diff --git a/src/command/adapters/websocket.rs b/src/command/adapters/websocket.rs
index 148d867..e089978 100644
--- a/src/command/adapters/websocket.rs
+++ b/src/command/adapters/websocket.rs
@@ -78,7 +78,7 @@ impl OutputAdapter for WebSocketOutputAdapter {
                     id: response.request_id.to_string(),
                     content: msg.content.clone(),
                     role: "assistant".to_string(),
-                    attachments: Vec::new(), subagent_task_id: None, timestamp: Some(crate::protocol::now_timestamp()),
+                    attachments: Vec::new(), subagent_task_id: None, topic_id: None, timestamp: Some(crate::protocol::now_timestamp()),
                 },
                 MessageKind::Notification => {
                     // 根据元数据判断具体类型
@@ -98,7 +98,7 @@ impl OutputAdapter for WebSocketOutputAdapter {
                                 id: response.request_id.to_string(),
                                 content: msg.content.clone(),
                                 role: "assistant".to_string(),
-                                attachments: Vec::new(), subagent_task_id: None, timestamp: Some(crate::protocol::now_timestamp()),
+                                attachments: Vec::new(), subagent_task_id: None, topic_id: None, timestamp: Some(crate::protocol::now_timestamp()),
                             },
                         }
                     } else if let Some(session_id) = response.metadata.get("session_id") {
@@ -137,7 +137,7 @@ impl OutputAdapter for WebSocketOutputAdapter {
                                 id: response.request_id.to_string(),
                                 content: msg.content.clone(),
                                 role: "assistant".to_string(),
-                                attachments: Vec::new(), subagent_task_id: None, timestamp: Some(crate::protocol::now_timestamp()),
+                                attachments: Vec::new(), subagent_task_id: None, topic_id: None, timestamp: Some(crate::protocol::now_timestamp()),
                             },
                         }
                     } else if let Some(sessions_json) = response.metadata.get("sessions") {
@@ -155,7 +155,7 @@ impl OutputAdapter for WebSocketOutputAdapter {
                                 id: response.request_id.to_string(),
                                 content: msg.content.clone(),
                                 role: "assistant".to_string(),
-                                attachments: Vec::new(), subagent_task_id: None, timestamp: Some(crate::protocol::now_timestamp()),
+                                attachments: Vec::new(), subagent_task_id: None, topic_id: None, timestamp: Some(crate::protocol::now_timestamp()),
                             },
                         }
                     } else if let Some(topics_json) = response.metadata.get("topics") {
@@ -174,7 +174,7 @@ impl OutputAdapter for WebSocketOutputAdapter {
                                 id: response.request_id.to_string(),
                                 content: msg.content.clone(),
                                 role: "assistant".to_string(),
-                                attachments: Vec::new(), subagent_task_id: None, timestamp: Some(crate::protocol::now_timestamp()),
+                                attachments: Vec::new(), subagent_task_id: None, topic_id: None, timestamp: Some(crate::protocol::now_timestamp()),
                             },
                         }
                     } else {
@@ -183,7 +183,7 @@ impl OutputAdapter for WebSocketOutputAdapter {
                             id: response.request_id.to_string(),
                             content: msg.content.clone(),
                             role: "assistant".to_string(),
-                            attachments: Vec::new(), subagent_task_id: None, timestamp: Some(crate::protocol::now_timestamp()),
+                            attachments: Vec::new(), subagent_task_id: None, topic_id: None, timestamp: Some(crate::protocol::now_timestamp()),
                         }
                     }
                 }
@@ -196,7 +196,7 @@ impl OutputAdapter for WebSocketOutputAdapter {
                     id: response.request_id.to_string(),
                     content: msg.content.clone(),
                     role: "assistant".to_string(),
-                    attachments: Vec::new(), subagent_task_id: None, timestamp: Some(crate::protocol::now_timestamp()),
+                    attachments: Vec::new(), subagent_task_id: None, topic_id: None, timestamp: Some(crate::protocol::now_timestamp()),
                 },
             };
             outbounds.push(outbound);
diff --git a/src/gateway/processor.rs b/src/gateway/processor.rs
index 036c2f8..5335132 100644
--- a/src/gateway/processor.rs
+++ b/src/gateway/processor.rs
@@ -244,12 +244,17 @@ impl InboundProcessor {
         }
 
