Discovery

Where vlx looks

vlx lists these directories, one level deep, and keeps only Unix sockets:

Directory	What lives there
/run/varlink/registry	systemd v258+'s registry of public Varlink services
/run/systemd	most io.systemd.* services, PID 1's io.systemd.Manager
/run/systemd/resolve	io.systemd.Resolve, io.systemd.Resolve.Monitor
/run/systemd/userdb	io.systemd.Multiplexer and user database providers
/run/systemd/machine	io.systemd.Machine, io.systemd.MachineImage
/run/systemd/netif	io.systemd.Network
/run/systemd/journal	io.systemd.journal
/run/systemd/oom	io.systemd.ManagedOOM
/run/systemd/report	io.systemd.Metrics providers
/run/udev	io.systemd.Udev
$XDG_RUNTIME_DIR/systemd	your user manager's services
$XDG_RUNTIME_DIR/vlx	the vlx demo service

Add more with --search DIR or search_paths in the config. Sockets reached through several paths (registry symlinks) are listed once.

Discovery only reads directories. It never connects to a socket, and it does not follow symlinked directories. vlx list --probe additionally sends each socket a read-only GetInfo.

How SERVICE resolves

Wherever a command takes SERVICE, vlx tries, in order:

1. A path — anything containing /, such as /run/systemd/io.systemd.Hostname or ./my.sock.
2. A Varlink address — unix:/run/systemd/io.systemd.Hostname (options after ; are ignored).
3. An exact socket name — io.systemd.Hostname.
4. A short name, any case — hostname, Resolve.Monitor.
5. A unique fragment, any case — multiplex matches io.systemd.Multiplexer.

If a fragment matches more than one socket, vlx lists them and asks you to be more specific (exit code 5).