Sepolia Testnet

Contract

0xF0069856AF5214Bc7E37701d1A13634E9ddeDF8c

Overview

ETH Balance

0 ETH

Multichain Info

N/A
Transaction Hash
Method
Block
From
To
0x6101206039337582023-07-21 2:37:12363 days ago1689907032IN
 Contract Creation
0 ETH0.003347413.00000006

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Similar Match Source Code
This contract matches the deployed Bytecode of the Source Code for Contract 0xBffC7ed4...417C05c3f
The constructor portion of the code might be different and could alter the actual behaviour of the contract

Contract Name:
L1ERC721Bridge

Compiler Version
v0.8.15+commit.e14f2714

Optimization Enabled:
Yes with 999999 runs

Other Settings:
default evmVersion

Contract Source Code (Solidity Standard Json-Input format)

File 1 of 27 : L1ERC721Bridge.sol
// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;

import { ERC721Bridge } from "../universal/ERC721Bridge.sol";
import { IERC721 } from "@openzeppelin/contracts/token/ERC721/IERC721.sol";
import { L2ERC721Bridge } from "../L2/L2ERC721Bridge.sol";
import { Semver } from "../universal/Semver.sol";

/**
 * @title L1ERC721Bridge
 * @notice The L1 ERC721 bridge is a contract which works together with the L2 ERC721 bridge to
 *         make it possible to transfer ERC721 tokens from Ethereum to Optimism. This contract
 *         acts as an escrow for ERC721 tokens deposited into L2.
 */
contract L1ERC721Bridge is ERC721Bridge, Semver {
    /**
     * @notice Mapping of L1 token to L2 token to ID to boolean, indicating if the given L1 token
     *         by ID was deposited for a given L2 token.
     */
    mapping(address => mapping(address => mapping(uint256 => bool))) public deposits;

    /**
     * @custom:semver 1.1.1
     *
     * @param _messenger   Address of the CrossDomainMessenger on this network.
     * @param _otherBridge Address of the ERC721 bridge on the other network.
     */
    constructor(address _messenger, address _otherBridge)
        Semver(1, 1, 1)
        ERC721Bridge(_messenger, _otherBridge)
    {}

    /**
     * @notice Completes an ERC721 bridge from the other domain and sends the ERC721 token to the
     *         recipient on this domain.
     *
     * @param _localToken  Address of the ERC721 token on this domain.
     * @param _remoteToken Address of the ERC721 token on the other domain.
     * @param _from        Address that triggered the bridge on the other domain.
     * @param _to          Address to receive the token on this domain.
     * @param _tokenId     ID of the token being deposited.
     * @param _extraData   Optional data to forward to L2. Data supplied here will not be used to
     *                     execute any code on L2 and is only emitted as extra data for the
     *                     convenience of off-chain tooling.
     */
    function finalizeBridgeERC721(
        address _localToken,
        address _remoteToken,
        address _from,
        address _to,
        uint256 _tokenId,
        bytes calldata _extraData
    ) external onlyOtherBridge {
        require(_localToken != address(this), "L1ERC721Bridge: local token cannot be self");

        // Checks that the L1/L2 NFT pair has a token ID that is escrowed in the L1 Bridge.
        require(
            deposits[_localToken][_remoteToken][_tokenId] == true,
            "L1ERC721Bridge: Token ID is not escrowed in the L1 Bridge"
        );

        // Mark that the token ID for this L1/L2 token pair is no longer escrowed in the L1
        // Bridge.
        deposits[_localToken][_remoteToken][_tokenId] = false;

        // When a withdrawal is finalized on L1, the L1 Bridge transfers the NFT to the
        // withdrawer.
        IERC721(_localToken).safeTransferFrom(address(this), _to, _tokenId);

        // slither-disable-next-line reentrancy-events
        emit ERC721BridgeFinalized(_localToken, _remoteToken, _from, _to, _tokenId, _extraData);
    }

    /**
     * @inheritdoc ERC721Bridge
     */
    function _initiateBridgeERC721(
        address _localToken,
        address _remoteToken,
        address _from,
        address _to,
        uint256 _tokenId,
        uint32 _minGasLimit,
        bytes calldata _extraData
    ) internal override {
        require(_remoteToken != address(0), "L1ERC721Bridge: remote token cannot be address(0)");

        // Construct calldata for _l2Token.finalizeBridgeERC721(_to, _tokenId)
        bytes memory message = abi.encodeWithSelector(
            L2ERC721Bridge.finalizeBridgeERC721.selector,
            _remoteToken,
            _localToken,
            _from,
            _to,
            _tokenId,
            _extraData
        );

        // Lock token into bridge
        deposits[_localToken][_remoteToken][_tokenId] = true;
        IERC721(_localToken).transferFrom(_from, address(this), _tokenId);

