Bundler API

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;

import "@account-abstraction/contracts/interfaces/IEntryPoint.sol";
import "@account-abstraction/contracts/interfaces/UserOperation.sol";

contract UserOpHelper {
    IEntryPoint public immutable entryPoint;

    constructor(address _entryPoint) {
        entryPoint = IEntryPoint(_entryPoint);
    }

    // Encode a simple ETH transfer for UserOp callData
    function encodeTransfer(address to, uint256 value) external pure returns (bytes memory) {
        return abi.encodeWithSignature("execute(address,uint256,bytes)", to, value, "");
    }

    // Encode ERC20 transfer for UserOp callData
    function encodeERC20Transfer(
        address token,
        address to,
        uint256 amount
    ) external pure returns (bytes memory) {
        bytes memory tokenCall = abi.encodeWithSignature("transfer(address,uint256)", to, amount);
        return abi.encodeWithSignature("execute(address,uint256,bytes)", token, 0, tokenCall);
    }

    // Encode batch execution for UserOp callData
    function encodeBatch(
        address[] calldata targets,
        uint256[] calldata values,
        bytes[] calldata datas
    ) external pure returns (bytes memory) {
        return abi.encodeWithSignature(
            "executeBatch(address[],uint256[],bytes[])",
            targets, values, datas
        );
    }

    // Get gas limits for simulation
    function estimateGas(UserOperation calldata userOp) external returns (
        uint256 preVerificationGas,
        uint256 verificationGasLimit,
        uint256 callGasLimit
    ) {
        // Simulate execution to estimate gas
        try entryPoint.simulateValidation(userOp) {}
        catch (bytes memory result) {
            // Parse simulation result for gas estimates
        }
    }

    // Get current nonce for account
    function getNonce(address account) external view returns (uint256) {
        return entryPoint.getNonce(account, 0);
    }
}