Add reasoning-only status surface item (#25504)

Closes #24886.

## Why
Users can configure the TUI status line and terminal title with
`model-with-reasoning`, but issue #24886 asks for a compact
reasoning-only item. That lets a setup show just `default`, `low`,
`medium`, `high`, or `xhigh` without repeating the model name.

## What changed
- Added a `reasoning` item for `/statusline` and `/title` setup flows.
- Rendered the item from the effective reasoning effort, including
collaboration-mode overrides.
- Registered `reasoning` with `codex doctor` so Codex-generated
terminal-title config is not reported as invalid.
- Updated TUI setup snapshots so the picker previews include the new
item.

codex-rs/cli/src/doctor/title.rs

@@ -143,6 +143,7 @@ fn terminal_title_item_id(item: &str) -> Option<&'static str> {
         "fast-mode" => Some("fast-mode"),
         "model" | "model-name" => Some("model"),
         "model-with-reasoning" => Some("model-with-reasoning"),
+        "reasoning" => Some("reasoning"),
         "task-progress" => Some("task-progress"),
         _ => None,
     }

codex-rs/tui/src/bottom_pane/snapshots/codex_tui__bottom_pane__status_line_setup__tests__setup_view_snapshot_uses_runtime_preview_values.snap

@@ -14,8 +14,8 @@ expression: "render_lines(&view, 72)"
   [x] current-dir           Current working directory                   
   [x] git-branch            Current Git branch (omitted when unavaila…  
   [ ] model-with-reasoning  Current model name with reasoning level     
+  [ ] reasoning             Current reasoning level                     
   [ ] project-name          Project name (omitted when unavailable)     
-  [ ] pull-request-number   Open pull request number for the current …  
                                                                         
   gpt-5-codex · ~/codex-rs · jif/statusline-preview                     
   Press space to toggle; ←/→ to move; enter to confirm and close; esc to

codex-rs/tui/src/bottom_pane/status_line_setup.rs

@@ -60,6 +60,9 @@ pub(crate) enum StatusLineItem {
     /// Model name with reasoning level suffix.
     ModelWithReasoning,
 
+    /// Current reasoning level.
+    Reasoning,
+
     /// Current working directory path.
     CurrentDir,
 
@@ -144,6 +147,7 @@ impl StatusLineItem {
         match self {
             StatusLineItem::ModelName => "Current model name",
             StatusLineItem::ModelWithReasoning => "Current model name with reasoning level",
+            StatusLineItem::Reasoning => "Current reasoning level",
             StatusLineItem::CurrentDir => "Current working directory",
             StatusLineItem::ProjectRoot => "Project name (omitted when unavailable)",
             StatusLineItem::GitBranch => "Current Git branch (omitted when unavailable)",
@@ -191,6 +195,7 @@ impl StatusLineItem {
         match self {
             StatusLineItem::ModelName => StatusSurfacePreviewItem::Model,
             StatusLineItem::ModelWithReasoning => StatusSurfacePreviewItem::ModelWithReasoning,
+            StatusLineItem::Reasoning => StatusSurfacePreviewItem::Reasoning,
             StatusLineItem::CurrentDir => StatusSurfacePreviewItem::CurrentDir,
             StatusLineItem::ProjectRoot => StatusSurfacePreviewItem::ProjectRoot,
             StatusLineItem::GitBranch => StatusSurfacePreviewItem::GitBranch,
@@ -450,6 +455,15 @@ mod tests {
         );
     }
 
+    #[test]
+    fn reasoning_is_selectable_id() {
+        assert_eq!(StatusLineItem::Reasoning.to_string(), "reasoning");
+        assert_eq!(
+            "reasoning".parse::<StatusLineItem>(),
+            Ok(StatusLineItem::Reasoning)
+        );
+    }
+
     #[test]
     fn run_state_is_canonical_and_accepts_status_legacy_id() {
         assert_eq!(StatusLineItem::Status.to_string(), "run-state");

codex-rs/tui/src/bottom_pane/status_line_style.rs

@@ -30,7 +30,9 @@ enum StatusLineAccent {
 impl StatusLineAccent {
     fn for_item(item: StatusLineItem) -> Self {
         match item {
-            StatusLineItem::ModelName | StatusLineItem::ModelWithReasoning => Self::Model,
+            StatusLineItem::ModelName
+            | StatusLineItem::ModelWithReasoning
+            | StatusLineItem::Reasoning => Self::Model,
             StatusLineItem::CurrentDir | StatusLineItem::ProjectRoot => Self::Path,
             StatusLineItem::GitBranch
             | StatusLineItem::PullRequestNumber

codex-rs/tui/src/bottom_pane/status_surface_preview.rs

@@ -32,6 +32,7 @@ pub(crate) enum StatusSurfacePreviewItem {
     RawOutput,
     Model,
     ModelWithReasoning,
+    Reasoning,
     TaskProgress,
 }
 
