diff --git a/include/app_config.hpp b/include/app_config.hpp
index ecc44ef..5a041e2 100644
--- a/include/app_config.hpp
+++ b/include/app_config.hpp
@@ -76,9 +76,6 @@ struct AppConfig
     std::vector<Camera> cameras;
     MQTTConfig mqtt;
 
-    // ⭐ 运行期从 orin 获取的 VID（优先生效）
-    std::string runtime_vid;
-
     static AppConfig load_from_file(const std::string& filepath)
     {
         AppConfig cfg;
diff --git a/src/mqtt_client_wrapper.cpp b/src/mqtt_client_wrapper.cpp
index 6728dd1..680681e 100644
--- a/src/mqtt_client_wrapper.cpp
+++ b/src/mqtt_client_wrapper.cpp
@@ -19,47 +19,6 @@ std::atomic<bool> g_streaming{false};
 std::string g_dispatch_id;
 std::mutex g_dispatch_id_mutex;
 
-static std::atomic<bool> g_mqtt_activated{false};
-static std::string g_last_vid;
-static VehicleMQTTTopics g_prev_topics;
-
-static bool try_activate_mqtt()
-{
-    if (g_app_config.runtime_vid.empty()) return false;
-    if (!mqtt_client || !mqtt_client->isConnected()) return false;
-
-    // 如果已激活且 VID 未变化，什么都不做
-    if (g_mqtt_activated.load() && g_last_vid == g_app_config.runtime_vid) return true;
-
-    // ---------- 1. 如果是 VID 变化，先取消旧订阅 ----------
-    if (g_mqtt_activated.load())
-    {
-        LOG_INFO("[MQTT] VID changed, unsubscribe old topics: " + g_last_vid);
-
-        mqtt_client->unsubscribe(g_prev_topics.video_down);
-        mqtt_client->unsubscribe(g_prev_topics.record_query);
-        mqtt_client->unsubscribe(g_prev_topics.record_play);
-        mqtt_client->unsubscribe(g_prev_topics.vehicle_ctrl);
-        mqtt_client->unsubscribe(g_prev_topics.heartbeat_up);
-    }
-
-    // ---------- 2. 切换到新 VID ----------
-    g_app_config.mqtt.topics.fill_with_veh_id(g_app_config.runtime_vid);
-    g_prev_topics = g_app_config.mqtt.topics;
-    g_last_vid = g_app_config.runtime_vid;
-
-    LOG_INFO("[MQTT] Activated with VID=" + g_last_vid);
-
-    // ---------- 3. 订阅新 topic ----------
-    mqtt_client->subscribe(g_app_config.mqtt.topics.video_down);
-    mqtt_client->subscribe(g_app_config.mqtt.topics.record_query);
-    mqtt_client->subscribe(g_app_config.mqtt.topics.record_play);
-    mqtt_client->subscribe(g_app_config.mqtt.topics.vehicle_ctrl);
-
-    g_mqtt_activated.store(true);
-    return true;
-}
-
 static void send_heartbeat()
 {
     if (!mqtt_client || !mqtt_client->isConnected()) return;
@@ -110,7 +69,14 @@ static void send_heartbeat()
 static void on_mqtt_connected()
 {
     LOG_INFO("[MQTT] Connected to broker: " + g_app_config.mqtt.server_ip);
-    g_mqtt_activated.store(false);  // 重连后需要重新激活
+
+    // 一次性订阅（VID 来自配置文件，永远不变）
+    mqtt_client->subscribe(g_app_config.mqtt.topics.video_down);
+    mqtt_client->subscribe(g_app_config.mqtt.topics.record_query);
+    mqtt_client->subscribe(g_app_config.mqtt.topics.record_play);
+    mqtt_client->subscribe(g_app_config.mqtt.topics.vehicle_ctrl);
+
+    LOG_INFO("[MQTT] Subscribed all topics for VID=" + g_app_config.mqtt.vehicle_id);
 }
 
 static void on_mqtt_disconnected() { LOG_WARN("[MQTT] Disconnected from broker: " + g_app_config.mqtt.server_ip); }
@@ -401,12 +367,8 @@ void mqtt_client_thread_func()
         // 主循环：心跳
         while (g_running && mqtt_client->isConnected())
         {
-            try_activate_mqtt();  // VID 到来时触发订阅
+            send_heartbeat();
 
-            if (g_mqtt_activated.load())
-            {
-                send_heartbeat();
-            }
             auto sleep_time = heartbeat_interval;
             while (sleep_time.count() > 0 && g_running && mqtt_client->isConnected())
             {
diff --git a/src/serial_AT.cpp b/src/serial_AT.cpp
index f6943bd..470998c 100644
--- a/src/serial_AT.cpp
+++ b/src/serial_AT.cpp
@@ -65,44 +65,19 @@ void start_http_server(int port)
                               return;
                           }
 
-                          // ---------- 2. 解析请求体（尝试获取 VID） ----------
-                          std::string vid;
+                          // ---------- 2. 请求体当前不承载身份（忽略即可） ----------
                           if (!req.body.empty())
                           {
-                              try
-                              {
-                                  auto jreq = nlohmann::json::parse(req.body);
-                                  if (jreq.contains("vid") && jreq["vid"].is_string())
-                                  {
-                                      vid = jreq["vid"].get<std::string>();
-                                      LOG_INFO("[http] register vid = " + vid);
-
-                                      // ⭐ 运行期 VID：只记录，不判断
-                                      g_app_config.runtime_vid = vid;
-                                  }
-                              }
-                              catch (const std::exception& e)
-                              {
-                                  LOG_WARN(std::string("[http] invalid json payload: ") + e.what());
-                              }
-                          }
-                          else
-                          {
-                              LOG_WARN("[http] empty register payload");
+                              LOG_INFO("[http] register payload ignored");
                           }
 
-                          // ---------- 3. 返回 B 的身份 ----------
-                          std::string imei = get_imei();
-
+                          // ---------- 3. 返回 B 的身份（唯一事实源） ----------
                           nlohmann::json jres;
                           jres["ok"] = true;
-                          jres["server"] = {{"device_type", "neardi"}, {"imei", imei}, {"fw", "b-v2.1.0"}};
-
-                          // 可选：把 vid 回显（方便 A / 调试）
-                          if (!vid.empty())
-                          {
-                              jres["peer"] = {{"vid", vid}};
-                          }
+                          jres["device"] = {{"device_type", "neardi"},
+                                            {"imei", get_imei()},
+                                            {"vid", g_app_config.mqtt.vehicle_id},
+                                            {"fw", "b-v2.1.0"}};
 
                           res.set_content(jres.dump(), "application/json");
                       });