diff --git a/Cargo.toml b/Cargo.toml
index af5c027..d6633e5 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -19,3 +19,6 @@ futures-util = "0.3"
 clap = { version = "4", features = ["derive"] }
 dirs = "6.0.0"
 prost = "0.14"
+tracing = "0.1"
+tracing-subscriber = { version = "0.3", features = ["env-filter", "json"] }
+tracing-appender = "0.2"
diff --git a/src/agent/agent_loop.rs b/src/agent/agent_loop.rs
index ee2134b..4555cc3 100644
--- a/src/agent/agent_loop.rs
+++ b/src/agent/agent_loop.rs
@@ -29,6 +29,8 @@ impl AgentLoop {
             })
             .collect();
 
+        tracing::debug!(history_len = self.history.len(), "Sending request to LLM");
+
         let request = ChatCompletionRequest {
             messages,
             temperature: None,
@@ -37,7 +39,12 @@ impl AgentLoop {
         };
 
         let response = (*self.provider).chat(request).await
-            .map_err(|e| AgentError::LlmError(e.to_string()))?;
+            .map_err(|e| {
+                tracing::error!(error = %e, "LLM request failed");
+                AgentError::LlmError(e.to_string())
+            })?;
+
+        tracing::debug!(response_len = response.content.len(), "LLM response received");
 
         let assistant_message = ChatMessage::assistant(response.content);
         self.history.push(assistant_message.clone());
@@ -46,7 +53,9 @@ impl AgentLoop {
     }
 
     pub fn clear_history(&mut self) {
+        let len = self.history.len();
         self.history.clear();
+        tracing::debug!(previous_len = len, "Chat history cleared");
     }
 
     pub fn history(&self) -> &[ChatMessage] {
diff --git a/src/channels/feishu.rs b/src/channels/feishu.rs
index e8ec13b..c982acb 100644
--- a/src/channels/feishu.rs
+++ b/src/channels/feishu.rs
@@ -264,7 +264,7 @@ impl FeishuChannel {
 
     /// Handle incoming message - delegate to message handler and send response
     async fn handle_message(&self, open_id: &str, chat_id: &str, content: &str) -> Result<(), ChannelError> {
-        println!("Feishu: processing message from {} in chat {}: {}", open_id, chat_id, content);
+        tracing::info!(open_id, chat_id, "Processing message from Feishu");
 
         // Delegate to message handler (Gateway)
         let response = self.message_handler
@@ -277,7 +277,7 @@ impl FeishuChannel {
         let receive_id_type = if chat_id.starts_with("oc_") { "chat_id" } else { "open_id" };
 
         self.send_message(receive_id, receive_id_type, &response).await?;
-        println!("Feishu: sent response to {}", receive_id);
+        tracing::info!(receive_id, "Sent response to Feishu");
 
         Ok(())
     }
@@ -363,14 +363,14 @@ impl FeishuChannel {
         let (wss_url, client_config) = self.get_ws_endpoint(&self.http_client).await?;
 
         let service_id = Self::extract_service_id(&wss_url);
-        println!("Feishu: connecting to {}", wss_url);
+        tracing::info!(url = %wss_url, "Connecting to Feishu WebSocket");
 
         let (ws_stream, _) = tokio_tungstenite::connect_async(&wss_url)
             .await
             .map_err(|e| ChannelError::ConnectionError(format!("WebSocket connection failed: {}", e)))?;
 
         *self.connected.write().await = true;
-        println!("Feishu channel connected");
+        tracing::info!("Feishu WebSocket connected");
 
         let (mut write, mut read) = ws_stream.split();
 
@@ -409,20 +409,20 @@ impl FeishuChannel {
                                     Ok(Some(parsed)) => {
                                         // Send ACK immediately (Feishu requires within 3 s)
                                         if let Err(e) = Self::send_ack(&frame, &mut write).await {
-                                            eprintln!("Error sending ack: {}", e);
+                                            tracing::error!(error = %e, "Failed to send ACK to Feishu");
                                         }
 
