How it stores things

Each variable is one keyring item carrying two attributes: service is monkeys, and account is <profile>/<NAME>, or <NAME> alone in the personal profile. The label is monkeys: followed by the account. Your desktop's own keyring tools see the same items, and deleting one there deletes it for monkeys.

On macOS that is a generic password in the login keychain. Search Keychain Access for monkeys, or ask for one by name:

security find-generic-password -s monkeys -a OPENROUTER_API_KEY
security find-generic-password -s monkeys -a foo/OPENROUTER_API_KEY

Items are created with kSecAttrAccessibleAfterFirstUnlock, so a shell that starts while the screen is locked can still read them.

On Linux the same attributes go to the Secret Service D-Bus API through secret-tool, which is gnome-keyring on most desktops and KWallet on KDE:

secret-tool lookup service monkeys account foo/OPENROUTER_API_KEY