diff --git a/gotelegram-bot/bot.py b/gotelegram-bot/bot.py
index 8c4ade7..999e49a 100644
--- a/gotelegram-bot/bot.py
+++ b/gotelegram-bot/bot.py
@@ -100,7 +100,7 @@ logger = logging.getLogger(__name__)
 # CONFIGURATION
 # ============================================================================
 
-GOTELEGRAM_VERSION = "2.4.2"
+GOTELEGRAM_VERSION = "2.4.3"
 GOTELEGRAM_CONFIG = "/opt/gotelegram/config.json"
 TELEMT_CONFIG = "/etc/telemt/config.toml"
 TELEMT_SERVICE = "telemt"
diff --git a/install.sh b/install.sh
index fa1c0cf..4e0e8be 100755
--- a/install.sh
+++ b/install.sh
@@ -1323,8 +1323,45 @@ bot_action_change_lite_domain() {
     return 0
 }
 
-# Main dispatcher — called from main() when --action=X is present
+# Main dispatcher — called from main() when --action=X is present.
+# Uses a file lock (flock) so concurrent CLI invocations (from multiple bot
+# users, or from bot + manual CLI) serialize cleanly. Without this, two
+# parallel `change-lite-domain` calls raced on the jq-rewrite of config.json
+# and one process would see a truncated file ("no secret in config").
 bot_action_dispatch() {
+    local lock_file="/var/lock/gotelegram-bot-action.lock"
+    # Make sure /var/lock exists (it does on Debian/Ubuntu; be defensive for minimal images)
+    [ -d /var/lock ] || mkdir -p /var/lock 2>/dev/null || true
+
+    if command -v flock >/dev/null 2>&1; then
+        # Wait up to 30 seconds for the lock — bot actions are fast (<5s
+        # typical), so 30s is plenty for legitimate serialization but short
+        # enough to surface a stuck process.
+        (
+            flock -w 30 9 || {
+                # If we time out, emit JSON error for the bot parent.
+                local json_out=0 a
+                for a in "$@"; do
+                    [ "$a" = "--json" ] && json_out=1
+                done
+                if [ "$json_out" = "1" ]; then
+                    bot_emit_json "error" "another action in progress (lock timeout)" "code=lock_timeout"
+                fi
+                exit 75  # EX_TEMPFAIL
+            }
+            _bot_action_dispatch_locked "$@"
+        ) 9>"$lock_file"
+        return $?
+    else
+        # No flock installed — run unlocked with a warning. ensure_deps/check_deps
+        # normally ensures util-linux is present, so this branch is defensive.
+        log_warning "flock not available — bot actions not serialized"
+        _bot_action_dispatch_locked "$@"
+        return $?
+    fi
+}
+
+_bot_action_dispatch_locked() {
     local action="" tpl_id="" domain="" json_out=0 arg
     for arg in "$@"; do
         case "$arg" in
diff --git a/lib/common.sh b/lib/common.sh
old mode 100755
new mode 100644
index 4366676..536e1a8
--- a/lib/common.sh
+++ b/lib/common.sh
@@ -3,7 +3,7 @@
 # Colors, logging, spinner, system helpers, v1 compat, i18n-aware
 
 # ── Version ───────────────────────────────────────────────────────────────────
-GOTELEGRAM_VERSION="2.4.2"
+GOTELEGRAM_VERSION="2.4.3"
 GOTELEGRAM_NAME="GoTelegram"
 
 # ── Пути ──────────────────────────────────────────────────────────────────────
@@ -277,6 +277,7 @@ apt_pkg_for_cmd() {
         host)      echo "dnsutils" ;;
         ss)        echo "iproute2" ;;
         netstat)   echo "net-tools" ;;
+        flock)     echo "util-linux" ;;
         *)         echo "$1" ;;            # команда == имя пакета
     esac
 }
@@ -287,13 +288,17 @@ dnf_pkg_for_cmd() {
         xxd)               echo "vim-common" ;;
         ss)                echo "iproute" ;;
         netstat)           echo "net-tools" ;;
+        flock)             echo "util-linux" ;;
         *)                 echo "$1" ;;
     esac
 }
 
 ensure_deps() {
-    # Критические зависимости — без них скрипт не работает
-    local critical=(curl jq openssl git xxd tar dig)
+    # Критические зависимости — без них скрипт не работает.
+    # flock используется bot_action_dispatch для сериализации параллельных
+    # вызовов (иначе гонка на config.json при одновременных change-template /
+    # change-lite-domain из бота).
+    local critical=(curl jq openssl git xxd tar dig flock)
     # Желательные — есть fallback, устанавливать всё равно, но не падать если не смогли
     local optional=(qrencode bc)
 
@@ -386,7 +391,7 @@ ensure_deps() {
 # main() чтобы не дёргать apt-get update при каждом запуске меню.
 check_deps_present() {
     local cmd
-    for cmd in curl jq openssl git xxd tar dig; do
+    for cmd in curl jq openssl git xxd tar dig flock; do
         command -v "$cmd" &>/dev/null || return 1
     done
     return 0