                                         // Then process message asynchronously (don't await)
                                         let channel = self.clone();
                                         tokio::spawn(async move {
                                             if let Err(e) = channel.handle_message(&parsed.open_id, &parsed.chat_id, &parsed.content).await {
-                                                eprintln!("Error handling message: {}", e);
+                                                tracing::error!(error = %e, open_id = %parsed.open_id, chat_id = %parsed.chat_id, "Failed to handle Feishu message");
                                             }
                                         });
                                     }
                                     Ok(None) => {}
                                     Err(e) => {
-                                        eprintln!("Error handling frame: {}", e);
+                                        tracing::warn!(error = %e, "Failed to parse Feishu frame");
                                     }
                                 }
                             }
@@ -442,10 +442,11 @@ impl FeishuChannel {
                             let _ = write.send(tokio_tungstenite::tungstenite::Message::Binary(pong.encode_to_vec().into())).await;
                         }
                         Some(Ok(tokio_tungstenite::tungstenite::Message::Close(_))) | None => {
+                            tracing::debug!("Feishu WebSocket closed");
                             break;
                         }
                         Some(Err(e)) => {
-                            eprintln!("WS error: {}", e);
+                            tracing::warn!(error = %e, "Feishu WebSocket error");
                             break;
                         }
                         _ => {}
@@ -465,12 +466,12 @@ impl FeishuChannel {
                         payload: None,
                     };
                     if write.send(tokio_tungstenite::tungstenite::Message::Binary(ping.encode_to_vec().into())).await.is_err() {
-                        eprintln!("Feishu: ping failed, reconnecting");
+                        tracing::warn!("Feishu ping failed, reconnecting");
                         break;
                     }
                 }
                 _ = shutdown_rx.recv() => {
-                    println!("Feishu channel shutdown signal received");
+                    tracing::info!("Feishu channel shutdown signal received");
                     break;
                 }
             }
@@ -552,13 +553,13 @@ impl Channel for FeishuChannel {
                 let shutdown_rx = shutdown_tx.subscribe();
                 match channel.run_ws_loop(shutdown_rx).await {
                     Ok(_) => {
-                        println!("Feishu WebSocket disconnected");
+                        tracing::info!("Feishu WebSocket disconnected");
                     }
                     Err(e) => {
                         consecutive_failures += 1;
-                        eprintln!("Feishu WebSocket error (attempt {}): {}", consecutive_failures, e);
+                        tracing::error!(attempt = consecutive_failures, error = %e, "Feishu WebSocket error");
                         if consecutive_failures >= max_failures {
-                            eprintln!("Feishu channel: max failures reached, stopping");
+                            tracing::error!("Feishu channel: max failures reached, stopping");
                             break;
                         }
                     }
@@ -568,15 +569,15 @@ impl Channel for FeishuChannel {
                     break;
                 }
 
-                println!("Feishu channel retrying in 5s...");
+                tracing::info!("Feishu channel retrying in 5s...");
                 tokio::time::sleep(tokio::time::Duration::from_secs(5)).await;
             }
 
             *channel.running.write().await = false;
-            println!("Feishu channel stopped");
+            tracing::info!("Feishu channel stopped");
         });
 
-        println!("Feishu channel started");
+        tracing::info!("Feishu channel started");
         Ok(())
     }
 
