run-script allows you to execute CLI commands (or a script) via REST API.
It's not meant for interactive use (which vpn tu clear is), where SSH + Paramiko might be a better option.
However, it appears the vpn shell commands will give you similar information and, thus, might be better suited for usage with run-script.
As for something that doesn't involve a CLI command (i.e. a native REST API endpoint), one does not appear to exist for this purpose.
In R82, I know we export certain VPN information through OpenTelemetry, but not sure it's what you're looking for.