2"
     if [ -e "$INSTALL_DIR" ] && [ ! -d "$INSTALL_DIR" ]; then
-        die "'$INSTALL_DIR' is not a directory."
+        die "'$INSTALL_DIR' $L_ERR_INSTALL_DIR"
     fi
 
-    $SUDO mkdir -p "$INSTALL_DIR" || die "Failed to create install directory"
+    $SUDO mkdir -p "$INSTALL_DIR" || die "$L_ERR_MKDIR"
     
     $SUDO rm -f "$bin_dst" 2>/dev/null || true
 
     if command -v install >/dev/null 2>&1; then
-        $SUDO install -m 0755 "$bin_src" "$bin_dst" || die "Failed to install binary"
+        $SUDO install -m 0755 "$bin_src" "$bin_dst" || die "$L_ERR_BIN_INSTALL"
     else
-        $SUDO cp "$bin_src" "$bin_dst" && $SUDO chmod 0755 "$bin_dst" || die "Failed to copy binary"
+        $SUDO cp "$bin_src" "$bin_dst" && $SUDO chmod 0755 "$bin_dst" || die "$L_ERR_BIN_COPY"
     fi
 
-    $SUDO sh -c '[ -x "$1" ]' _ "$bin_dst" || die "Binary not executable: $bin_dst"
+    $SUDO sh -c '[ -x "$1" ]' _ "$bin_dst" || die "$L_ERR_BIN_EXEC $bin_dst"
 
     if command -v setcap >/dev/null 2>&1; then
         $SUDO setcap cap_net_bind_service,cap_net_admin=+ep "$bin_dst" 2>/dev/null || true
@@ -404,40 +598,32 @@ EOF
 
 install_config() {
     if is_config_exists; then
-        say "  -> Config already exists at $CONFIG_FILE. Updating parameters..."
+        say "  -> $L_INFO_CONF_EXISTS"
 
         tmp_conf="${TEMP_DIR}/config.tmp"
         $SUDO cat "$CONFIG_FILE" > "$tmp_conf"
         
         escaped_domain="$(printf '%s\n' "$TLS_DOMAIN" | tr -d '[:cntrl:]' | sed 's/\\/\\\\/g; s/"/\\"/g')"
 
-        export AWK_PORT="$SERVER_PORT"
-        export AWK_SECRET="$USER_SECRET"
-        export AWK_DOMAIN="$escaped_domain"
-        export AWK_AD_TAG="$AD_TAG"
-        export AWK_FLAG_P="$PORT_PROVIDED"
-        export AWK_FLAG_S="$SECRET_PROVIDED"
-        export AWK_FLAG_D="$DOMAIN_PROVIDED"
-        export AWK_FLAG_A="$AD_TAG_PROVIDED"
-
-        awk '
+        awk -v port="$SERVER_PORT" -v secret="$USER_SECRET" -v domain="$escaped_domain" -v ad_tag="$AD_TAG" \
+            -v flag_p="$PORT_PROVIDED" -v flag_s="$SECRET_PROVIDED" -v flag_d="$DOMAIN_PROVIDED" -v flag_a="$AD_TAG_PROVIDED" '
         BEGIN { ad_tag_handled = 0 }
         
-        ENVIRON["AWK_FLAG_P"] == "1" && /^[ \t]*port[ \t]*=/ { print "port = " ENVIRON["AWK_PORT"]; next }
-        ENVIRON["AWK_FLAG_S"] == "1" && /^[ \t]*hello[ \t]*=/ { print "hello = \"" ENVIRON["AWK_SECRET"] "\""; next }
-        ENVIRON["AWK_FLAG_D"] == "1" && /^[ \t]*tls_domain[ \t]*=/ { print "tls_domain = \"" ENVIRON["AWK_DOMAIN"] "\""; next }
+        flag_p == "1" && /^[ \t]*port[ \t]*=/ { print "port = " port; next }
+        flag_s == "1" && /^[ \t]*hello[ \t]*=/ { print "hello = \"" secret "\""; next }
+        flag_d == "1" && /^[ \t]*tls_domain[ \t]*=/ { print "tls_domain = \"" domain "\""; next }
         
