##Ronin-Smart-Contracts
The smart contracts that power Ronin.
Only validators can produce blocks on Ronin. Validators can also acknowledge deposit and withdrawal events to facilitate asset transfers.
Each validator contract has a minimum threshold that must be reached when the state changes such as transfer of assets and addition/removal of validators. There is one validator contract on Ethereum and a corresponding validator contract on Ronin. An admin has the right to manage validators on Ethereum (in the future this will be upgraded to a multi-sig walllet). These changes are relayed to Ronin through the Bridge component.
When an event happens on Ethereum, the Bridge component in each validator node will pick it up and relay it to Ronin by sending a corresponding transaction.
Depending on the action, these transactions will be relayed to SideChainValidator (changes in the validator list/updates to the consensus threshold) or SidechainGatewayManager (deposits, withdrawals).
If there are enough acknowledgements (# of acknowledgement/# of validator >= ratio), the event will be confirmed on Ronin.
An admin account will need to send a transaction to add the new validator to MainchainValidator. Next, the Bridge in each validator node will acknowledge and approve the new validator. After having enough acknowledgements, the new validator can start proposing blocks.
Users can deposit ETH, ERC20, and ERC721 (NFTs) by sending transactions to MainchainGatewayManager and waiting for the deposit to be verified on Ronin. The gateway should have a mapping between token contracts on Ethereum and on Ronin before the deposit can take place.
Similar to deposits, there should be token mapping between Ronin and Ethereum before users can withdraw. However, instead of sending a relay transaction on Ethereum, the validators simply provide a signature that the withdrawal event has taken place. The withdrawal then needs to collect enough signatures before it can be claimed by the user on Ethereum.