calibre-server(1) on Linux
The text 3cf57c502211, as Debian 10 (Buster) shipped it.
calibre-server Start the calibre Content server. The calibre Content server exposes your calibre libraries over the internet. You can specify the path to the library folders as arguments to calibre-server. If you do not specify any paths, all the libraries that the main calibre program knows about will be used. Whenever you pass arguments to calibre-server that have spaces in them, enclose the arguments in quotation marks. For example: "/some path/with spaces"