diff --git a/src/index.ts b/src/index.ts
index 6f8c0e49..a67d96b9 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -7,10 +7,16 @@
 import * as Blockly from 'blockly/core';
 import {NavigationController} from './navigation_controller';
 import {CursorOptions, LineCursor} from './line_cursor';
+import * as Constants from './constants';
+
+export interface ExternalToolbox {
+  focus(): void;
+}
 
 /** Options object for KeyboardNavigation instances. */
 export type NavigationOptions = {
-  cursor: Partial<CursorOptions>;
+  cursor?: Partial<CursorOptions>;
+  externalToolbox?: ExternalToolbox;
 };
 
 /** Default options for LineCursor instances. */
@@ -22,6 +28,12 @@ const defaultOptions: NavigationOptions = {
 export class KeyboardNavigation {
   /** The workspace. */
   protected workspace: Blockly.WorkspaceSvg;
+  /**
+   * Workaround: Tracks when we're focusing the workspace just to get flyout
+   * keyboard navigation working. In this case we need to avoid resetting the
+   * flyout. In future, we hope the flyout can take focus.
+   */
+  private focusingWorkspaceForFlyoutKeyboardNavigation = false;
 
   /** Event handler run when the workspace gains focus. */
   private focusListener: () => void;
@@ -48,17 +60,15 @@ export class KeyboardNavigation {
    *
    * @param workspace The workspace that the plugin will
    *     be added to.
+   * @param options Options.
    */
-  constructor(
-    workspace: Blockly.WorkspaceSvg,
-    options: Partial<NavigationOptions>,
-  ) {
+  constructor(workspace: Blockly.WorkspaceSvg, options: NavigationOptions) {
     this.workspace = workspace;
 
     // Regularise options and apply defaults.
     options = {...defaultOptions, ...options};
 
-    this.navigationController = new NavigationController();
+    this.navigationController = new NavigationController(options);
     this.navigationController.init();
     this.navigationController.addWorkspace(workspace);
     this.navigationController.enable(workspace);
@@ -82,7 +92,11 @@ export class KeyboardNavigation {
     workspace.getParentSvg().setAttribute('tabindex', '-1');
 
     this.focusListener = () => {
-      this.navigationController.setHasFocus(workspace, true);
+      this.navigationController.setHasFocus(
+        workspace,
+        true,
+        this.focusingWorkspaceForFlyoutKeyboardNavigation,
+      );
     };
     this.blurListener = () => {
       this.navigationController.setHasFocus(workspace, false);
@@ -137,6 +151,29 @@ export class KeyboardNavigation {
     this.navigationController.dispose();
   }
 
+  /**
+   * Focus the flyout if open.
+   *
+   * Generally not required if Blockly manages your toolbox.
+   */
+  focusFlyout(): void {
+    this.navigationController.navigation.focusFlyout(this.workspace);
+    this.focusingWorkspaceForFlyoutKeyboardNavigation = true;
+    (this.workspace.getSvgGroup() as SVGElement).focus();
+    this.focusingWorkspaceForFlyoutKeyboardNavigation = false;
+  }
+
+  /**
+   * Called when an external toolbox loses the focus.
+   */
+  onExternalToolboxBlur(): void {
+    if (
+      this.navigationController.navigation.getState(this.workspace) !==
+      Constants.STATE.FLYOUT
+    ) {
+      this.navigationController.navigation.resetFlyout(this.workspace, true);
+    }
+
   /**
    * Toggle visibility of a help dialog for the keyboard shortcuts.
    */
diff --git a/src/navigation.ts b/src/navigation.ts
index 1d44c9c6..5f002874 100644
--- a/src/navigation.ts
+++ b/src/navigation.ts
@@ -17,6 +17,7 @@ import {
   registrationType as cursorRegistrationType,
   FlyoutCursor,
 } from './flyout_cursor';
+import {NavigationOptions} from './index';
 import {PassiveFocus} from './passive_focus';
 
