That's an interesting question. The simplest way would be listening to state changes in the store and then syncing the state with the server. Since undos/redos are normal redux actions, you can just handle them like any other action in redux.

For example, in an application I wrote, I do `store.subscribe(autoSaveFunction)` which will automatically save all changes to the state. Of course, you can also only store parts of the state, etc, but this is more redux related than redux-undo related.