Keep remote directory up to date is unique feature of WinSCP. With it you may let WinSCP watch for changes in a local directory and have it automatically reflect the changes on the selected remote directory.
Using it, you can, with some limitations, work with local files using your favourite tools and the effect would be as if you were working with remote files directly. In other words, the feature partially replaces commercial remote directory drive mapping tools.
Find the function in Commands > Keep Remote Directory Up To Date. The Options dialog will appear.
If you use WinSCP to synchronize your files only, you can use command-line parameter /keepuptodate to quickly open options dialog.
Note that you will be warned if number of subdirectories found exceeds 500. Watching for changes in large number of directories can significantly degrade the performace of your computer.
Once you start the function, WinSCP will register to receive notification whenever something changes in the selected local directory (and optionally in all its subdirectries). Once you make a change, for example when you save file in your favourite editor, WinSCP will receive notification about the change in the respective directory. Then it will perform synchronization of the local directory with the corresponding remote directory. Thus your change will be automatically reflected on the remote side.
WinSCP can even (optionally) delete remote files when you delete local files.
Files and directories excluded from transfer are ignored by the function.
Before using the function you should know that:
For automation, use scripting command keepuptodate.