         // 普通消息进入 AgentLoop
+        // 构建 emitter metadata：包含 forwarded_metadata 和 topic_id（用于前端消息隔离）
+        let mut emitter_metadata = inbound.forwarded_metadata.clone();
+        if let Some(ref topic_id) = current_topic {
+            emitter_metadata.insert("topic_id".to_string(), topic_id.clone());
+        }
         let live_emitter = Arc::new(PersistingEmittedMessageHandler::new(
             BusToolCallEmitter::new(
                 self.bus.clone(),
                 inbound.channel.clone(),
                 inbound.chat_id.clone(),
-                inbound.forwarded_metadata.clone(),
+                emitter_metadata,
             ),
             self.session_manager.store(),
             &session_id,
@@ -283,6 +288,10 @@ impl InboundProcessor {
             Ok(outbound_messages) => {
                 for mut outbound in outbound_messages {
                     outbound.metadata.extend(inbound.forwarded_metadata.clone());
+                    // 注入 topic_id 到 outbound metadata，用于前端按话题隔离消息
+                    if let Some(ref topic_id) = current_topic {
+                        outbound.metadata.insert("topic_id".to_string(), topic_id.clone());
+                    }
                     if let Err(error) = self.bus.publish_outbound(outbound).await {
                         tracing::error!(error = %error, "Failed to publish outbound");
                     }
diff --git a/src/gateway/ws.rs b/src/gateway/ws.rs
index c9a9b37..c0d8e06 100644
--- a/src/gateway/ws.rs
+++ b/src/gateway/ws.rs
@@ -717,6 +717,7 @@ fn chat_message_to_ws_outbound(msg: &crate::bus::ChatMessage) -> Option<WsOutbou
                         content: format!("{}\nargs: {}", tool_call.name, tool_call.arguments),
                         role: msg.role.clone(),
                         subagent_task_id: None,
+                        topic_id: None,
                         timestamp: Some(crate::protocol::now_timestamp()),
                     });
                 }
@@ -728,6 +729,7 @@ fn chat_message_to_ws_outbound(msg: &crate::bus::ChatMessage) -> Option<WsOutbou
                 role: msg.role.clone(),
                 attachments: Vec::new(),
                 subagent_task_id: None,
+                topic_id: None,
                 timestamp: Some(crate::protocol::now_timestamp()),
             })
         }
@@ -741,6 +743,7 @@ fn chat_message_to_ws_outbound(msg: &crate::bus::ChatMessage) -> Option<WsOutbou
                     content: msg.content.clone(),
                     role: msg.role.clone(),
                     subagent_task_id: None,
+                    topic_id: None,
                     duration_ms: msg.tool_duration_ms,
                     timestamp: Some(crate::protocol::now_timestamp()),
                 }),
@@ -752,6 +755,7 @@ fn chat_message_to_ws_outbound(msg: &crate::bus::ChatMessage) -> Option<WsOutbou
                     role: msg.role.clone(),
                     resume_hint: "完成外部操作后，直接发一条继续消息即可。".to_string(),
                     subagent_task_id: None,
+                    topic_id: None,
                     timestamp: Some(crate::protocol::now_timestamp()),
                 }),
             }
@@ -762,6 +766,7 @@ fn chat_message_to_ws_outbound(msg: &crate::bus::ChatMessage) -> Option<WsOutbou
             role: msg.role.clone(),
             attachments,
             subagent_task_id: None,
+            topic_id: None,
             timestamp: Some(crate::protocol::now_timestamp()),
         }),
         _ => None,
diff --git a/src/protocol/mod.rs b/src/protocol/mod.rs
index dca8b4a..440b28e 100644
--- a/src/protocol/mod.rs
+++ b/src/protocol/mod.rs
@@ -117,6 +117,8 @@ pub enum WsOutbound {
         #[serde(default, skip_serializing_if = "Option::is_none")]
         subagent_task_id: Option<String>,
         #[serde(default, skip_serializing_if = "Option::is_none")]
+        topic_id: Option<String>,
+        #[serde(default, skip_serializing_if = "Option::is_none")]
         timestamp: Option<i64>,
     },
     #[serde(rename = "tool_call")]
@@ -130,6 +132,8 @@ pub enum WsOutbound {
         #[serde(default, skip_serializing_if = "Option::is_none")]
         subagent_task_id: Option<String>,
         #[serde(default, skip_serializing_if = "Option::is_none")]
+        topic_id: Option<String>,
+        #[serde(default, skip_serializing_if = "Option::is_none")]
         timestamp: Option<i64>,
     },
     #[serde(rename = "tool_result")]
@@ -142,6 +146,8 @@ pub enum WsOutbound {
         #[serde(default, skip_serializing_if = "Option::is_none")]
         subagent_task_id: Option<String>,
         #[serde(default, skip_serializing_if = "Option::is_none")]
+        topic_id: Option<String>,
+        #[serde(default, skip_serializing_if = "Option::is_none")]
         duration_ms: Option<u64>,
         #[serde(default, skip_serializing_if = "Option::is_none")]
         timestamp: Option<i64>,
@@ -157,6 +163,8 @@ pub enum WsOutbound {
         #[serde(default, skip_serializing_if = "Option::is_none")]
         subagent_task_id: Option<String>,
         #[serde(default, skip_serializing_if = "Option::is_none")]
+        topic_id: Option<String>,
+        #[serde(default, skip_serializing_if = "Option::is_none")]
         timestamp: Option<i64>,
     },
     #[serde(rename = "error")]
diff --git a/src/protocol/ws_adapter.rs b/src/protocol/ws_adapter.rs
index 14a35cb..5a7097b 100644
--- a/src/protocol/ws_adapter.rs
+++ b/src/protocol/ws_adapter.rs
@@ -22,6 +22,8 @@ pub(crate) fn ws_outbound_from_chat_message(message: &ChatMessage) -> Vec<WsOutb
                         role: message.role.clone(),
                         attachments: Vec::new(),
                         subagent_task_id: None,
+                        topic_id: None,
+                        timestamp: None,
                     });
                 }
 
