How to List Installed Packages Using Snap

I'd like to get a list of packages installed manually by snap and be able to find out whether a foobar package was installed manually by system installer.

For example:

$ snap list
Name Version Rev Tracking Publisher Notes
canonical-livepatch 9.5.5 95 latest/stable canonical✓ -
core 16-2.45.2 9665 latest/stable canonical✓ core
core18 20200707 1880 latest/stable canonical✓ base
discord 0.0.10 109 latest/stable snapcrafters -
gnome-3-28-1804 3.28.0-17-gde3d74c.de3d74c 128 latest/stable canonical✓ -
gnome-3-34-1804 0+git.3009fc7 36 latest/stable/… canonical✓ -
gtk-common-themes 0.1-36-gc75f853 1506 latest/stable/… canonical✓ -
ripgrep 12.1.0 9 latest/stable icey classic
simplenote 1.20.0 368 latest/stable snapcrafters -
slack 4.7.0 25 latest/stable slack✓ classic
snap-store 3.36.0-80-g208fd61 467 latest/stable/… canonical✓ -
snapd 2.45.2 8542 latest/stable canonical✓ snapd
zoom-client 5.1.422789.0705 92 latest/stable ogra -

Here, core, core18 were not manually installed by me (at least not explicitly), so my try was:

$ snap list | grep -v Publisher | grep -v canonical | awk '{print $1}' | tr '\n' ' '
discord ripgrep simplenote slack zoom-client

However, I'm not sure if this is the right way to exclude automatically installed packages. Is there any neat way of doing that from the command line?

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