-        ENVIRON["AWK_FLAG_A"] == "1" && /^[ \t]*ad_tag[ \t]*=/ { 
+        flag_a == "1" && /^[ \t]*ad_tag[ \t]*=/ { 
             if (!ad_tag_handled) { 
-                print "ad_tag = \"" ENVIRON["AWK_AD_TAG"] "\""; 
+                print "ad_tag = \"" ad_tag "\""; 
                 ad_tag_handled = 1; 
             } 
             next 
         }
-        ENVIRON["AWK_FLAG_A"] == "1" && /^\[general\]/ { 
+        flag_a == "1" && /^\[general\]/ { 
             print; 
             if (!ad_tag_handled) { 
-                print "ad_tag = \"" ENVIRON["AWK_AD_TAG"] "\""; 
+                print "ad_tag = \"" ad_tag "\""; 
                 ad_tag_handled = 1; 
             } 
             next 
@@ -446,10 +632,10 @@ install_config() {
         { print }
         ' "$tmp_conf" > "${tmp_conf}.new" && mv "${tmp_conf}.new" "$tmp_conf"
 
-        [ "$PORT_PROVIDED" -eq 1 ] && say "  -> Updated port: $SERVER_PORT"
-        [ "$SECRET_PROVIDED" -eq 1 ] && say "  -> Updated secret for user 'hello'"
-        [ "$DOMAIN_PROVIDED" -eq 1 ] && say "  -> Updated tls_domain: $TLS_DOMAIN"
-        [ "$AD_TAG_PROVIDED" -eq 1 ] && say "  -> Updated ad_tag"
+        [ "$PORT_PROVIDED" -eq 1 ] && say "  -> $L_INFO_UPD_PORT $SERVER_PORT"
+        [ "$SECRET_PROVIDED" -eq 1 ] && say "  -> $L_INFO_UPD_SEC"
+        [ "$DOMAIN_PROVIDED" -eq 1 ] && say "  -> $L_INFO_UPD_DOM $TLS_DOMAIN"
+        [ "$AD_TAG_PROVIDED" -eq 1 ] && say "  -> $L_INFO_UPD_TAG"
 
         write_root "$CONFIG_FILE" < "$tmp_conf"
         rm -f "$tmp_conf"
@@ -457,14 +643,14 @@ install_config() {
     fi
 
     if [ -z "$USER_SECRET" ]; then
-        USER_SECRET="$(generate_secret)" || die "Failed to generate secret."
+        USER_SECRET="$(generate_secret)" || die "$L_ERR_GEN_SEC"
     fi
 
-    generate_config_content "$USER_SECRET" "$AD_TAG" | write_root "$CONFIG_FILE" || die "Failed to install config"
+    generate_config_content "$USER_SECRET" "$AD_TAG" | write_root "$CONFIG_FILE" || die "$L_ERR_CONF_INST"
     $SUDO chown root:telemt "$CONFIG_FILE" && $SUDO chmod 640 "$CONFIG_FILE"
 
-    say "  -> Config created successfully."
-    say "  -> Configured secret for user 'hello': $USER_SECRET"
+    say "  -> $L_INFO_CONF_OK"
+    say "  -> $L_INFO_CONF_SEC $USER_SECRET"
 }
 
 generate_systemd_content() {
@@ -517,7 +703,7 @@ install_service() {
         $SUDO systemctl enable "$SERVICE_NAME" || true
 
         if ! $SUDO systemctl start "$SERVICE_NAME"; then
-            say "[WARNING] Failed to start service"
+            say "[WARNING] $L_WARN_SVC_FAIL"
             SERVICE_START_FAILED=1
         fi
     elif [ "$svc" = "openrc" ]; then
@@ -527,15 +713,15 @@ install_service() {
         $SUDO rc-update add "$SERVICE_NAME" default 2>/dev/null || true
 
