diff --git a/crates/agent_ui/src/agent_diff.rs b/crates/agent_ui/src/agent_diff.rs
index dd11a3f2ccb88e38138d5c5f0e77805833a9a358..a0f117b0bf30abee9d2182cf8c3fadd10099b1f0 100644
--- a/crates/agent_ui/src/agent_diff.rs
+++ b/crates/agent_ui/src/agent_diff.rs
@@ -576,6 +576,10 @@ impl Item for AgentDiffPane {
         });
     }
 
+    fn can_split(&self) -> bool {
+        true
+    }
+
     fn clone_on_split(
         &self,
         _workspace_id: Option<workspace::WorkspaceId>,
diff --git a/crates/collab_ui/src/channel_view.rs b/crates/collab_ui/src/channel_view.rs
index 18847363bf1b012acb7916bb7b6a9c0adde4de28..5db588fdb3aad3f523864b5f90600e49eca9d8b6 100644
--- a/crates/collab_ui/src/channel_view.rs
+++ b/crates/collab_ui/src/channel_view.rs
@@ -493,6 +493,10 @@ impl Item for ChannelView {
         None
     }
 
+    fn can_split(&self) -> bool {
+        true
+    }
+
     fn clone_on_split(
         &self,
         _: Option<WorkspaceId>,
diff --git a/crates/diagnostics/src/buffer_diagnostics.rs b/crates/diagnostics/src/buffer_diagnostics.rs
index 1a7a97c68691d7bdf941322660eddeb70fa15037..1205cef385fdd91af8e3f986b432b9fff4ad3ac6 100644
--- a/crates/diagnostics/src/buffer_diagnostics.rs
+++ b/crates/diagnostics/src/buffer_diagnostics.rs
@@ -688,6 +688,10 @@ impl Item for BufferDiagnosticsEditor {
         true
     }
 
+    fn can_split(&self) -> bool {
+        true
+    }
+
     fn clone_on_split(
         &self,
         _workspace_id: Option<workspace::WorkspaceId>,
diff --git a/crates/diagnostics/src/diagnostics.rs b/crates/diagnostics/src/diagnostics.rs
index b96e8f891fda3cc470c7091eba8e92847b59562b..5a43fd135391a5e3d97d5c65e6d3be826210f102 100644
--- a/crates/diagnostics/src/diagnostics.rs
+++ b/crates/diagnostics/src/diagnostics.rs
@@ -727,6 +727,10 @@ impl Item for ProjectDiagnosticsEditor {
         });
     }
 
+    fn can_split(&self) -> bool {
+        true
+    }
+
     fn clone_on_split(
         &self,
         _workspace_id: Option<workspace::WorkspaceId>,
diff --git a/crates/editor/src/items.rs b/crates/editor/src/items.rs
index 6dab57db52700bc499376abb0ab80e9cdb45e5e9..346574eba440622a40139a52be6977e55e909980 100644
--- a/crates/editor/src/items.rs
+++ b/crates/editor/src/items.rs
@@ -757,6 +757,10 @@ impl Item for Editor {
         self.buffer.read(cx).is_singleton()
     }
 
+    fn can_split(&self) -> bool {
+        true
+    }
+
     fn clone_on_split(
         &self,
         _workspace_id: Option<WorkspaceId>,
diff --git a/crates/extension_host/src/wasm_host.rs b/crates/extension_host/src/wasm_host.rs
index 00e6321fdb5450a08aa331380a5d410652b66582..bf3732b7e8497a09d5067e11ab78e7165fb54a46 100644
--- a/crates/extension_host/src/wasm_host.rs
+++ b/crates/extension_host/src/wasm_host.rs
@@ -69,6 +69,7 @@ pub struct WasmExtension {
     pub work_dir: Arc<Path>,
     #[allow(unused)]
     pub zed_api_version: SemanticVersion,
+    _task: Arc<Task<Result<(), gpui_tokio::JoinError>>>,
 }
 
