diff --git a/codex-rs/mcp-server/src/lib.rs b/codex-rs/mcp-server/src/lib.rs
index 702cb501..f4bebdf5 100644
--- a/codex-rs/mcp-server/src/lib.rs
+++ b/codex-rs/mcp-server/src/lib.rs
@@ -59,7 +59,7 @@ pub async fn run_main(
 
     // Set up channels.
     let (incoming_tx, mut incoming_rx) = mpsc::channel::<JSONRPCMessage>(CHANNEL_CAPACITY);
-    let (outgoing_tx, mut outgoing_rx) = mpsc::channel::<OutgoingMessage>(CHANNEL_CAPACITY);
+    let (outgoing_tx, mut outgoing_rx) = mpsc::unbounded_channel::<OutgoingMessage>();
 
     // Task: read from stdin, push to `incoming_tx`.
     let stdin_reader_handle = tokio::spawn({
diff --git a/codex-rs/mcp-server/src/outgoing_message.rs b/codex-rs/mcp-server/src/outgoing_message.rs
index 5f206cb0..abfc542e 100644
--- a/codex-rs/mcp-server/src/outgoing_message.rs
+++ b/codex-rs/mcp-server/src/outgoing_message.rs
@@ -24,12 +24,12 @@ use crate::error_code::INTERNAL_ERROR_CODE;
 /// Sends messages to the client and manages request callbacks.
 pub(crate) struct OutgoingMessageSender {
     next_request_id: AtomicI64,
-    sender: mpsc::Sender<OutgoingMessage>,
+    sender: mpsc::UnboundedSender<OutgoingMessage>,
     request_id_to_callback: Mutex<HashMap<RequestId, oneshot::Sender<Result>>>,
 }
 
 impl OutgoingMessageSender {
-    pub(crate) fn new(sender: mpsc::Sender<OutgoingMessage>) -> Self {
+    pub(crate) fn new(sender: mpsc::UnboundedSender<OutgoingMessage>) -> Self {
         Self {
             next_request_id: AtomicI64::new(0),
             sender,
@@ -55,7 +55,7 @@ impl OutgoingMessageSender {
             method: method.to_string(),
             params,
         });
-        let _ = self.sender.send(outgoing_message).await;
+        let _ = self.sender.send(outgoing_message);
         rx_approve
     }
 
@@ -81,7 +81,7 @@ impl OutgoingMessageSender {
         match serde_json::to_value(response) {
             Ok(result) => {
                 let outgoing_message = OutgoingMessage::Response(OutgoingResponse { id, result });
-                let _ = self.sender.send(outgoing_message).await;
+                let _ = self.sender.send(outgoing_message);
             }
             Err(err) => {
                 self.send_error(
@@ -130,17 +130,17 @@ impl OutgoingMessageSender {
         };
         let outgoing_message =
             OutgoingMessage::Notification(OutgoingNotification { method, params });
-        let _ = self.sender.send(outgoing_message).await;
+        let _ = self.sender.send(outgoing_message);
     }
 
     pub(crate) async fn send_notification(&self, notification: OutgoingNotification) {
         let outgoing_message = OutgoingMessage::Notification(notification);
-        let _ = self.sender.send(outgoing_message).await;
+        let _ = self.sender.send(outgoing_message);
     }
 
     pub(crate) async fn send_error(&self, id: RequestId, error: JSONRPCErrorError) {
         let outgoing_message = OutgoingMessage::Error(OutgoingError { id, error });
-        let _ = self.sender.send(outgoing_message).await;
+        let _ = self.sender.send(outgoing_message);
     }
 }
 
@@ -250,7 +250,7 @@ mod tests {
 
     #[tokio::test]
     async fn test_send_event_as_notification() {
-        let (outgoing_tx, mut outgoing_rx) = mpsc::channel::<OutgoingMessage>(2);
+        let (outgoing_tx, mut outgoing_rx) = mpsc::unbounded_channel::<OutgoingMessage>();
         let outgoing_message_sender = OutgoingMessageSender::new(outgoing_tx);
 
         let event = Event {
@@ -281,7 +281,7 @@ mod tests {
 
     #[tokio::test]
     async fn test_send_event_as_notification_with_meta() {
-        let (outgoing_tx, mut outgoing_rx) = mpsc::channel::<OutgoingMessage>(2);
+        let (outgoing_tx, mut outgoing_rx) = mpsc::unbounded_channel::<OutgoingMessage>();
         let outgoing_message_sender = OutgoingMessageSender::new(outgoing_tx);
 
         let session_configured_event = SessionConfiguredEvent {