diff --git a/backend/crates/gateway-api/src/openai/responses/websocket/connection/frame.rs b/backend/crates/gateway-api/src/openai/responses/websocket/connection/frame.rs
index 4e9bd4a74..24a12040d 100644
--- a/backend/crates/gateway-api/src/openai/responses/websocket/connection/frame.rs
+++ b/backend/crates/gateway-api/src/openai/responses/websocket/connection/frame.rs
@@ -10,6 +10,8 @@ pub(super) const DOWNSTREAM_WRITE_TIMEOUT: Duration = Duration::from_secs(5 * 60
 pub(super) const DOWNSTREAM_CLOSE_TIMEOUT: Duration = Duration::from_secs(1);
 pub(super) const CONNECTION_MAX_AGE: Duration = Duration::from_secs(60 * 60);
 pub(super) const DOWNSTREAM_PING_INTERVAL: Duration = Duration::from_secs(25);
+pub(super) const DOWNSTREAM_PONG_TIMEOUT: Duration = Duration::from_secs(30);
+pub(super) const DOWNSTREAM_PING_WRITE_TIMEOUT: Duration = Duration::from_secs(5);
 
 /// WebSocket pump 的写入与生命周期预算
 #[derive(Clone, Copy)]
@@ -124,6 +126,7 @@ pub enum PumpExitReason {
     ReadError,
     WriteError,
     WriteTimeout,
+    PongTimeout,
     LifecycleShutdown,
     ConnectionMaxAge,
     CoordinatorDropped,
@@ -141,6 +144,7 @@ impl PumpExitReason {
             Self::ReadError => "read_error",
             Self::WriteError => "write_error",
             Self::WriteTimeout => "write_timeout",
+            Self::PongTimeout => "pong_timeout",
             Self::LifecycleShutdown => "lifecycle_shutdown",
             Self::ConnectionMaxAge => "connection_max_age",
             Self::CoordinatorDropped => "coordinator_dropped",
diff --git a/backend/crates/gateway-api/src/openai/responses/websocket/connection/handle.rs b/backend/crates/gateway-api/src/openai/responses/websocket/connection/handle.rs
index dbc68e834..45ddaf0ba 100644
--- a/backend/crates/gateway-api/src/openai/responses/websocket/connection/handle.rs
+++ b/backend/crates/gateway-api/src/openai/responses/websocket/connection/handle.rs
@@ -30,6 +30,7 @@ use tokio::{
 pub struct ResponsesWebSocketConnection {
     connection_id: Arc<str>,
     opened_at: Instant,
+    cancellation: CancellationToken,
     expired: Arc<AtomicBool>,
     commands: Option<mpsc::Sender<ConnectionCommand>>,
     incoming: mpsc::Receiver<PendingConnectionEvent>,
@@ -266,7 +267,9 @@ impl ResponsesWebSocketConnection {
     }
 
     fn terminate(&mut self, reason: PumpExitReason) {
+        let reason = self.exited.try_recv().unwrap_or(reason);
         self.exit_reason.get_or_insert(reason);
+        self.cancellation.cancel();
         self.commands.take();
         if let Some(task) = self.pump_task.take() {
             task.abort();
@@ -306,6 +309,7 @@ impl ResponsesWebSocketConnection {
 
 impl Drop for ResponsesWebSocketConnection {
     fn drop(&mut self) {
+        self.cancellation.cancel();
         self.commands.take();
         if let Some(task) = self.pump_task.take() {
             task.abort();
@@ -314,6 +318,7 @@ impl Drop for ResponsesWebSocketConnection {
 }
 
 /// 为 WebSocket transport 启动包含冻结中间件计划的单 owner pump
+/// cancellation 必须属于本连接，连接退出或句柄释放时会取消它
 pub fn spawn_connection<S, E>(
     socket: S,
     connection_id: Arc<str>,
@@ -341,7 +346,7 @@ where
         incoming_tx,
         exit_tx,
         Arc::clone(&connection_id),
-        cancellation,
+        cancellation.clone(),
         opened_at,
         Arc::clone(&expired),
         Arc::clone(&stats),
@@ -353,6 +358,7 @@ where
     ResponsesWebSocketConnection {
         connection_id,
         opened_at,
+        cancellation,
         expired,
         commands: Some(command_tx),
         incoming: incoming_rx,
diff --git a/backend/crates/gateway-api/src/openai/responses/websocket/connection/pump.rs b/backend/crates/gateway-api/src/openai/responses/websocket/connection/pump.rs
index 8de82f5e5..6d6df01af 100644
--- a/backend/crates/gateway-api/src/openai/responses/websocket/connection/pump.rs
+++ b/backend/crates/gateway-api/src/openai/responses/websocket/connection/pump.rs
@@ -19,7 +19,7 @@ use std::{
     },
 };
 use tokio::{
-    sync::{Semaphore, mpsc, oneshot},
+    sync::{Semaphore, mpsc, oneshot, watch},
     time::Instant,
 };
 
@@ -42,6 +42,7 @@ pub(super) async fn run_pump<S, E>(
     S: Stream<Item = Result<Message, E>> + Sink<Message, Error = E> + Unpin + Send + 'static,
     E: fmt::Display + Send + 'static,
 {
+    let _connection_lifetime = middleware::CancelOnDrop(Some(cancellation.clone()));
     let context = Arc::new(PumpContext {
         extensions,
         connection_id,
@@ -57,11 +58,13 @@ pub(super) async fn run_pump<S, E>(
     let (writer, mut reader) = socket.split();
     let writer = Arc::new(middleware::Writer::new(writer, context.clone()));
     let sender: Arc<dyn contract::Sender> = writer.clone();
-    // 同一个受管任务同时驱动两侧；等待写入不能阻塞入站控制、关闭或取消
+    let (activity, received_activity) = watch::channel(());
+    // 心跳独立于业务写入等待，但共享唯一 writer，避免长写入或排队阻止失联检测
     let reason = tokio::select! {
         biased;
-        reason = read_connection(&mut reader, &incoming, sender.clone(), &context) => reason,
+        reason = read_connection(&mut reader, &incoming, sender.clone(), &activity, &context) => reason,
         reason = write_connection(writer.clone(), commands, &context) => reason,
+        reason = heartbeat_connection(writer.clone(), received_activity, &context) => reason,
     };
     if matches!(reason, PumpExitReason::ClientClose) {
         if let Err(error) = writer.finish_peer_close(&cancellation).await {
@@ -78,6 +81,7 @@ async fn read_connection<S, E>(
     socket: &mut S,
     incoming: &mpsc::Sender<PendingConnectionEvent>,
     sender: Arc<dyn contract::Sender>,
+    activity: &watch::Sender<()>,
     context: &PumpContext,
 ) -> PumpExitReason
 where
@@ -103,6 +107,10 @@ where
             }
             message = socket.next() => {
                 if matches!(&message, Some(Ok(_))) { context.stats.record_read(context.opened_at); }
+                if matches!(&message, Some(Ok(message)) if !matches!(message, Message::Close(_))) {
+                    // 链路活动以真实入站为准，插件丢弃消息不应抹掉对端已经响应的事实
+                    activity.send_replace(());
+                }
                 let message = match message {
                     Some(Ok(message)) => match middleware::transform(message, contract::Direction::Incoming, sender.clone(), context).await {
                         Ok(Some(message)) => Some(Ok(message)),
@@ -145,40 +153,22 @@ where
     S: Sink<Message, Error = E> + Unpin + Send + 'static,
     E: fmt::Display + Send + 'static,
 {
-    let mut heartbeat = tokio::time::interval_at(
-        context.opened_at + DOWNSTREAM_PING_INTERVAL,
-        DOWNSTREAM_PING_INTERVAL,
-    );
-    heartbeat.set_missed_tick_behavior(tokio::time::MissedTickBehavior::Skip);
-    let mut ping_sequence = 0_u64;
     loop {
-        let message = tokio::select! {
+        let command = tokio::select! {
             biased;
             () = context.cancellation.cancelled() => return PumpExitReason::LifecycleShutdown,
-            command = commands.recv() => {
-                let Some(command) = command else { return PumpExitReason::CoordinatorDropped; };
-                let ConnectionCommand { message, context: write_context, acknowledged } = command;
-                let closing = matches!(message, Message::Close(_));
-                let result = match middleware::transform(message, contract::Direction::Outgoing, writer.clone(), context).await {
-                    Ok(Some(message)) => writer.write(message).await.map(|()| WriteOutcome::Written),
-                    Ok(None) => Ok(WriteOutcome::Suppressed),
-                    Err(error) => Err(ConnectionWriteError::Transport { message: error.to_string() }),
-                };
-                let reason = result.as_ref().err().map(|error| write_exit_reason(error, context));
-                if let Err(error) = &result {
-                    tracing::debug!(websocket_connection_id = %context.connection_id, request_id = write_context.request_id.as_deref().unwrap_or(""), frame_phase = write_context.phase.as_str(), error = %error, "Responses WebSocket pump transport write failed");
-                }
-                let _ = acknowledged.send(result);
-                if let Some(reason) = reason { return reason; }
-                if closing { return PumpExitReason::ServerClose; }
-                continue;
-            }
-            _ = heartbeat.tick() => {
-                ping_sequence = ping_sequence.wrapping_add(1);
-                Message::Ping(ping_sequence.to_be_bytes().to_vec().into())
-            }
+            command = commands.recv() => command,
         };
-        let message = match middleware::transform(
+        let Some(command) = command else {
+            return PumpExitReason::CoordinatorDropped;
+        };
+        let ConnectionCommand {
+            message,
+            context: write_context,
+            acknowledged,
+        } = command;
+        let closing = matches!(message, Message::Close(_));
+        let result = match middleware::transform(
             message,
             contract::Direction::Outgoing,
             writer.clone(),
@@ -186,21 +176,125 @@ where
         )
         .await
         {
-            Ok(Some(message)) => message,
-            Ok(None) => continue,
-            Err(_) => return PumpExitReason::MiddlewareFailed,
+            Ok(Some(message)) => writer.write(message).await.map(|()| WriteOutcome::Written),
+            Ok(None) => Ok(WriteOutcome::Suppressed),
+            Err(error) => Err(ConnectionWriteError::Transport {
+                message: error.to_string(),
+            }),
         };
-        if let Err(error) = writer.write(message).await {
-            tracing::info!(websocket_connection_id = %context.connection_id, error = %error, "Responses WebSocket control write failed");
-            return write_exit_reason(&error, context);
+        let reason = result
+            .as_ref()
+            .err()
+            .map(|error| write_exit_reason(error, context));
+        if let Err(error) = &result {
+            tracing::debug!(websocket_connection_id = %context.connection_id, request_id = write_context.request_id.as_deref().unwrap_or(""), frame_phase = write_context.phase.as_str(), error = %error, "Responses WebSocket pump transport write failed");
+        }
+        let _ = acknowledged.send(result);
+        if let Some(reason) = reason {
+            return reason;
+        }
+        if closing {
+            return PumpExitReason::ServerClose;
         }
-        context
-            .stats
-            .ping_written_count
-            .fetch_add(1, Ordering::Relaxed);
     }
 }
 
+async fn heartbeat_connection<S, E>(
+    writer: Arc<middleware::Writer<S>>,
+    mut activity: watch::Receiver<()>,
+    context: &PumpContext,
+) -> PumpExitReason
+where
+    S: Sink<Message, Error = E> + Unpin + Send + 'static,
+    E: fmt::Display + Send + 'static,
+{
+    let mut heartbeat = tokio::time::interval_at(
+        context.opened_at + DOWNSTREAM_PING_INTERVAL,
+        DOWNSTREAM_PING_INTERVAL,
+    );
+    heartbeat.set_missed_tick_behavior(tokio::time::MissedTickBehavior::Skip);
+    let mut ping_sequence = 0_u64;
+    let pong_deadline = tokio::time::sleep(DOWNSTREAM_PONG_TIMEOUT);
+    tokio::pin!(pong_deadline);
+    let mut pending_ping = false;
+    loop {
+        tokio::select! {
+            biased;
+            () = context.cancellation.cancelled() => return PumpExitReason::LifecycleShutdown,
+            changed = activity.changed() => {
+                if changed.is_err() { return PumpExitReason::PumpStopped; }
+                pending_ping = false;
+                continue;
+            }
+            () = &mut pong_deadline, if pending_ping => return PumpExitReason::PongTimeout,
+            _ = heartbeat.tick() => {}
+        }
+        ping_sequence = ping_sequence.wrapping_add(1);
+        let write = tokio::time::timeout(
+            DOWNSTREAM_PING_WRITE_TIMEOUT,
+            write_heartbeat(&writer, ping_sequence, context),
+        );
+        tokio::pin!(write);
+        let mut received_during_write = false;
+        loop {
+            tokio::select! {
+                biased;
+                () = context.cancellation.cancelled() => return PumpExitReason::LifecycleShutdown,
+                changed = activity.changed() => {
+                    if changed.is_err() { return PumpExitReason::PumpStopped; }
+                    pending_ping = false;
+                    received_during_write = true;
+                }
+                () = &mut pong_deadline, if pending_ping => return PumpExitReason::PongTimeout,
+                result = &mut write => {
+                    match result {
+                        Ok(Ok(true)) => {
+                            context.stats.ping_written_count.fetch_add(1, Ordering::Relaxed);
+                            // 重复 Ping 不顺延截止，写入完成前已经收到的响应也不能丢失
+                            if !pending_ping && !received_during_write {
+                                pong_deadline.as_mut().reset(Instant::now() + DOWNSTREAM_PONG_TIMEOUT);
+                                pending_ping = true;
+                            }
+                        }
+                        Ok(Ok(false)) => {}
+                        Ok(Err(reason)) => return reason,
+                        Err(_) => return PumpExitReason::WriteTimeout,
+                    }
+                    break;
+                }
+            }
+        }
+    }
+}
+
+async fn write_heartbeat<S, E>(
+    writer: &Arc<middleware::Writer<S>>,
+    sequence: u64,
+    context: &PumpContext,
+) -> Result<bool, PumpExitReason>
+where
+    S: Sink<Message, Error = E> + Unpin + Send + 'static,
+    E: fmt::Display + Send + 'static,
+{
+    let message = middleware::transform(
+        Message::Ping(sequence.to_be_bytes().to_vec().into()),
+        contract::Direction::Outgoing,
+        writer.clone(),
+        context,
+    )
+    .await
+    .map_err(|_| PumpExitReason::MiddlewareFailed)?;
+    let Some(message) = message else {
+        return Ok(false);
+    };
+    let is_ping = matches!(message, Message::Ping(_));
+    writer.write(message).await.map_err(|error| {
+        tracing::info!(websocket_connection_id = %context.connection_id, error = %error, "Responses WebSocket control write failed");
+        write_exit_reason(&error, context)
+    })?;
+    Ok(is_ping)
+}
+
 fn write_exit_reason(error: &ConnectionWriteError, context: &PumpContext) -> PumpExitReason {
     match error {
         ConnectionWriteError::Timeout { .. } => PumpExitReason::WriteTimeout,
diff --git a/backend/crates/gateway-api/src/openai/responses/websocket/mod.rs b/backend/crates/gateway-api/src/openai/responses/websocket/mod.rs
index 1ce93e93b..b4cc7c941 100644
--- a/backend/crates/gateway-api/src/openai/responses/websocket/mod.rs
+++ b/backend/crates/gateway-api/src/openai/responses/websocket/mod.rs
@@ -181,13 +181,15 @@ async fn serve_responses_websocket(socket: WebSocket, session: ResponsesWebSocke
         "Responses WebSocket connected"
     );
     let _connection_guard = connection_guard;
-    let cancellation = lifecycle.cancellation();
+    let cancellation = lifecycle.cancellation().child_token();
+    let _connection_cancellation =
+        crate::middleware::websocket::CancelOnDrop(Some(cancellation.clone()));
     let request_headers =
         request_headers.with_downstream_websocket_connection_id(connection_id.clone());
     let mut connection = ResponsesWebSocketConnection::new(
         socket,
         connection_id,
-        cancellation,
+        cancellation.clone(),
         middleware,
         encode_headers(&raw_headers).into(),
     );
@@ -299,7 +301,11 @@ async fn serve_responses_websocket(socket: WebSocket, session: ResponsesWebSocke
             }
             execution.prepare_execution(client).await
         };
-        let prepared = match preparation.await {
+        let prepared = match tokio::select! {
+            biased;
+            _ = connection.wait_for_exit() => break,
+            prepared = preparation => prepared,
+        } {
             Ok(prepared) => prepared,
             Err(error) => {
                 trace_rejected_request(
@@ -317,6 +323,7 @@ async fn serve_responses_websocket(socket: WebSocket, session: ResponsesWebSocke
                 continue;
             }
         };
+        let prepared = prepared.with_connection_cancellation(cancellation.clone());
         let request_id = Arc::<str>::from(prepared.request_id().to_string());
         response_control = prepared.response_control();
         let capture = new_replay_capture();
diff --git a/backend/crates/gateway-api/tests/openai/responses/websocket/connection/mod.rs b/backend/crates/gateway-api/tests/openai/responses/websocket/connection/mod.rs
index 4d6bc7c47..1d7609b9f 100644
--- a/backend/crates/gateway-api/tests/openai/responses/websocket/connection/mod.rs
+++ b/backend/crates/gateway-api/tests/openai/responses/websocket/connection/mod.rs
@@ -557,7 +557,7 @@ async fn outbound_commands_are_written_in_acknowledged_order() {
 }
 
 #[tokio::test(start_paused = true)]
-async fn stalled_write_times_out_at_three_hundred_seconds_and_aborts_the_pump() {
+async fn stalled_business_write_cannot_block_the_heartbeat_write_deadline() {
     let PumpHarness {
         mut connection,
         incoming: _incoming,
@@ -566,6 +566,7 @@ async fn stalled_write_times_out_at_three_hundred_seconds_and_aborts_the_pump()
         ..
     } = test_connection(true);
     let request_id = Arc::<str>::from("req_test");
+    let started = tokio::time::Instant::now();
 
     let error = connection
         .send_text(
@@ -573,12 +574,14 @@ async fn stalled_write_times_out_at_three_hundred_seconds_and_aborts_the_pump()
             WriteContext::request(&request_id, FramePhase::First),
         )
         .await
-        .expect_err("stalled write must time out");
+        .expect_err("heartbeat deadline must interrupt the stalled business write");
     tokio::task::yield_now().await;
 
-    assert!(
-        matches!(error, ConnectionWriteError::Timeout { timeout } if timeout == Duration::from_secs(300))
-            && dropped.load(Ordering::Acquire)
+    assert!(matches!(error, ConnectionWriteError::Closed) && dropped.load(Ordering::Acquire));
+    assert_eq!(started.elapsed(), Duration::from_secs(25 + 5));
+    assert_eq!(
+        connection.wait_for_exit().await,
+        PumpExitReason::WriteTimeout
     );
 }
 
@@ -586,10 +589,19 @@ async fn stalled_write_times_out_at_three_hundred_seconds_and_aborts_the_pump()
 async fn pump_marks_the_connection_expired_at_sixty_minutes() {
     let PumpHarness {
         mut connection,
-        incoming: _incoming,
-        written: _written,
+        incoming,
+        mut written,
         ..
     } = test_connection(false);
+    let peer = tokio::spawn(async move {
+        while let Some(message) = written.recv().await {
+            if let Message::Ping(payload) = message {
+                incoming
+                    .send(Ok(Message::Pong(payload)))
+                    .expect("reply to Ping");
+            }
+        }
+    });
 
     let event = connection
         .next_event()
@@ -597,6 +609,7 @@ async fn pump_marks_the_connection_expired_at_sixty_minutes() {
         .expect("deadline must emit an event");
 
     assert!(matches!(event, ConnectionEvent::Expired) && connection.is_expired());
+    peer.abort();
 }
 
 #[tokio::test]
@@ -606,6 +619,7 @@ async fn dropping_the_connection_aborts_and_drops_the_socket_owner() {
         incoming: _incoming,
         written: _written,
         dropped,
+        cancellation,
         ..
     } = test_connection(false);
 
@@ -613,6 +627,7 @@ async fn dropping_the_connection_aborts_and_drops_the_socket_owner() {
     tokio::task::yield_now().await;
 
     assert!(dropped.load(Ordering::Acquire));
+    assert!(cancellation.is_cancelled());
 }
 
 #[tokio::test(start_paused = true)]
@@ -1122,7 +1137,7 @@ async fn client_close_should_cancel_active_execution_without_starting_queued_req
 async fn idle_pump_sends_heartbeat_without_bursting_after_a_delay() {
     let PumpHarness {
         connection,
-        incoming: _incoming,
+        incoming,
         mut written,
         ..
     } = test_connection(false);
@@ -1132,6 +1147,10 @@ async fn idle_pump_sends_heartbeat_without_bursting_after_a_delay() {
     tokio::time::advance(Duration::from_secs(25)).await;
     let first = written.recv().await.expect("first heartbeat");
     assert!(matches!(first, Message::Ping(_)));
+    incoming
+        .send(Ok(Message::Pong(vec![1].into())))
+        .expect("reply before scheduler delay");
+    tokio::task::yield_now().await;
 
     tokio::time::advance(Duration::from_secs(120)).await;
     let second = written.recv().await.expect("heartbeat after delay");
@@ -1143,7 +1162,35 @@ async fn idle_pump_sends_heartbeat_without_bursting_after_a_delay() {
 }
 
