It runs locally. Through UI, there is also a way to connect your host to a control plane if you want to visualize and monitor the transfer, but that part is optional. I found it useful to track and monitor all my previous transfers.
The tool currently supports a variety of connectors. If something is missing, connectors are easy to add here: https://github.com/Polign/vector-transfer/blob/main/CONTRIBU...
I would love to have some feedback, or any features/performance stuff worth updating.