         if ! $SUDO rc-service "$SERVICE_NAME" start 2>/dev/null; then
-            say "[WARNING] Failed to start service"
+            say "[WARNING] $L_WARN_SVC_FAIL"
             SERVICE_START_FAILED=1
         fi
     else
         cmd="\"${INSTALL_DIR}/${BIN_NAME}\" \"${CONFIG_FILE}\""
         if [ -n "$SUDO" ]; then
-            say "  -> Service manager not found. Start manually: sudo -u telemt $cmd"
+            say "  -> $L_INFO_MANUAL_START sudo -u telemt $cmd"
         else
-            say "  -> Service manager not found. Start manually: su -s /bin/sh telemt -c '$cmd'"
+            say "  -> $L_INFO_MANUAL_START su -s /bin/sh telemt -c '$cmd'"
         fi
     fi
 }
@@ -566,12 +752,12 @@ kill_user_procs() {
 }
 
 uninstall() {
-    say "Starting uninstallation of $BIN_NAME..."
+    say "$L_INFO_UNINST_START $BIN_NAME..."
 
-    say ">>> Stage 1: Stopping services"
+    say "$L_U_STAGE_1"
     stop_service
 
-    say ">>> Stage 2: Removing service configuration"
+    say "$L_U_STAGE_2"
     svc="$(get_svc_mgr)"
     if [ "$svc" = "systemd" ]; then
         $SUDO systemctl disable "$SERVICE_NAME" 2>/dev/null || true
@@ -582,28 +768,30 @@ uninstall() {
         $SUDO rm -f "/etc/init.d/${SERVICE_NAME}"
     fi
 
-    say ">>> Stage 3: Terminating user processes"
+    say "$L_U_STAGE_3"
     kill_user_procs
 
-    say ">>> Stage 4: Removing binary"
+    say "$L_U_STAGE_4"
     $SUDO rm -f "${INSTALL_DIR}/${BIN_NAME}"
 
     if [ "$ACTION" = "purge" ]; then
-        say ">>> Stage 5: Purging configuration, data, and user"
+        say "$L_U_STAGE_5"
         $SUDO rm -rf "$CONFIG_DIR" "$WORK_DIR"
         $SUDO rm -f "$CONFIG_FILE"
-        sleep 1 
-        $SUDO userdel telemt 2>/dev/null || $SUDO deluser telemt 2>/dev/null || true
+        
+        if check_os_entity passwd telemt; then
+            $SUDO userdel telemt 2>/dev/null || $SUDO deluser telemt 2>/dev/null || true
+        fi
         
         if check_os_entity group telemt; then
             $SUDO groupdel telemt 2>/dev/null || $SUDO delgroup telemt 2>/dev/null || true
         fi
     else
-        say "Note: Configuration and user kept. Run with 'purge' to remove completely."
+        say "$L_INFO_KEEP_CONF"
     fi
 
     printf '\n====================================================================\n'
-    printf '                    UNINSTALLATION COMPLETE\n'
+    printf '                    %s\n' "$L_OUT_UNINST_H"
     printf '====================================================================\n\n'
     exit 0
 }
@@ -612,21 +800,45 @@ case "$ACTION" in
     help) show_help ;;
     uninstall|purge) verify_common; uninstall ;;
     install)
-        say "Starting installation of $BIN_NAME (Version: $TARGET_VERSION)"
+        say "$L_INFO_I_START $BIN_NAME (Version: $TARGET_VERSION)"
 
-        say ">>> Stage 1: Verifying environment and dependencies"
+        say "$L_I_STAGE_1"
         verify_common
         verify_install_deps
 
-        if is_config_exists && [ "$PORT_PROVIDED" -eq 0 ]; then
+        if is_config_exists; then
             ext_port="$($SUDO awk -F'=' '/^[ \t]*port[ \t]*=/ {gsub(/[^0-9]/, "", $2); print $2; exit}' "$CONFIG_FILE" 2>/dev/null || true)"
-            if [ -n "$ext_port" ]; then
+            if [ -n "$ext_port" ] && [ "$PORT_PROVIDED" -eq 0 ]; then
                 SERVER_PORT="$ext_port"
             fi
+
+            ext_secret="$($SUDO awk -F'"' '/^[ \t]*hello[ \t]*=/ {print $2; exit}' "$CONFIG_FILE" 2>/dev/null || true)"
+            if [ -n "$ext_secret" ] && [ "$SECRET_PROVIDED" -eq 0 ]; then
+                USER_SECRET="$ext_secret"
+            fi
+
+            ext_domain="$($SUDO awk -F'"' '/^[ \t]*tls_domain[ \t]*=/ {print $2; exit}' "$CONFIG_FILE" 2>/dev/null || true)"
+            if [ -n "$ext_domain" ] && [ "$DOMAIN_PROVIDED" -eq 0 ]; then
+                TLS_DOMAIN="$ext_domain"
+            fi
         fi
 