 impl Drop for WasmExtension {
@@ -649,21 +650,26 @@ impl WasmHost {
 
             anyhow::Ok((
                 extension_task,
-                WasmExtension {
-                    manifest: manifest.clone(),
-                    work_dir: this.work_dir.join(manifest.id.as_ref()).into(),
-                    tx,
-                    zed_api_version,
-                },
+                manifest.clone(),
+                this.work_dir.join(manifest.id.as_ref()).into(),
+                tx,
+                zed_api_version,
             ))
         };
         cx.spawn(async move |cx| {
-            let (extension_task, extension) = load_extension_task.await?;
+            let (extension_task, manifest, work_dir, tx, zed_api_version) =
+                load_extension_task.await?;
             // we need to run run the task in an extension context as wasmtime_wasi may
             // call into tokio, accessing its runtime handle
-            gpui_tokio::Tokio::spawn(cx, extension_task)?.detach();
+            let task = Arc::new(gpui_tokio::Tokio::spawn(cx, extension_task)?);
 
-            Ok(extension)
+            Ok(WasmExtension {
+                manifest,
+                work_dir,
+                tx,
+                zed_api_version,
+                _task: task,
+            })
         })
     }
 
diff --git a/crates/git_ui/src/commit_view.rs b/crates/git_ui/src/commit_view.rs
index 2430796c89f68e9b5032c3d05f7106b6f6de0bec..0a0c4c18e1f528a9ebaad9a8d9862982632dd04f 100644
--- a/crates/git_ui/src/commit_view.rs
+++ b/crates/git_ui/src/commit_view.rs
@@ -556,6 +556,10 @@ impl Item for CommitView {
         });
     }
 
+    fn can_split(&self) -> bool {
+        true
+    }
+
     fn clone_on_split(
         &self,
         _workspace_id: Option<workspace::WorkspaceId>,
diff --git a/crates/git_ui/src/project_diff.rs b/crates/git_ui/src/project_diff.rs
index e6f8099c732826d3546680fab9ef94c8e1d3db32..5c49ca286eb901a9e97281f27dcaef5c993d73b1 100644
--- a/crates/git_ui/src/project_diff.rs
+++ b/crates/git_ui/src/project_diff.rs
@@ -709,6 +709,10 @@ impl Item for ProjectDiff {
         });
     }
 
+    fn can_split(&self) -> bool {
+        true
+    }
+
     fn clone_on_split(
         &self,
         _workspace_id: Option<workspace::WorkspaceId>,
diff --git a/crates/gpui_tokio/src/gpui_tokio.rs b/crates/gpui_tokio/src/gpui_tokio.rs
index 8384f2a88ec82b96c0490913019b701cdf01239c..61dcfc48efb1dfecc04c4a131ddc32691e01e255 100644
--- a/crates/gpui_tokio/src/gpui_tokio.rs
+++ b/crates/gpui_tokio/src/gpui_tokio.rs
@@ -1,9 +1,10 @@
 use std::future::Future;
 
 use gpui::{App, AppContext, Global, ReadGlobal, Task};
-use tokio::task::JoinError;
 use util::defer;
 
+pub use tokio::task::JoinError;
+
 pub fn init(cx: &mut App) {
     cx.set_global(GlobalTokio::new());
 }
diff --git a/crates/image_viewer/src/image_viewer.rs b/crates/image_viewer/src/image_viewer.rs
index 17259d15f1d81ac2f46e027fcf7889cdbbe9d011..f9a2cc9e045ae67ac7d993250f87cf7ee23789c0 100644
--- a/crates/image_viewer/src/image_viewer.rs
+++ b/crates/image_viewer/src/image_viewer.rs
@@ -174,6 +174,10 @@ impl Item for ImageView {
         }])
     }
 
