Diagram data storage and user data flow in Confluence and Jira Cloud
The draw.io apps for Confluence Cloud and Jira Cloud are both static plugins. That means they are delivered as complete web applications to the users' browser and work without needing to contact our servers.
Diagram data is only stored as attachments on pages in your Confluence Cloud instance, or on issues in your Jira Cloud instance and nowhere else. When you save and load diagrams, data transfer occurs only between Atlassian's servers and the users' browser - diagram data does not transit through another server during these operations.
There is one case where data is sent to our *.diagrams.net servers to perform a function the client browser is not capable of: Export to PDF. The operation is performed, the result returned and both the input and output are not persisted in any way.
Tip: If you want to disable all communication except between the user's browser and the location where it is stored in your Atlassian product (draw.io advanced edition only), set lockdown to true.