feat: add optional pane border labels

5 files changed, 57 insertions, 1 deletions

diff --git a/src/ui/dialogs.rs b/src/ui/dialogs.rs
index 78f1d1cb..3c481a97 100644
--- a/src/ui/dialogs.rs
+++ b/src/ui/dialogs.rs
@@ -42,6 +42,7 @@ pub(super) fn render_rename_overlay(app: &AppState, frame: &mut Frame, area: Rec
         Mode::RenameWorkspace => "rename workspace",
         Mode::RenameTab if app.creating_new_tab => "new tab",
         Mode::RenameTab => "rename tab",
+        Mode::RenamePane => "rename pane",
         _ => return,
     };
 
diff --git a/src/ui/keybind_help.rs b/src/ui/keybind_help.rs
index 2bb05c50..fdc600c4 100644
--- a/src/ui/keybind_help.rs
+++ b/src/ui/keybind_help.rs
@@ -82,6 +82,7 @@ pub(super) fn keybind_help_groups(
         (kb.split_vertical_label.clone(), "split vertical"),
         (kb.split_horizontal_label.clone(), "split horizontal"),
         (kb.close_pane_label.clone(), "close pane"),
+        (optional_keybind_label(&kb.rename_pane_label), "rename pane"),
         (kb.fullscreen_label.clone(), "fullscreen"),
         (kb.resize_mode_label.clone(), "resize mode"),
         (kb.toggle_sidebar_label.clone(), "toggle sidebar"),
diff --git a/src/ui/panes.rs b/src/ui/panes.rs
index 818ee9fd..72a5c30c 100644
--- a/src/ui/panes.rs
+++ b/src/ui/panes.rs
@@ -18,6 +18,30 @@ pub(crate) fn pane_is_scrolled_back(rt: &PaneRuntime) -> bool {
         .is_some_and(|metrics| metrics.offset_from_bottom > 0)
 }
 
+fn truncate_label(text: &str, max_width: usize) -> String {
+    let len = text.chars().count();
+    if len <= max_width {
+        return text.to_string();
+    }
+    if max_width == 0 {
+        return String::new();
+    }
+    if max_width == 1 {
+        return "…".to_string();
+    }
+    let prefix: String = text.chars().take(max_width.saturating_sub(1)).collect();
+    format!("{prefix}…")
+}
+
+fn pane_border_title(label: &str, pane_width: u16) -> Option<String> {
+    let label = label.trim();
+    if label.is_empty() || pane_width <= 4 {
+        return None;
+    }
+    let max_label_width = pane_width.saturating_sub(4) as usize;
+    Some(format!(" {} ", truncate_label(label, max_label_width)))
+}
+
 fn stable_terminal_inner_rect(pane_inner: Rect) -> Rect {
     if pane_inner.width <= 4 {
         return pane_inner;
@@ -174,10 +198,17 @@ pub(super) fn render_panes(app: &AppState, frame: &mut Frame, area: Rect) {
                     )
                 };
 
-                let block = Block::default()
+                let mut block = Block::default()
                     .borders(Borders::ALL)
                     .border_style(border_style)
                     .border_set(border_set);
+                if let Some(title) = ws
+                    .pane_state(info.id)
+                    .and_then(|pane| pane.border_label(app.show_agent_labels_on_pane_borders))
+                    .and_then(|label| pane_border_title(label, info.rect.width))
+                {
+                    block = block.title(Line::from(Span::styled(title, border_style)));
+                }
                 frame.render_widget(block, info.rect);
             }
 
@@ -303,6 +334,17 @@ mod tests {
     use crate::pane::PaneRuntime;
     use crate::workspace::Workspace;
 
+    #[test]
+    fn pane_border_title_trims_and_truncates() {
+        assert_eq!(
+            pane_border_title(" claude ", 20).as_deref(),
+            Some(" claude ")
+        );
+        assert_eq!(pane_border_title("", 20), None);
+        assert_eq!(pane_border_title("abcdef", 8).as_deref(), Some(" abc… "));
+        assert_eq!(pane_border_title("abcdef", 4), None);
+    }
+
     #[tokio::test]
     async fn pane_scrollbar_gutter_is_reserved_before_scrollback_exists() {
         let mut app = AppState::test_new();
diff --git a/src/ui/settings.rs b/src/ui/settings.rs
index 5269f380..ef80d85a 100644
--- a/src/ui/settings.rs
+++ b/src/ui/settings.rs
@@ -106,6 +106,17 @@ pub(super) fn render_settings_overlay(app: &AppState, frame: &mut Frame, area: R
                 2,
             );
         }
+        SettingsSection::PaneLabels => {
+            render_settings_toggle(
+                frame,
+                content_area,
+                p,
+                "agent border labels",
+                "show detected agent names in split pane borders",
+                app.agent_border_labels_enabled(),
+                app.settings.list.selected,
+            );
+        }
     }
 
     if let Some(footer_area) = stack.footer {
diff --git a/src/ui/sidebar.rs b/src/ui/sidebar.rs
index 83ceebe0..8a104dba 100644
--- a/src/ui/sidebar.rs
+++ b/src/ui/sidebar.rs
@@ -70,6 +70,7 @@ fn agent_panel_current_workspace_idx(app: &AppState) -> Option<usize> {
         app.mode,
         Mode::Navigate
             | Mode::RenameWorkspace
+            | Mode::RenamePane
             | Mode::Resize
             | Mode::ConfirmClose
             | Mode::ContextMenu