+    fn can_split(&self) -> bool {
+        true
+    }
+
     fn clone_on_split(
         &self,
         _workspace_id: Option<WorkspaceId>,
diff --git a/crates/language_tools/src/key_context_view.rs b/crates/language_tools/src/key_context_view.rs
index e704d6bbf03eea18ae717f7aa11b25466dd68e9e..cc34838010bfaf8cacd3773a18fde90fbefc105b 100644
--- a/crates/language_tools/src/key_context_view.rs
+++ b/crates/language_tools/src/key_context_view.rs
@@ -153,6 +153,10 @@ impl Item for KeyContextView {
         None
     }
 
+    fn can_split(&self) -> bool {
+        true
+    }
+
     fn clone_on_split(
         &self,
         _workspace_id: Option<workspace::WorkspaceId>,
diff --git a/crates/language_tools/src/lsp_log_view.rs b/crates/language_tools/src/lsp_log_view.rs
index b1e24303c47e722460d20023d4f7444a8b006406..d480eadc73b9546e5a59b204b036a3ff88a018c7 100644
--- a/crates/language_tools/src/lsp_log_view.rs
+++ b/crates/language_tools/src/lsp_log_view.rs
@@ -758,6 +758,10 @@ impl Item for LspLogView {
         }
     }
 
+    fn can_split(&self) -> bool {
+        true
+    }
+
     fn clone_on_split(
         &self,
         _workspace_id: Option<WorkspaceId>,
diff --git a/crates/language_tools/src/syntax_tree_view.rs b/crates/language_tools/src/syntax_tree_view.rs
index 9e5a0374f54f97fc3d75ebc68e2247bf4b904f0c..e2a0cd4c33a93b7806710e68abca6404290808ce 100644
--- a/crates/language_tools/src/syntax_tree_view.rs
+++ b/crates/language_tools/src/syntax_tree_view.rs
@@ -568,6 +568,10 @@ impl Item for SyntaxTreeView {
         None
     }
 
+    fn can_split(&self) -> bool {
+        true
+    }
+
     fn clone_on_split(
         &self,
         _: Option<workspace::WorkspaceId>,
diff --git a/crates/onboarding/src/onboarding.rs b/crates/onboarding/src/onboarding.rs
index 913d92d48c4018759f5ba91bb61d514160ba1b3f..562dea8748eaddad415d7098f6c34f0bea7b5169 100644
--- a/crates/onboarding/src/onboarding.rs
+++ b/crates/onboarding/src/onboarding.rs
@@ -378,6 +378,10 @@ impl Item for Onboarding {
         false
     }
 
+    fn can_split(&self) -> bool {
+        true
+    }
+
     fn clone_on_split(
         &self,
         _workspace_id: Option<WorkspaceId>,
diff --git a/crates/repl/src/notebook/notebook_ui.rs b/crates/repl/src/notebook/notebook_ui.rs
index 209948685ce263361101e508ce6ab65839b132cb..eaeff234bc1a8e21471cee74f98636dfdd995ca4 100644
--- a/crates/repl/src/notebook/notebook_ui.rs
+++ b/crates/repl/src/notebook/notebook_ui.rs
@@ -694,6 +694,10 @@ impl EventEmitter<()> for NotebookEditor {}
 impl Item for NotebookEditor {
     type Event = ();
 
+    fn can_split(&self) -> bool {
+        true
+    }
+
     fn clone_on_split(
         &self,
         _workspace_id: Option<workspace::WorkspaceId>,
diff --git a/crates/search/src/project_search.rs b/crates/search/src/project_search.rs
index 3a9367db724257d4ba32c343c578ba27bea412d7..f407a0a4dbfd00b6515a392f18572c373499d2cc 100644
--- a/crates/search/src/project_search.rs
+++ b/crates/search/src/project_search.rs
@@ -567,6 +567,10 @@ impl Item for ProjectSearchView {
             .update(cx, |editor, cx| editor.reload(project, window, cx))
     }
 