@@ -33,6 +35,8 @@ pub(crate) fn ws_outbound_from_chat_message(message: &ChatMessage) -> Vec<WsOutb
                     content: format_tool_call_content(&tool_call.name, &tool_call.arguments),
                     role: message.role.clone(),
                     subagent_task_id: None,
+                    topic_id: None,
+                    timestamp: None,
                 }));
                 outbound
             } else {
@@ -42,6 +46,8 @@ pub(crate) fn ws_outbound_from_chat_message(message: &ChatMessage) -> Vec<WsOutb
                     role: message.role.clone(),
                     attachments: Vec::new(),
                     subagent_task_id: None,
+                    topic_id: None,
+                    timestamp: None,
                 }]
             }
         }
@@ -57,7 +63,9 @@ pub(crate) fn ws_outbound_from_chat_message(message: &ChatMessage) -> Vec<WsOutb
                 content: message.content.clone(),
                 role: message.role.clone(),
                 subagent_task_id: None,
+                topic_id: None,
                 duration_ms: None,
+                timestamp: None,
             }],
             ToolMessageState::PendingUserAction => vec![WsOutbound::ToolPending {
                 id: message.id.clone(),
@@ -67,6 +75,8 @@ pub(crate) fn ws_outbound_from_chat_message(message: &ChatMessage) -> Vec<WsOutb
                 role: message.role.clone(),
                 resume_hint: TOOL_PENDING_RESUME_HINT.to_string(),
                 subagent_task_id: None,
+                topic_id: None,
+                timestamp: None,
             }],
         },
         _ => Vec::new(),
@@ -93,6 +103,7 @@ pub(crate) fn ws_outbound_from_outbound_message(message: &OutboundMessage) -> Ve
                 role: message.role.clone(),
                 attachments,
                 subagent_task_id: message.metadata.get("subagent_task_id").cloned(),
+                topic_id: message.metadata.get("topic_id").cloned(),
                 timestamp: Some(crate::protocol::now_timestamp()),
             }]
         }
@@ -110,6 +121,7 @@ pub(crate) fn ws_outbound_from_outbound_message(message: &OutboundMessage) -> Ve
             content: message.content.clone(),
             role: message.role.clone(),
             subagent_task_id: message.metadata.get("subagent_task_id").cloned(),
+            topic_id: message.metadata.get("topic_id").cloned(),
             timestamp: Some(crate::protocol::now_timestamp()),
         }],
         OutboundEventKind::ToolResult => vec![WsOutbound::ToolResult {
@@ -122,6 +134,7 @@ pub(crate) fn ws_outbound_from_outbound_message(message: &OutboundMessage) -> Ve
             content: message.content.clone(),
             role: message.role.clone(),
             subagent_task_id: message.metadata.get("subagent_task_id").cloned(),
+            topic_id: message.metadata.get("topic_id").cloned(),
             duration_ms: message
                 .metadata
                 .get("tool_duration_ms")
@@ -139,6 +152,7 @@ pub(crate) fn ws_outbound_from_outbound_message(message: &OutboundMessage) -> Ve
             role: message.role.clone(),
             resume_hint: TOOL_PENDING_RESUME_HINT.to_string(),
             subagent_task_id: message.metadata.get("subagent_task_id").cloned(),
+            topic_id: message.metadata.get("topic_id").cloned(),
             timestamp: Some(crate::protocol::now_timestamp()),
         }],
         OutboundEventKind::ErrorNotification => vec![WsOutbound::Error {
diff --git a/web/src/hooks/useChat.ts b/web/src/hooks/useChat.ts
index 4a190d6..2bbec72 100644
--- a/web/src/hooks/useChat.ts
+++ b/web/src/hooks/useChat.ts
@@ -392,6 +392,8 @@ export function useChat(): UseChatReturn {
 
