Vim mode (#3936)

packages/cli/src/ui/commands/types.ts

@@ -58,6 +58,7 @@ export interface CommandContext {
     loadHistory: UseHistoryManagerReturn['loadHistory'];
     /** Toggles a special display mode. */
     toggleCorgiMode: () => void;
+    toggleVimEnabled: () => Promise<boolean>;
   };
   // Session-specific data
   session: {

packages/cli/src/ui/commands/vimCommand.ts

@@ -0,0 +1,25 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { CommandKind, SlashCommand } from './types.js';
+
+export const vimCommand: SlashCommand = {
+  name: 'vim',
+  description: 'toggle vim mode on/off',
+  kind: CommandKind.BUILT_IN,
+  action: async (context, _args) => {
+    const newVimState = await context.ui.toggleVimEnabled();
+
+    const message = newVimState
+      ? 'Entered Vim mode. Run /vim again to exit.'
+      : 'Exited Vim mode.';
+    return {
+      type: 'message',
+      messageType: 'info',
+      content: message,
+    };
+  },
+};