Part of macOS
ssh-agentSSH keys
○ Leave it
Holds your SSH keys so you don’t retype passphrases.
What it is
Keeps unlocked SSH keys in memory for Terminal and developer tools.
If you stop it
You’ll be asked for key passphrases again. Leave it.
The verdict
○ Leave it. Part of macOS, or something that starts again by itself. You never need to close these.
In Activity Monitor
ssh-agent
From Procession’s guide, in the words the app shows.