       case 'assistant_response': {
         const msg = message as AssistantResponse
+        // 按 topic_id 隔离：如果消息属于其他话题则丢弃
+        if (msg.topic_id && msg.topic_id !== selectedTopicRef.current) return
         const role = msg.role === 'user' || msg.role === 'tool' ? msg.role : 'assistant'
         setMessages((prev) => [
           ...prev,
@@ -416,6 +418,8 @@ export function useChat(): UseChatReturn {
 
       case 'tool_call': {
         const msg = message as ToolCall
+        // 按 topic_id 隔离：如果消息属于其他话题则丢弃
+        if (msg.topic_id && msg.topic_id !== selectedTopicRef.current) return
         setMessages((prev) => [
           ...prev,
           {
@@ -435,6 +439,8 @@ export function useChat(): UseChatReturn {
 
       case 'tool_result': {
         const msg = message as ToolResult
+        // 按 topic_id 隔离：如果消息属于其他话题则丢弃
+        if (msg.topic_id && msg.topic_id !== selectedTopicRef.current) return
         setMessages((prev) => [
           ...prev,
           {
@@ -454,6 +460,8 @@ export function useChat(): UseChatReturn {
 
       case 'tool_pending': {
         const msg = message as ToolPending
+        // 按 topic_id 隔离：如果消息属于其他话题则丢弃
+        if (msg.topic_id && msg.topic_id !== selectedTopicRef.current) return
         setMessages((prev) => [
           ...prev,
           {
diff --git a/web/src/types/protocol.ts b/web/src/types/protocol.ts
index 6e0ba2e..4154a3e 100644
--- a/web/src/types/protocol.ts
+++ b/web/src/types/protocol.ts
@@ -43,6 +43,7 @@ export interface AssistantResponse {
   role: string
   attachments?: Attachment[]
   subagent_task_id?: string
+  topic_id?: string
   timestamp?: number
 }
 
@@ -55,6 +56,7 @@ export interface ToolCall {
   content: string
   role: string
   subagent_task_id?: string
+  topic_id?: string
   timestamp?: number
 }
 
@@ -66,6 +68,7 @@ export interface ToolResult {
   content: string
   role: string
   subagent_task_id?: string
+  topic_id?: string
   duration_ms?: number
   timestamp?: number
 }
@@ -79,6 +82,7 @@ export interface ToolPending {
   role: string
   resume_hint: string
   subagent_task_id?: string
+  topic_id?: string
   timestamp?: number
 }