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MultiSig Wallet

Source Code

Gnosis Safe

Build a Treasury wallet with Gnosis Safe

Variations and Use Cases

Code

The wallet owners can

  • submit a transaction
  • approve and revoke approval of pending transactions
  • anyone can execute a transaction after enough owners has approved it
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.10;

contract MultiSigWallet {
event Deposit(address indexed sender, uint amount, uint balance);
event SubmitTransaction(
address indexed owner,
uint indexed txIndex,
address indexed to,
uint value,
bytes data
);
event ConfirmTransaction(address indexed owner, uint indexed txIndex);
event RevokeConfirmation(address indexed owner, uint indexed txIndex);
event ExecuteTransaction(address indexed owner, uint indexed txIndex);

address[] public owners;
mapping(address => bool) public isOwner;
uint public numConfirmationsRequired;

struct Transaction {
address to;
uint value;
bytes data;
bool executed;
uint numConfirmations;
}

// mapping from tx index => owner => bool
mapping(uint => mapping(address => bool)) public isConfirmed;

Transaction[] public transactions;

modifier onlyOwner() {
require(isOwner[msg.sender], "not owner");
_;
}

modifier txExists(uint _txIndex) {
require(_txIndex < transactions.length, "tx does not exist");
_;
}

modifier notExecuted(uint _txIndex) {
require(!transactions[_txIndex].executed, "tx already executed");
_;
}

modifier notConfirmed(uint _txIndex) {
require(!isConfirmed[_txIndex][msg.sender], "tx already confirmed");
_;
}

constructor(address[] memory _owners, uint _numConfirmationsRequired) {
require(_owners.length > 0, "owners required");
require(
_numConfirmationsRequired > 0 &&
_numConfirmationsRequired <= _owners.length,
"invalid number of required confirmations"
);

for (uint i = 0; i < _owners.length; i++) {
address owner = _owners[i];

require(owner != address(0), "invalid owner");
require(!isOwner[owner], "owner not unique");

isOwner[owner] = true;
owners.push(owner);
}

numConfirmationsRequired = _numConfirmationsRequired;
}

receive() external payable {
emit Deposit(msg.sender, msg.value, address(this).balance);
}

function submitTransaction(
address _to,
uint _value,
bytes memory _data
) public onlyOwner {
uint txIndex = transactions.length;

transactions.push(
Transaction({
to: _to,
value: _value,
data: _data,
executed: false,
numConfirmations: 0
})
);

emit SubmitTransaction(msg.sender, txIndex, _to, _value, _data);
}

function confirmTransaction(uint _txIndex)
public
onlyOwner
txExists(_txIndex)
notExecuted(_txIndex)
notConfirmed(_txIndex)
{
Transaction storage transaction = transactions[_txIndex];
transaction.numConfirmations += 1;
isConfirmed[_txIndex][msg.sender] = true;

emit ConfirmTransaction(msg.sender, _txIndex);
}

function executeTransaction(uint _txIndex)
public
onlyOwner
txExists(_txIndex)
notExecuted(_txIndex)
{
Transaction storage transaction = transactions[_txIndex];

require(
transaction.numConfirmations >= numConfirmationsRequired,
"cannot execute tx"
);

transaction.executed = true;

(bool success, ) = transaction.to.call{value: transaction.value}(
transaction.data
);
require(success, "tx failed");

emit ExecuteTransaction(msg.sender, _txIndex);
}

function revokeConfirmation(uint _txIndex)
public
onlyOwner
txExists(_txIndex)
notExecuted(_txIndex)
{
Transaction storage transaction = transactions[_txIndex];

require(isConfirmed[_txIndex][msg.sender], "tx not confirmed");

transaction.numConfirmations -= 1;
isConfirmed[_txIndex][msg.sender] = false;

emit RevokeConfirmation(msg.sender, _txIndex);
}

function getOwners() public view returns (address[] memory) {
return owners;
}

function getTransactionCount() public view returns (uint) {
return transactions.length;
}

function getTransaction(uint _txIndex)
public
view
returns (
address to,
uint value,
bytes memory data,
bool executed,
uint numConfirmations
)
{
Transaction storage transaction = transactions[_txIndex];

return (
transaction.to,
transaction.value,
transaction.data,
transaction.executed,
transaction.numConfirmations
);
}
}