@@ -63,6 +64,7 @@ impl StatusSurfacePreviewItem {
             StatusSurfacePreviewItem::RawOutput => "raw output",
             StatusSurfacePreviewItem::Model => "gpt-5.2-codex",
             StatusSurfacePreviewItem::ModelWithReasoning => "gpt-5.2-codex medium",
+            StatusSurfacePreviewItem::Reasoning => "medium",
             StatusSurfacePreviewItem::TaskProgress => "Tasks 0/0",
         }
     }
@@ -94,6 +96,7 @@ impl StatusSurfacePreviewItem {
             Self::RawOutput,
             Self::Model,
             Self::ModelWithReasoning,
+            Self::Reasoning,
             Self::TaskProgress,
         ]
         .into_iter()

codex-rs/tui/src/bottom_pane/title_setup.rs

@@ -82,6 +82,8 @@ pub(crate) enum TerminalTitleItem {
     Model,
     /// Current model name with reasoning level.
     ModelWithReasoning,
+    /// Current reasoning level.
+    Reasoning,
     /// Latest checklist task progress from `update_plan` (if available).
     TaskProgress,
 }
@@ -122,6 +124,7 @@ impl TerminalTitleItem {
             TerminalTitleItem::FastMode => "Whether Fast mode is currently active",
             TerminalTitleItem::Model => "Current model name",
             TerminalTitleItem::ModelWithReasoning => "Current model name with reasoning level",
+            TerminalTitleItem::Reasoning => "Current reasoning level",
             TerminalTitleItem::TaskProgress => {
                 "Latest task progress from update_plan (omitted until available)"
             }
@@ -153,6 +156,7 @@ impl TerminalTitleItem {
             TerminalTitleItem::ModelWithReasoning => {
                 Some(StatusSurfacePreviewItem::ModelWithReasoning)
             }
+            TerminalTitleItem::Reasoning => Some(StatusSurfacePreviewItem::Reasoning),
             TerminalTitleItem::TaskProgress => Some(StatusSurfacePreviewItem::TaskProgress),
         }
     }
@@ -516,6 +520,15 @@ mod tests {
         );
     }
 
+    #[test]
+    fn reasoning_is_selectable_id() {
+        assert_eq!(TerminalTitleItem::Reasoning.to_string(), "reasoning");
+        assert_eq!(
+            "reasoning".parse::<TerminalTitleItem>(),
+            Ok(TerminalTitleItem::Reasoning)
+        );
+    }
+
     #[test]
     fn parse_terminal_title_items_accepts_kebab_case_variants() {
         let items = parse_terminal_title_items(
@@ -530,6 +543,7 @@ mod tests {
                 "project-name",
                 "model",
                 "model-with-reasoning",
+                "reasoning",
                 "weekly-limit",
                 "codex-version",
                 "used-tokens",
@@ -553,6 +567,7 @@ mod tests {
                 TerminalTitleItem::Project,
                 TerminalTitleItem::Model,
                 TerminalTitleItem::ModelWithReasoning,
+                TerminalTitleItem::Reasoning,
                 TerminalTitleItem::WeeklyLimit,
                 TerminalTitleItem::CodexVersion,
                 TerminalTitleItem::UsedTokens,

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

@@ -14,7 +14,7 @@ expression: status_line_popup_snapshot(&mut chat)
   [x] thread-title          Current thread title, or thread identifier when unnamed
   [ ] model                 Current model name
   [ ] model-with-reasoning  Current model name with reasoning level
-  [ ] current-dir           Current working directory
+  [ ] reasoning             Current reasoning level
 
   my-project · feat/awesome-feature · thread title
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codex-rs/tui/src/chatwidget/snapshots/codex_tui__chatwidget__tests__status_line_setup_popup_live_only.snap

@@ -14,7 +14,7 @@ expression: status_line_popup_snapshot(&mut chat)
   [x] thread-title          Current thread title, or thread identifier when unnamed
   [ ] model                 Current model name
   [ ] model-with-reasoning  Current model name with reasoning level
-  [ ] current-dir           Current working directory
+  [ ] reasoning             Current reasoning level
 
   preview-live-root · feature/live-preview-branch · Live preview thread
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codex-rs/tui/src/chatwidget/snapshots/codex_tui__chatwidget__tests__status_line_setup_popup_mixed.snap

@@ -14,7 +14,7 @@ expression: status_line_popup_snapshot(&mut chat)
   [x] thread-title          Current thread title, or thread identifier when unnamed
   [ ] model                 Current model name
   [ ] model-with-reasoning  Current model name with reasoning level
-  [ ] current-dir           Current working directory
+  [ ] reasoning             Current reasoning level
 
   my-project · feature/mixed-preview · Mixed preview thread
   Press space to toggle; ←/→ to move; enter to confirm and close; esc to close