        // Send calldata into L2
        MESSENGER.sendMessage(OTHER_BRIDGE, message, _minGasLimit);
        emit ERC721BridgeInitiated(_localToken, _remoteToken, _from, _to, _tokenId, _extraData);
    }
}

File 2 of 27 : Initializable.sol
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (proxy/utils/Initializable.sol)

pragma solidity ^0.8.2;

import "../../utils/AddressUpgradeable.sol";

/**
 * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
 * behind a proxy. Since proxied contracts do not make use of a constructor, it's common to move constructor logic to an
 * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
 * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
 *
 * The initialization functions use a version number. Once a version number is used, it is consumed and cannot be
 * reused. This mechanism prevents re-execution of each "step" but allows the creation of new initialization steps in
 * case an upgrade adds a module that needs to be initialized.
 *
 * For example:
 *
 * [.hljs-theme-light.nopadding]
 * ```
 * contract MyToken is ERC20Upgradeable {
 *     function initialize() initializer public {
 *         __ERC20_init("MyToken", "MTK");
 *     }
 * }
 * contract MyTokenV2 is MyToken, ERC20PermitUpgradeable {
 *     function initializeV2() reinitializer(2) public {
 *         __ERC20Permit_init("MyToken");
 *     }
 * }
 * ```
 *
 * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
 * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.
 *
 * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
 * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
 *
 * [CAUTION]
 * ====
 * Avoid leaving a contract uninitialized.
 *
 * An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation
 * contract, which may impact the proxy. To prevent the implementation contract from being used, you should invoke
 * the {_disableInitializers} function in the constructor to automatically lock it when it is deployed:
 *
 * [.hljs-theme-light.nopadding]
 * ```
 * /// @custom:oz-upgrades-unsafe-allow constructor
 * constructor() {
 *     _disableInitializers();
 * }
 * ```
 * ====
 */
abstract contract Initializable {
    /**
     * @dev Indicates that the contract has been initialized.
     * @custom:oz-retyped-from bool
     */
    uint8 private _initialized;

    /**
     * @dev Indicates that the contract is in the process of being initialized.
     */
    bool private _initializing;

    /**
     * @dev Triggered when the contract has been initialized or reinitialized.
     */
    event Initialized(uint8 version);

    /**
     * @dev A modifier that defines a protected initializer function that can be invoked at most once. In its scope,
     * `onlyInitializing` functions can be used to initialize parent contracts. Equivalent to `reinitializer(1)`.
     */
    modifier initializer() {
        bool isTopLevelCall = !_initializing;
        require(
            (isTopLevelCall && _initialized < 1) || (!AddressUpgradeable.isContract(address(this)) && _initialized == 1),
            "Initializable: contract is already initialized"
        );
        _initialized = 1;
        if (isTopLevelCall) {
            _initializing = true;
        }
        _;
        if (isTopLevelCall) {
            _initializing = false;
            emit Initialized(1);
        }
    }

    /**
     * @dev A modifier that defines a protected reinitializer function that can be invoked at most once, and only if the
     * contract hasn't been initialized to a greater version before. In its scope, `onlyInitializing` functions can be
     * used to initialize parent contracts.
     *
     * `initializer` is equivalent to `reinitializer(1)`, so a reinitializer may be used after the original
     * initialization step. This is essential to configure modules that are added through upgrades and that require
     * initialization.
     *
     * Note that versions can jump in increments greater than 1; this implies that if multiple reinitializers coexist in
     * a contract, executing them in the right order is up to the developer or operator.
     */
    modifier reinitializer(uint8 version) {
        require(!_initializing && _initialized < version, "Initializable: contract is already initialized");
        _initialized = version;
        _initializing = true;
        _;
        _initializing = false;
        emit Initialized(version);
    }

    /**
     * @dev Modifier to protect an initialization function so that it can only be invoked by functions with the
     * {initializer} and {reinitializer} modifiers, directly or indirectly.
     */
    modifier onlyInitializing() {
        require(_initializing, "Initializable: contract is not initializing");
        _;
    }

    /**
     * @dev Locks the contract, preventing any future reinitialization. This cannot be part of an initializer call.
     * Calling this in the constructor of a contract will prevent that contract from being initialized or reinitialized
     * to any version. It is recommended to use this to lock implementation contracts that are designed to be called
     * through proxies.
     */
    function _disableInitializers() internal virtual {
        require(!_initializing, "Initializable: contract is initializing");
        if (_initialized < type(uint8).max) {
            _initialized = type(uint8).max;
            emit Initialized(type(uint8).max);
        }
    }
}

File 3 of 27 : AddressUpgradeable.sol
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (utils/Address.sol)

pragma solidity ^0.8.1;

