mcs-on-evm.md

EVM Chains Contract

Contract Address

Here to get MAPO mainnet and testnet MCS contract address.

contract interface

interface EvmChainContract {
    function initialize(address _wToken, address _lightNode)external;
    
    function transferOutToken(address _token, bytes memory _to, uint256 _amount, uint256 _toChain) external;
    
    function transferOutNative(bytes memory _to, uint _toChain) external;
    
    function depositToken(address _token, address _to, uint _amount) external;
    
    function depositNative(address _to) external;
    
    function transferIn(uint256 _chainId, bytes memory _receiptProof) external;
    
    function isBridgeable(address _token, uint256 _toChain) public view returns (bool);
    
    function isMintable(address _token) public view returns (bool);
 
}

User Interface

transferOutToken

Cross-chain transfer out token

function

function transferOutToken(address _token, bytes memory _to, uint256 _amount, uint256 _toChain) external

parameters

parameter	type	comment
_token	address	Token address to transfer tokens from
_to	bytes	The destination chain receiving address of the token to be transferred out
_amount	uint256	Amount of tokens to be transferred
_toChain	uint256	Target chain id to transfer out

transferOutNative

Cross-chain transfer out of the native coin

function

function transferOutNative(bytes memory _to, uint _toChain) external

parameters

parameter	type	comment
_to	bytes	The destination chain receiving address of the token to be transferred out
_toChain	uint256	Target chain to transfer out

depositToken

Deposit token to vault

function

function depositToken(address _token, address _to, uint _amount) external

parameters

parameter	type	comment
_token	address	Token address to transfer tokens from
_to	address	Target chain to transfer out
_amount	uint	Amount of tokens to be deposited

depositNative

Deposit native coin to vault

function

function depositNative(address _to) external

parameters

parameter	type	comment
_to	address	The destination chain receiving address of the token to be transferred out

Messenger Interface

transferIn

Perform cross-chain transfer

function

function transferIn(uint256 _chainId, bytes memory _receiptProof) external

parameters

parameter	type	comment
_chainId	uint256	source chain id
_receiptProof	bytes	source chain transfer proof

Management Interface

initialize

perform initialization

function

function initialize(address _wToken, address _lightNode)public

parameters

parameter	type	comment
_wToken	address	This is wrap contract address
_lightNode	address	This is the LightClient contract address

Data structure

ReceiptProof includes the proof and the receipt to prove.

struct istanbulExtra {
    //Addresses of added committee members
    address[] validators;
    //The public key of the added committee member
    bytes[] addedPubKey;
    //G1 public key of the added committee member
    bytes[] addedG1PubKey;
    //Members removed from the previous committee are removed by bit 1 after binary encoding
    uint256 removeList;
    //The signature of the previous committee on the current header
    //Reference for specific signature and encoding rules
    bytes seal;
    //Information on current committees
    istanbulAggregatedSeal aggregatedSeal;
    //Information on the previous committee
    istanbulAggregatedSeal parentAggregatedSeal;
}

 struct TxReceiptRlp {
     //This is an indication of the type of transaction
     uint256 receiptType;
     // This is the rlp encoded data of the transaction log
     bytes receiptRlp;
 }

struct receiptProof {
    // the block header where the receipt exists
    blockHeader header;
    //the istanbulExtra struct
    istanbulExtra ist;
    // the aggregated G2 public key of the signed validators
    G2 aggPk;
    // the TxReceiptRlp struct
    TxReceiptRlp txReceiptRlp;
    // the index of the receipt in the block
    bytes keyIndex;
    // the proof to prove the existance of the above receipt
    bytes[] proof;
}