diff --git a/frontend/src/lib/components/sessions/PreviewTabHost.svelte b/frontend/src/lib/components/sessions/PreviewTabHost.svelte
index fcd1aeeed2..fdb0ca5731 100644
--- a/frontend/src/lib/components/sessions/PreviewTabHost.svelte
+++ b/frontend/src/lib/components/sessions/PreviewTabHost.svelte
@@ -334,6 +334,7 @@
 		bind:this={overlayHostEl}
 		class="absolute inset-0 flex flex-col min-h-0 bg-surface {visibility}"
 		aria-hidden={!active}
+		inert={permissions.moveStarted}
 	>
 		<!-- Only the side the tab shows is mounted. A hidden editor would be a second editor on
 		     the item's one cell that tab dedupe, reading URLs, cannot see; a hidden side's drawers
@@ -439,6 +440,7 @@
 		bind:this={overlayHostEl}
 		class="absolute inset-0 flex flex-col min-h-0 bg-surface {visibility}"
 		aria-hidden={!active}
+		inert={permissions.moveStarted}
 	>
 		<!-- Waits for the host element, as the run form does: the editors' own drawers and
 		     modals portal when they mount, and resolve their host only then. -->
@@ -455,6 +457,7 @@
 		bind:this={overlayHostEl}
 		class="absolute inset-0 flex flex-col min-h-0 bg-surface {visibility}"
 		aria-hidden={!active}
+		inert={permissions.moveStarted}
 	>
 		{#if overlayHostEl}
 			{#await import('./PageListView.svelte')}
@@ -476,6 +479,7 @@
 		bind:this={overlayHostEl}
 		class="absolute inset-0 flex flex-col min-h-0 bg-surface {visibility}"
 		aria-hidden={!active}
+		inert={permissions.moveStarted}
 	>
 		{#if overlayHostEl}
 			{#await import('./RunViewerView.svelte')}
@@ -499,6 +503,7 @@
 		bind:this={overlayHostEl}
 		class="absolute inset-0 flex flex-col min-h-0 bg-surface {visibility}"
 		aria-hidden={!active}
+		inert={permissions.moveStarted}
 	>
 		{#if artifact && runtime}
 			<ArtifactViewer
@@ -516,6 +521,7 @@
 		bind:this={overlayHostEl}
 		class="absolute inset-0 flex flex-col min-h-0 bg-surface {visibility}"
 		aria-hidden={!active}
+		inert={permissions.moveStarted}
 	>
 		<!-- Waits for the host element itself: Drawer portals when it mounts, and the portal
 		     action reads its target once, so a form mounted in the same pass as this div would
diff --git a/frontend/src/lib/components/sessions/sessionPermissions.svelte.ts b/frontend/src/lib/components/sessions/sessionPermissions.svelte.ts
index cd84eee925..e2524e3c0f 100644
--- a/frontend/src/lib/components/sessions/sessionPermissions.svelte.ts
+++ b/frontend/src/lib/components/sessions/sessionPermissions.svelte.ts
@@ -42,7 +42,11 @@ export function useSessionReadOnly(workspace: () => string | undefined) {
 }
 
 /** The session chat whose work mode the session UI follows. */
-type WorkModeHost = { readonly workMode: AIWorkMode; readonly moving?: boolean }
+type WorkModeHost = {
+	readonly workMode: AIWorkMode
+	readonly moving?: boolean
+	readonly moveStarted?: boolean
+}
 
 /**
  * What the session UI may offer in `workspace`. Its editors save drafts, so it reads
@@ -70,6 +74,7 @@ export function useSessionPermissions(
 			host?.workMode === AIWorkMode.USE
 	)
 	const moving = $derived(!!host?.moving)
+	const moveStarted = $derived(!!host?.moveStarted)
 	const workspaces = fromStore(userWorkspaces)
 	const entry = $derived(workspaces.current.find((w) => w.id === workspace()))
 
@@ -82,6 +87,12 @@ export function useSessionPermissions(
 		get moving() {
 			return moving
 		},
+		/** A move has started: the preview takes no more input, so what its editors hold can be
+		 * drained before `moving` closes them. A keystroke after the drain would be lost with the
+		 * editor. */
+		get moveStarted() {
+			return moveStarted
+		},
 		/** Whether this user can save the drafts the `kind` editor writes. */
 		canOpenEditor: (kind: string) => !readOnly && !moving && rights.roleCanDraft(kind),
 		/** The same, and this item's own permissions let them write it. */