Add session header to chat widget

codex-rs/tui/src/app.rs

@@ -295,7 +295,7 @@ impl App {
                 self.on_update_reasoning_effort(effort);
             }
             AppEvent::UpdateModel(model) => {
-                self.chat_widget.set_model(model.clone());
+                self.chat_widget.set_model(&model);
                 self.config.model = model.clone();
                 if let Some(family) = find_family_for_model(&model) {
                     self.config.model_family = family;

codex-rs/tui/src/chatwidget.rs

@@ -74,6 +74,8 @@ use self::interrupts::InterruptManager;
 mod agent;
 use self::agent::spawn_agent;
 use self::agent::spawn_agent_from_existing;
+mod session_header;
+use self::session_header::SessionHeader;
 use crate::streaming::controller::AppEventHistorySink;
 use crate::streaming::controller::StreamController;
 use codex_common::approval_presets::ApprovalPreset;
@@ -109,6 +111,7 @@ pub(crate) struct ChatWidget {
     bottom_pane: BottomPane,
     active_exec_cell: Option<ExecCell>,
     config: Config,
+    session_header: SessionHeader,
     initial_user_message: Option<UserMessage>,
     token_info: Option<TokenUsageInfo>,
     // Stream lifecycle controller
@@ -165,9 +168,11 @@ impl ChatWidget {
             .set_history_metadata(event.history_log_id, event.history_entry_count);
         self.conversation_id = Some(event.session_id);
         let initial_messages = event.initial_messages.clone();
+        let model_for_header = event.model.clone();
         if let Some(messages) = initial_messages {
             self.replay_initial_messages(messages);
         }
+        self.session_header.set_model(&model_for_header);
         self.add_to_history(history_cell::new_session_info(
             &self.config,
             event,
@@ -609,14 +614,23 @@ impl ChatWidget {
         ));
     }
 
-    fn layout_areas(&self, area: Rect) -> [Rect; 2] {
+    fn layout_areas(&self, area: Rect) -> [Rect; 3] {
+        let bottom_min = self.bottom_pane.desired_height(area.width).min(area.height);
+        let remaining = area.height.saturating_sub(bottom_min);
+
+        let active_desired = self
+            .active_exec_cell
+            .as_ref()
+            .map_or(0, |c| c.desired_height(area.width) + 1);
+        let active_height = active_desired.min(remaining);
+        // Note: no header area; remaining is not used beyond computing active height.
+
+        let header_height = 0u16;
+
         Layout::vertical([
-            Constraint::Max(
-                self.active_exec_cell
-                    .as_ref()
-                    .map_or(0, |c| c.desired_height(area.width) + 1),
-            ),
-            Constraint::Min(self.bottom_pane.desired_height(area.width)),
+            Constraint::Length(header_height),
+            Constraint::Length(active_height),
+            Constraint::Min(bottom_min),
         ])
         .areas(area)
     }
@@ -651,6 +665,7 @@ impl ChatWidget {
             }),
             active_exec_cell: None,
             config: config.clone(),
+            session_header: SessionHeader::new(config.model.clone()),
             initial_user_message: create_initial_user_message(
                 initial_prompt.unwrap_or_default(),
                 initial_images,
@@ -703,6 +718,7 @@ impl ChatWidget {
             }),
             active_exec_cell: None,
             config: config.clone(),
+            session_header: SessionHeader::new(config.model.clone()),
             initial_user_message: create_initial_user_message(
                 initial_prompt.unwrap_or_default(),
                 initial_images,
@@ -1281,8 +1297,9 @@ impl ChatWidget {
     }
 
