Also, "gar nichts". But we would say gar nix for short.
(I know Amis people [1], but don't think it would be relevant here).
> (informal, mildly derogatory) Yank, Yankee, American (native or inhabitant of the USA)
"Ami – go home!" is a popular enough slogan that it has it's own Wikipedia entry[1], unsurprisingly only in German and French.
[1] https://de.m.wikipedia.org/wiki/Ami_–_go_home!
EDIT: For some reason the link doesn't work on HN. Either copy and paste "https://de.m.wikipedia.org/wiki/Ami_–_go_home!" or use https://bit.ly/3CZXNxh
It was in fact from the German. I like the suggestion that the CI should feel like "nothing at all" (rather than the painful slow trial-and-error process of setting up most CIs, which makes you very much aware of them).
I also happen to live very near where Marlene Dietrich lived, who has a famous song in which "und sonst gar nichts/nix" is the refrain ("and nothing else") [0]. When garnix becomes a noun of its own, as here, it reads instead as "and otherwise, garnix", which I find mildly funny.