Unison uses LayerZero's cross-chain messaging.The following contracts are the part of unison's architecture.
Forwarder : The forwarder contract enables users from any chain to deposit into vault, using Stargate bridge. Deposits are batched and transferred to vault, reducing gas consumption.
Vault : The vault contract is hosted on Arbitrum, this is central part of the protocol where all assets are deposited and further deployed. The strategies from all chains report to vault on various metrics.
Strategies : Strategies deploy assets to major protocols across the ecosystem of all supported chains, and then harvests the rewards to auto-compound it's yield.
Withdrawal : The users initiates withdrawal from the Unison app, which then triggers the vault with parameters about amount.If vault has enough free-funds, the withdrawal takes place instantly between vault and the user. In case of insufficient free-funds, it informs the strategy one by one with the amount needed and withdrawal takes place based on impact on APR, and finally routes it back to user's wallet.