## *Core App*: FileTransfer
### Note: This app is pre-installed in Cytoscape 3.9 or later
**_You should not download this app_ from the store yourself. If Cytoscape detects that a new version is available in the App Store, it will notify you as it's starting and will give you a chance to download it directly.**
**_You should not download this app_ if your Cytoscape is earlier than 3.9. An earlier version of this app is pre-installed in your Cytoscape, and this app cannot replace it.**
*__Download this app if__ you are creating an automated Cytoscape workflow using Python and [py4cytoscape](https://py4cytoscape.readthedocs.io/en/latest/) in a Jupyter Notebook running on a remote server (e.g., [Google Colab](https://colab.research.google.com/) or [GenePattern Notebook](https://notebook.genepattern.org/)).*
The FileTransfer app supports Cytoscape workflow execution in
a Jupyter Notebook executing on a remote server. Such Notebooks can be
written in Python (via [py4cytoscape](https://github.com/cytoscape/py4cytoscape))
or other languages when/if such support becomes available for them.
To execute a workflow, a remote Notebook must have bi-directional
communication with a workstation-based Cytoscape instance, which is automatically provided
by the [Jupyter-Bridge](https://github.com/cytoscape/jupyter-bridge).
Given this link, the FileTransfer app enables a workflow author to send files (e.g., .cys and .csv) to a Cytoscape workstation, and then fetch Cytoscape files (e.g., png and .pdf) for further analysis. This app is not necessary for workflows executing directly on the Cytoscape workstation where the Python code shares a file system with Cytoscape, but it is crucial for workflows executing on remote servers.
To understand how to execute Cytoscape workflows in a Jupyter Notebook running on a remote server, see [this article](https://py4cytoscape.readthedocs.io/en/latest/concepts.html#jupyter-notebook).
This app has no user interface, and is intended to be called by Jupyter Notebooks via CyREST over Jupyter-Bridge. For more information on this app,
see the [functional documentation in GitHub](https://github.com/cytoscape/file-transfer-app)
or in the Swagger "filetransfer" section accessible from Cytoscape via the **Help | Automation | CyREST Command API** menu.
To understand the sandbox features supported by this app, see [this article](https://py4cytoscape.readthedocs.io/en/latest/concepts.html#sandboxing).
