# Communication between a host page and a JupyterLite instance running in an IFrame
When a JupyterLite instance is embedded in a website via an IFrame, it may be relevant
to establish a communication channel between the host page and the instance.
## Using the `jupyter-iframe-commands` extension
The [jupyter-iframe-commands](https://github.com/TileDB-Inc/jupyter-iframe-commands)
extension is a JupyterLab extension that provides an API to execute JupyterLab commands
from a host page, with JupyterLite embedded in an iframe.
### Installation
Install the extension in your environment:
```bash
pip install jupyter-iframe-commands
```
Then rebuild your JupyterLite site:
```bash
jupyter lite build
```
### Usage
The extension consists of two packages:
1. `jupyter-iframe-commands`: The JupyterLab extension that runs inside the iframe
2. `jupyter-iframe-commands-host`: A JavaScript package for the host page interacting
with the JupyterLite instance
To use the extension in your host page:
```html
JupyterLite in an iframe
JupyterLite with command bridge
```
The `jupyter-iframe-commands` extension provides access to all JupyterLab commands, so
you can control various aspects of the JupyterLite instance, such as:
- Toggling UI elements (sidebars, panels, etc.)
- Creating new notebooks or files
- Changing the theme
For more information, refer to the
[jupyter-iframe-commands repository](https://github.com/TileDB-Inc/jupyter-iframe-commands).
## Exposing additional functionality
If you need additional functionality beyond what the `jupyter-iframe-commands` extension
provides, you can develop your own custom JupyterLab extension. Custom extensions can
implement new commands to expose more functionality to the host page.
For information on developing JupyterLab extensions, refer to the
[JupyterLab Extension Developer Guide](https://jupyterlab.readthedocs.io/en/stable/extension/extension_dev.html).