ssh-add

Store identity passphrase in keychain

The copy of OpenSSH bundled with macOS exposes a couple of additional options for managing identities:

• --apple-load-keychain (formerly -A, deprecated in Monterey) adds all identities with passphrases stored in Keychain.
• --apple-use-keychain (formerly -K, deprecated in Monterey) stores passphrase in the Keychain.

You can avoid invoking ssh-add -A by adding the following stanza to ~/.ssh/config:

Host *
  IgnoreUnknown UseKeychain
  AddKeysToAgent yes
  UseKeychain yes

Items

Keychain items used for storage of identity passphrases are named SSH: /file/name. The private key filename is also stored in the Account field.