         check_port_availability
 
+        if [ "$DOMAIN_PROVIDED" -eq 0 ]; then
+            say "$L_I_STAGE_1_5"
+            if [ -t 0 ] || [ -c /dev/tty ]; then
+                printf "$L_I_PROMPT_DOM" "$TLS_DOMAIN"
+                read -r input_domain </dev/tty || input_domain=""
+                if [ -n "$input_domain" ]; then
+                    TLS_DOMAIN="$input_domain"
+                fi
+            else
+                say "[WARNING] $L_WARN_NO_TTY $TLS_DOMAIN"
+            fi
+            DOMAIN_PROVIDED=1
+        fi
+
         if [ "$TARGET_VERSION" != "latest" ]; then
             TARGET_VERSION="${TARGET_VERSION#v}"
         fi
@@ -640,15 +852,15 @@ case "$ACTION" in
             DL_URL="https://github.com/${REPO}/releases/download/${TARGET_VERSION}/${FILE_NAME}"
         fi
 
-        say ">>> Stage 2: Downloading archive"
-        TEMP_DIR="$(mktemp -d)" || die "Temp directory creation failed"
+        say "$L_I_STAGE_2"
+        TEMP_DIR="$(mktemp -d)" || die "$L_ERR_TMP_DIR"
         if [ -z "$TEMP_DIR" ] || [ ! -d "$TEMP_DIR" ]; then
-            die "Temp directory is invalid or was not created"
+            die "$L_ERR_TMP_INV"
         fi
 
         if ! fetch_file "$DL_URL" "${TEMP_DIR}/${FILE_NAME}"; then
             if [ "$ARCH" = "x86_64-v3" ]; then
-                say "  -> x86_64-v3 build not found, falling back to standard x86_64..."
+                say "  -> $L_INFO_FALLBACK"
                 ARCH="x86_64"
                 FILE_NAME="${BIN_NAME}-${ARCH}-linux-${LIBC}.tar.gz"
                 if [ "$TARGET_VERSION" = "latest" ]; then
@@ -656,64 +868,58 @@ case "$ACTION" in
                 else
                     DL_URL="https://github.com/${REPO}/releases/download/${TARGET_VERSION}/${FILE_NAME}"
                 fi
-                fetch_file "$DL_URL" "${TEMP_DIR}/${FILE_NAME}" || die "Download failed"
+                fetch_file "$DL_URL" "${TEMP_DIR}/${FILE_NAME}" || die "$L_ERR_DL_FAIL"
             else
-                die "Download failed"
+                die "$L_ERR_DL_FAIL"
             fi
         fi
 
-        say ">>> Stage 3: Extracting archive"
+        say "$L_I_STAGE_3"
         if ! gzip -dc "${TEMP_DIR}/${FILE_NAME}" | tar -xf - -C "$TEMP_DIR" 2>/dev/null; then
-            die "Extraction failed (downloaded archive might be invalid or 404)."
+            die "$L_ERR_EXTRACT"
         fi
 
         EXTRACTED_BIN="$(find "$TEMP_DIR" -type f -name "$BIN_NAME" -print 2>/dev/null | head -n 1 || true)"
-        [ -n "$EXTRACTED_BIN" ] || die "Binary '$BIN_NAME' not found in archive"
+        [ -n "$EXTRACTED_BIN" ] || die "$L_ERR_BIN_NOT_FOUND"
 
-        say ">>> Stage 4: Setting up environment (User, Group, Directories)"
+        say "$L_I_STAGE_4"
         ensure_user_group; setup_dirs; stop_service
 
