# toolbar.history

Part of [Toolbar](https://kernstra.com/docs/web-sdk/config/toolbar) in the Kernstra Web SDK 1.0.0 configuration reference.

- Type: `boolean`
- Default: `true`
- Page: https://kernstra.com/docs/web-sdk/config/toolbar/history

Show the Undo and Redo buttons. Off under a license that lets no change happen. `history: false` removes them from every layout; Ctrl / ⌘ + Z still undoes (turn every shortcut off with [`navigation.keyboardShortcuts`](https://kernstra.com/docs/web-sdk/config/navigation/keyboardshortcuts)), and `viewer.undo()` / `viewer.redo()` stay available for your own buttons.

```ts
toolbar: { history: false }
```

Web page: https://kernstra.com/docs/web-sdk/config/toolbar/history