diff --git a/src/channels/manager.rs b/src/channels/manager.rs
index 2369d21..6b1a0ec 100644
--- a/src/channels/manager.rs
+++ b/src/channels/manager.rs
@@ -52,9 +52,9 @@ impl ChannelManager {
                     .write()
                     .await
                     .insert("feishu".to_string(), Arc::new(channel));
-                println!("Feishu channel registered");
+                tracing::info!("Feishu channel registered");
             } else {
-                println!("Feishu channel disabled in config");
+                tracing::info!("Feishu channel disabled in config");
             }
         }
         Ok(())
@@ -63,9 +63,9 @@ impl ChannelManager {
     pub async fn start_all(&self) -> Result<(), ChannelError> {
         let channels = self.channels.read().await;
         for (name, channel) in channels.iter() {
-            println!("Starting channel: {}", name);
+            tracing::info!(channel = %name, "Starting channel");
             if let Err(e) = channel.start().await {
-                eprintln!("Warning: Failed to start channel {}: {}", name, e);
+                tracing::error!(channel = %name, error = %e, "Failed to start channel");
             }
         }
         Ok(())
@@ -74,9 +74,9 @@ impl ChannelManager {
     pub async fn stop_all(&self) -> Result<(), ChannelError> {
         let mut channels = self.channels.write().await;
         for (name, channel) in channels.iter() {
-            println!("Stopping channel: {}", name);
+            tracing::info!(channel = %name, "Stopping channel");
             if let Err(e) = channel.stop().await {
-                eprintln!("Error stopping channel {}: {}", name, e);
+                tracing::error!(channel = %name, error = %e, "Error stopping channel");
             }
         }
         channels.clear();
diff --git a/src/client/mod.rs b/src/client/mod.rs
index 64d2b44..29998d2 100644
--- a/src/client/mod.rs
+++ b/src/client/mod.rs
@@ -11,7 +11,7 @@ fn parse_message(raw: &str) -> Result<WsOutbound, serde_json::Error> {
 
 pub async fn run(gateway_url: &str) -> Result<(), Box<dyn std::error::Error>> {
     let (ws_stream, _) = connect_async(gateway_url).await?;
-    println!("Connected to gateway");
+    tracing::info!(url = %gateway_url, "Connected to gateway");
 
     let (mut sender, mut receiver) = ws_stream.split();
 
@@ -35,6 +35,7 @@ pub async fn run(gateway_url: &str) -> Result<(), Box<dyn std::error::Error>> {
                                     input.write_output(&format!("Error: {}", message)).await?;
                                 }
                                 WsOutbound::SessionEstablished { session_id } => {
+                                    tracing::debug!(session_id = %session_id, "Session established");
                                     input.write_output(&format!("Session: {}\n", session_id)).await?;
                                 }
                                 _ => {}
@@ -42,6 +43,7 @@ pub async fn run(gateway_url: &str) -> Result<(), Box<dyn std::error::Error>> {
                         }
                     }
                     Some(Ok(Message::Close(_))) | None => {
+                        tracing::info!("Gateway disconnected");
                         input.write_output("Gateway disconnected").await?;
                         break;
                     }
@@ -75,14 +77,14 @@ pub async fn run(gateway_url: &str) -> Result<(), Box<dyn std::error::Error>> {
                         };
                         if let Ok(text) = serialize_inbound(&inbound) {
                             if sender.send(Message::Text(text.into())).await.is_err() {
-                                eprintln!("Failed to send message");
+                                tracing::error!("Failed to send message to gateway");
                                 break;
                             }
                         }
                     }
                     Ok(None) => break,
                     Err(e) => {
-                        eprintln!("Input error: {}", e);
+                        tracing::error!(error = %e, "Input error");
                         break;
                     }
                 }
diff --git a/src/config/mod.rs b/src/config/mod.rs
index dc6b315..f15dabc 100644
--- a/src/config/mod.rs
+++ b/src/config/mod.rs
@@ -138,13 +138,13 @@ impl Config {
     fn load_from(path: &Path) -> Result<Self, Box<dyn std::error::Error>> {
         load_env_file()?;
         let content = if path.exists() {
-            println!("Config loaded from: {}", path.display());
+            tracing::info!(path = %path.display(), "Config loaded");
             fs::read_to_string(path)?
         } else {
             // Fallback to current directory
             let fallback = Path::new("config.json");
             if fallback.exists() {
-                println!("Config loaded from: {}", fallback.display());
+                tracing::info!(path = %fallback.display(), "Config loaded from fallback path");
                 fs::read_to_string(fallback)?
             } else {
                 return Err(Box::new(ConfigError::ConfigNotFound(
diff --git a/src/gateway/mod.rs b/src/gateway/mod.rs
index e75b9ba..88c9165 100644
--- a/src/gateway/mod.rs
+++ b/src/gateway/mod.rs
@@ -64,7 +64,7 @@ pub async fn run(host: Option<String>, port: Option<u16>) -> Result<(), Box<dyn
 
