AA 4337 Wallet https://x.com/i/grok/share/UMpepPjqcgAfZyqwT0y1qsVl0

AAWallet.sol

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

import "@openzeppelin/contracts/utils/cryptography/ECDSA.sol";
import "@openzeppelin/contracts/interfaces/IERC1271.sol";
import "./IEntryPoint.sol";

// Simple Account Abstraction wallet with passkey-based signature verification
contract AAWallet is IERC1271 {
    using ECDSA for bytes32;

    // Owner's public key (or passkey-derived public key)
    address public immutable owner;
    // EntryPoint contract address
    IEntryPoint public immutable entryPoint;
    // Nonce for replay protection
    uint256 public nonce;

    // Events
    event TransactionExecuted(address indexed target, uint256 value, bytes data);
    event OwnershipTransferred(address indexed oldOwner, address indexed newOwner);

    // Errors
    error Unauthorized();
    error InvalidSignature();
    error InvalidEntryPoint();
    error ExecutionFailed();

    // Constructor: Initialize owner and EntryPoint
    constructor(address _owner, address _entryPoint) {
        owner = _owner;
        entryPoint = IEntryPoint(_entryPoint);
    }

    // Modifier to restrict access to EntryPoint
    modifier onlyEntryPoint() {
        if (msg.sender != address(entryPoint)) {
            revert InvalidEntryPoint();
        }
        _;
    }

    // Fallback function to receive ETH
    receive() external payable {}

    // Validate UserOperation (called by EntryPoint)
    function validateUserOp(
        UserOperation calldata userOp,
        bytes32 userOpHash,
        uint256 missingAccountFunds
    ) external onlyEntryPoint returns (uint256 validationData) {
        // Verify passkey signature
        if (!_verifySignature(userOpHash, userOp.signature)) {
            revert InvalidSignature();
        }

        // Increment nonce
        nonce++;

        // Pay prefunded gas if needed
        if (missingAccountFunds > 0) {
            (bool success, ) = payable(msg.sender).call{value: missingAccountFunds}("");
            require(success, "Funding failed");
        }

        // Return 0 for valid signature
        return 0;
    }

    // Execute transaction (called by EntryPoint)
    function execute(
        address target,
        uint256 value,
        bytes calldata data
    ) external onlyEntryPoint {
        (bool success, ) = target.call{value: value}(data);
        if (!success) {
            revert ExecutionFailed();
        }
        emit TransactionExecuted(target, value, data);
    }

    // Verify passkey signature (ECDSA-based)
    function _verifySignature(bytes32 hash, bytes memory signature) internal view returns (bool) {
        bytes32 ethSignedHash = hash.toEthSignedMessageHash();
        address signer = ethSignedHash.recover(signature);
        return signer == owner;
    }

    // IERC1271: Validate signature for smart contract wallets
    function isValidSignature(
        bytes32 hash,
        bytes memory signature
    ) external view override returns (bytes4 magicValue) {
        if (_verifySignature(hash, signature)) {
            return 0x1626ba7e; // IERC1271 magic value
        }
        return 0xffffffff;
    }

    // Transfer ownership to a new passkey-derived public key
    function transferOwnership(address newOwner) external {
        if (msg.sender != address(this)) {
            revert Unauthorized();
        }
        emit OwnershipTransferred(owner, newOwner);
        // Note: Owner is immutable, so this would require a new deployment or a proxy pattern
    }

    // Get current nonce
    function getNonce() external view returns (uint256) {
        return nonce;
    }
}

// Minimal ERC-4337 UserOperation struct
struct UserOperation {
    address sender;
    uint256 nonce;
    bytes initCode;
    bytes callData;
    uint256 callGasLimit;
    uint256 verificationGasLimit;
    uint256 preVerificationGas;
    uint256 maxFeePerGas;
    uint256 maxPriorityFeePerGas;
    bytes paymasterAndData;
    bytes signature;
}

// IEntryPoint interface (simplified)
interface IEntryPoint {
    function handleOps(UserOperation[] calldata ops, address payable beneficiary) external;
}