 #[tokio::test(start_paused = true)]
-async fn missing_pongs_do_not_cancel_the_connection_or_block_business_frames() {
+async fn missing_responses_expire_from_the_first_ping_without_extending_on_repeated_pings() {
+    let PumpHarness {
+        mut connection,
+        incoming,
+        mut written,
+        dropped,
+        cancellation,
+        ..
+    } = test_connection(false);
+    let started = tokio::time::Instant::now();
+    for _ in 0..32 {
+        incoming
+            .send(Ok(Message::Text("queued request".into())))
+            .expect("fill the business queue before probing");
+    }
+
+    assert_eq!(
+        connection.wait_for_exit().await,
+        PumpExitReason::PongTimeout
+    );
+    assert_eq!(started.elapsed(), Duration::from_secs(25 + 30));
+    assert!(matches!(written.try_recv(), Ok(Message::Ping(_))));
+    assert!(matches!(written.try_recv(), Ok(Message::Ping(_))));
+    assert!(dropped.load(Ordering::Acquire));
+    assert!(cancellation.is_cancelled());
+}
+
+#[tokio::test(start_paused = true)]
+async fn business_frames_keep_the_connection_healthy_without_pongs() {
     let PumpHarness {
         mut connection,
         incoming,
@@ -1153,15 +1200,14 @@ async fn missing_pongs_do_not_cancel_the_connection_or_block_business_frames() {
     for _ in 0..13 {
         tokio::time::advance(Duration::from_secs(25)).await;
         assert!(matches!(written.recv().await, Some(Message::Ping(_))));
+        incoming
+            .send(Ok(Message::Text("still connected".into())))
+            .expect("send business frame instead of Pong");
+        assert!(matches!(
+            connection.next_event().await,
+            Some(ConnectionEvent::Text(text)) if text == "still connected"
+        ));
     }
-
-    incoming
-        .send(Ok(Message::Text("still connected".into())))
-        .expect("send business frame after 325 seconds without Pong");
-    assert!(matches!(
-        connection.next_event().await,
-        Some(ConnectionEvent::Text(text)) if text == "still connected"
-    ));
     incoming.send(Ok(Message::Close(None))).expect("close peer");
     assert_eq!(
         connection.wait_for_exit().await,
@@ -1192,7 +1238,7 @@ async fn stalled_heartbeat_can_be_cancelled_without_waiting_for_write_timeout()
 }
 
 #[tokio::test(start_paused = true)]
-async fn stalled_heartbeat_obeys_the_existing_write_timeout() {
+async fn stalled_heartbeat_uses_a_short_write_timeout() {
     let PumpHarness {
         mut connection,
         incoming: _incoming,
@@ -1205,7 +1251,7 @@ async fn stalled_heartbeat_obeys_the_existing_write_timeout() {
         connection.wait_for_exit().await,
         PumpExitReason::WriteTimeout
     );
-    assert_eq!(started.elapsed(), Duration::from_secs(25 + 300));
+    assert_eq!(started.elapsed(), Duration::from_secs(25 + 5));
     assert!(dropped.load(Ordering::Acquire));
 }
 
diff --git a/backend/crates/gateway-core/src/engine/execution/contract.rs b/backend/crates/gateway-core/src/engine/execution/contract.rs
index 0a234884d..8cb7ffffa 100644
--- a/backend/crates/gateway-core/src/engine/execution/contract.rs
+++ b/backend/crates/gateway-core/src/engine/execution/contract.rs
@@ -211,6 +211,15 @@ impl PreparedRootExecution {
         self.response_control.clone()
     }
 
+    /// 连接退出同时撤销跨轮次保留的上游资源，不改变单次执行的取消范围
+    #[must_use]
+    pub fn with_connection_cancellation(mut self, cancellation: CancellationToken) -> Self {
+        self.response_control = self
+            .response_control
+            .with_connection_cancellation(cancellation);
+        self
+    }
+
     pub(super) fn new(client: AuthenticatedClient) -> Result<Self, GatewayError> {
         let started_at = SystemTime::now();
         let deadline_at = Deadline::from_timeout(started_at, client.execution_timeout())
diff --git a/backend/crates/gateway-core/src/engine/response_control.rs b/backend/crates/gateway-core/src/engine/response_control.rs
index 880c419d7..3cbb15d60 100644
--- a/backend/crates/gateway-core/src/engine/response_control.rs
+++ b/backend/crates/gateway-core/src/engine/response_control.rs
@@ -3,6 +3,7 @@
 use std::fmt;
 use std::sync::{Arc, Mutex, Weak};
 
+use crate::lifecycle::CancellationToken;
 use async_trait::async_trait;
 
 /// Provider 实现的连接控制通道，消息内容由上游协议解释
@@ -22,6 +23,7 @@ pub struct ResponseControlUnavailable;
 #[derive(Clone, Default)]
 pub struct ResponseControl {
     target: Arc<Mutex<Option<Weak<dyn ResponseControlTransport>>>>,
+    connection_cancellation: Option<CancellationToken>,
 }
 
 /// 某次已交付响应所属的弱连接快照，重绑后不能把旧消息发送到新连接
@@ -50,6 +52,18 @@ impl fmt::Debug for ResponseControl {
 }
 
 impl ResponseControl {
+    /// 下游连接跨多轮存续，不能使用单次响应的取消信号代替
+    #[must_use]
+    pub fn with_connection_cancellation(mut self, cancellation: CancellationToken) -> Self {
+        self.connection_cancellation = Some(cancellation);
+        self
+    }
+
+    #[must_use]
+    pub fn connection_cancellation(&self) -> Option<&CancellationToken> {
+        self.connection_cancellation.as_ref()
+    }
+
     /// 仅保存弱引用，不延长旧 attempt 的连接生命周期
     #[must_use]
     pub fn binding(&self) -> Option<ResponseControlBinding> {
diff --git a/backend/crates/providers/openai/src/config.rs b/backend/crates/providers/openai/src/config.rs
index 790ccd2a0..999e700c1 100644
--- a/backend/crates/providers/openai/src/config.rs
+++ b/backend/crates/providers/openai/src/config.rs
@@ -169,15 +169,22 @@ pub struct CodexWebSocketPoolSettings {
     pub enabled: bool,
     pub max_age_ms: u64,
     pub max_connecting: usize,
+    #[serde(default = "default_websocket_pool_idle_timeout_ms")]
+    pub idle_timeout_ms: u64,
     pub stream_idle_timeout_ms: u64,
 }
 
+const fn default_websocket_pool_idle_timeout_ms() -> u64 {
+    300_000
+}
+
 impl Default for CodexWebSocketPoolSettings {
     fn default() -> Self {
         Self {
             enabled: true,
             max_age_ms: 55 * 60 * 1000,
             max_connecting: 8,
+            idle_timeout_ms: default_websocket_pool_idle_timeout_ms(),
             stream_idle_timeout_ms: 300_000,
         }
     }
@@ -185,7 +192,7 @@ impl Default for CodexWebSocketPoolSettings {
 
 impl CodexWebSocketPoolSettings {
     fn validate(&self) -> Result<(), OpenAiConfigError> {
-        if self.max_age_ms == 0 || self.max_connecting == 0 {
+        if self.max_age_ms == 0 || self.max_connecting == 0 || self.idle_timeout_ms == 0 {
             return Err(OpenAiConfigError::InvalidField("openai.ws_pool"));
         }
         Ok(())
@@ -196,6 +203,7 @@ impl CodexWebSocketPoolSettings {
             enabled: self.enabled,
             max_age: Duration::from_millis(self.max_age_ms),
             max_connecting: self.max_connecting,
+            idle_timeout: Duration::from_millis(self.idle_timeout_ms),
             stream_idle_timeout: (self.stream_idle_timeout_ms != 0)
                 .then(|| Duration::from_millis(self.stream_idle_timeout_ms)),
             ..CodexWebSocketPoolConfig::default()
diff --git a/backend/crates/providers/openai/src/provider/execution.rs b/backend/crates/providers/openai/src/provider/execution.rs
index 21422032f..cf21b514a 100644
--- a/backend/crates/providers/openai/src/provider/execution.rs
+++ b/backend/crates/providers/openai/src/provider/execution.rs
@@ -827,7 +827,7 @@ pub(super) fn cold_response_stream(response: ColdResponse) -> EventStream {
                 &authorization,
                 cookie_header.as_ref(),
                 account_selection,
-            ).with_trace(&trace),
+            ).with_trace(&trace).with_response_control(context.response_control()),
             active_account.id().as_str(),
             context.deadline(),
             &cancellation,
diff --git a/backend/crates/providers/openai/src/provider/failure.rs b/backend/crates/providers/openai/src/provider/failure.rs
index 836e1ffee..9c7635804 100644
--- a/backend/crates/providers/openai/src/provider/failure.rs
+++ b/backend/crates/providers/openai/src/provider/failure.rs
@@ -1246,7 +1246,7 @@ fn websocket_diagnostic_message(error: &CodexWebSocketExchangeError) -> Provider
             let mut message =
                 format!("OpenAI WebSocket stream ended before a terminal response ({reason})");
             if let Some(timeout) = timeout {
-                message.push_str(&format!("; local keepalive timeout after {timeout:?}"));
+                message.push_str(&format!("; local Pong write timeout after {timeout:?}"));
             }
             if let Some(last_event_type) = last_event_type {
                 message.push_str("; last event type: ");
diff --git a/backend/crates/providers/openai/src/provider/mod.rs b/backend/crates/providers/openai/src/provider/mod.rs
index e07f87586..d033e059e 100644
--- a/backend/crates/providers/openai/src/provider/mod.rs
+++ b/backend/crates/providers/openai/src/provider/mod.rs
@@ -1108,7 +1108,6 @@ impl CodexProvider {
                 .map_err(|error| map_client_error(error, UpstreamSendState::NotSent, false).error)?
                 .with_responses_api_base_url(lease.authentication().responses_api_base_url())
                 .with_connection_budget(context.connection_budget().clone())
-                .with_response_control(context.response_control().cloned())
                 .with_middleware_headers(middleware_headers)
                 .with_outbound_middleware(outbound_middleware)
                 .with_privacy(context.privacy(), context.cancellation().clone()),
diff --git a/backend/crates/providers/openai/src/provider/observation.rs b/backend/crates/providers/openai/src/provider/observation.rs
index 38865c5ac..bbe36ac33 100644
--- a/backend/crates/providers/openai/src/provider/observation.rs
+++ b/backend/crates/providers/openai/src/provider/observation.rs
@@ -678,6 +678,7 @@ pub(super) fn codex_request_context<'a>(
     account_selection: CodexAccountSelectionTelemetry<'a>,
 ) -> CodexRequestContext<'a> {
     CodexRequestContext {
+        response_control: None,
         trace: None,
         authorization: authorization.expose_secret(),
         account_id: account.upstream_account_id(),
diff --git a/backend/crates/providers/openai/src/transport/client.rs b/backend/crates/providers/openai/src/transport/client.rs
index 0f8026165..280caeb66 100644
--- a/backend/crates/providers/openai/src/transport/client.rs
+++ b/backend/crates/providers/openai/src/transport/client.rs
@@ -464,6 +464,8 @@ impl<'a> CodexAccountSelectionTelemetry<'a> {
 /// 单次 Codex 上游请求的上下文
 #[derive(Clone, Copy)]
 pub struct CodexRequestContext<'a> {
+    /// 本次根执行的控制与下游连接生命周期，不由共享 HTTP client 持有
+    pub response_control: Option<&'a gateway_core::engine::response_control::ResponseControl>,
     /// 显式传递的请求诊断上下文，跨连接任务共享
     pub trace: Option<&'a gateway_core::diagnostics::TraceContext>,
     /// Provider 已构造并脱敏持有的完整 Authorization 值
@@ -512,6 +514,7 @@ impl<'a> CodexRequestContext<'a> {
     ) -> Self {
         Self {
             trace: None,
+            response_control: None,
             authorization,
             account_id,
             request_id,
@@ -537,6 +540,15 @@ impl<'a> CodexRequestContext<'a> {
         self.trace = Some(trace);
         self
     }
+
+    #[must_use]
+    pub fn with_response_control(
+        mut self,
+        control: Option<&'a gateway_core::engine::response_control::ResponseControl>,
+    ) -> Self {
+        self.response_control = control;
+        self
+    }
 }
 
 impl fmt::Debug for CodexRequestContext<'_> {
@@ -689,7 +701,6 @@ pub struct CodexBackendClient {
         gateway_core::lifecycle::CancellationToken,
     )>,
     pub(super) timezone: gateway_core::time::DeploymentTimeZone,
-    pub(super) response_control: Option<gateway_core::engine::response_control::ResponseControl>,
     pub(super) connection_budget: Option<gateway_core::engine::connection::ConnectionBudget>,
     pub(super) client: Client,
     pub(super) direct_client: Client,
@@ -716,14 +727,6 @@ impl CodexBackendClient {
         self
     }
 
-    pub(crate) fn with_response_control(
-        mut self,
-        control: Option<gateway_core::engine::response_control::ResponseControl>,
-    ) -> Self {
-        self.response_control = control;
-        self
-    }
-
     pub(crate) fn with_connection_budget(
         mut self,
         budget: gateway_core::engine::connection::ConnectionBudget,
diff --git a/backend/crates/providers/openai/src/transport/client_sse.rs b/backend/crates/providers/openai/src/transport/client_sse.rs
index bc5a42ad7..34229240b 100644
--- a/backend/crates/providers/openai/src/transport/client_sse.rs
+++ b/backend/crates/providers/openai/src/transport/client_sse.rs
@@ -69,7 +69,6 @@ impl CodexBackendClient {
             privacy: None,
             timezone: Default::default(),
             connection_budget: None,
-            response_control: None,
             direct_client: client.clone(),
             client,
             websocket_origin_key: websocket_origin_key(&base_url),
@@ -115,6 +114,14 @@ impl CodexBackendClient {
         upstream_request: &CodexResponsesRequest,
         context: CodexRequestContext<'_>,
     ) -> CodexClientResult<CodexBackendStreamingResponse> {
+        if let (Some(pool), Some(connection_id)) = (
+            &self.websocket_pool,
+            upstream_request
+                .downstream_websocket_connection_id
+                .as_deref(),
+        ) {
+            pool.release_downstream_connections(connection_id).await;
+        }
         let profile = self.profile.snapshot();
         let mut headers =
             self.request_headers_for_http_response(&profile, upstream_request, context)?;
@@ -395,7 +402,21 @@ impl CodexBackendClient {
         let pool_key =
             self.websocket_pool_key(request, context, pool_account_id, &connection_profile);
         let pool_log_context = pool_key.as_ref().map(WebSocketPoolLogContext::from_key);
-        let pool = self.websocket_pool.as_deref().map(|pool| (pool, pool_key));
+        let downstream_cancellation = context.response_control.and_then(
+            gateway_core::engine::response_control::ResponseControl::connection_cancellation,
+        );
+        if pool_key.is_none()
+            && let (Some(pool), Some(connection_id)) = (
+                &self.websocket_pool,
+                request.downstream_websocket_connection_id.as_deref(),
+            )
+        {
+            pool.release_downstream_connections(connection_id).await;
+        }
+        let pool = self
+            .websocket_pool
+            .as_deref()
+            .map(|pool| (pool, pool_key, downstream_cancellation));
         let fast_path_budget = match requirement {
             TransportRequirement::PersistedContinuation | TransportRequirement::NewChain => {
                 Some(WEBSOCKET_FAST_PATH_BUDGET)
@@ -553,7 +574,7 @@ impl CodexBackendClient {
                 let mut exchange = execute_prepared_response_create_request_stream(
                     &websocket_request,
                     prepared,
-                    self.response_control.clone(),
+                    context.response_control.cloned(),
                     context
                         .trace
                         .cloned()
diff --git a/backend/crates/providers/openai/src/transport/websocket/control.rs b/backend/crates/providers/openai/src/transport/websocket/control.rs
index eec55bf90..1300ce5f5 100644
--- a/backend/crates/providers/openai/src/transport/websocket/control.rs
+++ b/backend/crates/providers/openai/src/transport/websocket/control.rs
@@ -8,6 +8,7 @@ use gateway_core::engine::response_control::{
 };
 use tokio::sync::{Mutex, mpsc, oneshot};
 use tokio_tungstenite::tungstenite::{self, Message};
+use tokio_util::sync::CancellationToken;
 
 use super::CodexWebSocketExchangeError;
 
@@ -25,6 +26,7 @@ pub(super) type SharedMessages = Arc<Mutex<mpsc::Receiver<Result<Message, tungst
 pub(super) struct PumpControl {
     pub(super) tx_command: mpsc::Sender<PumpCommand>,
     pub(super) rx_message: SharedMessages,
+    pub(super) cancellation: CancellationToken,
 }
 
 pub(super) async fn send_message(
@@ -45,17 +47,23 @@ pub(super) async fn send_message(
 #[async_trait]
 impl ResponseControlTransport for PumpControl {
     async fn send(&self, payload: &str) -> Result<(), ResponseControlUnavailable> {
-        tokio::time::timeout(
-            WEBSOCKET_SEND_TIMEOUT,
-            send_message(&self.tx_command, Message::Text(payload.to_owned().into())),
-        )
-        .await
-        .map_err(|_| ResponseControlUnavailable)?
-        .map_err(|_| ResponseControlUnavailable)
+        tokio::select! {
+            biased;
+            () = self.cancellation.cancelled() => Err(ResponseControlUnavailable),
+            result = tokio::time::timeout(
+                WEBSOCKET_SEND_TIMEOUT,
+                send_message(&self.tx_command, Message::Text(payload.to_owned().into())),
+            ) => result.map_err(|_| ResponseControlUnavailable)?.map_err(|_| ResponseControlUnavailable),
+        }
     }
 
     async fn receive(&self) -> Result<String, ResponseControlUnavailable> {
-        match self.rx_message.lock().await.recv().await {
+        let message = tokio::select! {
+            biased;
+            () = self.cancellation.cancelled() => return Err(ResponseControlUnavailable),
+            message = async { self.rx_message.lock().await.recv().await } => message,
+        };
+        match message {
             Some(Ok(Message::Text(text))) => Ok(text.to_string()),
             _ => Err(ResponseControlUnavailable),
         }
diff --git a/backend/crates/providers/openai/src/transport/websocket/coordinator.rs b/backend/crates/providers/openai/src/transport/websocket/coordinator.rs
index b3979fa3b..7d750db3b 100644
--- a/backend/crates/providers/openai/src/transport/websocket/coordinator.rs
+++ b/backend/crates/providers/openai/src/transport/websocket/coordinator.rs
@@ -29,7 +29,7 @@ use super::{
         WebSocketPoolConnectLease, WebSocketPoolConnectOutcome, WebSocketPoolDecision,
         WebSocketPoolLease,
     },
-    pump::{PumpKeepalive, PumpLogContext, PumpedWebSocket, transport_metric_reason},
+    pump::{PumpLogContext, PumpedWebSocket, transport_metric_reason},
 };
 
 pub(crate) const WEBSOCKET_FAST_PATH_BUDGET: Duration = Duration::from_millis(800);
@@ -112,7 +112,11 @@ impl PreparedWebSocket {
 /// 只建立或租用 WebSocket，不发送 payload
 pub(crate) async fn prepare_response_create_request_with_pool(
     request: &CodexWebSocketRequest,
-    pool: Option<(&CodexWebSocketPool, Option<CodexWebSocketPoolKey>)>,
+    pool: Option<(
+        &CodexWebSocketPool,
+        Option<CodexWebSocketPoolKey>,
+        Option<&gateway_core::lifecycle::CancellationToken>,
+    )>,
     breaker: &WebSocketOriginBreaker,
     origin_key: &str,
     fast_path_budget: Option<Duration>,
@@ -120,7 +124,7 @@ pub(crate) async fn prepare_response_create_request_with_pool(
     fallback_stream_idle_timeout: Option<Duration>,
 ) -> Result<WebSocketFastPath<PreparedWebSocket>, CodexWebSocketExchangeError> {
     let decision_started_at = Instant::now();
-    let Some((pool, Some(key))) = pool else {
+    let Some((pool, Some(key), downstream_cancellation)) = pool else {
         if require_pool || !request.continuation().permits_fresh_connection() {
             return Err(continuation_unavailable(
                 PreviousResponseUnavailableReason::PoolUnavailable,
@@ -133,7 +137,7 @@ pub(crate) async fn prepare_response_create_request_with_pool(
             fast_path_budget,
             fallback_stream_idle_timeout,
             decision_started_at,
-            pool.map(|(pool, _)| pool),
+            pool.map(|(pool, _, _)| pool),
         )
         .await;
     };
@@ -151,6 +155,7 @@ pub(crate) async fn prepare_response_create_request_with_pool(
             &key,
             required_response_id,
             request.connection().outbound_proxy.as_ref(),
+            downstream_cancellation,
         )
         .await
     {
@@ -237,7 +242,6 @@ async fn prepare_unpooled_websocket(
     let context = pump_log_context_from_connection(request.connection());
     let connected = connect_with_budget(
         request.connection(),
-        PumpKeepalive::disabled(),
         fast_path_budget,
         context,
         proxy_permit,
@@ -343,7 +347,6 @@ fn start_pooled_websocket_connect(
     let task_key = connect_lease.key().clone();
     let started_at = connect_lease.started_at();
     let cancellation = connect_lease.cancellation_token();
-    let keepalive = pool.keepalive();
     let context = PumpLogContext::new(
         Some(task_key.account_id().to_owned()),
         Some(task_key.conversation_id_hash()),
@@ -365,7 +368,7 @@ fn start_pooled_websocket_connect(
                 );
                 return;
             }
-            result = connect_websocket_connection(&connection, keepalive, context, fast_path, proxy_permit) => result,
+            result = connect_websocket_connection(&connection, context, fast_path, proxy_permit) => result,
         };
         match finish_breaker_attempt(permit, connected) {
             Ok((connection, connect_elapsed)) => {
@@ -465,7 +468,6 @@ fn pump_log_context_from_connection(connection: &CodexWebSocketConnection) -> Pu
 
