diff --git a/studio-frontend/src/app/app.element.ts b/studio-frontend/src/app/app.element.ts
index e1ce04e..da2ace6 100644
--- a/studio-frontend/src/app/app.element.ts
+++ b/studio-frontend/src/app/app.element.ts
@@ -31,6 +31,8 @@ import "@storyteller/studio-web/transform-toolbar";
 import "./anim-editor.element";
 import "./help.element";
 
+import "./blocking.element";
+
 import "./app.element.scss";
 
 @customElement("app-root")
@@ -149,6 +151,8 @@ export class AppElement extends LitElement {
 				<sts-anim-editor
 					class="timeline v-end h-start h-before-hierarchy"
 				></sts-anim-editor>
+
+				<sts-blocking></sts-blocking>
 			` : nothing}
 
 			<!-- Dialogs and modals -->
diff --git a/studio-frontend/src/app/blocking.element.scss b/studio-frontend/src/app/blocking.element.scss
new file mode 100644
index 0000000..19a9a3d
--- /dev/null
+++ b/studio-frontend/src/app/blocking.element.scss
@@ -0,0 +1,8 @@
+:host {
+	display: grid;
+	grid-template-columns: 1fr 1fr;
+	gap: 1rem;
+	position: absolute;
+	top: 60px;
+	left: 16px;
+}
\ No newline at end of file
diff --git a/studio-frontend/src/app/blocking.element.ts b/studio-frontend/src/app/blocking.element.ts
new file mode 100644
index 0000000..9b88573
--- /dev/null
+++ b/studio-frontend/src/app/blocking.element.ts
@@ -0,0 +1,41 @@
+
+import { LitElement, html, nothing, unsafeCSS } from "lit";
+
+import styles from "./blocking.element.scss?inline";
+import { customElement } from "lit/decorators.js";
+import * as studio from "@storyteller/studio";
+
+@customElement("sts-blocking")
+export class BlockingElement extends LitElement {
+    static override styles = unsafeCSS(styles);
+
+    override render = () => html`
+        <sts-button
+            @click=${() => {
+                studio.dispatchBlockingCommand(studio.BlockingCommand.Cube);
+            }}>
+            Cube
+        </sts-button>
+
+        <sts-button
+            @click=${() => {
+                studio.dispatchBlockingCommand(studio.BlockingCommand.Sphere);
+            }}>
+            Sphere
+        </sts-button>
+
+        <sts-button
+            @click=${() => {
+                studio.dispatchBlockingCommand(studio.BlockingCommand.Cylinder);
+            }}>
+            Cylinder
+        </sts-button>
+
+        <sts-button
+            @click=${() => {
+                studio.dispatchBlockingCommand(studio.BlockingCommand.Torus);
+            }}>
+            Torus
+        </sts-button>
+    `;
+}
\ No newline at end of file
diff --git a/studio/src/ui/blocking.rs b/studio/src/ui/blocking.rs
new file mode 100644
index 0000000..b32a766
--- /dev/null
+++ b/studio/src/ui/blocking.rs
@@ -0,0 +1,83 @@
+use std::sync::Arc;
+
+use bevy::prelude::*;
+use bevy_mod_picking::PickableBundle;
+use space_editor::prelude::{
+    space_undo::{AddedEntity, NewChange},
+    *,
+};
+use wasm_bindgen::prelude::*;
+
+use crate::{
+    interaction::Selectable,
+    scene::SceneElement,
+    wasm::{StaticBuffer, WasmMessageBuffer},
+};
+
+pub struct UiBlockingPlugin;
+
+impl Plugin for UiBlockingPlugin {
+    fn build(&self, app: &mut App) {
+        app.add_systems(Update, read_command_system);
+    }
+}
+
+fn read_command_system(mut commands: Commands, mut change_event: EventWriter<NewChange>) {
+    let Some(cmd) = COMMAND.take_message() else {
+        return;
+    };
+
+    let mut new_entity = commands.spawn((
+        SpatialBundle::default(),
+        PrefabMarker,
+        Selectable,
+        SceneElement::Mesh,
+        PickableBundle::default(),
+    ));
+
+    match cmd {
+        BlockingCommand::Cube => {
+            new_entity
+                .insert(MeshPrimitivePrefab::Cube(1.0))
+                .insert(Name::new("Cube"));
+        }
+        BlockingCommand::Sphere => {
+            new_entity
+                .insert(MeshPrimitivePrefab::Sphere(SpherePrefab { r: 1.0 }))
+                .insert(Name::new("Sphere"));
+        }
+        BlockingCommand::Torus => {
+            new_entity
+                .insert(MeshPrimitivePrefab::Torus(TorusPrefab::default()))
+                .insert(Name::new("Torus"));
+        }
+        BlockingCommand::Cylinder => {
+            new_entity
+                .insert(MeshPrimitivePrefab::Cylinder(CylinderPrefab::default()))
+                .insert(Name::new("Cylinder"));
+        }
+    };
+
+    change_event.send(NewChange {
+        change: Arc::new(AddedEntity {
+            entity: new_entity.id(),
+        }),
+    });
+}
+
+#[derive(Clone, Copy, Debug)]
+#[wasm_bindgen]
+pub enum BlockingCommand {
+    Cube,
+    Sphere,
+    Torus,
+    Cylinder,
+}
+
+static COMMAND: WasmMessageBuffer<BlockingCommand> = WasmMessageBuffer::new();
+
+#[wasm_bindgen(js_name = dispatchBlockingCommand)]
+pub fn dispatch_command(command: BlockingCommand) {
+    info!("Dispatching blocking command: {command:?}");
+    COMMAND.write_message(command);
+}
diff --git a/studio/src/ui/mod.rs b/studio/src/ui/mod.rs
index d3f0385..fa48932 100644
--- a/studio/src/ui/mod.rs
+++ b/studio/src/ui/mod.rs
@@ -4,6 +4,9 @@ use self::fps::FpsCounterPlugin;
 
 mod fps;
 
+#[cfg(feature = "wasm")]
+mod blocking;
+
 #[cfg(feature = "wasm")]
 pub mod inspector;
 
@@ -14,6 +17,9 @@ impl Plugin for UiLayerPlugin {
         app.add_plugins(FpsCounterPlugin);
 
         #[cfg(feature = "wasm")]
-        app.add_plugins(inspector::InspectorPlugin);
+        {
+            app.add_plugins(inspector::InspectorPlugin);
+            app.add_plugins(blocking::UiBlockingPlugin);
+        }
     }
 }