     /// Set the model in the widget's config copy.
-    pub(crate) fn set_model(&mut self, model: String) {
-        self.config.model = model;
+    pub(crate) fn set_model(&mut self, model: &str) {
+        self.session_header.set_model(model);
+        self.config.model = model.to_string();
     }
 
     pub(crate) fn add_info_message(&mut self, message: String, hint: Option<String>) {
@@ -1403,14 +1420,14 @@ impl ChatWidget {
     }
 
     pub fn cursor_pos(&self, area: Rect) -> Option<(u16, u16)> {
-        let [_, bottom_pane_area] = self.layout_areas(area);
+        let [_, _, bottom_pane_area] = self.layout_areas(area);
         self.bottom_pane.cursor_pos(bottom_pane_area)
     }
 }
 
 impl WidgetRef for &ChatWidget {
     fn render_ref(&self, area: Rect, buf: &mut Buffer) {
-        let [active_cell_area, bottom_pane_area] = self.layout_areas(area);
+        let [_, active_cell_area, bottom_pane_area] = self.layout_areas(area);
         (&self.bottom_pane).render(bottom_pane_area, buf);
         if !active_cell_area.is_empty()
             && let Some(cell) = &self.active_exec_cell

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

@@ -0,0 +1,16 @@
+pub(crate) struct SessionHeader {
+    model: String,
+}
+
+impl SessionHeader {
+    pub(crate) fn new(model: String) -> Self {
+        Self { model }
+    }
+
+    /// Updates the header's model text.
+    pub(crate) fn set_model(&mut self, model: &str) {
+        if self.model != model {
+            self.model = model.to_string();
+        }
+    }
+}

codex-rs/tui/src/chatwidget/snapshots/codex_tui__chatwidget__tests__approval_modal_exec.snap

@@ -1,6 +1,5 @@
 ---
 source: tui/src/chatwidget/tests.rs
-assertion_line: 728
 expression: terminal.backend()
 ---
 "                                                                                "

codex-rs/tui/src/chatwidget/snapshots/codex_tui__chatwidget__tests__approval_modal_patch.snap

@@ -1,6 +1,5 @@
 ---
 source: tui/src/chatwidget/tests.rs
-assertion_line: 794
 expression: terminal.backend()
 ---
 "                                                                                "

codex-rs/tui/src/chatwidget/snapshots/codex_tui__chatwidget__tests__status_widget_and_approval_modal.snap

@@ -1,6 +1,5 @@
 ---
 source: tui/src/chatwidget/tests.rs
-assertion_line: 921
 expression: terminal.backend()
 ---
 "                                                                                "

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

@@ -79,7 +79,9 @@ fn final_answer_without_newline_is_flushed_immediately() {
 
     // Set up a VT100 test terminal to capture ANSI visual output
     let width: u16 = 80;
-    let height: u16 = 2000;
+    // Increased height to keep the initial banner/help lines in view even if
+    // the session renders an extra header line or minor layout changes occur.
+    let height: u16 = 2500;
     let viewport = Rect::new(0, height - 1, width, 1);
     let backend = ratatui::backend::TestBackend::new(width, height);
     let mut terminal = crate::custom_terminal::Terminal::with_options(backend)
@@ -230,6 +232,7 @@ fn make_chatwidget_manual() -> (
         bottom_pane: bottom,
         active_exec_cell: None,
         config: cfg.clone(),
+        session_header: SessionHeader::new(cfg.model.clone()),
         initial_user_message: None,
         token_info: None,
         stream: StreamController::new(cfg),
@@ -773,10 +776,11 @@ async fn binary_size_transcript_snapshot() {
     // Consider content only after the last session banner marker. Skip the transient
     // 'thinking' header if present, and start from the first non-empty content line
     // that follows. This keeps the snapshot stable across sessions.
-    const MARKER_PREFIX: &str = ">_ You are using OpenAI Codex in ";
+    const MARKER_PREFIX: &str =
+        "Describe a task to get started or try one of the following commands:";
     let last_marker_line_idx = lines
         .iter()
-        .rposition(|l| l.starts_with(MARKER_PREFIX))
+        .rposition(|l| l.trim_start().starts_with(MARKER_PREFIX))
         .expect("marker not found in visible output");
     // Prefer the first assistant content line (blockquote '>' prefix) after the marker;
     // fallback to the first non-empty, non-'thinking' line.