 async fn connect_with_budget(
     connection: &CodexWebSocketConnection,
-    keepalive: PumpKeepalive,
     fast_path_budget: Option<Duration>,
     context: PumpLogContext,
     proxy_permit: Option<pool::ProxyConnectionPermit>,
@@ -475,7 +477,6 @@ async fn connect_with_budget(
         fast_path_budget,
         connect_websocket_connection(
             connection,
-            keepalive,
             context,
             fast_path_budget.is_some(),
             proxy_permit,
@@ -490,14 +491,13 @@ async fn connect_with_budget(
 
 async fn connect_websocket_connection(
     connection: &CodexWebSocketConnection,
-    keepalive: PumpKeepalive,
     context: PumpLogContext,
     fast_path: bool,
     proxy_permit: Option<pool::ProxyConnectionPermit>,
 ) -> Result<(PooledWebSocketConnection, Duration), CodexWebSocketExchangeError> {
     let started_at = Instant::now();
     let (websocket, response) =
-        connect_pumped_websocket(connection, keepalive, context, fast_path, proxy_permit).await?;
+        connect_pumped_websocket(connection, context, fast_path, proxy_permit).await?;
     Ok((
         PooledWebSocketConnection {
             websocket,
diff --git a/backend/crates/providers/openai/src/transport/websocket/exchange/stream.rs b/backend/crates/providers/openai/src/transport/websocket/exchange/stream.rs
index 6cf896ac9..486a5fe81 100644
--- a/backend/crates/providers/openai/src/transport/websocket/exchange/stream.rs
+++ b/backend/crates/providers/openai/src/transport/websocket/exchange/stream.rs
@@ -69,6 +69,10 @@ pub(in crate::transport::websocket) fn stream_websocket_response(
     response_control: Option<ResponseControl>,
 ) -> CodexWebSocketStreamingExchange {
     websocket.bind_control(response_control.as_ref());
+    let downstream_cancellation = response_control
+        .as_ref()
+        .and_then(ResponseControl::connection_cancellation)
+        .cloned();
     let websocket_connection_id = websocket.connection_id();
     let response_metadata = metadata.clone();
     let rate_limit_updates = Arc::new(Mutex::new(Vec::new()));
@@ -94,6 +98,7 @@ pub(in crate::transport::websocket) fn stream_websocket_response(
             stream_idle_timeout,
             trace,
             shutdown,
+            downstream_cancellation,
             rate_limit_updates: rate_limit_updates_for_task,
             response_metadata_updates: response_metadata_updates_for_task,
             tx,
@@ -133,6 +138,7 @@ struct WebSocketStreamForwardState {
     reused_connection: bool,
     stream_idle_timeout: Option<Duration>,
     shutdown: CancellationToken,
+    downstream_cancellation: Option<gateway_core::lifecycle::CancellationToken>,
     rate_limit_updates: CodexWebSocketRateLimitUpdates,
     response_metadata_updates: CodexWebSocketResponseMetadataUpdates,
     tx: mpsc::Sender<Result<Bytes, CodexWebSocketExchangeError>>,
@@ -147,6 +153,7 @@ async fn forward_websocket_response_stream(state: WebSocketStreamForwardState) {
         reused_connection,
         stream_idle_timeout,
         shutdown,
+        downstream_cancellation,
         rate_limit_updates,
         response_metadata_updates,
         tx,
@@ -163,6 +170,20 @@ async fn forward_websocket_response_stream(state: WebSocketStreamForwardState) {
     loop {
         let message = tokio::select! {
             biased;
+            () = async {
+                match &downstream_cancellation {
+                    Some(cancellation) => cancellation.cancelled().await,
+                    None => std::future::pending().await,
+                }
+            } => {
+                trace.record("upstream.cancelled", json!({"reason": "downstream_connection_closed"}));
+                discard_stream_websocket(
+                    websocket,
+                    pool_return,
+                    StreamWebSocketDiscardReason::ClientCancelled,
+                ).await;
+                return;
+            }
             // 客户端断开下游 SSE 流：立即丢弃连接并释放池 slot，
             // 不再傻等上游 idle 超时（否则同会话后续请求会一直 bypass/busy）
             () = tx.closed() => {
@@ -382,10 +403,7 @@ async fn forward_websocket_response_stream(state: WebSocketStreamForwardState) {
         reason => CodexWebSocketExchangeError::StreamEndedBeforeTerminal {
             reason: reason.map_or("stream_eof", PumpExitReason::as_str),
             timeout: match reason {
-                Some(
-                    PumpExitReason::PongTimeout { timeout }
-                    | PumpExitReason::LivenessTimeout { timeout },
-                ) => Some(*timeout),
+                Some(PumpExitReason::PongWriteTimeout { timeout }) => Some(*timeout),
                 _ => None,
             },
             last_event_type,
@@ -414,7 +432,7 @@ async fn finish_stream_websocket(
     pool_return: Option<WebSocketStreamPoolReturn>,
 ) {
     let Some(pool_return) = pool_return else {
-        websocket.close().await;
+        websocket.close_and_wait().await;
         return;
     };
     pool_return
diff --git a/backend/crates/providers/openai/src/transport/websocket/handshake.rs b/backend/crates/providers/openai/src/transport/websocket/handshake.rs
index 180d503df..a2084dbce 100644
--- a/backend/crates/providers/openai/src/transport/websocket/handshake.rs
+++ b/backend/crates/providers/openai/src/transport/websocket/handshake.rs
@@ -30,7 +30,7 @@ use super::{
     error::CodexWebSocketExchangeError,
     model::{CodexWebSocketConnection, CodexWebSocketRequest, WebSocketContinuationRequirement},
     pool::CodexWebSocketConnectionMetadata,
-    pump::{PumpKeepalive, PumpLogContext, PumpedWebSocket, RawWsStream},
+    pump::{PumpLogContext, PumpedWebSocket, RawWsStream},
 };
 
 use super::control::WEBSOCKET_SEND_TIMEOUT;
@@ -153,16 +153,12 @@ pub(super) async fn connect_sideband_websocket(
 
 pub(super) async fn connect_pumped_websocket(
     connection: &CodexWebSocketConnection,
-    keepalive: PumpKeepalive,
     context: PumpLogContext,
     fast_path: bool,
     proxy_permit: Option<super::pool::ProxyConnectionPermit>,
 ) -> Result<(PumpedWebSocket, WsResponse<Option<Vec<u8>>>), CodexWebSocketExchangeError> {
     let (raw, response) = connect_websocket(connection, fast_path).await?;
-    Ok((
-        PumpedWebSocket::new(raw, keepalive, context, proxy_permit),
-        response,
-    ))
+    Ok((PumpedWebSocket::new(raw, context, proxy_permit), response))
 }
 
 pub(super) async fn send_websocket_request(
diff --git a/backend/crates/providers/openai/src/transport/websocket/pool/capacity.rs b/backend/crates/providers/openai/src/transport/websocket/pool/capacity.rs
index 6581bb939..6bce41f17 100644
--- a/backend/crates/providers/openai/src/transport/websocket/pool/capacity.rs
+++ b/backend/crates/providers/openai/src/transport/websocket/pool/capacity.rs
@@ -98,7 +98,7 @@ impl CodexWebSocketPool {
                     .filter_map(|(key, slot)| match slot {
                         WebSocketPoolSlot::Idle { idle_since, .. }
                             if key.proxy_capacity_key == proxy_key
-                                && key.downstream_connection_id.is_empty() =>
+                                && !state.has_downstream_binding(key) =>
                         {
                             Some((key, *idle_since))
                         }
diff --git a/backend/crates/providers/openai/src/transport/websocket/pool/downstream.rs b/backend/crates/providers/openai/src/transport/websocket/pool/downstream.rs
new file mode 100644
index 000000000..41f318855
--- /dev/null
+++ b/backend/crates/providers/openai/src/transport/websocket/pool/downstream.rs
@@ -0,0 +1,134 @@
+//! 下游连接的取消监督与池内归属转移
+
+use std::sync::Arc;
+
+use gateway_core::lifecycle::CancellationToken;
+use tokio::time::Instant;
+
+use super::state::{
+    PooledWebSocketConnection, WebSocketPoolSlot, WebSocketPoolState, close_pooled_connections,
+};
+use super::{CodexWebSocketPool, CodexWebSocketPoolKey, WebSocketPoolConnectOutcome};
+
+impl CodexWebSocketPool {
+    pub(super) fn register_downstream(
+        &self,
+        key: &CodexWebSocketPoolKey,
+        cancellation: &CancellationToken,
+    ) {
+        if key.downstream_connection_id.is_empty() {
+            return;
+        }
+        let connection_id = key.downstream_connection_id.clone();
+        {
+            let mut state = self.lock_state();
+            if state.shutting_down || state.downstream_connections.contains_key(&connection_id) {
+                return;
+            }
+            state
+                .downstream_connections
+                .insert(connection_id.clone(), cancellation.clone());
+        }
+        let inner = Arc::downgrade(&self.inner);
+        let cancellation = cancellation.clone();
+        let shutdown = self.shutdown.clone();
+        let capacity_changed = Arc::clone(&self.capacity_changed);
+        drop(self.tasks.spawn(async move {
+            tokio::select! {
+                biased;
+                () = shutdown.cancelled() => return,
+                () = cancellation.cancelled() => {}
+            }
+            let Some(inner) = inner.upgrade() else { return };
+            let close = {
+                let mut state = inner
+                    .lock()
+                    .unwrap_or_else(std::sync::PoisonError::into_inner);
+                let close = state.take_downstream_connections(
+                    &connection_id,
+                    None,
+                    "downstream_connection_closed",
+                );
+                state.downstream_connections.remove(&connection_id);
+                close
+            };
+            close_pooled_connections(close).await;
+            capacity_changed.notify_waiters();
+        }));
+    }
+
+    /// 实际切到 HTTP 或无池连接时撤销旧 WS 绑定，保留客户端本身的生命周期监督
+    pub(crate) async fn release_downstream_connections(&self, connection_id: &str) {
+        let close = self.lock_state().take_downstream_connections(
+            connection_id,
+            None,
+            "downstream_rebound",
+        );
+        close_pooled_connections(close).await;
+        self.capacity_changed.notify_waiters();
+    }
+
+    pub(super) fn close_retired_connections(&self, connections: Vec<PooledWebSocketConnection>) {
+        if connections.is_empty() {
+            return;
+        }
+        let capacity_changed = Arc::clone(&self.capacity_changed);
+        drop(self.tasks.spawn(async move {
+            close_pooled_connections(connections).await;
+            capacity_changed.notify_waiters();
+        }));
+    }
+}
+
+impl WebSocketPoolState {
+    pub(super) fn has_downstream_binding(&self, key: &CodexWebSocketPoolKey) -> bool {
+        self.downstream_connections
+            .get(&key.downstream_connection_id)
+            .is_some_and(|token| !token.is_cancelled())
+    }
+
+    pub(super) fn downstream_closed(&self, key: &CodexWebSocketPoolKey) -> bool {
+        self.downstream_connections
+            .get(&key.downstream_connection_id)
+            .is_some_and(CancellationToken::is_cancelled)
+    }
+
+    pub(super) fn take_downstream_connections(
+        &mut self,
+        connection_id: &str,
+        keep: Option<&CodexWebSocketPoolKey>,
+        reason: &'static str,
+    ) -> Vec<PooledWebSocketConnection> {
+        if connection_id.is_empty() {
+            return Vec::new();
+        }
+        let keys = self
+            .slots
+            .keys()
+            .filter(|key| key.downstream_connection_id == connection_id && Some(*key) != keep)
+            .cloned()
+            .collect::<Vec<_>>();
+        let mut close = Vec::new();
+        for key in keys {
+            match self.slots.remove(&key) {
+                Some(WebSocketPoolSlot::Idle { connection, .. }) => {
+                    self.remember_continuation_loss(
+                        &key,
+                        connection.continuation.latest_response_id(),
+                        connection.websocket.observation().with_exit_reason(reason),
+                        Instant::now(),
+                    );
+                    close.push(*connection);
+                }
+                Some(WebSocketPoolSlot::Connecting(connecting)) => {
+                    connecting.cancellation.cancel();
+                    connecting
+                        .outcome
+                        .send_replace(WebSocketPoolConnectOutcome::Failed);
+                }
+                Some(WebSocketPoolSlot::Busy(_)) | None => {}
+            }
+        }
+        close
+    }
+}
diff --git a/backend/crates/providers/openai/src/transport/websocket/pool/mod.rs b/backend/crates/providers/openai/src/transport/websocket/pool/mod.rs
index d2471e504..de58655f5 100644
--- a/backend/crates/providers/openai/src/transport/websocket/pool/mod.rs
+++ b/backend/crates/providers/openai/src/transport/websocket/pool/mod.rs
@@ -1,6 +1,7 @@
 //! Codex WebSocket 连接池
 
 mod capacity;
+mod downstream;
 mod lease;
 mod state;
 mod supervisor;
@@ -18,9 +19,8 @@ use uuid::Uuid;
 
 use self::state::{
     WebSocketPoolConnecting, WebSocketPoolSlot, WebSocketPoolState, close_pooled_connection,
-    close_pooled_connections,
+    close_pooled_connections, idle_connection_loss,
 };
-use super::pump::PumpKeepalive;
 use super::pump::WebSocketConnectionObservation;
 
 use self::capacity::ProxyCapacity;
@@ -38,10 +38,8 @@ pub(crate) use self::{
 
 const DEFAULT_MAX_CONNECTING: usize = 16;
 const DEFAULT_MAX_AGE: Duration = Duration::from_mins(55);
-const DEFAULT_MAINTENANCE_INTERVAL: Duration = Duration::from_secs(25);
-const DEFAULT_PING_INTERVAL: Duration = Duration::from_secs(25);
-// 心跳也覆盖正在生成的连接，给短时链路停顿留出恢复余量
-const DEFAULT_PING_TIMEOUT: Duration = Duration::from_secs(30);
+const DEFAULT_MAINTENANCE_INTERVAL: Duration = Duration::from_secs(5);
+const DEFAULT_IDLE_TIMEOUT: Duration = Duration::from_secs(300);
 pub(crate) const DEFAULT_STREAM_IDLE_TIMEOUT: Duration = Duration::from_secs(300);
 
 /// WebSocket 连接池
@@ -74,12 +72,8 @@ pub struct CodexWebSocketPoolConfig {
     pub max_connecting: usize,
     /// 后台维护间隔；`None` 表示不启动后台任务
     pub maintenance_interval: Option<Duration>,
-    /// 池化连接的探活 ping 间隔（包括正在生成的连接）；`None` 表示不主动 ping
-    pub ping_interval: Option<Duration>,
-    /// 发送 ping 后等待任意入站帧的超时时间；零值表示不校验 Pong deadline
-    pub ping_timeout: Duration,
-    /// idle socket 无活动多久后视为失活
-    pub liveness_timeout: Option<Duration>,
+    /// 未绑定下游 WS 的连接归池后可空闲的时间，不由 Ping/Pong 刷新
+    pub idle_timeout: Duration,
     /// 等待下一条上游消息的空闲超时；`None` 或零值使用默认 300 秒
     pub stream_idle_timeout: Option<Duration>,
 }
@@ -91,35 +85,18 @@ impl Default for CodexWebSocketPoolConfig {
             max_age: DEFAULT_MAX_AGE,
             max_connecting: DEFAULT_MAX_CONNECTING,
             maintenance_interval: Some(DEFAULT_MAINTENANCE_INTERVAL),
-            ping_interval: Some(DEFAULT_PING_INTERVAL),
-            ping_timeout: DEFAULT_PING_TIMEOUT,
-            // idle 连接不设失活截断：靠 ping/pong 保活，只在 max_age（55 分钟）
-            // 或 ping 失败时关闭，维持跨轮可复用连接
-            liveness_timeout: None,
+            idle_timeout: DEFAULT_IDLE_TIMEOUT,
             stream_idle_timeout: Some(DEFAULT_STREAM_IDLE_TIMEOUT),
         }
     }
 }
 
-impl CodexWebSocketPoolConfig {
-    /// pump 后台任务的保活策略：从连接池配置派生出 ping/pong 与 liveness 策略
-    pub(crate) fn keepalive(&self) -> PumpKeepalive {
-        PumpKeepalive {
-            ping_interval: self.ping_interval,
-            ping_timeout: (!self.ping_timeout.is_zero()).then_some(self.ping_timeout),
-            liveness_timeout: self.liveness_timeout,
-        }
-    }
-}
-
 impl CodexWebSocketPool {
-    /// 使用指定连接总寿命构造连接池，不启动定时保活与清理
+    /// 使用指定连接总寿命构造连接池，不启动定时清理
     pub fn new(max_age: Duration) -> Self {
         Self::with_config(CodexWebSocketPoolConfig {
             max_age,
             maintenance_interval: None,
-            ping_interval: None,
-            liveness_timeout: None,
             ..CodexWebSocketPoolConfig::default()
         })
     }
@@ -140,11 +117,6 @@ impl CodexWebSocketPool {
         pool
     }
 
-    /// pump 后台任务的保活策略（供建连时传入）
-    pub(crate) fn keepalive(&self) -> PumpKeepalive {
-        self.config.keepalive()
-    }
-
     /// 等待下一条上游消息的空闲超时；`None` 或零值使用默认 300 秒
     pub(crate) fn stream_idle_timeout(&self) -> Option<Duration> {
         self.config.stream_idle_timeout
@@ -160,17 +132,26 @@ impl CodexWebSocketPool {
         key: &CodexWebSocketPoolKey,
         required_response_id: Option<&str>,
         proxy: Option<&gateway_core::account::OutboundProxy>,
+        downstream_cancellation: Option<&gateway_core::lifecycle::CancellationToken>,
     ) -> WebSocketPoolAcquire {
         self.spawn_maintenance_task();
+        if let Some(cancellation) = downstream_cancellation {
+            self.register_downstream(key, cancellation);
+        }
         let mut proxy_permit = None;
         loop {
             let mut connections_to_close = Vec::new();
             let acquire = {
                 let mut state = self.lock_state();
                 let mut continuation_loss = None;
-                if !self.config.enabled || state.shutting_down {
+                if !self.config.enabled
+                    || state.shutting_down
+                    || downstream_cancellation
+                        .is_some_and(gateway_core::lifecycle::CancellationToken::is_cancelled)
+                {
                     return WebSocketPoolAcquire::Bypass(WebSocketPoolBypassReason::Disabled);
                 }
+                let requested_key = key;
                 let key = if let Some(response_id) = required_response_id {
                     let Some(key) = state.slots.iter().find_map(|(candidate, slot)| {
                         (candidate.same_logical_connection(key)
@@ -201,35 +182,57 @@ impl CodexWebSocketPool {
                         });
                     }
                     Some(WebSocketPoolSlot::Idle { .. }) => {
-                        let Some(WebSocketPoolSlot::Idle { connection, .. }) =
-                            state.slots.remove(&key)
+                        let Some(WebSocketPoolSlot::Idle {
+                            mut connection,
+                            idle_since,
+                        }) = state.slots.remove(&key)
                         else {
                             return WebSocketPoolAcquire::Bypass(WebSocketPoolBypassReason::Busy);
                         };
-                        // 零成本探活：后台 pump 已实时感知连接死亡（RST/Close/EOF/失活），
-                        // 复用前只需读取 is_closed 标志，避免复用到静默死连接后卡到超时
-                        let expired = connection.created_at.elapsed() >= self.config.max_age;
-                        let closed = connection.websocket.is_closed();
-                        if !expired && !closed {
+                        // 取得时与后台扫描共用到期判断，避免维护周期内重新借出过期连接
+                        let loss = idle_connection_loss(
+                            state.has_downstream_binding(&key),
+                            &connection,
+                            idle_since,
+                            tokio::time::Instant::now(),
+                            &self.config,
+                        )
+                        .or_else(|| {
+                            state.downstream_closed(&key).then(|| {
+                                connection
+                                    .websocket
+                                    .observation()
+                                    .with_exit_reason("downstream_connection_closed")
+                            })
+                        });
+                        let Some(observation) = loss else {
+                            connection.websocket.revoke_control();
+                            let retired = state.take_downstream_connections(
+                                &requested_key.downstream_connection_id,
+                                Some(&key),
+                                "downstream_rebound",
+                            );
+                            // 精确续接可接手另一条下游连接的 socket，池键必须跟随新 owner
+                            let key = key.with_downstream_connection_id(
+                                requested_key.downstream_connection_id.clone(),
+                            );
                             let lease = WebSocketPoolLease::reserve(
                                 self.clone(),
                                 key.clone(),
                                 connection.continuation.latest_response_id(),
                             );
-                            state.slots.insert(
-                                key.clone(),
-                                WebSocketPoolSlot::Busy(lease.reservation.clone()),
-                            );
+                            state
+                                .slots
+                                .insert(key, WebSocketPoolSlot::Busy(lease.reservation.clone()));
+                            self.close_retired_connections(retired);
                             return WebSocketPoolAcquire::Reused { connection, lease };
-                        }
-                        let observation = if expired && !closed {
-                            connection
-                                .websocket
-                                .observation()
-                                .with_exit_reason("max_age_expired")
-                        } else {
-                            connection.websocket.observation()
                         };
+                        tracing::info!(
+                            websocket_connection_id = %connection.websocket.connection_id(),
+                            exit_reason = observation.exit_reason(),
+                            idle_age_ms = idle_since.elapsed().as_millis(),
+                            "Removed unavailable idle WebSocket before reuse"
+                        );
                         state.remember_continuation_loss(
                             &key,
                             connection.continuation.latest_response_id(),
@@ -244,6 +247,11 @@ impl CodexWebSocketPool {
                     None => {}
                 }
 