+    fn can_split(&self) -> bool {
+        true
+    }
+
     fn clone_on_split(
         &self,
         _workspace_id: Option<WorkspaceId>,
diff --git a/crates/terminal_view/src/terminal_view.rs b/crates/terminal_view/src/terminal_view.rs
index 5111f3a99b49d35a7f3a7ba141e20d4dc7cc4828..ff169e48e53b01f29ca1ab1682927ea116f320fc 100644
--- a/crates/terminal_view/src/terminal_view.rs
+++ b/crates/terminal_view/src/terminal_view.rs
@@ -1213,6 +1213,10 @@ impl Item for TerminalView {
         workspace::item::ItemBufferKind::Singleton
     }
 
+    fn can_split(&self) -> bool {
+        true
+    }
+
     fn clone_on_split(
         &self,
         workspace_id: Option<WorkspaceId>,
diff --git a/crates/workspace/src/item.rs b/crates/workspace/src/item.rs
index a328bb67924f9be7bcbdc457153699a672fea08b..b77075f92bf69dc292cf69ac7eac147043d7d8b7 100644
--- a/crates/workspace/src/item.rs
+++ b/crates/workspace/src/item.rs
@@ -213,16 +213,21 @@ pub trait Item: Focusable + EventEmitter<Self::Event> + Render + Sized {
         ItemBufferKind::None
     }
     fn set_nav_history(&mut self, _: ItemNavHistory, _window: &mut Window, _: &mut Context<Self>) {}
+
+    fn can_split(&self) -> bool {
+        false
+    }
     fn clone_on_split(
         &self,
-        _workspace_id: Option<WorkspaceId>,
-        _window: &mut Window,
-        _: &mut Context<Self>,
+        workspace_id: Option<WorkspaceId>,
+        window: &mut Window,
+        cx: &mut Context<Self>,
     ) -> Task<Option<Entity<Self>>>
     where
         Self: Sized,
     {
-        Task::ready(None)
+        _ = (workspace_id, window, cx);
+        unimplemented!("clone_on_split() must be implemented if can_split() returns true")
     }
     fn is_dirty(&self, _: &App) -> bool {
         false
@@ -418,6 +423,7 @@ pub trait ItemHandle: 'static + Send {
     );
     fn buffer_kind(&self, cx: &App) -> ItemBufferKind;
     fn boxed_clone(&self) -> Box<dyn ItemHandle>;
+    fn can_split(&self, cx: &App) -> bool;
     fn clone_on_split(
         &self,
         workspace_id: Option<WorkspaceId>,
@@ -631,6 +637,10 @@ impl<T: Item> ItemHandle for Entity<T> {
         Box::new(self.clone())
     }
 
+    fn can_split(&self, cx: &App) -> bool {
+        self.read(cx).can_split()
+    }
+
     fn clone_on_split(
         &self,
         workspace_id: Option<WorkspaceId>,
@@ -1503,6 +1513,10 @@ pub mod test {
             self.push_to_nav_history(cx);
         }
 