     let addr = format!("{}:{}", bind_host, bind_port);
     let listener = TcpListener::bind(&addr).await?;
-    println!("Gateway listening on {}", addr);
+    tracing::info!(address = %addr, "Gateway listening");
 
     // Graceful shutdown using oneshot channel
     let (shutdown_tx, shutdown_rx) = tokio::sync::oneshot::channel::<()>();
@@ -73,7 +73,7 @@ pub async fn run(host: Option<String>, port: Option<u16>) -> Result<(), Box<dyn
     // Spawn ctrl_c handler
     tokio::spawn(async move {
         tokio::signal::ctrl_c().await.ok();
-        println!("Shutting down...");
+        tracing::info!("Shutdown signal received");
         let _ = channel_manager.stop_all().await;
         let _ = shutdown_tx.send(());
     });
diff --git a/src/gateway/session.rs b/src/gateway/session.rs
index f01be10..19a7ffd 100644
--- a/src/gateway/session.rs
+++ b/src/gateway/session.rs
@@ -36,8 +36,10 @@ impl Session {
     /// 获取或创建指定 chat_id 的 AgentLoop
     pub async fn get_or_create_agent(&mut self, chat_id: &str) -> Result<Arc<Mutex<AgentLoop>>, AgentError> {
         if let Some(agent) = self.chat_agents.get(chat_id) {
+            tracing::trace!(chat_id = %chat_id, "Reusing existing agent");
             return Ok(agent.clone());
         }
+        tracing::debug!(chat_id = %chat_id, "Creating new agent for chat");
         let agent = AgentLoop::new(self.provider_config.clone())?;
         let arc = Arc::new(Mutex::new(agent));
         self.chat_agents.insert(chat_id.to_string(), arc.clone());
@@ -99,8 +101,15 @@ impl SessionManager {
         let mut inner = self.inner.lock().await;
 
         let should_recreate = if let Some(last_active) = inner.session_timestamps.get(channel_name) {
-            last_active.elapsed() > inner.session_ttl
+            let elapsed = last_active.elapsed();
+            if elapsed > inner.session_ttl {
+                tracing::info!(channel = %channel_name, elapsed_hours = elapsed.as_secs() / 3600, "Session expired, recreating");
+                true
+            } else {
+                false
+            }
         } else {
+            tracing::debug!(channel = %channel_name, "Creating new session");
             true
         };
 
@@ -140,6 +149,8 @@ impl SessionManager {
         chat_id: &str,
         content: &str,
     ) -> Result<String, AgentError> {
+        tracing::debug!(channel = %channel_name, chat_id = %chat_id, content_len = content.len(), "Routing message to agent");
+
         // 确保 session 存在（可能需要重建）
         self.ensure_session(channel_name).await?;
 
@@ -161,6 +172,8 @@ impl SessionManager {
         let user_msg = ChatMessage::user(content);
         let response = agent.process(user_msg).await?;
 
