[tui] Show speed in session header (#13446)

- add a speed row to the startup/session header under the model row
- render the speed row with the same styling pattern as the model row,
using /fast to change
- show only Fast or Standard to users and update the affected snapshots

---------

Co-authored-by: Codex <noreply@openai.com>

codex-rs/app-server/src/codex_message_processor.rs

@@ -6493,6 +6493,14 @@ fn collect_resume_override_mismatches(
             config_snapshot.model_provider_id
         ));
     }
+    if let Some(requested_service_tier) = request.service_tier.as_ref()
+        && requested_service_tier != &config_snapshot.service_tier
+    {
+        mismatch_details.push(format!(
+            "service_tier requested={requested_service_tier:?} active={:?}",
+            config_snapshot.service_tier
+        ));
+    }
     if let Some(requested_cwd) = request.cwd.as_deref() {
         let requested_cwd_path = std::path::PathBuf::from(requested_cwd);
         if requested_cwd_path != config_snapshot.cwd {
@@ -7259,6 +7267,43 @@ mod tests {
         validate_dynamic_tools(&tools).expect("valid schema");
     }
 
+    #[test]
+    fn collect_resume_override_mismatches_includes_service_tier() {
+        let request = ThreadResumeParams {
+            thread_id: "thread-1".to_string(),
+            history: None,
+            path: None,
+            model: None,
+            model_provider: None,
+            service_tier: Some(Some(codex_protocol::config_types::ServiceTier::Fast)),
+            cwd: None,
+            approval_policy: None,
+            sandbox: None,
+            config: None,
+            base_instructions: None,
+            developer_instructions: None,
+            personality: None,
+            persist_extended_history: false,
+        };
+        let config_snapshot = ThreadConfigSnapshot {
+            model: "gpt-5".to_string(),
+            model_provider_id: "openai".to_string(),
+            service_tier: Some(codex_protocol::config_types::ServiceTier::Flex),
+            approval_policy: codex_protocol::protocol::AskForApproval::OnRequest,
+            sandbox_policy: codex_protocol::protocol::SandboxPolicy::DangerFullAccess,
+            cwd: PathBuf::from("/tmp"),
+            ephemeral: false,
+            reasoning_effort: None,
+            personality: None,
+            session_source: SessionSource::Cli,
+        };
+
+        assert_eq!(
+            collect_resume_override_mismatches(&request, &config_snapshot),
+            vec!["service_tier requested=Some(Fast) active=Some(Flex)".to_string()]
+        );
+    }
+
     #[test]
     fn extract_conversation_summary_prefers_plain_user_messages() -> Result<()> {
         let conversation_id = ThreadId::from_string("3f941c35-29b3-493b-b0a4-e25800d9aeb0")?;

codex-rs/tui/src/app.rs

@@ -806,6 +806,8 @@ impl App {
         history_cell::SessionHeaderHistoryCell::new(
             self.chat_widget.current_model().to_string(),
             self.chat_widget.current_reasoning_effort(),
+            self.chat_widget
+                .should_show_fast_status(self.chat_widget.current_service_tier()),
             self.config.cwd.clone(),
             version,
         )
@@ -5178,6 +5180,7 @@ mod tests {
                 is_first,
                 None,
                 None,
+                false,
             )) as Arc<dyn HistoryCell>
         };
 
@@ -5827,6 +5830,7 @@ mod tests {
                 is_first,
                 None,
                 None,
+                false,
             )) as Arc<dyn HistoryCell>
         };
 

codex-rs/tui/src/chatwidget.rs

@@ -1224,6 +1224,7 @@ impl ChatWidget {
         self.sync_fast_command_enabled();
         self.sync_personality_command_enabled();
         let startup_tooltip_override = self.startup_tooltip_override.take();
+        let show_fast_status = self.should_show_fast_status(event.service_tier);
         let session_info_cell = history_cell::new_session_info(
             &self.config,
             &model_for_header,
@@ -1233,6 +1234,7 @@ impl ChatWidget {
             self.auth_manager
                 .auth_cached()
                 .and_then(|auth| auth.account_plan_type()),
+            show_fast_status,
         );
         self.apply_session_info_cell(session_info_cell);
 
@@ -7221,6 +7223,15 @@ impl ChatWidget {
         self.config.service_tier
     }
 
+    pub(crate) fn should_show_fast_status(&self, service_tier: Option<ServiceTier>) -> bool {
+        matches!(service_tier, Some(ServiceTier::Fast))
+            && self
+                .auth_manager
+                .auth_cached()
+                .as_ref()
+                .is_some_and(CodexAuth::is_chatgpt_auth)
+    }
+
     fn fast_mode_enabled(&self) -> bool {
         self.config.features.enabled(Feature::FastMode)
     }
@@ -7555,6 +7566,7 @@ impl ChatWidget {
             DEFAULT_MODEL_DISPLAY_NAME.to_string(),
             placeholder_style,
             None,
+            false,
             config.cwd.clone(),
             CODEX_CLI_VERSION,
         ))

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

@@ -7458,6 +7458,26 @@ async fn user_turn_carries_service_tier_after_fast_toggle() {
     }
 }
 
