fix(tui): keep subagent panel out of transcript history

codex-rs/tui/src/chatwidget.rs

@@ -5495,6 +5495,14 @@ impl ChatWidget {
 
     fn flush_active_cell(&mut self) {
         if let Some(active) = self.active_cell.take() {
+            // Subagent status is a transient panel, not transcript history. If we
+            // flush it into history every time another cell is inserted, the
+            // transcript gets spammed with repeated identical "Subagents ..." blocks.
+            // Keep the panel mounted so later transcript cells do not make it disappear.
+            if active.as_any().is::<SubagentStatusCell>() {
+                self.active_cell = Some(active);
+                return;
+            }
             self.needs_final_message_separator = true;
             self.app_event_tx.send(AppEvent::InsertHistoryCell(active));
         }

codex-rs/tui/src/chatwidget/tests.rs

@@ -14,6 +14,9 @@ use crate::bottom_pane::FeedbackAudience;
 use crate::bottom_pane::LocalImageAttachment;
 use crate::bottom_pane::MentionBinding;
 use crate::chatwidget::realtime::RealtimeConversationPhase;
+use crate::history_cell::SubagentPanelAgent;
+use crate::history_cell::SubagentPanelState;
+use crate::history_cell::SubagentStatusCell;
 use crate::history_cell::UserHistoryCell;
 use crate::model_catalog::ModelCatalog;
 use crate::test_backend::VT100Backend;
@@ -197,6 +200,7 @@ use std::collections::BTreeMap;
 use std::collections::HashMap;
 use std::collections::HashSet;
 use std::path::PathBuf;
+use std::sync::Mutex as StdMutex;
 use tempfile::NamedTempFile;
 use tempfile::tempdir;
 use tokio::sync::mpsc::error::TryRecvError;
@@ -2431,6 +2435,42 @@ fn status_line_text(chat: &ChatWidget) -> Option<String> {
     chat.status_line_text()
 }
 
+async fn subagent_panel_is_not_flushed_into_transcript_history() {
+    let (mut chat, mut rx, _op_rx) = make_chatwidget_manual(None).await;
+
+    let state = Arc::new(StdMutex::new(SubagentPanelState {
+        started_at: Instant::now(),
+        total_agents: 1,
+        running_count: 0,
+        running_agents: vec![SubagentPanelAgent {
+            ordinal: 1,
+            name: "user-request-derisk-implement".to_string(),
+            status: AgentStatus::PendingInit,
+            is_watchdog: true,
+            preview: "watchdog idle".to_string(),
+            latest_update_at: Instant::now(),
+        }],
+    }));
+    chat.on_subagent_panel_updated(Arc::new(SubagentStatusCell::new(state, true)));
+
+    chat.add_to_history(history_cell::new_error_event("follow-up cell".to_string()));
+
+    let inserted = drain_insert_history(&mut rx);
+    assert_eq!(
+        inserted.len(),
+        1,
+        "subagent panel should remain transient and not be inserted into transcript history"
+    );
+    let rendered = lines_to_single_string(&inserted[0]);
+    assert!(rendered.contains("follow-up cell"));
+    assert!(!rendered.contains("Subagents"));
+    assert!(
+        chat.active_cell
+            .as_ref()
+            .is_some_and(|cell| cell.as_any().is::<SubagentStatusCell>()),
+        "subagent panel should stay mounted after other history cells are inserted"
+    );
+}
 fn make_token_info(total_tokens: i64, context_window: i64) -> TokenUsageInfo {
     fn usage(total_tokens: i64) -> TokenUsage {
         TokenUsage {