+        tracing::debug!(channel = %channel_name, chat_id = %chat_id, response_len = response.content.len(), "Agent response received");
+
         Ok(response.content)
     }
 
diff --git a/src/gateway/ws.rs b/src/gateway/ws.rs
index 91e9b2d..bdab4d1 100644
--- a/src/gateway/ws.rs
+++ b/src/gateway/ws.rs
@@ -20,7 +20,7 @@ async fn handle_socket(ws: WebSocket, state: Arc<GatewayState>) {
     let provider_config = match state.config.get_provider_config("default") {
         Ok(cfg) => cfg,
         Err(e) => {
-            eprintln!("Failed to get provider config: {}", e);
+            tracing::error!(error = %e, "Failed to get provider config");
             return;
         }
     };
@@ -32,12 +32,13 @@ async fn handle_socket(ws: WebSocket, state: Arc<GatewayState>) {
     let session = match Session::new(channel_name.clone(), provider_config, sender).await {
         Ok(s) => Arc::new(Mutex::new(s)),
         Err(e) => {
-            eprintln!("Failed to create session: {}", e);
+            tracing::error!(error = %e, "Failed to create session");
             return;
         }
     };
 
     let session_id = session.lock().await.id;
+    tracing::info!(session_id = %session_id, "CLI session established");
 
     let _ = session.lock().await.send(WsOutbound::SessionEstablished {
         session_id: session_id.to_string(),
@@ -46,10 +47,12 @@ async fn handle_socket(ws: WebSocket, state: Arc<GatewayState>) {
     let (mut ws_sender, mut ws_receiver) = ws.split();
 
     let mut receiver = receiver;
+    let session_id_for_sender = session_id;
     tokio::spawn(async move {
         while let Some(msg) = receiver.recv().await {
             if let Ok(text) = serialize_outbound(&msg) {
                 if ws_sender.send(WsMessage::Text(text.into())).await.is_err() {
+                    tracing::debug!(session_id = %session_id_for_sender, "WebSocket send error");
                     break;
                 }
             }
@@ -65,6 +68,7 @@ async fn handle_socket(ws: WebSocket, state: Arc<GatewayState>) {
                         handle_inbound(&session, inbound).await;
                     }
                     Err(e) => {
+                        tracing::warn!(error = %e, "Failed to parse inbound message");
                         let _ = session.lock().await.send(WsOutbound::Error {
                             code: "PARSE_ERROR".to_string(),
                             message: e.to_string(),
@@ -73,11 +77,14 @@ async fn handle_socket(ws: WebSocket, state: Arc<GatewayState>) {
                 }
             }
             Ok(WsMessage::Close(_)) | Err(_) => {
+                tracing::debug!(session_id = %session_id, "WebSocket closed");
                 break;
             }
             _ => {}
         }
     }
+
+    tracing::info!(session_id = %session_id, "CLI session ended");
 }
 
 async fn handle_inbound(session: &Arc<Mutex<Session>>, inbound: WsInbound) {
@@ -100,6 +107,7 @@ async fn handle_inbound(session: &Arc<Mutex<Session>>, inbound: WsInbound) {
     let agent = match session_guard.get_or_create_agent(&chat_id).await {
         Ok(a) => a,
         Err(e) => {
+            tracing::error!(chat_id = %chat_id, error = %e, "Failed to get or create agent");
             let _ = session_guard.send(WsOutbound::Error {
                 code: "AGENT_ERROR".to_string(),
                 message: e.to_string(),
@@ -112,6 +120,7 @@ async fn handle_inbound(session: &Arc<Mutex<Session>>, inbound: WsInbound) {
     let mut agent = agent.lock().await;
     match agent.process(user_msg).await {
         Ok(response) => {
+            tracing::debug!(chat_id = %chat_id, "Agent response sent");
             let _ = session.lock().await.send(WsOutbound::AssistantResponse {
                 id: response.id,
                 content: response.content,
@@ -119,6 +128,7 @@ async fn handle_inbound(session: &Arc<Mutex<Session>>, inbound: WsInbound) {
             }).await;
         }
         Err(e) => {
+            tracing::error!(chat_id = %chat_id, error = %e, "Agent process error");
             let _ = session.lock().await.send(WsOutbound::Error {
                 code: "LLM_ERROR".to_string(),
                 message: e.to_string(),