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

@@ -13,8 +13,8 @@ expression: status_line_popup_snapshot(&mut chat)
   [x] weekly-limit          Remaining usage on the weekly usage limit (omitted when unavailable)
   [ ] model                 Current model name
   [ ] model-with-reasoning  Current model name with reasoning level
+  [ ] reasoning             Current reasoning level
   [ ] current-dir           Current working directory
-  [ ] project-name          Project name (omitted when unavailable)
 
   monthly 65% left · weekly 50% left
   Press space to toggle; ←/→ to move; enter to confirm and close; esc to close

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

@@ -562,6 +562,7 @@ impl ChatWidget {
         match item {
             StatusLineItem::ModelName => Some(self.model_display_name().to_string()),
             StatusLineItem::ModelWithReasoning => Some(self.model_with_reasoning_display_name()),
+            StatusLineItem::Reasoning => Some(self.reasoning_display_name().to_string()),
             StatusLineItem::CurrentDir => {
                 Some(format_directory_display(
                     self.status_line_cwd(),
@@ -694,6 +695,7 @@ impl ChatWidget {
             StatusSurfacePreviewItem::RawOutput => StatusLineItem::RawOutput,
             StatusSurfacePreviewItem::Model => StatusLineItem::ModelName,
             StatusSurfacePreviewItem::ModelWithReasoning => StatusLineItem::ModelWithReasoning,
+            StatusSurfacePreviewItem::Reasoning => StatusLineItem::Reasoning,
         };
         self.status_line_value_for_item(status_line_item)
     }
@@ -759,12 +761,20 @@ impl ChatWidget {
                 self.model_with_reasoning_display_name(),
                 /*max_chars*/ 32,
             )),
+            TerminalTitleItem::Reasoning => Some(Self::truncate_terminal_title_part(
+                self.reasoning_display_name().to_string(),
+                /*max_chars*/ 32,
+            )),
             TerminalTitleItem::TaskProgress => self.terminal_title_task_progress(),
         }
     }
 
+    fn reasoning_display_name(&self) -> &'static str {
+        Self::status_line_reasoning_effort_label(self.effective_reasoning_effort())
+    }
+
     fn model_with_reasoning_display_name(&self) -> String {
-        let label = Self::status_line_reasoning_effort_label(self.effective_reasoning_effort());
+        let label = self.reasoning_display_name();
         let service_tier_label = self
             .current_service_tier()
             .and_then(|service_tier| {

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

@@ -2208,6 +2208,37 @@ async fn terminal_title_model_updates_on_model_change_without_manual_refresh() {
     assert_eq!(chat.last_terminal_title, Some("gpt-5.3-codex".to_string()));
 }
 
+#[tokio::test]
+async fn status_line_and_terminal_title_reasoning_render_only_effort() {
+    let (mut chat, _rx, _op_rx) = make_chatwidget_manual(Some("gpt-5.4")).await;
+    chat.config.tui_status_line = Some(vec!["reasoning".to_string()]);
+    chat.config.tui_terminal_title = Some(vec!["reasoning".to_string()]);
+    chat.set_reasoning_effort(Some(ReasoningEffortConfig::XHigh));
+    chat.set_service_tier(Some(ServiceTier::Fast.request_value().to_string()));
+
+    chat.refresh_status_line();
+    chat.refresh_terminal_title();
+
+    assert_eq!(status_line_text(&chat), Some("xhigh".to_string()));
+    assert_eq!(chat.last_terminal_title, Some("xhigh".to_string()));
+}
+
+#[tokio::test]
+async fn status_line_reasoning_updates_on_mode_switch_without_manual_refresh() {
+    let (mut chat, _rx, _op_rx) = make_chatwidget_manual(Some("gpt-5.3-codex")).await;
+    chat.set_feature_enabled(Feature::CollaborationModes, /*enabled*/ true);
+    chat.config.tui_status_line = Some(vec!["reasoning".to_string()]);
+    chat.set_reasoning_effort(Some(ReasoningEffortConfig::High));
+
+    assert_eq!(status_line_text(&chat), Some("high".to_string()));
+
+    let plan_mask = collaboration_modes::plan_mask(chat.model_catalog.as_ref())
+        .expect("expected plan collaboration mode");
+    chat.set_collaboration_mask(plan_mask);
+
+    assert_eq!(status_line_text(&chat), Some("medium".to_string()));
+}
+
 #[tokio::test]
 async fn status_line_model_with_reasoning_updates_on_mode_switch_without_manual_refresh() {
     let (mut chat, _rx, _op_rx) = make_chatwidget_manual(Some("gpt-5.3-codex")).await;