Your smart wallet is secured by your passkey, which does not generally require a backup if you set up your passkey using a cloud-based method such as iCloud keychain, Google password manager, or a password manager such as 1Password. However, certain passkey methods are associated with your device, and are not accessible if the device is lost.
Smart wallet allows you to set up a recovery key to prevent lost access to a passkey either through deletion or device loss (in case of a hardware, Chrome profile or Windows Hello based passkey). This recovery key generates a new signer onchain that can add a new passkey and recover your wallet in the event of an emergency.
Generate a recovery key
Go to keys.coinbase.com/settings/account-recovery.
If you're not signed in to your smart wallet yet, first go to wallet.coinbase.com and select Connect -> Coinbase Wallet -> Smart wallet -> I already have a wallet, then sign in with your passkey.
Set up a recovery key by signing the transaction and paying for the network fee.
Store the recovery key somewhere safe, and don’t close the window until you do. Coinbase does not have any access to your recovery key, and sharing it with anyone will give them access to your account and the ability to remove you as an original owner. We recommend storing it in a safe place and not sharing it with anyone, ever.
Restore a wallet using a recovery key
Go to keys.coinbase.com/settings, and if you are already signed in, select sign out.
Enter your recovery key.
You will be asked to set up a new passkey.
Pay the network fee.
You now have restored access to your wallet and have a new passkey.
Since the wallet itself is a smart contract, any signer change including generation of a recovery key is subject to a network fee. The network fee must be paid once for each chain in use.