 /**
@@ -76,8 +77,9 @@ export class Navigation {
 
   /**
    * Constructor for keyboard navigation.
+   * @param options Options.
    */
-  constructor() {
+  constructor(private options: NavigationOptions) {
     this.wsChangeWrapper = this.workspaceChangeListener.bind(this);
     this.flyoutChangeWrapper = this.flyoutChangeListener.bind(this);
   }
@@ -419,7 +421,9 @@ export class Navigation {
     this.setState(workspace, Constants.STATE.TOOLBOX);
     this.resetFlyout(workspace, false /* shouldHide */);
 
-    if (!toolbox.getSelectedItem()) {
+    if (this.options.externalToolbox) {
+      this.options.externalToolbox.focus();
+    } else if (!toolbox.getSelectedItem()) {
       // Find the first item that is selectable.
       const toolboxItems = (toolbox as any).getToolboxItems();
       for (let i = 0, toolboxItem; (toolboxItem = toolboxItems[i]); i++) {
diff --git a/src/navigation_controller.ts b/src/navigation_controller.ts
index 724799c3..d369e954 100644
--- a/src/navigation_controller.ts
+++ b/src/navigation_controller.ts
@@ -23,6 +23,7 @@ import {
 
 import * as Constants from './constants';
 import {Navigation} from './navigation';
+import {NavigationOptions} from './index';
 import {Announcer} from './announcer';
 import {LineCursor} from './line_cursor';
 import {ShortcutDialog} from './shortcut_dialog';
@@ -40,26 +41,17 @@ const createSerializedKey = ShortcutRegistry.registry.createSerializedKey.bind(
  * Class for registering shortcuts for keyboard navigation.
  */
 export class NavigationController {
-  navigation: Navigation = new Navigation();
+  navigation: Navigation;
   announcer: Announcer = new Announcer();
   shortcutDialog: ShortcutDialog = new ShortcutDialog();
 
   /** Context menu and keyboard action for deletion. */
-  deleteAction: DeleteAction = new DeleteAction(
-    this.navigation,
-    this.canCurrentlyEdit.bind(this),
-  );
+  deleteAction: DeleteAction;
 
   /** Context menu and keyboard action for insertion. */
-  insertAction: InsertAction = new InsertAction(
-    this.navigation,
-    this.canCurrentlyEdit.bind(this),
-  );
+  insertAction: InsertAction;
 
-  clipboard: Clipboard = new Clipboard(
-    this.navigation,
-    this.canCurrentlyEdit.bind(this),
-  );
+  clipboard: Clipboard;
 
   workspaceMovement: WorkspaceMovement = new WorkspaceMovement(
     this.canCurrentlyEdit.bind(this),
@@ -75,6 +67,25 @@ export class NavigationController {
     | typeof Blockly.Toolbox.prototype.onShortcut
     | null = null;
 
+  constructor(options: NavigationOptions) {
+    this.navigation = new Navigation(options);
+
+    this.deleteAction = new DeleteAction(
+      this.navigation,
+      this.canCurrentlyEdit.bind(this),
+    );
+
+    this.insertAction = new InsertAction(
+      this.navigation,
+      this.canCurrentlyEdit.bind(this),
+    );
+
+    this.clipboard = new Clipboard(
+      this.navigation,
+      this.canCurrentlyEdit.bind(this),
+    );
+  }
+
   /**
    * Registers the default keyboard shortcuts for keyboard navigation.
    */
@@ -162,10 +173,15 @@ export class NavigationController {
    *
    * @param workspace the workspace that now has input focus.
    * @param isFocused whether the environment has browser focus.
+   * @param isFocusedForFlyoutKeyboardNavigation avoid workspace modifications.
    */
-  setHasFocus(workspace: WorkspaceSvg, isFocused: boolean) {
+  setHasFocus(
+    workspace: WorkspaceSvg,
+    isFocused: boolean,
+    isFocusedForFlyoutKeyboardNavigation = false,
+  ) {
     this.hasNavigationFocus = isFocused;
-    if (isFocused) {
+    if (isFocused && !isFocusedForFlyoutKeyboardNavigation) {
       this.navigation.focusWorkspace(workspace, true);
     }
   }