+                connections_to_close.extend(state.take_downstream_connections(
+                    &requested_key.downstream_connection_id,
+                    Some(&key),
+                    "downstream_rebound",
+                ));
                 let acquire = if let Some(observation) = continuation_loss {
                     Some(WebSocketPoolAcquire::ContinuationLost(observation))
                 } else if required_response_id.is_some() {
@@ -285,7 +293,17 @@ impl CodexWebSocketPool {
             if let Some(acquire) = acquire {
                 return acquire;
             }
-            match self.acquire_proxy_capacity(proxy, Some(key)).await {
+            let capacity = tokio::select! {
+                biased;
+                () = async {
+                    match downstream_cancellation {
+                        Some(cancellation) => cancellation.cancelled().await,
+                        None => std::future::pending().await,
+                    }
+                } => return WebSocketPoolAcquire::Bypass(WebSocketPoolBypassReason::Disabled),
+                capacity = self.acquire_proxy_capacity(proxy, Some(key)) => capacity,
+            };
+            match capacity {
                 Ok(permit) => proxy_permit = permit,
                 Err(_) => return WebSocketPoolAcquire::Bypass(WebSocketPoolBypassReason::Disabled),
             }
diff --git a/backend/crates/providers/openai/src/transport/websocket/pool/state.rs b/backend/crates/providers/openai/src/transport/websocket/pool/state.rs
index b5e439250..981aeeffc 100644
--- a/backend/crates/providers/openai/src/transport/websocket/pool/state.rs
+++ b/backend/crates/providers/openai/src/transport/websocket/pool/state.rs
@@ -5,6 +5,7 @@ use std::{
     time::Duration,
 };
 
+use futures::{StreamExt, stream::FuturesUnordered};
 use sha2::{Digest, Sha256};
 use tokio::{sync::watch, time::Instant};
 use tokio_util::sync::CancellationToken;
@@ -107,6 +108,7 @@ const MAX_CONTINUATION_TOMBSTONES: usize = 4_096;
 #[derive(Default)]
 pub(super) struct WebSocketPoolState {
     pub(super) slots: HashMap<CodexWebSocketPoolKey, WebSocketPoolSlot>,
+    pub(super) downstream_connections: HashMap<String, gateway_core::lifecycle::CancellationToken>,
     continuation_tombstones: VecDeque<WebSocketContinuationTombstone>,
     pub(super) shutting_down: bool,
 }
@@ -237,18 +239,33 @@ pub(super) async fn close_pooled_connection(connection: PooledWebSocketConnectio
 }
 
 pub(super) async fn close_pooled_connections(connections: Vec<PooledWebSocketConnection>) {
-    for connection in connections {
-        close_pooled_connection(connection).await;
-    }
+    // 每条连接独立执行有界关闭，避免批量回收累计握手等待并拖延后续扫描
+    let mut closing = connections
+        .into_iter()
+        .map(close_pooled_connection)
+        .collect::<FuturesUnordered<_>>();
+    while closing.next().await.is_some() {}
 }
 
-/// idle 连接是否应从池中摘除：被后台 pump 标记死亡，或已超过 `max_age`
-pub(super) fn should_close_idle_connection(
+/// 取得连接和维护扫描共用的失效判断，保留原生续接丢失的具体原因
+pub(super) fn idle_connection_loss(
+    has_downstream_binding: bool,
     connection: &PooledWebSocketConnection,
+    idle_since: Instant,
     now: Instant,
-    max_age: Duration,
-) -> bool {
-    connection.websocket.is_closed() || now.duration_since(connection.created_at) >= max_age
+    config: &super::CodexWebSocketPoolConfig,
+) -> Option<WebSocketConnectionObservation> {
+    if connection.websocket.is_closed() {
+        return Some(connection.websocket.observation());
+    }
+    let reason = if now.duration_since(connection.created_at) >= config.max_age {
+        "max_age_expired"
+    } else if !has_downstream_binding && now.duration_since(idle_since) >= config.idle_timeout {
+        "idle_timeout_expired"
+    } else {
+        return None;
+    };
+    Some(connection.websocket.observation().with_exit_reason(reason))
 }
 
 fn short_sha256<'a>(parts: impl IntoIterator<Item = &'a str>) -> String {
diff --git a/backend/crates/providers/openai/src/transport/websocket/pool/supervisor.rs b/backend/crates/providers/openai/src/transport/websocket/pool/supervisor.rs
index 0b53b189c..ae69f6de3 100644
--- a/backend/crates/providers/openai/src/transport/websocket/pool/supervisor.rs
+++ b/backend/crates/providers/openai/src/transport/websocket/pool/supervisor.rs
@@ -10,8 +10,7 @@ use tokio::time::Instant;
 use super::CodexWebSocketPool;
 use super::lease::WebSocketPoolConnectOutcome;
 use super::state::{
-    PooledWebSocketConnection, WebSocketPoolSlot, close_pooled_connections,
-    should_close_idle_connection,
+    PooledWebSocketConnection, WebSocketPoolSlot, close_pooled_connections, idle_connection_loss,
 };
 
 impl CodexWebSocketPool {
@@ -71,11 +70,7 @@ impl CodexWebSocketPool {
         self.tasks.wait().await;
     }
 
-    /// 维护池 slot：清扫已死亡或超龄的 idle 连接，以及异常残留的 Busy reservation
-    ///
-    /// 保活（ping/pong）与失活检测已下沉到每条连接的 pump 任务内部，此处不再做
-    /// 同步 ping 探活，只负责把「后台已标记 closed」或「超过 max_age」的 idle
-    /// 连接从池中摘除并关闭，避免它们占用 slot
+    /// 清扫已关闭、超龄或空闲到期的连接，以及超龄残留的 reservation
     pub async fn maintain_idle_connections(&self) {
         let close = self.take_expired_slots().await;
         close_pooled_connections(close).await;
@@ -156,43 +151,50 @@ impl CodexWebSocketPool {
             .slots
             .iter()
             .filter_map(|(key, slot)| match slot {
-                WebSocketPoolSlot::Idle { connection, .. }
-                    if should_close_idle_connection(connection, now, self.config.max_age) =>
-                {
-                    Some(key.clone())
-                }
+                WebSocketPoolSlot::Idle {
+                    connection,
+                    idle_since,
+                } => idle_connection_loss(
+                    state.has_downstream_binding(key),
+                    connection,
+                    *idle_since,
+                    now,
+                    &self.config,
+                )
+                .map(|observation| (key.clone(), Some(observation))),
                 WebSocketPoolSlot::Busy(reservation)
                     if now.duration_since(reservation.reserved_at) >= self.config.max_age =>
                 {
-                    Some(key.clone())
+                    Some((key.clone(), None))
                 }
                 WebSocketPoolSlot::Connecting(connecting)
                     if now.duration_since(connecting.started_at) >= self.config.max_age =>
                 {
-                    Some(key.clone())
+                    Some((key.clone(), None))
                 }
-                WebSocketPoolSlot::Idle { .. }
-                | WebSocketPoolSlot::Busy(_)
-                | WebSocketPoolSlot::Connecting(_) => None,
+                WebSocketPoolSlot::Busy(_) | WebSocketPoolSlot::Connecting(_) => None,
             })
             .collect::<Vec<_>>();
-        for key in keys {
+        for (key, observation) in keys {
             match state.slots.remove(&key) {
-                Some(WebSocketPoolSlot::Idle { connection, .. }) => {
-                    let observation = if connection.websocket.is_closed() {
-                        connection.websocket.observation()
-                    } else {
-                        connection
-                            .websocket
-                            .observation()
-                            .with_exit_reason("max_age_expired")
-                    };
-                    state.remember_continuation_loss(
-                        &key,
-                        connection.continuation.latest_response_id(),
-                        observation,
-                        now,
-                    );
+                Some(WebSocketPoolSlot::Idle {
+                    connection,
+                    idle_since,
+                }) => {
+                    if let Some(observation) = observation {
+                        tracing::info!(
+                            websocket_connection_id = %connection.websocket.connection_id(),
+                            exit_reason = observation.exit_reason(),
+                            idle_age_ms = now.duration_since(idle_since).as_millis(),
+                            "Removed unavailable idle WebSocket during maintenance"
+                        );
+                        state.remember_continuation_loss(
+                            &key,
+                            connection.continuation.latest_response_id(),
+                            observation,
+                            now,
+                        );
+                    }
                     close.push(*connection);
                 }
                 Some(WebSocketPoolSlot::Busy(reservation)) => {
diff --git a/backend/crates/providers/openai/src/transport/websocket/pump.rs b/backend/crates/providers/openai/src/transport/websocket/pump.rs
index 44a2a5e58..68288e2aa 100644
--- a/backend/crates/providers/openai/src/transport/websocket/pump.rs
+++ b/backend/crates/providers/openai/src/transport/websocket/pump.rs
@@ -1,17 +1,7 @@
-//! 常驻后台的 WebSocket 泵（对齐官方 Codex CLI 的连接管理）
+//! 单 owner 驱动上游 WebSocket，被动回复心跳并在终止后有界释放 socket
 //!
-//! 每条上游 WebSocket 连接都由一个后台 pump 任务独占：
-//! - 持续读取 socket：一旦观察到 `Close` / EOF / 传输错误，立即把连接标记为 `closed`
-//! - 自动回应上游 `Ping`，并按 `ping_interval` 主动 `Ping`；收到非关闭入站帧即解除本次心跳 deadline
-//! - 可选 `liveness_timeout`：长时间无任何入站活动时判定连接失活并退出
-//!
-//! 因此空闲连接的“死没死”在后台被实时感知；复用方只需零成本读取 [`PumpedWebSocket::is_closed`]，
-//! 无需在请求路径上做同步探活 ping（消除“复用到静默死连接才卡住超时”的长尾）
-//!
-//! 收发都通过 channel 与 pump 任务交互：
-//! - 发送：`send` 走 command channel，等待 pump 回执
-//! - 接收：`next` 从 message channel 取出 pump 转发的入站帧（`Ping`/`Pong` 已被 pump 吞掉）
-//! - 入站缓冲满时暂停读取 socket 和主动探活，仅继续处理发送/关闭命令；消费恢复后按原顺序继续转发
+//! 业务消息通过有界队列交付，Ping/Pong 由 pump 消费，不刷新生成期间的消息等待超时
+//! 入站背压暂停读取，仍可接收关闭命令；已观察到的终止先释放 socket，再等待终止消息交付
 
 use gateway_core::engine::response_control::{ResponseControl, ResponseControlTransport};
 
@@ -22,11 +12,7 @@ use std::sync::{
 use std::time::Duration;
 
 use futures::{Sink, SinkExt, Stream, StreamExt};
-use tokio::{
-    sync::mpsc,
-    task::JoinHandle,
-    time::{Instant, MissedTickBehavior},
-};
+use tokio::{sync::mpsc, task::JoinHandle, time::Instant};
 use tokio_tungstenite::tungstenite::Message;
 use uuid::Uuid;
 
@@ -55,6 +41,8 @@ impl<T> WebSocketIo for T where
 pub(crate) type RawWsStream = Box<dyn WebSocketIo>;
 
 const PUMP_COMMAND_BUFFER: usize = 32;
+const CLOSE_TIMEOUT: Duration = Duration::from_secs(1);
+const PONG_WRITE_TIMEOUT: Duration = Duration::from_secs(5);
 
 /// pump 日志的账号级关联上下文；空闲连接被上游重置等场景用于回溯归属
 #[derive(Debug, Clone, Default)]
@@ -72,28 +60,6 @@ impl PumpLogContext {
     }
 }
 
-/// pump 保活策略
-#[derive(Debug, Clone, Copy)]
-pub(crate) struct PumpKeepalive {
-    /// 主动 `Ping` 间隔；`None` 表示 pump 不主动 ping（仅被动读取 + 回应上游 ping）
-    pub(crate) ping_interval: Option<Duration>,
-    /// 主动 `Ping` 发出后等待任意入站帧的 deadline；`None` 表示不校验响应
-    pub(crate) ping_timeout: Option<Duration>,
-    /// 无入站活动多久后判定失活；`None` 表示只靠显式 close/传输错误发现死亡
-    pub(crate) liveness_timeout: Option<Duration>,
-}
-
-impl PumpKeepalive {
-    /// 不做主动保活（用于即用即弃的非池化连接）
-    pub(crate) fn disabled() -> Self {
-        Self {
-            ping_interval: None,
-            ping_timeout: None,
-            liveness_timeout: None,
-        }
-    }
-}
-
 const PUMP_MESSAGE_BUFFER: usize = 64;
 
 #[derive(Debug, Clone)]
@@ -112,10 +78,7 @@ pub(crate) enum PumpExitReason {
         message: String,
         metric_reason: &'static str,
     },
-    PongTimeout {
-        timeout: Duration,
-    },
-    LivenessTimeout {
+    PongWriteTimeout {
         timeout: Duration,
     },
     KeepaliveTransportError {
@@ -134,8 +97,7 @@ impl PumpExitReason {
             Self::UpstreamCloseFrame { .. } => "upstream_close_frame",
             Self::UpstreamEof => "upstream_eof",
             Self::InboundTransportError { .. } => "inbound_transport_error",
-            Self::PongTimeout { .. } => "pong_timeout",
-            Self::LivenessTimeout { .. } => "liveness_timeout",
+            Self::PongWriteTimeout { .. } => "pong_write_timeout",
             Self::KeepaliveTransportError { .. } => "keepalive_transport_error",
             Self::MessageReceiverClosed => "message_receiver_closed",
         }
@@ -147,9 +109,7 @@ impl PumpExitReason {
             | Self::InboundTransportError { message, .. }
             | Self::KeepaliveTransportError { message, .. } => Some(message.clone()),
             Self::UpstreamCloseFrame { close } => close.as_ref().map(ToString::to_string),
-            Self::PongTimeout { timeout } | Self::LivenessTimeout { timeout } => {
-                Some(format!("{timeout:?}"))
-            }
+            Self::PongWriteTimeout { timeout } => Some(format!("{timeout:?}")),
             Self::CommandChannelClosed
             | Self::LocalClose
             | Self::UpstreamEof
@@ -172,8 +132,7 @@ impl PumpExitReason {
                 }
             }
             Self::UpstreamEof => "eof",
-            Self::PongTimeout { .. } => "pong_timeout",
-            Self::LivenessTimeout { .. } => "liveness_timeout",
+            Self::PongWriteTimeout { .. } => "pong_write_timeout",
             Self::MessageReceiverClosed => "message_receiver_closed",
         }
     }
@@ -191,8 +150,7 @@ impl PumpExitReason {
             Self::OutboundTransportError { .. }
                 | Self::UpstreamEof
                 | Self::InboundTransportError { .. }
-                | Self::PongTimeout { .. }
-                | Self::LivenessTimeout { .. }
+                | Self::PongWriteTimeout { .. }
                 | Self::KeepaliveTransportError { .. }
         )
     }
@@ -202,8 +160,6 @@ impl PumpExitReason {
             self,
             Self::CommandChannelClosed
                 | Self::UpstreamCloseFrame { .. }
-                | Self::PongTimeout { .. }
-                | Self::LivenessTimeout { .. }
                 | Self::MessageReceiverClosed
         )
     }
@@ -214,12 +170,6 @@ struct PendingInbound {
     exit_reason: Option<PumpExitReason>,
 }
 
-#[derive(Debug, Clone, Copy)]
-struct PendingPing {
-    payload: [u8; 8],
-    deadline: Instant,
-}
-
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct WebSocketConnectionObservation {
     connection_id: Uuid,
@@ -283,7 +233,7 @@ pub(crate) struct PumpedWebSocket {
     connection_id: Uuid,
     tx_command: mpsc::Sender<PumpCommand>,
     rx_message: SharedMessages,
-    control: Option<Arc<dyn ResponseControlTransport>>,
+    control: Option<Arc<PumpControl>>,
     closed: Arc<AtomicBool>,
     lifecycle: Arc<Mutex<PumpLifecycleState>>,
     pump: Option<JoinHandle<()>>,
@@ -308,7 +258,6 @@ impl PumpedWebSocket {
     /// 用底层流启动一个 pump 任务并返回句柄
     pub(crate) fn new(
         inner: RawWsStream,
-        keepalive: PumpKeepalive,
         context: PumpLogContext,
         proxy_permit: Option<super::pool::ProxyConnectionPermit>,
     ) -> Self {
@@ -335,7 +284,6 @@ impl PumpedWebSocket {
                 inner,
                 rx_command,
                 tx_message,
-                keepalive,
                 context,
                 closed_for_task,
                 lifecycle_for_task,
@@ -363,16 +311,26 @@ impl PumpedWebSocket {
 
     /// 每轮发送后替换控制 owner，旧执行的弱引用不能控制下一轮连接
     pub(crate) fn bind_control(&mut self, control: Option<&ResponseControl>) {
+        self.revoke_control();
         self.control = control.map(|control| {
-            let transport: Arc<dyn ResponseControlTransport> = Arc::new(PumpControl {
+            let transport = Arc::new(PumpControl {
                 tx_command: self.tx_command.clone(),
                 rx_message: Arc::clone(&self.rx_message),
+                cancellation: tokio_util::sync::CancellationToken::new(),
             });
-            control.bind(&transport);
+            let target: Arc<dyn ResponseControlTransport> = transport.clone();
+            control.bind(&target);
             transport
         });
     }
 
+    /// 弱引用升级后的在途读取仍持有强引用，复用前必须主动撤销，释放消息接收锁
+    pub(crate) fn revoke_control(&mut self) {
+        if let Some(control) = self.control.take() {
+            control.cancellation.cancel();
+        }
+    }
+
     /// 取出下一帧入站消息（`Ping`/`Pong` 已被 pump 处理，不会到达这里）
     ///
     /// 返回 `None` 表示连接已结束（pump 已退出且缓冲已排空）
@@ -406,7 +364,10 @@ impl PumpedWebSocket {
     }
 
     pub(crate) async fn close_and_wait(self) {
-        self.close().await;
+        if !self.is_closed() {
+            // 预算覆盖入队和回执，已阻塞的业务写入不能拖住连接回收
+            let _ = tokio::time::timeout(CLOSE_TIMEOUT, self.send(Message::Close(None))).await;
+        }
         self.abort_and_wait().await;
     }
 
@@ -418,13 +379,6 @@ impl PumpedWebSocket {
             let _ = pump.await;
         }
     }
-
-    /// 主动关闭连接（best-effort 发送 Close 帧）
-    pub(crate) async fn close(&self) {
-        if !self.is_closed() {
-            let _ = self.send(Message::Close(None)).await;
-        }
-    }
 }
 
 impl Drop for PumpedWebSocket {
@@ -435,38 +389,16 @@ impl Drop for PumpedWebSocket {
     }
 }
 