+#[tokio::test]
+async fn fast_status_indicator_requires_chatgpt_auth() {
+    let (mut chat, _rx, _op_rx) = make_chatwidget_manual(Some("gpt-5.3-codex")).await;
+    chat.set_service_tier(Some(ServiceTier::Fast));
+
+    assert!(!chat.should_show_fast_status(chat.current_service_tier()));
+
+    set_chatgpt_auth(&mut chat);
+
+    assert!(chat.should_show_fast_status(chat.current_service_tier()));
+}
+
+#[tokio::test]
+async fn fast_status_indicator_is_hidden_when_fast_mode_is_off() {
+    let (mut chat, _rx, _op_rx) = make_chatwidget_manual(Some("gpt-5.3-codex")).await;
+    set_chatgpt_auth(&mut chat);
+
+    assert!(!chat.should_show_fast_status(chat.current_service_tier()));
+}
+
 #[tokio::test]
 async fn approvals_popup_shows_disabled_presets() {
     let (mut chat, _rx, _op_rx) = make_chatwidget_manual(None).await;

codex-rs/tui/src/history_cell.rs

@@ -1047,6 +1047,7 @@ pub(crate) fn new_session_info(
     is_first_event: bool,
     tooltip_override: Option<String>,
     auth_plan: Option<PlanType>,
+    show_fast_status: bool,
 ) -> SessionInfoCell {
     let SessionConfiguredEvent {
         model,
@@ -1057,6 +1058,7 @@ pub(crate) fn new_session_info(
     let header = SessionHeaderHistoryCell::new(
         model.clone(),
         reasoning_effort,
+        show_fast_status,
         config.cwd.clone(),
         CODEX_CLI_VERSION,
     );
@@ -1143,6 +1145,7 @@ pub(crate) struct SessionHeaderHistoryCell {
     model: String,
     model_style: Style,
     reasoning_effort: Option<ReasoningEffortConfig>,
+    show_fast_status: bool,
     directory: PathBuf,
 }
 
@@ -1150,6 +1153,7 @@ impl SessionHeaderHistoryCell {
     pub(crate) fn new(
         model: String,
         reasoning_effort: Option<ReasoningEffortConfig>,
+        show_fast_status: bool,
         directory: PathBuf,
         version: &'static str,
     ) -> Self {
@@ -1157,6 +1161,7 @@ impl SessionHeaderHistoryCell {
             model,
             Style::default(),
             reasoning_effort,
+            show_fast_status,
             directory,
             version,
         )
@@ -1166,6 +1171,7 @@ impl SessionHeaderHistoryCell {
         model: String,
         model_style: Style,
         reasoning_effort: Option<ReasoningEffortConfig>,
+        show_fast_status: bool,
         directory: PathBuf,
         version: &'static str,
     ) -> Self {
@@ -1174,6 +1180,7 @@ impl SessionHeaderHistoryCell {
             model,
             model_style,
             reasoning_effort,
+            show_fast_status,
             directory,
         }
     }
@@ -1253,6 +1260,10 @@ impl HistoryCell for SessionHeaderHistoryCell {
                 spans.push(Span::from(" "));
                 spans.push(Span::from(reasoning));
             }
+            if self.show_fast_status {
+                spans.push("   ".into());
+                spans.push(Span::styled("fast", self.model_style.magenta()));
+            }
             spans.push("   ".dim());
             spans.push(CHANGE_MODEL_HINT_COMMAND.cyan());
             spans.push(CHANGE_MODEL_HINT_EXPLANATION.dim());
@@ -2612,6 +2623,7 @@ mod tests {
             false,
             Some("Model just became available".to_string()),
             Some(PlanType::Free),
+            false,
         );
 
         let rendered = render_transcript(&cell).join("\n");
@@ -2629,6 +2641,7 @@ mod tests {
             false,
             Some("Model just became available".to_string()),
             Some(PlanType::Free),
+            false,
         );
 
         let rendered = render_transcript(&cell).join("\n");
@@ -2645,6 +2658,7 @@ mod tests {
             true,
             Some("Model just became available".to_string()),
             Some(PlanType::Free),
+            false,
         );
 
         let rendered = render_transcript(&cell).join("\n");
@@ -2663,6 +2677,7 @@ mod tests {
             false,
             Some("Model just became available".to_string()),
             Some(PlanType::Free),
+            false,
         );
 
         let rendered = render_transcript(&cell).join("\n");
@@ -3295,18 +3310,39 @@ mod tests {
         let cell = SessionHeaderHistoryCell::new(
             "gpt-4o".to_string(),
             Some(ReasoningEffortConfig::High),
+            true,
             std::env::temp_dir(),
             "test",
         );
 
         let lines = render_lines(&cell.display_lines(80));
         let model_line = lines
-            .into_iter()
+            .iter()
+            .find(|line| line.contains("model:"))
+            .expect("model line");
+
+        assert!(model_line.contains("gpt-4o high   fast"));
+        assert!(model_line.contains("/model to change"));
+    }
+
+    #[test]
+    fn session_header_hides_fast_status_when_disabled() {
+        let cell = SessionHeaderHistoryCell::new(
+            "gpt-4o".to_string(),
+            Some(ReasoningEffortConfig::High),
+            false,
+            std::env::temp_dir(),
+            "test",
+        );
+
+        let lines = render_lines(&cell.display_lines(80));
+        let model_line = lines
+            .iter()
             .find(|line| line.contains("model:"))
             .expect("model line");
 
         assert!(model_line.contains("gpt-4o high"));
-        assert!(model_line.contains("/model to change"));
+        assert!(!model_line.contains("fast"));
     }
 
     #[test]

codex-rs/tui/src/snapshots/codex_tui__app__tests__clear_ui_after_long_transcript_fresh_header_only.snap

@@ -1,6 +1,5 @@
 ---
 source: tui/src/app.rs
-assertion_line: 3452
 expression: rendered
 ---
 ╭─────────────────────────────────────────────╮

codex-rs/tui/src/snapshots/codex_tui__history_cell__tests__session_info_availability_nux_tooltip_snapshot.snap

@@ -1,6 +1,5 @@
 ---
 source: tui/src/history_cell.rs
-assertion_line: 2608
 expression: rendered
 ---
 ╭─────────────────────────────────────╮