Sorry if it is, but I couldn’t find that mentioned in the doc.
How can I serve bk repos from my own server (Windows or OSX ideally)?
Is there something like bkbits.net freely available?
The server that you run to host your repo is called a bk bkd. That man page I linked has instructions on how to start it.
On Windows, we also have a bk service command that wraps the bkd in a Windows service so it runs is the background and restarts when you reboot.