-#[expect(
-    clippy::too_many_arguments,
-    reason = "pump owns one flat set of channel/state handles and log context"
-)]
 async fn pump_loop(
     connection_id: Uuid,
     mut inner: PumpSocket,
     mut rx_command: mpsc::Receiver<PumpCommand>,
     tx_message: mpsc::Sender<Result<Message, tungstenite::Error>>,
-    keepalive: PumpKeepalive,
     context: PumpLogContext,
     closed: Arc<AtomicBool>,
     lifecycle: Arc<Mutex<PumpLifecycleState>>,
 ) {
-    let mut last_activity = lifecycle
-        .lock()
-        .expect("WebSocket pump lifecycle lock poisoned")
-        .last_activity;
-    let ping_interval = keepalive.ping_interval.filter(|d| !d.is_zero());
-    let ping_timeout = keepalive.ping_timeout.filter(|d| !d.is_zero());
-    let liveness_timeout = keepalive.liveness_timeout.filter(|d| !d.is_zero());
-    let mut ping_ticker = ping_interval.map(|d| {
-        // 首个 tick 推迟一整个间隔：tokio::time::interval 默认会让首个 tick 立即就绪，
-        // 否则连接一建立就会立刻发一帧 Ping，与首个请求 Text 抢跑、打乱帧序
-        let mut ticker = tokio::time::interval_at(tokio::time::Instant::now() + d, d);
-        ticker.set_missed_tick_behavior(MissedTickBehavior::Skip);
-        ticker
-    });
-
-    let mut pending_inbound: Option<PendingInbound> = None;
-    let mut pending_ping: Option<PendingPing> = None;
-    let mut ping_sequence = 0_u64;
+    let mut pending_inbound = None;
     let mut backpressure_events = 0_u64;
 
     let reason = 'pump: loop {
@@ -479,12 +411,7 @@ async fn pump_loop(
                     let pending = pending_inbound
                         .take()
                         .expect("pending inbound frame must exist");
-                    permit.send(pending.item);
-                    if let Some(reason) = pending.exit_reason {
-                        break 'pump reason;
-                    }
-                    // 背压期间无法读取 socket，不能把这段本地下游阻塞误算成上游静默
-                    last_activity = Instant::now();
+                    permit.send(pending);
                 }
                 command = rx_command.recv() => {
                     let Some(command) = command else {
@@ -498,8 +425,6 @@ async fn pump_loop(
             continue;
         }
 
-        let pong_deadline = pending_ping.map(|ping| ping.deadline);
-        let liveness_deadline = liveness_timeout.map(|timeout| last_activity + timeout);
         tokio::select! {
             command = rx_command.recv() => {
                 let Some(command) = command else {
@@ -515,17 +440,22 @@ async fn pump_loop(
                     Some(Ok(message)) => {
                         // Close 是终止信号，不能刷新链路健康时间或抹掉关闭前的静默时长
                         if !matches!(message, Message::Close(_)) {
-                            last_activity = Instant::now();
-                            record_activity(&lifecycle, last_activity);
-                            observe_inbound(connection_id, &mut pending_ping, &message);
+                            record_activity(&lifecycle, Instant::now());
                         }
                         match message {
                             Message::Ping(payload) => {
-                                if let Err(error) = inner.stream.send(Message::Pong(payload)).await {
-                                    break 'pump PumpExitReason::KeepaliveTransportError {
+                                match tokio::time::timeout(
+                                    PONG_WRITE_TIMEOUT,
+                                    inner.stream.send(Message::Pong(payload)),
+                                ).await {
+                                    Ok(Ok(())) => {}
+                                    Ok(Err(error)) => break 'pump PumpExitReason::KeepaliveTransportError {
                                         message: error.to_string(),
                                         metric_reason: transport_metric_reason(&error),
-                                    };
+                                    },
+                                    Err(_) => break 'pump PumpExitReason::PongWriteTimeout {
+                                        timeout: PONG_WRITE_TIMEOUT,
+                                    },
                                 }
                             }
                             Message::Pong(_) => {}
@@ -580,28 +510,6 @@ async fn pump_loop(
                     }
                 }
             }
-            _ = tick(&mut ping_ticker) => {
-                if pending_ping.is_none() {
-                    match send_keepalive_ping(
-                        &mut inner.stream,
-                        &mut ping_sequence,
-                        ping_timeout,
-                    ).await {
-                        Ok(pending) => pending_ping = pending,
-                        Err(reason) => break 'pump reason,
-                    }
-                }
-            }
-            _ = wait_until(pong_deadline) => {
-                break 'pump PumpExitReason::PongTimeout {
-                    timeout: ping_timeout.expect("pending ping must have a timeout"),
-                };
-            }
-            _ = wait_until(liveness_deadline) => {
-                break 'pump PumpExitReason::LivenessTimeout {
-                    timeout: liveness_timeout.expect("liveness deadline must have a timeout"),
-                };
-            }
         }
     };
 
@@ -626,13 +534,18 @@ async fn pump_loop(
     );
 
     if reason.should_send_close() {
-        let _ = inner.stream.send(Message::Close(None)).await;
+        let _ = tokio::time::timeout(CLOSE_TIMEOUT, inner.stream.send(Message::Close(None))).await;
+    }
+    // 消费方可能仍在排空业务消息，连接和容量不能继续等它读取终止消息
+    drop(inner);
+    if let Some(pending) = pending_inbound {
+        let _ = tx_message.send(pending).await;
     }
 }
 
 fn enqueue_inbound(
     tx_message: &mpsc::Sender<Result<Message, tungstenite::Error>>,
-    pending_inbound: &mut Option<PendingInbound>,
+    pending_inbound: &mut Option<Result<Message, tungstenite::Error>>,
     connection_id: Uuid,
     backpressure_events: &mut u64,
     inbound: PendingInbound,
@@ -649,8 +562,8 @@ fn enqueue_inbound(
                     "Responses WebSocket pump applying inbound backpressure"
                 );
             }
-            *pending_inbound = Some(PendingInbound { item, exit_reason });
-            None
+            *pending_inbound = Some(item);
+            exit_reason
         }
         Err(mpsc::error::TrySendError::Closed(_)) => Some(PumpExitReason::MessageReceiverClosed),
     }
@@ -687,22 +600,6 @@ async fn handle_command(
     }
 }
 
-fn observe_inbound(connection_id: Uuid, pending_ping: &mut Option<PendingPing>, message: &Message) {
-    let Some(pending) = pending_ping else {
-        return;
-    };
-    if let Message::Pong(payload) = message
-        && payload.as_ref() != pending.payload
-    {
-        tracing::debug!(
-            websocket_connection_id = %connection_id,
-            "Responses WebSocket pump received a non-matching Pong"
-        );
-    }
-    // 匹配 Pong 是探针的直接回执；其他入站帧同样证明上游链路仍可达
-    *pending_ping = None;
-}
-
 fn record_activity(lifecycle: &Mutex<PumpLifecycleState>, observed_at: Instant) {
     lifecycle
         .lock()
@@ -748,26 +645,6 @@ fn duration_millis(duration: Duration) -> u64 {
     u64::try_from(duration.as_millis()).unwrap_or(u64::MAX)
 }
 
-async fn send_keepalive_ping(
-    inner: &mut RawWsStream,
-    sequence: &mut u64,
-    ping_timeout: Option<Duration>,
-) -> Result<Option<PendingPing>, PumpExitReason> {
-    let payload = sequence.to_be_bytes();
-    *sequence = sequence.wrapping_add(1);
-    inner
-        .send(Message::Ping(payload.to_vec().into()))
-        .await
-        .map_err(|error| PumpExitReason::KeepaliveTransportError {
-            message: error.to_string(),
-            metric_reason: transport_metric_reason(&error),
-        })?;
-    Ok(ping_timeout.map(|timeout| PendingPing {
-        payload,
-        deadline: Instant::now() + timeout,
-    }))
-}
-
 fn log_pump_exit(
     connection_id: Uuid,
     context: &PumpLogContext,
@@ -823,21 +700,3 @@ fn log_pump_exit(
         );
     }
 }
-
-/// 等待 ping ticker；`None` 时永远挂起，让 `select!` 分支实际禁用
-async fn tick(ticker: &mut Option<tokio::time::Interval>) {
-    match ticker {
-        Some(ticker) => {
-            ticker.tick().await;
-        }
-        None => std::future::pending::<()>().await,
-    }
-}
-
-/// 等待可选 deadline；`None` 时永远挂起，让 `select!` 分支实际禁用
-async fn wait_until(deadline: Option<Instant>) {
-    match deadline {
-        Some(deadline) => tokio::time::sleep_until(deadline).await,
-        None => std::future::pending::<()>().await,
-    }
-}
diff --git a/backend/crates/providers/openai/tests/config.rs b/backend/crates/providers/openai/tests/config.rs
index 6c9cce75f..ac34f1751 100644
--- a/backend/crates/providers/openai/tests/config.rs
+++ b/backend/crates/providers/openai/tests/config.rs
@@ -1,6 +1,6 @@
 //! 验证 OpenAI 配置解析、路径派生与上游地址约束
 
-use std::path::Path;
+use std::{path::Path, time::Duration};
 
 use provider_openai::config::{MAX_STREAM_MAX_RETRIES, OpenAiConfig};
 
@@ -95,6 +95,42 @@ fn openai_stream_retry_budget_uses_the_official_hard_cap() {
     );
 }
 
+#[test]
+fn websocket_pool_idle_timeout_accepts_existing_configs_and_explicit_overrides() {
+    for (idle_timeout_ms, expected) in [(None, 300_000), (Some(600_000), 600_000)] {
+        let mut document = serde_json::json!({
+            "ws_pool": {
+                "enabled": true,
+                "max_age_ms": 3_300_000,
+                "max_connecting": 8,
+                "stream_idle_timeout_ms": 300_000
+            }
+        });
+        if let Some(idle_timeout_ms) = idle_timeout_ms {
+            document["ws_pool"]["idle_timeout_ms"] = serde_json::json!(idle_timeout_ms);
+        }
+        let mut config: OpenAiConfig = serde_json::from_value(document).unwrap();
+        config
+            .resolve_and_validate(Path::new("/srv/gateway"))
+            .unwrap();
+        assert_eq!(
+            config.websocket_pool_config().idle_timeout,
+            Duration::from_millis(expected)
+        );
+    }
+}
+
+#[test]
+fn websocket_pool_idle_timeout_rejects_zero() {
+    let mut config = valid_config();
+    config.ws_pool.idle_timeout_ms = 0;
+    assert!(
+        config
+            .resolve_and_validate(Path::new("/srv/gateway"))
+            .is_err()
+    );
+}
+
 fn valid_config() -> OpenAiConfig {
     OpenAiConfig::default()
 }
diff --git a/backend/crates/providers/openai/tests/provider/contract/mod.rs b/backend/crates/providers/openai/tests/provider/contract/mod.rs
index 7c15f85a0..7237cd394 100644
--- a/backend/crates/providers/openai/tests/provider/contract/mod.rs
+++ b/backend/crates/providers/openai/tests/provider/contract/mod.rs
@@ -4433,130 +4433,6 @@ async fn websocket_idle_timeout_diagnosis_survives_ambiguous_send_wrapping() {
     );
 }
 
-#[tokio::test]
-async fn websocket_pong_timeout_diagnosis_survives_ambiguous_send_wrapping() {
-    for reuse in [false, true] {
-        const ACCOUNT_ID: &str = "acct_abrupt_disconnect";
-        let store = Arc::new(MemoryAccountStore::default());
-        create_account(&store, ACCOUNT_ID).await;
-        let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
-        let base_url = format!("http://{}", listener.local_addr().unwrap());
-        let (ping_seen_tx, ping_seen_rx) = oneshot::channel();
-        let server = tokio::spawn(async move {
-            let (stream, _) = listener.accept().await.unwrap();
-            let mut websocket = accept_codex_test_websocket(stream).await;
-            websocket.next().await.unwrap().unwrap();
-            if reuse {
-                websocket
-                    .send(Message::Text(
-                        json!({
-                            "type": "response.completed",
-                            "response": {
-                                "id": "resp_warmup",
-                                "model": "gpt-5.4",
-                                "status": "completed",
-                                "output": [],
-                                "usage": {"input_tokens": 1, "output_tokens": 1, "total_tokens": 2}
-                            }
-                        })
-                        .to_string()
-                        .into(),
-                    ))
-                    .await
-                    .unwrap();
-                websocket.next().await.unwrap().unwrap();
-            }
-            for event in [
-                json!({"type": "response.created", "response": {"id": "resp_pong", "model": "gpt-5.4"}}),
-                json!({"type": "response.output_text.delta", "delta": "private-response-body"}),
-            ] {
-                websocket
-                    .send(Message::Text(event.to_string().into()))
-                    .await
-                    .unwrap();
-            }
-            std::assert_matches!(websocket.next().await.unwrap().unwrap(), Message::Ping(_));
-            ping_seen_tx.send(()).unwrap();
-            // 停止 poll，避免 tungstenite 自动回 Pong，复现本地保活超时
-            futures::future::pending::<()>().await;
-        });
-        let operation = Operation::Generate(generate_with_persisted_session_context(
-            ACCOUNT_ID,
-            "conversation-pong-timeout",
-            "session-pong-timeout",
-            "turn-pong-timeout",
-        ));
-        let provider = provider_with_base_url(&store, base_url);
-        if reuse {
-            let mut warmup = Arc::clone(&provider)
-                .execute(
-                    planned_request("openai", operation.clone()),
-                    context("req_pong_warmup", CancellationToken::new()),
-                )
-                .await
-                .unwrap();
-            while let Some(event) = warmup.next().await {
-                event.unwrap();
-            }
-        }
-        let mut stream = provider
-            .execute(
-                planned_request("openai", operation),
-                context("req_pong_timeout", CancellationToken::new()),
-            )
-            .await
-            .unwrap();
-        let mut pool_kind = None;
-        loop {
-            let event = stream.next().await.unwrap().unwrap();
-            if let Some(observation) = event.response_observation() {
-                pool_kind = observation.websocket_pool().or(pool_kind);
-            }
-            if event.has_client_event() {
-                break;
-            }
-        }
-        assert_eq!(
-            pool_kind,
-            Some(if reuse {
-                WebSocketPoolKind::Reuse
-            } else {
-                WebSocketPoolKind::New
-            })
-        );
-        tokio::time::pause();
-        tokio::time::advance(Duration::from_secs(25)).await;
-        ping_seen_rx.await.unwrap();
-        tokio::time::advance(Duration::from_secs(31)).await;
-        let error = loop {
-            match stream.next().await {
-                Some(Ok(_)) => {}
-                Some(Err(error)) => break error,
-                None => panic!("Pong timeout must surface a provider error"),
-            }
-        };
-        server.abort();
-        tokio::time::resume();
-        assert_eq!(error.send_state(), UpstreamSendState::Ambiguous);
-        assert!(!error.replay_is_safe());
-        assert_eq!(error.pre_delivery_retry(), None);
-        assert_eq!(error.kind(), ProviderErrorKind::Transport);
-        assert_eq!(
-            error.connection_observation().unwrap().exit_reason(),
-            "pong_timeout"
-        );
-        let diagnostic = error.diagnostic().unwrap();
-        assert_eq!(diagnostic.code(), Some("pong_timeout"));
-        assert_eq!(diagnostic.stage(), Some("receive"));
-        assert_eq!(
-            diagnostic.as_str(),
-            "OpenAI WebSocket stream ended before a terminal response (pong_timeout); local keepalive timeout after 30s; last event type: response.output_text.delta",
-        );
-        assert!(error.raw_upstream_error().is_none());
-        assert!(error.client_visible_upstream_error().is_none());
-    }
-}
-
 #[tokio::test]
 async fn ambiguous_websocket_close_reconnects_and_retains_native_continuation() {
     const ACCOUNT_ID: &str = "acct_websocket_close";
diff --git a/backend/crates/providers/openai/tests/provider/contract/response_interrupt/cleanup.rs b/backend/crates/providers/openai/tests/provider/contract/response_interrupt/cleanup.rs
index 4392e8913..85ea4d641 100644
--- a/backend/crates/providers/openai/tests/provider/contract/response_interrupt/cleanup.rs
+++ b/backend/crates/providers/openai/tests/provider/contract/response_interrupt/cleanup.rs
@@ -1,4 +1,4 @@
-//! 验证控制帧写入阻塞时，接收超时和下游取消仍能结束响应并释放连接
+//! 验证控制消息写入阻塞时，超时、取消和空闲池回收仍能释放物理连接
 
 use super::*;
 use crate::transport::accept_codex_test_websocket_with;
@@ -13,6 +13,88 @@ async fn cancellation_should_abort_stalled_control_write() {
     assert_stalled_control_cleanup(true).await;
 }
 
+#[tokio::test]
+async fn pool_shutdown_should_abort_stalled_idle_control_write() {
+    let store = Arc::new(MemoryAccountStore::default());
+    create_account(&store, "acct_provider_contract").await;
+    let socket = tokio::net::TcpSocket::new_v4().unwrap();
+    socket.set_recv_buffer_size(8192).unwrap();
+    socket.bind("127.0.0.1:0".parse().unwrap()).unwrap();
+    let listener = socket.listen(1).unwrap();
+    let base_url = format!("http://{}", listener.local_addr().unwrap());
+    let (started, started_rx) = oneshot::channel();
+    let (drain, drain_rx) = oneshot::channel();
+    let server = tokio::spawn(async move {
+        let (socket, _) = listener.accept().await.unwrap();
+        let mut ws = accept_codex_test_websocket_with(socket, |_, response| {
+            response.headers_mut().remove("sec-websocket-extensions");
+        })
+        .await;
+        assert_eq!(next_json(&mut ws).await["type"], "response.create");
+        // 未协商压缩，直接写入终态，让连接归池后再阻塞下一条控制消息
+        let terminal = br#"{"type":"response.completed","response":{"id":"resp_idle_control","status":"completed","output":[]}}"#;
+        assert!(terminal.len() < 126);
+        ws.get_mut()
+            .write_all(&[0x81, u8::try_from(terminal.len()).unwrap()])
+            .await
+            .unwrap();
+        ws.get_mut().write_all(terminal).await.unwrap();
+        ws.get_mut().read_u8().await.unwrap();
+        started.send(()).unwrap();
+        drain_rx.await.unwrap();
+        tokio::io::copy(ws.get_mut(), &mut tokio::io::sink())
+            .await
+            .unwrap();
+    });
+    let (provider, pool) =
+        provider_with_cooldowns(&store, base_url, Arc::new(MemoryCooldownPort::new()));
+    let control = ResponseControl::default();
+    let request = generate_with_persisted_session_context(
+        "acct_provider_contract",
+        "idle-control-close",
+        "idle-control-session",
+        "idle-control-thread",
+    );
+    let mut stream = provider
+        .execute(
+            planned_request("openai", Operation::Generate(request)),
+            interrupt_context(control.clone(), None),
+        )
+        .await
+        .unwrap();
+    timeout(Duration::from_secs(3), async {
+        while let Some(event) = stream.next().await {
+            event.unwrap();
+        }
+    })
+    .await
+    .expect("the response must finish and return its connection to the pool");
+
+    let payload =
+        json!({"type": "future.control", "data": "x".repeat(16 * 1024 * 1024)}).to_string();
+    let pending = control.send(&payload);
+    tokio::pin!(pending);
+    tokio::select! {
+        result = &mut pending => panic!("control write should stall: {result:?}"),
+        ready = started_rx => ready.unwrap(),
+        () = tokio::time::sleep(Duration::from_secs(5)) => panic!("control write should start"),
+    }
+    timeout(Duration::from_secs(2), pool.shutdown())
+        .await
+        .expect("pool shutdown must bound Close queued behind a stalled write");
+    assert_eq!(
+        timeout(Duration::from_secs(1), pending)
+            .await
+            .expect("pool shutdown must stop the pending control write"),
+        Err(ResponseControlUnavailable)
+    );
+    drain.send(()).unwrap();
+    timeout(Duration::from_secs(5), server)
+        .await
+        .expect("pool shutdown must release the physical socket")
+        .unwrap();
+}
+
 async fn assert_stalled_control_cleanup(cancel_response: bool) {
     let store = Arc::new(MemoryAccountStore::default());
     create_account(&store, "acct_provider_contract").await;
diff --git a/backend/crates/providers/openai/tests/provider/contract/response_interrupt/mod.rs b/backend/crates/providers/openai/tests/provider/contract/response_interrupt/mod.rs
index d45e898cf..3a3280494 100644
--- a/backend/crates/providers/openai/tests/provider/contract/response_interrupt/mod.rs
+++ b/backend/crates/providers/openai/tests/provider/contract/response_interrupt/mod.rs
@@ -71,6 +71,7 @@ async fn controls_reject_closed_socket_without_losing_backpressured_close() {
     let base_url = format!("http://{}", listener.local_addr().unwrap());
     let (burst, ready) = oneshot::channel();
     let (closed, closing) = oneshot::channel();
+    let (released, released_rx) = oneshot::channel();
     let server = tokio::spawn(async move {
         let (socket, _) = listener.accept().await.unwrap();
         let mut ws = accept_codex_test_websocket(socket).await;
@@ -89,7 +90,7 @@ async fn controls_reject_closed_socket_without_losing_backpressured_close() {
         for _ in 0..81 {
             ws.send(delta.clone()).await.unwrap();
         }
-        // Pong 证明 pump 已读取前面的突发数据，随后 Close 必须等待下游排空
+        // Pong 证明 pump 已读取前面的突发数据，Close 的交付仍需等待下游排空
         ws.send(Message::Ping(vec![1].into())).await.unwrap();
         assert!(matches!(
             ws.next().await.unwrap().unwrap(),
@@ -102,8 +103,11 @@ async fn controls_reject_closed_socket_without_losing_backpressured_close() {
         .await
         .unwrap();
         closed.send(()).unwrap();
-        // 保留 TCP 直到客户端确认关闭，避免把 Close 场景变成连接重置
-        let _ = ws.next().await;
+        // 直接观察 TCP EOF，不能只凭客户端回了 Close 就认定物理连接已经释放
+        tokio::io::copy(ws.get_mut(), &mut tokio::io::sink())
+            .await
+            .unwrap();
+        released.send(()).unwrap();
     });
     let control = ResponseControl::default();
     let mut stream = provider_with_base_url(&store, base_url)
@@ -123,7 +127,10 @@ async fn controls_reject_closed_socket_without_losing_backpressured_close() {
         .await
         .unwrap()
         .unwrap();
-    tokio::time::sleep(Duration::from_millis(50)).await;
+    timeout(Duration::from_secs(2), released_rx)
+        .await
+        .expect("observed Close must release the socket before the response is drained")
+        .unwrap();
     assert_eq!(
         timeout(
             Duration::from_secs(2),
diff --git a/backend/crates/providers/openai/tests/transport/catalog.rs b/backend/crates/providers/openai/tests/transport/catalog.rs
index 8ac62109b..94446e5a3 100644
--- a/backend/crates/providers/openai/tests/transport/catalog.rs
+++ b/backend/crates/providers/openai/tests/transport/catalog.rs
@@ -437,6 +437,7 @@ fn profile() -> CodexWireProfileState {
 
