> ## Documentation Index
> Fetch the complete documentation index at: https://docs.theblockchainlibrary.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Multi-Signature Wallet

> A multi-signature wallet requiring M-of-N approvals before executing transactions.

# Multi-Signature Wallet

A multi-signature wallet requiring M-of-N approvals before executing transactions.

A multi-signature wallet requiring M-of-N approvals before executing transactions.

## Explanation

A multisig requires multiple owners to confirm a transaction before it executes. submit creates a transaction, confirm adds approval, and execute runs it once the threshold is met. This is the gold standard for treasury security.

## Code

```solidity theme={null}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;

contract MultiSigWallet {
    address[] public owners;
    mapping(address => bool) public isOwner;
    uint256 public required;

    struct Transaction { address to; uint256 value; bytes data; bool executed; uint256 confirmations; }
    mapping(uint256 => Transaction) public transactions;
    mapping(uint256 => mapping(address => bool)) public confirmed;
    uint256 public txCount;

    event Submit(uint256 indexed txId);
    event Confirm(address indexed sender, uint256 indexed txId);
    event Execute(uint256 indexed txId);

    constructor(address[] memory _owners, uint256 _required) {
        require(_owners.length > 0 && _required > 0 && _required <= _owners.length);
        for (uint256 i = 0; i < _owners.length; i++) {
            isOwner[_owners[i]] = true;
        }
        owners = _owners;
        required = _required;
    }

    function submit(address to, uint256 value, bytes memory data) external {
        require(isOwner[msg.sender], "Not owner");
        transactions[txCount] = Transaction(to, value, data, false, 0);
        emit Submit(txCount++);
    }

    function confirm(uint256 txId) external {
        require(isOwner[msg.sender] && !confirmed[txId][msg.sender]);
        confirmed[txId][msg.sender] = true;
        transactions[txId].confirmations++;
        emit Confirm(msg.sender, txId);
    }

    function execute(uint256 txId) external {
        Transaction storage t = transactions[txId];
        require(!t.executed && t.confirmations >= required, "Not enough confirmations");
        t.executed = true;
        (bool ok,) = t.to.call{value: t.value}(t.data);
        require(ok, "Tx failed");
        emit Execute(txId);
    }
}
```

***

**Canonical knowledge ID:** `code-example:multi-signature-wallet`