+        fn can_split(&self) -> bool {
+            true
+        }
+
         fn clone_on_split(
             &self,
             _workspace_id: Option<WorkspaceId>,
diff --git a/crates/workspace/src/pane.rs b/crates/workspace/src/pane.rs
index 178fbdff9f7a9ef8cf4ee293450e0a5b9ad549b3..9b6767086adffde00a0486b6a9cae62aaa8d41df 100644
--- a/crates/workspace/src/pane.rs
+++ b/crates/workspace/src/pane.rs
@@ -3292,18 +3292,22 @@ impl Pane {
                         else {
                             return;
                         };
-                        let task = item.clone_on_split(database_id, window, cx);
-                        let to_pane = to_pane.downgrade();
-                        cx.spawn_in(window, async move |_, cx| {
-                            if let Some(item) = task.await {
-                                to_pane
-                                    .update_in(cx, |pane, window, cx| {
-                                        pane.add_item(item, true, true, None, window, cx)
-                                    })
-                                    .ok();
-                            }
-                        })
-                        .detach();
+                        if item.can_split(cx) {
+                            let task = item.clone_on_split(database_id, window, cx);
+                            let to_pane = to_pane.downgrade();
+                            cx.spawn_in(window, async move |_, cx| {
+                                if let Some(item) = task.await {
+                                    to_pane
+                                        .update_in(cx, |pane, window, cx| {
+                                            pane.add_item(item, true, true, None, window, cx)
+                                        })
+                                        .ok();
+                                }
+                            })
+                            .detach();
+                        } else {
+                            move_item(&from_pane, &to_pane, item_id, ix, true, window, cx);
+                        }
                     } else {
                         move_item(&from_pane, &to_pane, item_id, ix, true, window, cx);
                     }
@@ -3597,6 +3601,11 @@ fn default_render_tab_bar_buttons(
     if !pane.has_focus(window, cx) && !pane.context_menu_focused(window, cx) {
         return (None, None);
     }
+    let (can_clone, can_split_move) = match pane.active_item() {
+        Some(active_item) if active_item.can_split(cx) => (true, false),
+        Some(_) => (false, pane.items_len() > 1),
+        None => (false, false),
+    };
     // Ideally we would return a vec of elements here to pass directly to the [TabBar]'s
     // `end_slot`, but due to needing a view here that isn't possible.
     let right_children = h_flex()
@@ -3633,17 +3642,26 @@ fn default_render_tab_bar_buttons(
         .child(
             PopoverMenu::new("pane-tab-bar-split")
                 .trigger_with_tooltip(
-                    IconButton::new("split", IconName::Split).icon_size(IconSize::Small),
+                    IconButton::new("split", IconName::Split)
+                        .icon_size(IconSize::Small)
+                        .disabled(!can_clone && !can_split_move),
                     Tooltip::text("Split Pane"),
                 )
                 .anchor(Corner::TopRight)
                 .with_handle(pane.split_item_context_menu_handle.clone())
                 .menu(move |window, cx| {
                     ContextMenu::build(window, cx, |menu, _, _| {
-                        menu.action("Split Right", SplitRight.boxed_clone())
-                            .action("Split Left", SplitLeft.boxed_clone())
-                            .action("Split Up", SplitUp.boxed_clone())
-                            .action("Split Down", SplitDown.boxed_clone())
+                        if can_split_move {
+                            menu.action("Split Right", SplitAndMoveRight.boxed_clone())
+                                .action("Split Left", SplitAndMoveLeft.boxed_clone())
+                                .action("Split Up", SplitAndMoveUp.boxed_clone())
+                                .action("Split Down", SplitAndMoveDown.boxed_clone())
+                        } else {
+                            menu.action("Split Right", SplitRight.boxed_clone())
+                                .action("Split Left", SplitLeft.boxed_clone())
+                                .action("Split Up", SplitUp.boxed_clone())
+                                .action("Split Down", SplitDown.boxed_clone())
+                        }
                     })
                     .into()
                 }),
diff --git a/crates/workspace/src/shared_screen.rs b/crates/workspace/src/shared_screen.rs
index 34c7d27df73b8b832e9b5b23b832a15161644e3a..3c009f613ea52906649b73bb9fd657bab6906c3b 100644
--- a/crates/workspace/src/shared_screen.rs
+++ b/crates/workspace/src/shared_screen.rs
@@ -109,6 +109,10 @@ impl Item for SharedScreen {
         self.nav_history = Some(history);
     }
 
+    fn can_split(&self) -> bool {
+        true
+    }
+
     fn clone_on_split(
         &self,
         _workspace_id: Option<WorkspaceId>,
diff --git a/crates/workspace/src/theme_preview.rs b/crates/workspace/src/theme_preview.rs
index 29067400bd72fe56a62af118a0bea6b52d9356df..94a280b4da1283178201898bd3e8c2c71e5f0b1f 100644
--- a/crates/workspace/src/theme_preview.rs
+++ b/crates/workspace/src/theme_preview.rs
@@ -97,6 +97,10 @@ impl Item for ThemePreview {
         None
     }
 