 fn context() -> CodexRequestContext<'static> {
     CodexRequestContext {
+        response_control: None,
         trace: None,
         authorization: "Bearer oauth-access",
         account_id: Some("acct_123"),
diff --git a/backend/crates/providers/openai/tests/transport/client.rs b/backend/crates/providers/openai/tests/transport/client.rs
index 2d89298fb..722408c0e 100644
--- a/backend/crates/providers/openai/tests/transport/client.rs
+++ b/backend/crates/providers/openai/tests/transport/client.rs
@@ -27,6 +27,7 @@ fn upstream_error_formatting_should_redact_body() {
 #[test]
 fn request_context_debug_should_redact_all_identity_material() {
     let context = CodexRequestContext {
+        response_control: None,
         trace: None,
         authorization: "Bearer access-secret-marker",
         account_id: Some("account-secret-marker"),
diff --git a/backend/crates/providers/openai/tests/transport/downstream/headers.rs b/backend/crates/providers/openai/tests/transport/downstream/headers.rs
index b868767df..a631b90d0 100644
--- a/backend/crates/providers/openai/tests/transport/downstream/headers.rs
+++ b/backend/crates/providers/openai/tests/transport/downstream/headers.rs
@@ -215,6 +215,7 @@ async fn backend_http_should_preserve_business_headers_without_downstream_transp
         .create_response(
             &request,
             CodexRequestContext {
+                response_control: None,
                 trace: None,
                 authorization: "Bearer lease-token",
                 account_id: Some("lease-account"),
@@ -360,6 +361,7 @@ async fn backend_websocket_should_preserve_business_headers_without_downstream_t
         .create_response(
             &request,
             CodexRequestContext {
+                response_control: None,
                 trace: None,
                 authorization: "Bearer lease-token",
                 account_id: Some("lease-account"),
diff --git a/backend/crates/providers/openai/tests/transport/headers.rs b/backend/crates/providers/openai/tests/transport/headers.rs
index bad262ed6..10988fbb5 100644
--- a/backend/crates/providers/openai/tests/transport/headers.rs
+++ b/backend/crates/providers/openai/tests/transport/headers.rs
@@ -172,6 +172,7 @@ async fn backend_websocket_should_forward_context_headers_and_preserve_payload_f
         .create_response(
             &request,
             CodexRequestContext {
+                response_control: None,
                 trace: None,
                 authorization: "Bearer access-token",
                 account_id: Some("chatgpt-account"),
@@ -289,6 +290,7 @@ async fn backend_http_should_send_codex_context_without_browser_headers() {
         .create_response(
             &request,
             CodexRequestContext {
+                response_control: None,
                 trace: None,
                 authorization: "Bearer access-token",
                 account_id: Some("chatgpt-account"),
@@ -416,6 +418,7 @@ async fn backend_http_should_ignore_unrepresentable_protocol_headers_without_blo
         .create_response(
             &request,
             CodexRequestContext {
+                response_control: None,
                 trace: None,
                 client_request_id: Some("opaque\nclient-request-id"),
                 session_id: Some("opaque\nsession"),
diff --git a/backend/crates/providers/openai/tests/transport/http_client.rs b/backend/crates/providers/openai/tests/transport/http_client.rs
index fa8cc4f0b..eea8e4149 100644
--- a/backend/crates/providers/openai/tests/transport/http_client.rs
+++ b/backend/crates/providers/openai/tests/transport/http_client.rs
@@ -123,6 +123,7 @@ async fn codex_backend_client_should_preserve_oversized_error_response() {
         .create_response(
             &request,
             CodexRequestContext {
+                response_control: None,
                 trace: None,
                 authorization: "Bearer access-token",
                 account_id: Some("chatgpt-account"),
@@ -223,6 +224,7 @@ async fn codex_backend_client_should_parse_retry_after_from_rate_limit_error_bod
         .create_response(
             &request,
             CodexRequestContext {
+                response_control: None,
                 trace: None,
                 authorization: "Bearer access-token",
                 account_id: Some("chatgpt-account"),
@@ -408,6 +410,7 @@ async fn codex_backend_client_should_capture_forwardable_response_metadata() {
         .create_response(
             &request,
             CodexRequestContext {
+                response_control: None,
                 trace: None,
                 authorization: "Bearer access-token",
                 account_id: Some("chatgpt-account"),
diff --git a/backend/crates/providers/openai/tests/transport/mod.rs b/backend/crates/providers/openai/tests/transport/mod.rs
index 8b19e0421..2c49a7c2b 100644
--- a/backend/crates/providers/openai/tests/transport/mod.rs
+++ b/backend/crates/providers/openai/tests/transport/mod.rs
@@ -150,6 +150,7 @@ fn request_context<'a>(
     account_id: Option<&'a str>,
 ) -> CodexRequestContext<'a> {
     CodexRequestContext {
+        response_control: None,
         trace: None,
         authorization: "Bearer access-token",
         account_id,
@@ -517,18 +518,12 @@ async fn write_empty_http_response(stream: &mut TcpStream) {
 
 fn websocket_pool_config_for_tests(
     maintenance_interval: Option<Duration>,
-    ping_interval: Option<Duration>,
-    liveness_timeout: Option<Duration>,
 ) -> CodexWebSocketPoolConfig {
     CodexWebSocketPoolConfig {
-        enabled: true,
         max_age: Duration::from_mins(1),
-        max_connecting: 16,
         maintenance_interval,
-        ping_interval,
-        ping_timeout: Duration::from_secs(1),
-        liveness_timeout,
         stream_idle_timeout: None,
+        ..CodexWebSocketPoolConfig::default()
     }
 }
 
diff --git a/backend/crates/providers/openai/tests/transport/proxy_capacity.rs b/backend/crates/providers/openai/tests/transport/proxy_capacity.rs
index 3b7da3f9c..a75cf6433 100644
--- a/backend/crates/providers/openai/tests/transport/proxy_capacity.rs
+++ b/backend/crates/providers/openai/tests/transport/proxy_capacity.rs
@@ -5,12 +5,13 @@ use gateway_core::{
     account::{CredentialRevision, OutboundProxy, ProviderAccount, ProviderAccountId},
     routing::ProviderKind,
 };
+use gateway_core::{engine::response_control::ResponseControl, lifecycle::CancellationToken};
 use provider_openai::transport::websocket::PreviousResponseUnavailableReason;
 
 fn limited_pool() -> Arc<CodexWebSocketPool> {
     Arc::new(CodexWebSocketPool::with_config(CodexWebSocketPoolConfig {
         max_age: Duration::from_mins(55),
-        ..websocket_pool_config_for_tests(None, None, None)
+        ..websocket_pool_config_for_tests(None)
     }))
 }
 
@@ -138,6 +139,276 @@ async fn proxy_capacity_preserves_idle_reuse_beyond_two_minutes_without_pressure
     pool.shutdown().await;
 }
 
+#[tokio::test]
+async fn proxy_capacity_idle_timeout_restarts_when_a_connection_is_returned() {
+    let proxy = LimitedProxy::start(32).await;
+    let pool = limited_pool();
+    let client = proxy.client(pool.clone(), "acct_a", 1);
+    respond(&client, "idle-reset").await;
+    for _ in 0..2 {
+        tokio::time::pause();
+        tokio::time::advance(Duration::from_secs(200)).await;
+        tokio::time::resume();
+        pool.maintain_idle_connections().await;
+        respond(&client, "idle-reset").await;
+    }
+    assert_eq!(proxy.opened.load(Ordering::SeqCst), 1);
+    pool.shutdown().await;
+}
+
+#[tokio::test]
+async fn proxy_capacity_releases_idle_sockets_after_five_minutes() {
+    let proxy = LimitedProxy::start(32).await;
+    let pool = limited_pool();
+    let client = proxy.client(pool.clone(), "acct_a", 1);
+    respond(&client, "idle-expired").await;
+    tokio::time::pause();
+    tokio::time::advance(Duration::from_secs(300)).await;
+    tokio::time::resume();
+    pool.maintain_idle_connections().await;
+    wait_until(|| proxy.active.load(Ordering::SeqCst) == 0).await;
+    timeout(
+        Duration::from_secs(3),
+        respond(&client, "after-idle-expiry"),
+    )
+    .await
+    .unwrap();
+    assert_eq!(proxy.opened.load(Ordering::SeqCst), 2);
+    pool.shutdown().await;
+}
+
+#[tokio::test]
+async fn proxy_capacity_preserves_bound_sockets_beyond_idle_timeout() {
+    let control = ResponseControl::default().with_connection_cancellation(CancellationToken::new());
+    let proxy = LimitedProxy::start(32).await;
+    let pool = limited_pool();
+    let client = proxy.client(pool.clone(), "acct_a", 1);
+    let mut request = pooled_websocket_request("bound-idle");
+    request.downstream_websocket_connection_id = Some("downstream-bound-idle".to_owned());
+    client
+        .create_response(
+            &request,
+            request_context("bound-first", Some("test-upstream"))
+                .with_response_control(Some(&control)),
+        )
+        .await
+        .unwrap();
+    tokio::time::pause();
+    tokio::time::advance(Duration::from_secs(301)).await;
+    tokio::time::resume();
+    pool.maintain_idle_connections().await;
+    client
+        .create_response(
+            &request,
+            request_context("bound-next", Some("test-upstream"))
+                .with_response_control(Some(&control)),
+        )
+        .await
+        .unwrap();
+    assert_eq!(proxy.opened.load(Ordering::SeqCst), 1);
+    pool.shutdown().await;
+}
+
+#[tokio::test]
+async fn downstream_close_releases_idle_socket_without_waiting_for_maintenance() {
+    let proxy = LimitedProxy::start(32).await;
+    let pool = limited_pool();
+    let client = proxy.client(pool.clone(), "acct_a", 1);
+    let cancellation = CancellationToken::new();
+    let control = ResponseControl::default().with_connection_cancellation(cancellation.clone());
+    let mut request = pooled_websocket_request("closed-client");
+    request.downstream_websocket_connection_id = Some("downstream-closed".to_owned());
+    client
+        .create_response(
+            &request,
+            request_context("bound", Some("test-upstream")).with_response_control(Some(&control)),
+        )
+        .await
+        .unwrap();
+    cancellation.cancel();
+    wait_until(|| proxy.active.load(Ordering::SeqCst) == 0).await;
+    timeout(Duration::from_secs(3), respond(&client, "next-client"))
+        .await
+        .unwrap();
+    assert_eq!(proxy.opened.load(Ordering::SeqCst), 2);
+    pool.shutdown().await;
+}
+
+#[tokio::test]
+async fn downstream_close_cancels_active_response_and_prevents_return_to_pool() {
+    let gate = Arc::new(tokio::sync::Semaphore::new(0));
+    let proxy = LimitedProxy::with_gates(32, None, Some(gate.clone())).await;
+    let pool = limited_pool();
+    let client = proxy.client(pool.clone(), "acct_a", 1);
+    let cancellation = CancellationToken::new();
+    let control = ResponseControl::default().with_connection_cancellation(cancellation.clone());
+    let mut request = pooled_websocket_request("active-client");
+    request.downstream_websocket_connection_id = Some("downstream-active".to_owned());
+    let task = tokio::spawn(async move {
+        client
+            .create_response(
+                &request,
+                request_context("active", Some("test-upstream"))
+                    .with_response_control(Some(&control)),
+            )
+            .await
+    });
+    wait_until(|| !proxy.requests.lock().unwrap().is_empty()).await;
+    cancellation.cancel();
+    let response = timeout(Duration::from_secs(3), task)
+        .await
+        .unwrap()
+        .unwrap()
+        .unwrap();
+    assert!(response.body.is_empty());
+    wait_until(|| proxy.active.load(Ordering::SeqCst) == 0).await;
+    gate.add_permits(2);
+    let client = proxy.client(pool.clone(), "acct_a", 1);
+    timeout(
+        Duration::from_secs(3),
+        respond(&client, "after-active-cancel"),
+    )
+    .await
+    .unwrap();
+    assert_eq!(proxy.opened.load(Ordering::SeqCst), 2);
+    pool.shutdown().await;
+}
+
+#[tokio::test]
+async fn downstream_close_cancels_connecting_socket_and_releases_proxy_capacity() {
+    let gate = Arc::new(tokio::sync::Semaphore::new(0));
+    let proxy = LimitedProxy::with_gates(32, Some(gate.clone()), None).await;
+    let pool = limited_pool();
+    let client = proxy.client(pool.clone(), "acct_a", 1);
+    let cancellation = CancellationToken::new();
+    let control = ResponseControl::default().with_connection_cancellation(cancellation.clone());
+    let mut request = pooled_websocket_request("opening-client");
+    request.downstream_websocket_connection_id = Some("downstream-opening".to_owned());
+    request.set_previous_response_id(None);
+    request.previous_response_scope = None;
+    let task = tokio::spawn(async move {
+        client
+            .create_response(
+                &request,
+                request_context("opening", Some("test-upstream"))
+                    .with_response_control(Some(&control)),
+            )
+            .await
+    });
+    wait_until(|| proxy.active.load(Ordering::SeqCst) == 1).await;
+    cancellation.cancel();
+    assert!(
+        timeout(Duration::from_secs(3), task)
+            .await
+            .unwrap()
+            .unwrap()
+            .is_err()
+    );
+    wait_until(|| proxy.active.load(Ordering::SeqCst) == 0).await;
+    gate.add_permits(2);
+    let client = proxy.client(pool.clone(), "acct_a", 1);
+    timeout(
+        Duration::from_secs(3),
+        respond(&client, "after-opening-cancel"),
+    )
+    .await
+    .unwrap();
+    pool.shutdown().await;
+}
+
+#[tokio::test]
+async fn old_downstream_close_does_not_destroy_a_transferred_continuation() {
+    let proxy = LimitedProxy::start(32).await;
+    let pool = limited_pool();
+    let client = proxy.client(pool.clone(), "acct_a", 1);
+    let old_cancellation = CancellationToken::new();
+    let new_cancellation = CancellationToken::new();
+    let old_control =
+        ResponseControl::default().with_connection_cancellation(old_cancellation.clone());
+    let new_control =
+        ResponseControl::default().with_connection_cancellation(new_cancellation.clone());
+    let mut request = pooled_websocket_request("transferred-chain");
+    request.downstream_websocket_connection_id = Some("downstream-old".to_owned());
+    client
+        .create_response(
+            &request,
+            request_context("old", Some("test-upstream")).with_response_control(Some(&old_control)),
+        )
+        .await
+        .unwrap();
+    request.downstream_websocket_connection_id = Some("downstream-new".to_owned());
+    let waiting_control = old_control.clone();
+    let old_reader = tokio::spawn(async move { waiting_control.receive().await });
+    tokio::task::yield_now().await;
+    request.set_previous_response_id(Some("resp_proxy_0".to_owned()));
+    request.previous_response_scope = Some(PreviousResponseScope::ConnectionLocal);
+    client
+        .create_response(
+            &request,
+            request_context("transferred", Some("test-upstream"))
+                .with_response_control(Some(&new_control)),
+        )
+        .await
+        .unwrap();
+    assert!(
+        timeout(Duration::from_secs(3), old_reader)
+            .await
+            .unwrap()
+            .unwrap()
+            .is_err()
+    );
+    assert!(
+        old_control
+            .send(r#"{"type":"response.interrupt"}"#)
+            .await
+            .is_err()
+    );
+    old_cancellation.cancel();
+    tokio::task::yield_now().await;
+    request.set_previous_response_id(Some("resp_proxy_0".to_owned()));
+    client
+        .create_response(
+            &request,
+            request_context("continued", Some("test-upstream"))
+                .with_response_control(Some(&new_control)),
+        )
+        .await
+        .unwrap();
+    assert_eq!(proxy.opened.load(Ordering::SeqCst), 1);
+    new_cancellation.cancel();
+    wait_until(|| proxy.active.load(Ordering::SeqCst) == 0).await;
+    pool.shutdown().await;
+}
+
+#[tokio::test]
+async fn rebinding_downstream_retires_old_socket_before_waiting_for_capacity() {
+    let proxy = LimitedProxy::start(32).await;
+    let pool = limited_pool();
+    let client = proxy.client(pool.clone(), "acct_a", 1);
+    let cancellation = CancellationToken::new();
+    let control = ResponseControl::default().with_connection_cancellation(cancellation.clone());
+    for conversation in ["old-chain", "replacement-chain"] {
+        let mut request = pooled_websocket_request(conversation);
+        request.downstream_websocket_connection_id = Some("same-downstream".to_owned());
+        timeout(
+            Duration::from_secs(3),
+            client.create_response(
+                &request,
+                request_context("rebind", Some("test-upstream"))
+                    .with_response_control(Some(&control)),
+            ),
+        )
+        .await
+        .unwrap()
+        .unwrap();
+    }
+    assert_eq!(proxy.opened.load(Ordering::SeqCst), 2);
+    assert!(proxy.peak.load(Ordering::SeqCst) <= 1);
+    cancellation.cancel();
+    wait_until(|| proxy.active.load(Ordering::SeqCst) == 0).await;
+    pool.shutdown().await;
+}
+
 #[tokio::test]
 async fn proxy_capacity_does_not_limit_direct_connections() {
     let pool = limited_pool();
@@ -208,13 +479,17 @@ async fn proxy_capacity_releases_failed_handshake_before_the_next_connection() {
 
 #[tokio::test]
 async fn proxy_capacity_protects_downstream_bindings_and_blocks_unpooled_bypass() {
+    let control = ResponseControl::default().with_connection_cancellation(CancellationToken::new());
     let proxy = LimitedProxy::start(32).await;
     let pool = limited_pool();
     let client = proxy.client(pool.clone(), "acct_a", 1);
     let mut pinned = pooled_websocket_request("pinned");
     pinned.downstream_websocket_connection_id = Some("downstream-a".to_owned());
     client
-        .create_response(&pinned, request_context("pinned", Some("test-upstream")))
+        .create_response(
+            &pinned,
+            request_context("pinned", Some("test-upstream")).with_response_control(Some(&control)),
+        )
         .await
         .unwrap();
     let unpooled = codex_request("gpt-test", "be brief", Vec::new());
@@ -233,7 +508,8 @@ async fn proxy_capacity_protects_downstream_bindings_and_blocks_unpooled_bypass(
     client
         .create_response(
             &pinned,
-            request_context("pinned-reuse", Some("test-upstream")),
+            request_context("pinned-reuse", Some("test-upstream"))
+                .with_response_control(Some(&control)),
         )
         .await
         .unwrap();
@@ -433,7 +709,16 @@ impl LimitedProxy {
                                 stream.write_all(b"HTTP/1.1 503 Service Unavailable\r\nContent-Length: 0\r\n\r\n").await.unwrap();
                                 return;
                             }
-                            if let Some(gate) = connect_gate { gate.acquire().await.unwrap().forget(); }
+                            if let Some(gate) = connect_gate {
+                                let mut byte = [0];
+                                tokio::select! {
+                                    permit = gate.acquire() => permit.unwrap().forget(),
+                                    result = stream.peek(&mut byte) => {
+                                        assert_eq!(result.unwrap(), 0, "cancelled opening must close TCP");
+                                        return;
+                                    }
+                                }
+                            }
                             stream.write_all(b"HTTP/1.1 200 Connection Established\r\n\r\n").await.unwrap();
                             if request.contains("X-Capacity-Probe: health") {
                                 let health = read_http_request(&mut stream).await;
@@ -449,7 +734,16 @@ impl LimitedProxy {
                                 match message {
                                     Message::Text(payload) => {
                                         requests.lock().unwrap().push(serde_json::from_str(&payload).unwrap());
-                                        if let Some(gate) = &response_gate { gate.acquire().await.unwrap().forget(); }
+                                        if let Some(gate) = &response_gate {
+                                            tokio::select! {
+                                                permit = gate.acquire() => permit.unwrap().forget(),
+                                                message = ws.next() => {
+                                                    assert!(matches!(message, None | Some(Err(_)) | Some(Ok(Message::Close(_)))));
+                                                    let _ = ws.flush().await;
+                                                    break;
+                                                }
+                                            }
+                                        }
                                         if ws.send(Message::Text(completed_websocket_response(&format!("resp_proxy_{id}"), 1, 1).into())).await.is_err() { break; }
                                     }
                                     Message::Ping(payload) => { if ws.send(Message::Pong(payload)).await.is_err() { break; } }
@@ -573,14 +867,22 @@ async fn proxy_capacity_enabling_and_lowering_limits_keeps_existing_socket_count
 
