diff --git a/codex-rs/tui/src/bottom_pane/command_popup.rs b/codex-rs/tui/src/bottom_pane/command_popup.rs
index 1c2291465e..f8ea0b41e1 100644
--- a/codex-rs/tui/src/bottom_pane/command_popup.rs
+++ b/codex-rs/tui/src/bottom_pane/command_popup.rs
@@ -464,7 +464,7 @@ mod tests {
     }
 
     #[test]
-    fn collab_command_hidden_when_collaboration_modes_disabled() {
+    fn plan_command_hidden_when_collaboration_modes_disabled() {
         let mut popup = CommandPopup::new(Vec::new(), CommandPopupFlags::default());
         popup.on_composer_text_change("/".to_string());
 
@@ -476,35 +476,12 @@ mod tests {
                 CommandItem::UserPrompt(_) => None,
             })
             .collect();
-        assert!(
-            !cmds.contains(&"collab"),
-            "expected '/collab' to be hidden when collaboration modes are disabled, got {cmds:?}"
-        );
         assert!(
             !cmds.contains(&"plan"),
             "expected '/plan' to be hidden when collaboration modes are disabled, got {cmds:?}"
         );
     }
 
-    #[test]
-    fn collab_command_visible_when_collaboration_modes_enabled() {
-        let mut popup = CommandPopup::new(
-            Vec::new(),
-            CommandPopupFlags {
-                collaboration_modes_enabled: true,
-                connectors_enabled: false,
-                personality_command_enabled: true,
-                windows_degraded_sandbox_active: false,
-            },
-        );
-        popup.on_composer_text_change("/collab".to_string());
-
-        match popup.selected_item() {
-            Some(CommandItem::Builtin(cmd)) => assert_eq!(cmd.command(), "collab"),
-            other => panic!("expected collab to be selected for exact match, got {other:?}"),
-        }
-    }
-
     #[test]
     fn plan_command_visible_when_collaboration_modes_enabled() {
         let mut popup = CommandPopup::new(
diff --git a/codex-rs/tui/src/bottom_pane/slash_commands.rs b/codex-rs/tui/src/bottom_pane/slash_commands.rs
index 4613161f2f..ae2b3731dc 100644
--- a/codex-rs/tui/src/bottom_pane/slash_commands.rs
+++ b/codex-rs/tui/src/bottom_pane/slash_commands.rs
@@ -20,7 +20,7 @@ pub(crate) fn builtins_for_input(
         .filter(|(_, cmd)| allow_elevate_sandbox || *cmd != SlashCommand::ElevateSandbox)
         .filter(|(_, cmd)| {
             collaboration_modes_enabled
-                || !matches!(*cmd, SlashCommand::Collab | SlashCommand::Plan)
+                || *cmd != SlashCommand::Plan
         })
         .filter(|(_, cmd)| connectors_enabled || *cmd != SlashCommand::Apps)
         .filter(|(_, cmd)| personality_command_enabled || *cmd != SlashCommand::Personality)
diff --git a/codex-rs/tui/src/chatwidget.rs b/codex-rs/tui/src/chatwidget.rs
index dcbee999bc..3fe4546b5c 100644
--- a/codex-rs/tui/src/chatwidget.rs
+++ b/codex-rs/tui/src/chatwidget.rs
@@ -3299,22 +3299,18 @@ impl ChatWidget {
                     );
                     return;
                 }
-                if let Some(mask) = collaboration_modes::plan_mask(self.models_manager.as_ref()) {
+                if self.active_mode_kind() == ModeKind::Plan {
+                    let Some(mask) = collaboration_modes::default_mask(self.models_manager.as_ref()) else {
+                        self.add_info_message("Default mode unavailable right now.".to_string(), None);
+                        return;
+                    };
+                    self.set_collaboration_mask(mask);
+                } else if let Some(mask) = collaboration_modes::plan_mask(self.models_manager.as_ref()) {
                     self.set_collaboration_mask(mask);
                 } else {
                     self.add_info_message("Plan mode unavailable right now.".to_string(), None);
                 }
             }
-            SlashCommand::Collab => {
-                if !self.collaboration_modes_enabled() {
-                    self.add_info_message(
-                        "Collaboration modes are disabled.".to_string(),
-                        Some("Enable collaboration modes to use /collab.".to_string()),
-                    );
-                    return;
-                }
-                self.open_collaboration_modes_popup();
-            }
             SlashCommand::Agent => {
                 self.app_event_tx.send(AppEvent::OpenAgentPicker);
             }
diff --git a/codex-rs/tui/src/chatwidget/tests.rs b/codex-rs/tui/src/chatwidget/tests.rs
index f069db9160..52751b21b6 100644
--- a/codex-rs/tui/src/chatwidget/tests.rs
+++ b/codex-rs/tui/src/chatwidget/tests.rs
@@ -3578,35 +3578,32 @@ async fn collab_mode_shift_tab_cycles_only_when_enabled_and_idle() {
 }
 
