How to use SSH agent forwarding on macOS to avoid being prompted for SSH passwords on remote server

Run:

ssh-add --apple-use-keychain ~/.ssh/id_ed25519

Configure your SSH host:

Host <alias>
  HostName <host-ip>
  User <remote-server-user>              
  IdentityFile ~/.ssh/id_ed25519
  IdentitiesOnly yes
  ForwardAgent yes

Now, when you SSH into the server and do something like git pull, you should be spared having to enter passwords.