 #[tokio::test]
 async fn proxy_capacity_enabling_limit_preserves_existing_downstream_bindings() {
+    let controls = [
+        ResponseControl::default().with_connection_cancellation(CancellationToken::new()),
+        ResponseControl::default().with_connection_cancellation(CancellationToken::new()),
+    ];
     let proxy = LimitedProxy::start(32).await;
     let pool = limited_pool();
     let unlimited = proxy.client(pool.clone(), "acct_a", 0);
-    for index in 0..2 {
+    for (index, control) in controls.iter().enumerate() {
         let mut request = pooled_websocket_request(&format!("pinned-{index}"));
         request.downstream_websocket_connection_id = Some(format!("downstream-{index}"));
         unlimited
-            .create_response(&request, request_context("pinned", Some("test-upstream")))
+            .create_response(
+                &request,
+                request_context("pinned", Some("test-upstream"))
+                    .with_response_control(Some(control)),
+            )
             .await
             .unwrap();
     }
@@ -590,7 +892,8 @@ async fn proxy_capacity_enabling_limit_preserves_existing_downstream_bindings()
     limited
         .create_response(
             &retained,
-            request_context("pinned-reused", Some("test-upstream")),
+            request_context("pinned-reused", Some("test-upstream"))
+                .with_response_control(Some(&controls[0])),
         )
         .await
         .unwrap();
diff --git a/backend/crates/providers/openai/tests/transport/usage.rs b/backend/crates/providers/openai/tests/transport/usage.rs
index 44ee71053..7d962b9cd 100644
--- a/backend/crates/providers/openai/tests/transport/usage.rs
+++ b/backend/crates/providers/openai/tests/transport/usage.rs
@@ -509,6 +509,7 @@ async fn fetch_should_use_wham_usage_headers_only() {
 
     let usage = client(&server.uri())
         .fetch_usage(CodexRequestContext {
+            response_control: None,
             trace: None,
             authorization: "Bearer oauth-access",
             account_id: Some("acct_123"),
@@ -908,6 +909,7 @@ fn profile() -> CodexWireProfileState {
 
 fn context() -> CodexRequestContext<'static> {
     CodexRequestContext {
+        response_control: None,
         trace: None,
         authorization: "Bearer oauth-access",
         account_id: Some("acct_123"),
diff --git a/backend/crates/providers/openai/tests/transport/websocket/cleanup.rs b/backend/crates/providers/openai/tests/transport/websocket/cleanup.rs
index 1a7d6ec1a..aa4028b5a 100644
--- a/backend/crates/providers/openai/tests/transport/websocket/cleanup.rs
+++ b/backend/crates/providers/openai/tests/transport/websocket/cleanup.rs
@@ -38,8 +38,6 @@ async fn send_timeout_should_abort_stalled_pump_and_allow_next_request() {
             .unwrap();
     });
     let pool = Arc::new(CodexWebSocketPool::with_config(CodexWebSocketPoolConfig {
-        ping_interval: None,
-        liveness_timeout: None,
         maintenance_interval: None,
         ..CodexWebSocketPoolConfig::default()
     }));
diff --git a/backend/crates/providers/openai/tests/transport/websocket/fingerprint.rs b/backend/crates/providers/openai/tests/transport/websocket/fingerprint.rs
index 08439fd92..15814ff4f 100644
--- a/backend/crates/providers/openai/tests/transport/websocket/fingerprint.rs
+++ b/backend/crates/providers/openai/tests/transport/websocket/fingerprint.rs
@@ -91,6 +91,7 @@ async fn official_websocket_wire_fingerprint_should_remain_aligned() {
         .create_response(
             &request,
             CodexRequestContext {
+                response_control: None,
                 trace: None,
                 turn_metadata: request.turn_metadata.as_deref(),
                 beta_features: request.beta_features.as_deref(),
diff --git a/backend/crates/providers/openai/tests/transport/websocket/mod.rs b/backend/crates/providers/openai/tests/transport/websocket/mod.rs
index ae5b89fcb..e5c69dcac 100644
--- a/backend/crates/providers/openai/tests/transport/websocket/mod.rs
+++ b/backend/crates/providers/openai/tests/transport/websocket/mod.rs
@@ -1855,9 +1855,7 @@ async fn codex_backend_client_stream_should_preserve_burst_during_downstream_bac
         let mut websocket = accept_codex_test_websocket(stream).await;
         let _message = websocket.next().await.unwrap().unwrap();
         let (mut sink, mut source) = websocket.split();
-        // 服务端持续读取控制帧，让 tungstenite 正常回 Pong
-        // 若客户端在本地入站背压
-        // 期间仍执行 Pong deadline，它仍会因为暂时读不到已返回的 Pong 而误杀连接
+        // 服务端持续读取关闭帧，业务背压不应丢失已发送的输出
         let control_frames = tokio::spawn(async move {
             while let Some(message) = source.next().await {
                 match message.unwrap() {
@@ -1900,12 +1898,9 @@ async fn codex_backend_client_stream_should_preserve_burst_during_downstream_bac
         let _ = sink.send(Message::Close(None)).await;
         control_frames.abort();
     });
-    let pool = Arc::new(CodexWebSocketPool::with_config(CodexWebSocketPoolConfig {
-        ping_interval: Some(Duration::from_millis(5)),
-        ping_timeout: Duration::from_millis(20),
-        liveness_timeout: None,
-        ..websocket_pool_config_for_tests(None, None, None)
-    }));
+    let pool = Arc::new(CodexWebSocketPool::with_config(
+        websocket_pool_config_for_tests(None),
+    ));
     let backend = CodexBackendClient::new(
         reqwest::Client::builder().no_proxy().build().unwrap(),
         format!("http://{addr}"),
@@ -2223,6 +2218,7 @@ async fn codex_backend_client_should_use_websocket_when_previous_response_id_is_
         .create_response(
             &request,
             CodexRequestContext {
+                response_control: None,
                 trace: None,
                 authorization: "Bearer access-token",
                 account_id: Some("chatgpt-account"),
diff --git a/backend/crates/providers/openai/tests/transport/websocket_pool.rs b/backend/crates/providers/openai/tests/transport/websocket_pool.rs
index 943fd738b..504681f6e 100644
--- a/backend/crates/providers/openai/tests/transport/websocket_pool.rs
+++ b/backend/crates/providers/openai/tests/transport/websocket_pool.rs
@@ -367,7 +367,7 @@ async fn codex_backend_client_should_open_fresh_socket_when_idle_pooled_websocke
     });
     // 无 maintenance、无主动 ping：完全依赖 pump 后台读取感知连接死亡
     let pool = Arc::new(CodexWebSocketPool::with_config(
-        websocket_pool_config_for_tests(None, None, None),
+        websocket_pool_config_for_tests(None),
     ));
     let backend = CodexBackendClient::new(
         reqwest::Client::builder().no_proxy().build().unwrap(),
@@ -460,7 +460,7 @@ async fn codex_backend_client_stream_should_keep_fresh_socket_after_structural_a
     });
     let pool = Arc::new(CodexWebSocketPool::with_config(CodexWebSocketPoolConfig {
         stream_idle_timeout: Some(Duration::from_millis(200)),
-        ..websocket_pool_config_for_tests(None, None, None)
+        ..websocket_pool_config_for_tests(None)
     }));
     let backend = CodexBackendClient::new(
         reqwest::Client::builder().no_proxy().build().unwrap(),
@@ -549,7 +549,7 @@ async fn codex_backend_client_stream_should_keep_reused_socket_after_structural_
     });
     let pool = Arc::new(CodexWebSocketPool::with_config(CodexWebSocketPoolConfig {
         stream_idle_timeout: Some(Duration::from_millis(200)),
-        ..websocket_pool_config_for_tests(None, None, None)
+        ..websocket_pool_config_for_tests(None)
     }));
     let backend = CodexBackendClient::new(
         reqwest::Client::builder().no_proxy().build().unwrap(),
@@ -607,7 +607,7 @@ async fn codex_backend_client_stream_should_use_http_when_connecting_limit_is_ex
     let pool = Arc::new(CodexWebSocketPool::with_config(CodexWebSocketPoolConfig {
         max_connecting: 0,
         stream_idle_timeout: Some(Duration::from_millis(200)),
-        ..websocket_pool_config_for_tests(None, None, None)
+        ..websocket_pool_config_for_tests(None)
     }));
     let backend = CodexBackendClient::new(
         reqwest::Client::builder().no_proxy().build().unwrap(),
@@ -1063,7 +1063,7 @@ async fn websocket_pool_should_keep_sixty_fifth_conversation_on_same_account_on_
     });
     let pool = Arc::new(CodexWebSocketPool::with_config(CodexWebSocketPoolConfig {
         max_connecting: 1,
-        ..websocket_pool_config_for_tests(None, None, None)
+        ..websocket_pool_config_for_tests(None)
     }));
     let backend = CodexBackendClient::new(
         reqwest::Client::builder().no_proxy().build().unwrap(),
@@ -1168,7 +1168,7 @@ async fn concurrent_pool_transport_counts(max_connecting: usize) -> (usize, usiz
     });
     let pool = Arc::new(CodexWebSocketPool::with_config(CodexWebSocketPoolConfig {
         max_connecting,
-        ..websocket_pool_config_for_tests(None, None, None)
+        ..websocket_pool_config_for_tests(None)
     }));
     let backend = CodexBackendClient::new(
         reqwest::Client::builder().no_proxy().build().unwrap(),
@@ -1210,70 +1210,46 @@ async fn concurrent_pool_transport_counts(max_connecting: usize) -> (usize, usiz
 }
 
 #[tokio::test]
-async fn websocket_pool_should_replace_idle_connection_after_pong_deadline() {
-    const PING_INTERVAL: Duration = Duration::from_secs(30);
-    const PONG_TIMEOUT: Duration = Duration::from_secs(30);
-
-    // 服务端读取 Ping 后暂不继续 poll，避免 tungstenite 自动回 Pong；pump 必须在独立
-    // deadline 到期时主动关闭连接，acquire 随后只读 closed 状态并直接新建连接
+async fn websocket_pool_should_reject_expired_idle_continuation_despite_upstream_ping() {
     let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
     let addr = listener.local_addr().unwrap();
-    let accepted_connections = Arc::new(AtomicUsize::new(0));
-    let accepted_connections_for_server = Arc::clone(&accepted_connections);
-    let (ping_seen_tx, ping_seen_rx) = tokio::sync::oneshot::channel();
-    let (inspect_close_tx, inspect_close_rx) = tokio::sync::oneshot::channel();
-    let (pong_timeout_closed_tx, pong_timeout_closed_rx) = tokio::sync::oneshot::channel();
+    let (send_ping_tx, send_ping_rx) = tokio::sync::oneshot::channel();
+    let (pong_seen_tx, pong_seen_rx) = tokio::sync::oneshot::channel();
     let server = tokio::spawn(async move {
-        let (first_stream, _) = listener.accept().await.unwrap();
-        accepted_connections_for_server.fetch_add(1, Ordering::SeqCst);
-        let mut first_websocket = accept_codex_test_websocket(first_stream).await;
-        let _first_message = first_websocket.next().await.unwrap().unwrap();
-        first_websocket
+        let (stream, _) = listener.accept().await.unwrap();
+        let mut first = accept_codex_test_websocket(stream).await;
+        first.next().await.unwrap().unwrap();
+        first
             .send(Message::Text(
-                completed_websocket_response("resp_no_pong_first", 2, 1).into(),
+                completed_websocket_response("resp_idle_first", 2, 1).into(),
             ))
             .await
             .unwrap();
-        let ping = timeout(Duration::from_secs(120), first_websocket.next())
+        send_ping_rx.await.unwrap();
+        let payload = b"upstream-idle-probe".to_vec();
+        first
+            .send(Message::Ping(payload.clone().into()))
             .await
-            .expect("pump should send a keepalive ping")
-            .expect("keepalive ping should be present")
-            .expect("keepalive ping should be valid");
-        let Message::Ping(payload) = ping else {
-            panic!("expected keepalive ping, got {ping:?}");
-        };
-        assert_eq!(payload.len(), 8);
-        ping_seen_tx.send(()).unwrap();
+            .unwrap();
+        let pong = first.next().await.unwrap().unwrap();
+        assert_eq!(pong, Message::Pong(payload.into()));
+        pong_seen_tx.send(()).unwrap();
+        std::assert_matches!(first.next().await.unwrap().unwrap(), Message::Close(_));
 
-        inspect_close_rx
-            .await
-            .expect("test should release the server after the Pong deadline");
-        let close = timeout(Duration::from_secs(120), first_websocket.next())
-            .await
-            .expect("Pong deadline should close the idle websocket")
-            .expect("Pong deadline should send a close frame")
-            .expect("close frame should be valid");
-        std::assert_matches!(close, Message::Close(_));
-        pong_timeout_closed_tx.send(()).unwrap();
-
-        let (second_stream, _) = listener.accept().await.unwrap();
-        accepted_connections_for_server.fetch_add(1, Ordering::SeqCst);
-        let mut second_websocket = accept_codex_test_websocket(second_stream).await;
-        let _second_message = second_websocket.next().await.unwrap().unwrap();
-        second_websocket
+        let (stream, _) = listener.accept().await.unwrap();
+        let mut second = accept_codex_test_websocket(stream).await;
+        second.next().await.unwrap().unwrap();
+        second
             .send(Message::Text(
-                completed_websocket_response("resp_no_pong_second", 2, 1).into(),
+                completed_websocket_response("resp_idle_second", 2, 1).into(),
             ))
             .await
             .unwrap();
-        second_websocket.close(None).await.unwrap();
+        second.close(None).await.unwrap();
     });
     let pool = Arc::new(CodexWebSocketPool::with_config(CodexWebSocketPoolConfig {
-        ping_interval: Some(PING_INTERVAL),
-        ping_timeout: PONG_TIMEOUT,
-        liveness_timeout: None,
         maintenance_interval: None,
-        ..websocket_pool_config_for_tests(None, None, None)
+        ..CodexWebSocketPoolConfig::default()
     }));
     let backend = CodexBackendClient::new(
         reqwest::Client::builder().no_proxy().build().unwrap(),
@@ -1281,66 +1257,60 @@ async fn websocket_pool_should_replace_idle_connection_after_pong_deadline() {
         test_wire_profile(),
     )
     .with_websocket_pool(Arc::clone(&pool));
-    let request = pooled_websocket_request("conversation-no-pong");
-
-    let first = backend
+    let request = pooled_websocket_request("conversation-idle-expiry");
+    backend
         .create_response(
             &request,
-            request_context("req_no_pong_first", Some("chatgpt-account")),
+            request_context("req_idle_first", Some("chatgpt-account")),
         )
         .await
-        .expect("first websocket response should succeed");
+        .unwrap();
+
     tokio::time::pause();
-    tokio::time::advance(PING_INTERVAL).await;
-    tokio::task::yield_now().await;
-    ping_seen_rx
-        .await
-        .expect("server should report the keepalive ping");
-    tokio::time::advance(PONG_TIMEOUT + Duration::from_secs(1)).await;
-    tokio::task::yield_now().await;
-    tokio::task::yield_now().await;
-    inspect_close_tx.send(()).unwrap();
-    pong_timeout_closed_rx
-        .await
-        .expect("server should report the Pong-timeout close");
+    tokio::time::advance(Duration::from_secs(299)).await;
     tokio::time::resume();
+    send_ping_tx.send(()).unwrap();
+    timeout(Duration::from_secs(2), pong_seen_rx)
+        .await
+        .unwrap()
+        .unwrap();
+    tokio::time::pause();
+    tokio::time::advance(Duration::from_secs(1)).await;
+    tokio::time::resume();
+
     let mut continuation = request.clone();
-    continuation.set_previous_response_id(Some("resp_no_pong_first".to_owned()));
+    continuation.set_previous_response_id(Some("resp_idle_first".to_owned()));
     continuation.previous_response_scope = Some(PreviousResponseScope::ConnectionLocal);
     let error = backend
         .create_response(
             &continuation,
-            request_context("req_no_pong_continuation", Some("chatgpt-account")),
+            request_context("req_idle_continuation", Some("chatgpt-account")),
         )
         .await
-        .expect_err("Pong-timeout connection cannot satisfy an exact continuation");
+        .expect_err("heartbeat must not extend the cached connection's idle lifetime");
     let CodexClientError::WebSocket(error) = error else {
-        panic!("Pong-timeout continuation should remain a typed WebSocket error");
+        panic!("expired continuation should remain a typed WebSocket error");
     };
     assert_eq!(
         error.continuation_unavailable_reason(),
         Some(PreviousResponseUnavailableReason::ReusedConnectionLost)
     );
     assert_eq!(
-        error
-            .connection_observation()
-            .expect("Pong-timeout tombstone should retain its lifecycle observation")
-            .exit_reason(),
-        "pong_timeout"
+        error.connection_observation().unwrap().exit_reason(),
+        "idle_timeout_expired"
     );
-    let second = backend
+
+    let response = backend
         .create_response(
             &request,
-            request_context("req_no_pong_second", Some("chatgpt-account")),
+            request_context("req_idle_second", Some("chatgpt-account")),
         )
         .await
-        .expect("second websocket response should use a fresh connection");
+        .unwrap();
+    assert!(response.body.contains("resp_idle_second"));
+    assert_eq!(response.websocket_pool_decision.unwrap().kind(), "new");
     server.await.unwrap();
-
-    assert!(first.body.contains("resp_no_pong_first"));
-    assert!(second.body.contains("resp_no_pong_second"));
-    assert_eq!(second.websocket_pool_decision.unwrap().kind(), "new");
-    assert_eq!(accepted_connections.load(Ordering::SeqCst), 2);
+    pool.shutdown().await;
 }
 
 #[tokio::test]
@@ -1384,8 +1354,6 @@ async fn websocket_pool_should_gc_expired_idle_connections() {
     let pool = Arc::new(CodexWebSocketPool::with_config(CodexWebSocketPoolConfig {
         max_age: MAX_AGE,
         maintenance_interval: None,
-        ping_interval: None,
-        liveness_timeout: None,
         ..CodexWebSocketPoolConfig::default()
     }));
     let backend = CodexBackendClient::new(
@@ -1428,8 +1396,6 @@ fn websocket_pool_constructed_outside_runtime_should_start_maintenance_on_first_
     let pool = Arc::new(CodexWebSocketPool::with_config(CodexWebSocketPoolConfig {
         max_age: MAX_AGE,
         maintenance_interval: Some(Duration::from_millis(20)),
-        ping_interval: None,
-        liveness_timeout: None,
         ..CodexWebSocketPoolConfig::default()
     }));
     let runtime = tokio::runtime::Builder::new_current_thread()
@@ -1490,90 +1456,44 @@ async fn websocket_pool_zero_maintenance_interval_should_not_start_a_panicking_t
 }
 
