#linuxhint - automatic opening of kde vaults on login
first step is to make your vault with #gocryptfs for example for ~/Documents. then create an entry in #kwallet by creating a password in your "Passwords"-group (create it too if not present) named "vaultpass" and enter the password you used for ~/Documents. then create a bash script and let it autostart:
gocryptfs --extpass="kwallet-query -f Passwords -r vaultpass kdewallet" [.enc folder] ~/Documents

have fun :)

https://github.com/rfjakob/gocryptfs/wiki/Mounting-on-login-with-KDE-Wallet