 #[tokio::test]
-async fn collab_slash_command_opens_picker_and_updates_mode() {
+async fn plan_slash_command_toggles_plan_mode() {
     let (mut chat, mut rx, mut op_rx) = make_chatwidget_manual(None).await;
-    chat.thread_id = Some(ThreadId::new());
     chat.set_feature_enabled(Feature::CollaborationModes, true);
+    let initial = chat.current_collaboration_mode().clone();
+    let default = initial.clone();
 
-    chat.dispatch_command(SlashCommand::Collab);
-    let popup = render_bottom_popup(&chat, 80);
-    assert!(
-        popup.contains("Select Collaboration Mode"),
-        "expected collaboration picker: {popup}"
-    );
+    chat.dispatch_command(SlashCommand::Plan);
 
-    chat.handle_key_event(KeyEvent::from(KeyCode::Enter));
-    let selected_mask = match rx.try_recv() {
-        Ok(AppEvent::UpdateCollaborationMode(mask)) => mask,
-        other => panic!("expected UpdateCollaborationMode event, got {other:?}"),
-    };
-    chat.set_collaboration_mask(selected_mask);
+    assert!(rx.try_recv().is_err(), "plan should not emit an app event");
+    assert_eq!(chat.active_collaboration_mode_kind(), ModeKind::Plan);
+    assert_eq!(chat.current_collaboration_mode(), &default);
+
+    chat.dispatch_command(SlashCommand::Plan);
+
+    assert_eq!(chat.active_collaboration_mode_kind(), ModeKind::Default);
+    assert_eq!(chat.current_collaboration_mode(), &initial);
 
     chat.bottom_pane
         .set_composer_text("hello".to_string(), Vec::new(), Vec::new());
     chat.handle_key_event(KeyEvent::from(KeyCode::Enter));
     match next_submit_op(&mut op_rx) {
         Op::UserTurn {
-            collaboration_mode:
-                Some(CollaborationMode {
-                    mode: ModeKind::Default,
-                    ..
-                }),
+            collaboration_mode: Some(CollaborationMode {
+                mode: ModeKind::Default,
+                ..
+            }),
             personality: Some(Personality::Pragmatic),
             ..
         } => {}
@@ -3614,7 +3611,6 @@ async fn collab_slash_command_opens_picker_and_updates_mode() {
             panic!("expected Op::UserTurn with code collab mode, got {other:?}")
         }
     }
-
     chat.bottom_pane
         .set_composer_text("follow up".to_string(), Vec::new(), Vec::new());
     chat.handle_key_event(KeyEvent::from(KeyCode::Enter));
@@ -3632,6 +3628,8 @@ async fn collab_slash_command_opens_picker_and_updates_mode() {
             panic!("expected Op::UserTurn with code collab mode, got {other:?}")
         }
     }
+    assert_eq!(chat.current_collaboration_mode(), &initial);
+    assert_eq!(chat.active_mode_kind(), ModeKind::Default);
 }
 
 #[tokio::test]
diff --git a/codex-rs/tui/src/slash_command.rs b/codex-rs/tui/src/slash_command.rs
index 16e767f802..b5abb3c1e0 100644
--- a/codex-rs/tui/src/slash_command.rs
+++ b/codex-rs/tui/src/slash_command.rs
@@ -29,7 +29,6 @@ pub enum SlashCommand {
     Init,
     Compact,
     Plan,
-    Collab,
     Agent,
     // Undo,
     Diff,
@@ -82,7 +81,6 @@ impl SlashCommand {
             SlashCommand::Model => "choose what model and reasoning effort to use",
             SlashCommand::Personality => "choose a communication style for Codex",
             SlashCommand::Plan => "switch to Plan mode",
-            SlashCommand::Collab => "change collaboration mode (experimental)",
             SlashCommand::Agent => "switch the active agent thread",
             SlashCommand::Approvals => "choose what Codex is allowed to do",
             SlashCommand::Permissions => "choose what Codex is allowed to do",
@@ -152,7 +150,6 @@ impl SlashCommand {
             | SlashCommand::Exit => true,
             SlashCommand::Rollout => true,
             SlashCommand::TestApproval => true,
-            SlashCommand::Collab => true,
             SlashCommand::Agent => true,
             SlashCommand::Statusline => false,
         }