 #[tokio::test]
-async fn codex_backend_client_should_keep_idle_pooled_websocket_alive_across_repeated_pings() {
+async fn codex_backend_client_should_reply_to_upstream_pings_and_reuse_idle_socket() {
     let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
     let addr = listener.local_addr().unwrap();
-    let ping_count = Arc::new(AtomicUsize::new(0));
-    let ping_count_for_server = Arc::clone(&ping_count);
-    let (pings_observed_tx, pings_observed_rx) = tokio::sync::oneshot::channel();
+    let (pongs_seen_tx, pongs_seen_rx) = tokio::sync::oneshot::channel();
     let server = tokio::spawn(async move {
         let (stream, _) = listener.accept().await.unwrap();
         let mut websocket = accept_codex_test_websocket(stream).await;
-        let _first_message = websocket.next().await.unwrap().unwrap();
+        websocket.next().await.unwrap().unwrap();
         websocket
             .send(Message::Text(
-                json!({
-                    "type": "response.completed",
-                    "response": {
-                        "id": "resp_pool_background_first",
-                        "object": "response",
-                        "output": [],
-                        "usage": {
-                            "input_tokens": 3,
-                            "output_tokens": 1,
-                            "total_tokens": 4
-                        }
-                    }
-                })
-                .to_string()
-                .into(),
+                completed_websocket_response("resp_passive_first", 3, 1).into(),
             ))
             .await
             .unwrap();
-
-        // pump 会在 idle 期间反复发送 keepalive ping；服务端计数并回 pong，
-        // 直到下一个业务请求（response.create）到达为止
-        let mut previous_ping = None;
-        let mut pings_observed_tx = Some(pings_observed_tx);
-        loop {
-            let message = timeout(Duration::from_secs(1), websocket.next())
+        for payload in [b"probe-a".to_vec(), b"probe-b".to_vec()] {
+            websocket
+                .send(Message::Ping(payload.clone().into()))
                 .await
-                .expect("pump keepalive / second request should arrive")
-                .expect("frame should be present")
-                .expect("frame should be valid");
-            match message {
-                Message::Ping(payload) => {
-                    assert_eq!(payload.len(), 8);
-                    if let Some(previous) = &previous_ping {
-                        assert_ne!(previous, &payload, "keepalive ping sequence must be unique");
-                    }
-                    previous_ping = Some(payload.clone());
-                    let ping_count = ping_count_for_server.fetch_add(1, Ordering::SeqCst) + 1;
-                    if ping_count == 2
-                        && let Some(pings_observed_tx) = pings_observed_tx.take()
-                    {
-                        pings_observed_tx.send(()).unwrap();
-                    }
-                    websocket.send(Message::Pong(payload)).await.unwrap();
-                }
-                Message::Text(_) => break,
-                other => panic!("unexpected frame while idle: {other:?}"),
-            }
+                .unwrap();
+            let frame = timeout(Duration::from_secs(2), websocket.next())
+                .await
+                .unwrap()
+                .unwrap()
+                .unwrap();
+            assert_eq!(frame, Message::Pong(payload.into()));
         }
+        pongs_seen_tx.send(()).unwrap();
+        std::assert_matches!(websocket.next().await.unwrap().unwrap(), Message::Text(_));
         websocket
             .send(Message::Text(
-                json!({
-                    "type": "response.completed",
-                    "response": {
-                        "id": "resp_pool_background_second",
-                        "object": "response",
-                        "output": [],
-                        "usage": {
-                            "input_tokens": 3,
-                            "output_tokens": 1,
-                            "total_tokens": 4
-                        }
-                    }
-                })
-                .to_string()
-                .into(),
+                completed_websocket_response("resp_passive_second", 3, 1).into(),
             ))
             .await
             .unwrap();
         websocket.close(None).await.unwrap();
     });
     let pool = Arc::new(CodexWebSocketPool::with_config(
-        websocket_pool_config_for_tests(None, Some(Duration::from_millis(10)), None),
+        websocket_pool_config_for_tests(None),
     ));
     let backend = CodexBackendClient::new(
         reqwest::Client::builder().no_proxy().build().unwrap(),
@@ -1581,43 +1501,33 @@ async fn codex_backend_client_should_keep_idle_pooled_websocket_alive_across_rep
         test_wire_profile(),
     )
     .with_websocket_pool(Arc::clone(&pool));
-    let mut request = codex_request_with_prompt_cache_key(
-        "gpt-5.5",
-        "be brief",
-        Vec::new(),
-        "conversation-pool-background",
-    );
-    request.set_previous_response_id(Some("resp_previous".to_string()));
-    request.previous_response_scope = Some(PreviousResponseScope::Persisted);
-
-    let first = backend
+    let request = pooled_websocket_request("conversation-passive-heartbeat");
+    backend
         .create_response(
             &request,
-            request_context("req_pool_background_first", Some("chatgpt-account")),
+            request_context("req_passive_first", Some("chatgpt-account")),
         )
         .await
-        .expect("first pooled websocket response should succeed");
-    timeout(Duration::from_secs(2), pings_observed_rx)
+        .unwrap();
+    timeout(Duration::from_secs(2), pongs_seen_rx)
         .await
-        .expect("pump should emit repeated keepalive pings")
-        .expect("server should observe repeated keepalive pings");
-    let second = backend
+        .unwrap()
+        .unwrap();
+    let response = backend
         .create_response(
             &request,
-            request_context("req_pool_background_second", Some("chatgpt-account")),
+            request_context("req_passive_second", Some("chatgpt-account")),
         )
         .await
-        .expect("second pooled websocket response should reuse the kept-alive socket");
+        .unwrap();
+    assert!(response.body.contains("resp_passive_second"));
+    assert_eq!(response.websocket_pool_decision.unwrap().kind(), "reuse");
     server.await.unwrap();
     pool.shutdown().await;
-
-    assert!(first.body.contains("resp_pool_background_first"));
-    assert!(second.body.contains("resp_pool_background_second"));
-    assert!(ping_count.load(Ordering::SeqCst) >= 2);
 }
 
 #[tokio::test]
-async fn codex_backend_client_should_treat_active_business_frames_as_ping_liveness() {
+async fn websocket_pool_should_not_apply_idle_timeout_to_active_stream() {
     let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
     let addr = listener.local_addr().unwrap();
     let server = tokio::spawn(async move {
@@ -1626,7 +1536,7 @@ async fn codex_backend_client_should_treat_active_business_frames_as_ping_livene
         let _request = websocket.next().await.unwrap().unwrap();
 
         for index in 0..8 {
-            tokio::time::sleep(Duration::from_secs(1)).await;
+            tokio::time::sleep(Duration::from_millis(30)).await;
             websocket
                 .send(Message::Text(
                     json!({
@@ -1648,10 +1558,8 @@ async fn codex_backend_client_should_treat_active_business_frames_as_ping_livene
         websocket.close(None).await.unwrap();
     });
     let pool = Arc::new(CodexWebSocketPool::with_config(CodexWebSocketPoolConfig {
-        ping_interval: Some(Duration::from_millis(100)),
-        ping_timeout: Duration::from_secs(5),
-        liveness_timeout: None,
-        ..websocket_pool_config_for_tests(None, None, None)
+        idle_timeout: Duration::from_millis(100),
+        ..websocket_pool_config_for_tests(Some(Duration::from_millis(20)))
     }));
     let backend = CodexBackendClient::new(
         reqwest::Client::builder().no_proxy().build().unwrap(),
@@ -1667,7 +1575,7 @@ async fn codex_backend_client_should_treat_active_business_frames_as_ping_livene
             request_context("req_active_without_pong", Some("chatgpt-account")),
         )
         .await
-        .expect("active business frames should satisfy the Ping liveness probe");
+        .expect("active stream should not be evicted by the idle pool timeout");
     server.await.unwrap();
 
     assert!(response.body.contains("active-0;"));
@@ -1740,7 +1648,7 @@ async fn codex_backend_client_should_close_idle_pooled_websocket_when_account_is
         second_websocket.close(None).await.unwrap();
     });
     let pool = Arc::new(CodexWebSocketPool::with_config(
-        websocket_pool_config_for_tests(None, None, None),
+        websocket_pool_config_for_tests(None),
     ));
     let backend = CodexBackendClient::new(
         reqwest::Client::builder().no_proxy().build().unwrap(),
@@ -1824,7 +1732,7 @@ async fn codex_backend_client_should_stop_reusing_pooled_websockets_after_shutdo
         write_completed_sse_response(&mut second_stream).await;
     });
     let pool = Arc::new(CodexWebSocketPool::with_config(
-        websocket_pool_config_for_tests(None, None, None),
+        websocket_pool_config_for_tests(None),
     ));
     let backend = CodexBackendClient::new(
         reqwest::Client::builder().no_proxy().build().unwrap(),
@@ -1869,118 +1777,66 @@ async fn codex_backend_client_should_stop_reusing_pooled_websockets_after_shutdo
 }
 
 #[tokio::test]
-async fn codex_backend_client_should_close_idle_pooled_websocket_after_liveness_timeout() {
-    const LIVENESS_TIMEOUT: Duration = Duration::from_secs(30);
-
+async fn websocket_pool_should_reclaim_idle_connections_on_maintenance_ticks() {
     let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
     let addr = listener.local_addr().unwrap();
-    let accepted_connections = Arc::new(AtomicUsize::new(0));
-    let accepted_connections_for_server = Arc::clone(&accepted_connections);
-    let (liveness_closed_tx, liveness_closed_rx) = tokio::sync::oneshot::channel();
+    let (closed_tx, closed_rx) = tokio::sync::oneshot::channel();
     let server = tokio::spawn(async move {
-        let (first_stream, _) = listener.accept().await.unwrap();
-        accepted_connections_for_server.fetch_add(1, Ordering::SeqCst);
-        let mut first_websocket = accept_codex_test_websocket(first_stream).await;
-        let _first_message = first_websocket.next().await.unwrap().unwrap();
-        first_websocket
+        let (stream, _) = listener.accept().await.unwrap();
+        let mut websocket = accept_codex_test_websocket(stream).await;
+        websocket.next().await.unwrap().unwrap();
+        websocket
             .send(Message::Text(
-                json!({
-                    "type": "response.completed",
-                    "response": {
-                        "id": "resp_pool_liveness_first",
-                        "object": "response",
-                        "output": [],
-                        "usage": {
-                            "input_tokens": 3,
-                            "output_tokens": 1,
-                            "total_tokens": 4
-                        }
-                    }
-                })
-                .to_string()
-                .into(),
+                completed_websocket_response("resp_maintenance_idle", 3, 1).into(),
             ))
             .await
             .unwrap();
-        let close = timeout(Duration::from_secs(60), first_websocket.next())
-            .await
-            .expect("liveness timeout should close the idle websocket")
-            .expect("liveness timeout should send a close frame")
-            .expect("close frame should be valid");
-        std::assert_matches!(close, Message::Close(_));
-        liveness_closed_tx.send(()).unwrap();
-
-        let (second_stream, _) = listener.accept().await.unwrap();
-        accepted_connections_for_server.fetch_add(1, Ordering::SeqCst);
-        let mut second_websocket = accept_codex_test_websocket(second_stream).await;
-        let _second_message = second_websocket.next().await.unwrap().unwrap();
-        second_websocket
-            .send(Message::Text(
-                json!({
-                    "type": "response.completed",
-                    "response": {
-                        "id": "resp_pool_liveness_second",
-                        "object": "response",
-                        "output": [],
-                        "usage": {
-                            "input_tokens": 4,
-                            "output_tokens": 1,
-                            "total_tokens": 5
-                        }
-                    }
-                })
-                .to_string()
-                .into(),
-            ))
-            .await
-            .unwrap();
-        second_websocket.close(None).await.unwrap();
+        let message = websocket.next().await.unwrap().unwrap();
+        std::assert_matches!(message, Message::Close(_));
+        closed_tx.send(()).unwrap();
     });
-    let pool = Arc::new(CodexWebSocketPool::with_config(
-        websocket_pool_config_for_tests(None, None, Some(LIVENESS_TIMEOUT)),
-    ));
+    let pool = Arc::new(CodexWebSocketPool::default());
     let backend = CodexBackendClient::new(
         reqwest::Client::builder().no_proxy().build().unwrap(),
         format!("http://{addr}"),
         test_wire_profile(),
     )
     .with_websocket_pool(Arc::clone(&pool));
-    let mut request = codex_request_with_prompt_cache_key(
-        "gpt-5.5",
-        "be brief",
-        Vec::new(),
-        "conversation-pool-liveness",
-    );
-    request.set_previous_response_id(Some("resp_previous".to_string()));
-    request.previous_response_scope = Some(PreviousResponseScope::Persisted);
-
-    let first = backend
+    let request = pooled_websocket_request("conversation-maintenance-idle");
+    backend
         .create_response(
             &request,
-            request_context("req_pool_liveness_first", Some("chatgpt-account")),
+            request_context("req_maintenance_idle", Some("chatgpt-account")),
         )
         .await
-        .expect("first pooled websocket response should succeed");
+        .unwrap();
     tokio::time::pause();
-    tokio::time::advance(LIVENESS_TIMEOUT).await;
-    tokio::task::yield_now().await;
-    liveness_closed_rx
-        .await
-        .expect("liveness watchdog should close the idle connection");
-    pool.maintain_idle_connections().await;
+    tokio::time::advance(Duration::from_secs(305)).await;
     tokio::time::resume();
-    let second = backend
+    timeout(Duration::from_secs(2), closed_rx)
+        .await
+        .unwrap()
+        .unwrap();
+
+    let mut continuation = request;
+    continuation.set_previous_response_id(Some("resp_maintenance_idle".to_owned()));
+    continuation.previous_response_scope = Some(PreviousResponseScope::ConnectionLocal);
+    let error = backend
         .create_response(
-            &request,
-            request_context("req_pool_liveness_second", Some("chatgpt-account")),
+            &continuation,
+            request_context("req_maintenance_continuation", Some("chatgpt-account")),
         )
         .await
-        .expect("second websocket response should open a fresh socket after liveness close");
+        .expect_err("maintenance should preserve the expired continuation's loss reason");
+    let CodexClientError::WebSocket(error) = error else {
+        panic!("expired continuation should remain a typed WebSocket error");
+    };
+    assert_eq!(
+        error.connection_observation().unwrap().exit_reason(),
+        "idle_timeout_expired"
+    );
     server.await.unwrap();
-
-    assert!(first.body.contains("resp_pool_liveness_first"));
-    assert!(second.body.contains("resp_pool_liveness_second"));
-    assert_eq!(accepted_connections.load(Ordering::SeqCst), 2);
+    pool.shutdown().await;
 }
 
 #[tokio::test]
diff --git a/deploy/README.md b/deploy/README.md
index 85689e93c..78625fec5 100644
--- a/deploy/README.md
+++ b/deploy/README.md
@@ -305,9 +305,10 @@ Responses 流式请求完成准入后，每 15 秒无输出会发送一次 SSE 
 `api.request_timeout_seconds` 默认 `null`，只控制 HTTP 路由返回响应前的等待，不是流式正文或 WebSocket 每轮执行的总时限。
 排队、插件显式执行期限与客户端断开的边界见 [请求期限](../docs/api.md#请求期限)
 
-OpenAI 上游池化 WebSocket 默认每 25 秒发送一次 Ping，发出后允许等待 30 秒；
-收到 Pong 或其他入站帧即解除本次心跳截止，持续无响应则以 `pong_timeout` 关闭连接。
-此策略也覆盖正在生成的请求，与等待下一条上游消息的 `stream_idle_timeout_ms` 分别计时
+OpenAI 上游 WebSocket 被动回应 Ping，不主动发送心跳；Pong 写入最多等待 5 秒。
+下游 Responses WebSocket 每 25 秒发送 Ping，第一条未响应的 Ping 发出后 30 秒没有 Pong 或其他有效入站帧即断开；
+后续 Ping 不延长这次截止，心跳入队及写入最多等待 5 秒。两段心跳各自处理，不跨 WS 转发或转换为 SSE 事件。
+心跳不重置上游业务消息的 `openai.ws_pool.stream_idle_timeout_ms`
 
 每条已保存代理可在管理端配置“上游 WS 连接上限”，默认留空、不限制连接数。
 预算限制单个 CPR 进程使用该代理的 OpenAI Responses 上游 WS 总数，关联账号共享，包含建连中、在途、空闲及非池化连接；直连不受影响。
@@ -316,7 +317,11 @@ OpenAI 上游池化 WebSocket 默认每 25 秒发送一次 Ping，发出后允
 修改上限对后续请求生效，已存在的连接继续计数；调低上限不会强制中断在途或绑定下游 WS 的连接。
 预算仅覆盖宿主原生 OpenAI Responses 连接，插件自建连接及其他 HTTP/WS 流量仍需预留容量
 
-有容量时继续复用，连接总寿命仍由 `max_age_ms` 控制，默认 55 分钟，不设置固定空闲回收时间。
+未绑定活跃客户端 WS 的池化连接，归池后按 `openai.ws_pool.idle_timeout_ms` 计时，默认 `300000`（5 分钟，必须大于零）。
+Ping/Pong 不延长空闲期限；默认每 5 秒扫描，通常在空闲 300～305 秒开始回收，复用前也检查是否到期。
+关闭先停止复用，最多等待 1 秒发送 Close，随后终止并等待 socket 释放，容量在物理连接释放后才归还。
+仍绑定活跃客户端 WS 的连接不受空闲期限约束；客户端退出会释放仍归它所有的上游连接，重新绑定或切到 HTTP 时释放失去用途的旧连接。
+连接总寿命由 `openai.ws_pool.max_age_ms` 控制，默认 55 分钟；到期退出复用，不为清池打断正在生成的响应。
 满额时优先关闭同代理下最久未使用的普通空闲 WS；在途、建连中和绑定下游 WS 的连接不参与容量淘汰。
 没有可回收连接时等待容量，受原请求期限、客户端取消和连接池关闭约束；无显式请求期限时不会额外设置排队超时。
 被回收连接上的精确续接沿用既有客户端完整回放合同，可能多一次恢复往返
diff --git a/deploy/config.example.yaml b/deploy/config.example.yaml
index 83534a9c7..7ae7ae9c8 100644
--- a/deploy/config.example.yaml
+++ b/deploy/config.example.yaml
@@ -82,6 +82,13 @@ openai:
   residency: us
   # 账号路由参考值：us、us_cr；填写值原样发送，省略或 null 时删除对应请求头
   account_routing_override: null
+  # 可选：完整的 Responses 上游 WS 池配置；省略整段使用以下默认值。
+  # ws_pool:
+  #   enabled: true
+  #   max_age_ms: 3300000
+  #   max_connecting: 8
+  #   idle_timeout_ms: 300000 # 仅回收未绑定活跃客户端 WS 的空闲连接，必须大于零。
+  #   stream_idle_timeout_ms: 300000
 
 # Compose 启动桥接区；密码仍只维护在 store 中。
 services:
diff --git a/docs/api.md b/docs/api.md
index 0539fcdbb..83ec01e10 100644
--- a/docs/api.md
+++ b/docs/api.md
@@ -466,6 +466,19 @@ Responses WebSocket 接受文本消息，`response.create` 在同一连接串行
 留在有界接收队列中，待当前响应完成终结和写出后再逐条校验、准入与执行，不因请求提前到达而断开。
 接收队列容量为 32 个事件，超载仍关闭连接；Ping/Pong、客户端关闭和服务关闭不等待队列中的请求执行
 
+网关分别维护两段链路的心跳：上游 WS 被动回复 Pong，下游 WS 独立探活；Ping/Pong 不跨段转发，也不转换为 SSE 事件。
+客户端断开时取消当前执行，并释放仍归该客户端所有的上游连接。`response.completed` 只结束本轮响应，保留客户端 WS 等待下一轮请求
+
+| 入站 → 上游 | 正常回答结束后的连接处理 |
+| --- | --- |
+| SSE → SSE | 结束本次响应流，底层 HTTP 连接由 HTTP 连接池管理 |
+| SSE → WS | 结束 SSE，上游 WS 归池，按无客户端绑定的空闲期限回收 |
+| WS → SSE | 上游本次响应结束，下游 WS 保留 |
+| WS → WS | 保留当前绑定的上游 WS，支持下一轮续接 |
+
+活跃客户端 WS 的绑定不受普通空闲回收期限约束；上游关闭、总寿命到期或连接被回收仍可能使连接内续接失效，
+客户端按既有 `previous_response_not_found` 合同完整重放。具体心跳和回收参数见[部署与运维](../deploy/README.md#公网访问)
+
 其余文本消息发送到当前执行绑定的上游 WebSocket，未知类型、模式和扩展字段由上游校验。
 `response.interrupt` 的 `discard_partial_items` 模式若指向当前逻辑请求已交付的响应 ID，
 网关会保留中断意图；重试交付新的 `response.created` 后，以新 ID 转发中断，避免换号空档丢失控制消息。
diff --git a/docs/architecture.md b/docs/architecture.md
index 5108ac141..65b37278e 100644
--- a/docs/architecture.md
+++ b/docs/architecture.md
@@ -485,6 +485,14 @@ API 暂存的下一轮请求和连接泵接收队列共用容量名额，控制
 Core 只理解 `Operation`、能力要求、Provider 候选、稳定错误和 canonical event，不读取 Provider SDK
 类型。Provider 独占 credential schema、OAuth、账号选择、模型目录、额度投影和上游 transport
 
+Responses 下游连接的心跳和退出由 API 拥有，每条 WS 使用独立取消信号，沿 Core 的 `ResponseControl` 传到 Provider 请求上下文。
+单轮执行结束不取消连接生命周期，连接退出则取消当前执行及仍归它所有的上游资源；API 不直接调用具体 Provider 清池。
+OpenAI 的连接池监督该取消信号，按当前归属保护绑定连接；精确续接接手 socket 时撤销旧控制收发并转移归属，旧客户端不能消费新响应或清理新 owner 的连接。
+重新绑定或切到 HTTP 时移除失去用途的旧连接，失效 reservation 不能重新归池。
+普通空闲期限复用池槽位的 `idle_since`，只在归池时重置；心跳不刷新业务空闲，建连与在途不参与空闲回收。
+回收先移出可复用集合，再在锁外有界关闭并等待 pump/socket 释放，物理容量随 socket 归还；批量关闭并行执行。
+协议合同与运行参数分别见 [Responses 传输](api.md#websocket-与上游传输)和[部署与运维](../deploy/README.md#公网访问)
+
 OpenAI 的 OAuth 与 API Key 共用现有账号和事务。API Key 的 Base URL、密钥和传输策略属于 Provider 凭据 JSON，
 随 credential revision 更新；普通详情只投影非敏感连接设置。API Key 客户端目录按账号、凭据版本和客户端版本隔离，
 标准 `data` 模型列表通过通用画像输出，完整 Codex `models` 目录保留原生对象。通用账号层按 Provider 提交的