Contract

The Account Linking contracts manage ChildAccounts to permit hybrid custody in scenarios where apps only want to share a subset of resources on their accounts with various parents. In many cases, this will be a user's primary wallet outside of the application a child account came from.

You can see the docs for account linking here

Network	Contract Address
Testnet/Crescendo	0x294e44e1ec6993c6
Mainnet	0xd8a7e05a7ac670c0