GAM is pretty sweet if you want to manage Google G Suite from the command line.
I miss
blanche
from MIT's Athena, though, so I
wrote a wrapper for gam's Google Groups functionality that feels very familiar.
It is not feature-complete; I implemented the pieces I needed and left it at
that. PRs very welcome! In particular, you may notice that all mailing lists
are unmoderated, allow external members (invited by list managers), etc. (This
fits, mostly, with the Moira lists blanche was used to manage.)
There's just one file, glanche. gam installs itself to ~/bin/gam/gam, so I
recommend installing gam (see above link) and just dropping glanche in next
to it. glanche will prompt you to create a config file on first run.