+    fn can_split(&self) -> bool {
+        true
+    }
+
     fn clone_on_split(
         &self,
         _workspace_id: Option<crate::WorkspaceId>,
diff --git a/crates/workspace/src/workspace.rs b/crates/workspace/src/workspace.rs
index 74c98d6818aff717f215ec92ba848dbba63a9a88..6933a6bcda8baffee618c219c3b05263f11738f5 100644
--- a/crates/workspace/src/workspace.rs
+++ b/crates/workspace/src/workspace.rs
@@ -3663,24 +3663,31 @@ impl Workspace {
         };
 
         if action.clone {
-            clone_active_item(
-                self.database_id(),
-                &self.active_pane,
-                &destination,
-                action.focus,
-                window,
-                cx,
-            )
-        } else {
-            move_active_item(
-                &self.active_pane,
-                &destination,
-                action.focus,
-                true,
-                window,
-                cx,
-            )
+            if self
+                .active_pane
+                .read(cx)
+                .active_item()
+                .is_some_and(|item| item.can_split(cx))
+            {
+                clone_active_item(
+                    self.database_id(),
+                    &self.active_pane,
+                    &destination,
+                    action.focus,
+                    window,
+                    cx,
+                );
+                return;
+            }
         }
+        move_active_item(
+            &self.active_pane,
+            &destination,
+            action.focus,
+            true,
+            window,
+            cx,
+        )
     }
 
     pub fn activate_next_pane(&mut self, window: &mut Window, cx: &mut App) {
@@ -3841,24 +3848,31 @@ impl Workspace {
         };
 
         if action.clone {
-            clone_active_item(
-                self.database_id(),
-                &self.active_pane,
-                &destination,
-                action.focus,
-                window,
-                cx,
-            )
-        } else {
-            move_active_item(
-                &self.active_pane,
-                &destination,
-                action.focus,
-                true,
-                window,
-                cx,
-            );
+            if self
+                .active_pane
+                .read(cx)
+                .active_item()
+                .is_some_and(|item| item.can_split(cx))
+            {
+                clone_active_item(
+                    self.database_id(),
+                    &self.active_pane,
+                    &destination,
+                    action.focus,
+                    window,
+                    cx,
+                );
+                return;
+            }
         }
+        move_active_item(
+            &self.active_pane,
+            &destination,
+            action.focus,
+            true,
+            window,
+            cx,
+        );
     }
 
     pub fn bounding_box_for_pane(&self, pane: &Entity<Pane>) -> Option<Bounds<Pixels>> {
@@ -4141,6 +4155,9 @@ impl Workspace {
         let Some(item) = pane.read(cx).active_item() else {
             return Task::ready(None);
         };
+        if !item.can_split(cx) {
+            return Task::ready(None);
+        }
         let task = item.clone_on_split(self.database_id(), window, cx);
         cx.spawn_in(window, async move |this, cx| {
             if let Some(clone) = task.await {
@@ -8225,6 +8242,9 @@ pub fn clone_active_item(
     let Some(active_item) = source.read(cx).active_item() else {
         return;
     };
+    if !active_item.can_split(cx) {
+        return;
+    }
     let destination = destination.downgrade();
     let task = active_item.clone_on_split(workspace_id, window, cx);
     window
diff --git a/crates/zed/src/zed/component_preview.rs b/crates/zed/src/zed/component_preview.rs
index 153d66f04e0b0aafe4b8d8dd14cedb05f44b496f..d62f39ef6306593eba4b5fe6bff427db036e82dc 100644
--- a/crates/zed/src/zed/component_preview.rs
+++ b/crates/zed/src/zed/component_preview.rs
@@ -715,6 +715,10 @@ impl Item for ComponentPreview {
         false
     }
 
+    fn can_split(&self) -> bool {
+        true
+    }
+
     fn clone_on_split(
         &self,
         _workspace_id: Option<WorkspaceId>,