-        say ">>> Stage 5: Installing binary"
+        say "$L_I_STAGE_5"
         install_binary "$EXTRACTED_BIN" "${INSTALL_DIR}/${BIN_NAME}"
 
-        say ">>> Stage 6: Generating/Updating configuration"
+        say "$L_I_STAGE_6"
         install_config
 
-        say ">>> Stage 7: Installing and starting service"
+        say "$L_I_STAGE_7"
         install_service
 
         if [ "${SERVICE_START_FAILED:-0}" -eq 1 ]; then
             printf '\n====================================================================\n'
-            printf '               INSTALLATION COMPLETED WITH WARNINGS\n'
+            printf '               %s\n' "$L_OUT_WARN_H"
             printf '====================================================================\n\n'
-            printf 'The service was installed but failed to start automatically.\n'
-            printf 'Please check the logs to determine the issue.\n\n'
+            printf '%b' "$L_OUT_WARN_D"
         else
             printf '\n====================================================================\n'
-            printf '                      INSTALLATION SUCCESS\n'
+            printf '                      %s\n' "$L_OUT_SUCC_H"
             printf '====================================================================\n\n'
         fi
 
-        svc="$(get_svc_mgr)"
-        if [ "$svc" = "systemd" ]; then
-            printf 'To check the status of your proxy service, run:\n'
-            printf '  systemctl status %s\n\n' "$SERVICE_NAME"
-        elif [ "$svc" = "openrc" ]; then
-            printf 'To check the status of your proxy service, run:\n'
-            printf '  rc-service %s status\n\n' "$SERVICE_NAME"
-        fi
+        SERVER_IP=""
+        if command -v curl >/dev/null 2>&1; then SERVER_IP="$(curl -s4 -m 3 ifconfig.me 2>/dev/null || curl -s4 -m 3 api.ipify.org 2>/dev/null || true)"
+        elif command -v wget >/dev/null 2>&1; then SERVER_IP="$(wget -qO- -T 3 ifconfig.me 2>/dev/null || wget -qO- -T 3 api.ipify.org 2>/dev/null || true)"; fi
+        [ -z "$SERVER_IP" ] && SERVER_IP="<YOUR_SERVER_IP>"
+        
+        if command -v xxd >/dev/null 2>&1; then HEX_DOMAIN="$(printf '%s' "$TLS_DOMAIN" | xxd -p | tr -d '\n')"
+        elif command -v hexdump >/dev/null 2>&1; then HEX_DOMAIN="$(printf '%s' "$TLS_DOMAIN" | hexdump -v -e '/1 "%02x"')"
+        elif command -v od >/dev/null 2>&1; then HEX_DOMAIN="$(printf '%s' "$TLS_DOMAIN" | od -A n -t x1 | tr -d ' \n')"
+        else HEX_DOMAIN=""; fi
 
-        API_LISTEN="$($SUDO awk -F'"' '/^[ \t]*listen[ \t]*=/ {print $2; exit}' "$CONFIG_FILE" 2>/dev/null || true)"
-        API_LISTEN="${API_LISTEN:-127.0.0.1:9091}"
+        CLIENT_SECRET="ee${USER_SECRET}${HEX_DOMAIN}"
 
-        printf 'To get your user connection links (for Telegram), run:\n'
-        if command -v jq >/dev/null 2>&1; then
-            printf '  curl -s http://%s/v1/users | jq -r '\''.data[]? | "User: \\(.username)\\n\\(.links.tls[0] // empty)\\n"'\''\n' "$API_LISTEN"
-        else
-            printf '  curl -s http://%s/v1/users\n' "$API_LISTEN"
-            printf '  (Tip: Install '\''jq'\'' for a much cleaner output)\n'
-        fi
+        printf '%b\n' "$L_OUT_LINK"
+        printf '  tg://proxy?server=%s&port=%s&secret=%s\n\n' "$SERVER_IP" "$SERVER_PORT" "$CLIENT_SECRET"
 
-        printf '\n====================================================================\n'
+        printf '====================================================================\n'
         ;;
 esac