/**
 * @dev Collection of functions related to the address type
 */
library AddressUpgradeable {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.

        return account.code.length > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCall(target, data, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");

        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");

        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly
                /// @solidity memory-safe-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

File 4 of 27 : Initializable.sol
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (proxy/utils/Initializable.sol)

pragma solidity ^0.8.2;

import "../../utils/Address.sol";

/**
 * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
 * behind a proxy. Since proxied contracts do not make use of a constructor, it's common to move constructor logic to an
 * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
 * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
 *
 * The initialization functions use a version number. Once a version number is used, it is consumed and cannot be
 * reused. This mechanism prevents re-execution of each "step" but allows the creation of new initialization steps in
 * case an upgrade adds a module that needs to be initialized.
 *
 * For example:
 *
 * [.hljs-theme-light.nopadding]
 * ```
 * contract MyToken is ERC20Upgradeable {
 *     function initialize() initializer public {
 *         __ERC20_init("MyToken", "MTK");
 *     }
 * }
 * contract MyTokenV2 is MyToken, ERC20PermitUpgradeable {
 *     function initializeV2() reinitializer(2) public {
 *         __ERC20Permit_init("MyToken");
 *     }
 * }
 * ```
 *
 * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
 * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.
 *
 * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
 * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
 *
 * [CAUTION]
 * ====
 * Avoid leaving a contract uninitialized.
 *
 * An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation
 * contract, which may impact the proxy. To prevent the implementation contract from being used, you should invoke
 * the {_disableInitializers} function in the constructor to automatically lock it when it is deployed:
 *
 * [.hljs-theme-light.nopadding]
 * ```
 * /// @custom:oz-upgrades-unsafe-allow constructor
 * constructor() {
 *     _disableInitializers();
 * }
 * ```
 * ====
 */
abstract contract Initializable {
    /**
     * @dev Indicates that the contract has been initialized.
     * @custom:oz-retyped-from bool
     */
    uint8 private _initialized;

    /**
     * @dev Indicates that the contract is in the process of being initialized.
     */
    bool private _initializing;

    /**
     * @dev Triggered when the contract has been initialized or reinitialized.
     */
    event Initialized(uint8 version);

    /**
     * @dev A modifier that defines a protected initializer function that can be invoked at most once. In its scope,
     * `onlyInitializing` functions can be used to initialize parent contracts. Equivalent to `reinitializer(1)`.
     */
    modifier initializer() {
        bool isTopLevelCall = !_initializing;
        require(
            (isTopLevelCall && _initialized < 1) || (!Address.isContract(address(this)) && _initialized == 1),
            "Initializable: contract is already initialized"
        );
        _initialized = 1;
        if (isTopLevelCall) {
            _initializing = true;
        }
        _;
        if (isTopLevelCall) {
            _initializing = false;
            emit Initialized(1);
        }
    }

    /**
     * @dev A modifier that defines a protected reinitializer function that can be invoked at most once, and only if the
     * contract hasn't been initialized to a greater version before. In its scope, `onlyInitializing` functions can be
     * used to initialize parent contracts.
     *
     * `initializer` is equivalent to `reinitializer(1)`, so a reinitializer may be used after the original
     * initialization step. This is essential to configure modules that are added through upgrades and that require
     * initialization.
     *
     * Note that versions can jump in increments greater than 1; this implies that if multiple reinitializers coexist in
     * a contract, executing them in the right order is up to the developer or operator.
     */
    modifier reinitializer(uint8 version) {
        require(!_initializing && _initialized < version, "Initializable: contract is already initialized");
        _initialized = version;
        _initializing = true;
        _;
        _initializing = false;
        emit Initialized(version);
    }

    /**
     * @dev Modifier to protect an initialization function so that it can only be invoked by functions with the
     * {initializer} and {reinitializer} modifiers, directly or indirectly.
     */
    modifier onlyInitializing() {
        require(_initializing, "Initializable: contract is not initializing");
        _;
    }

    /**
     * @dev Locks the contract, preventing any future reinitialization. This cannot be part of an initializer call.
     * Calling this in the constructor of a contract will prevent that contract from being initialized or reinitialized
     * to any version. It is recommended to use this to lock implementation contracts that are designed to be called
     * through proxies.
     */
    function _disableInitializers() internal virtual {
        require(!_initializing, "Initializable: contract is initializing");
        if (_initialized < type(uint8).max) {
            _initialized = type(uint8).max;
            emit Initialized(type(uint8).max);
        }
    }
}

File 5 of 27 : IERC721Enumerable.sol
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC721/extensions/IERC721Enumerable.sol)

pragma solidity ^0.8.0;

import "../IERC721.sol";

/**
 * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension
 * @dev See https://eips.ethereum.org/EIPS/eip-721
 */
interface IERC721Enumerable is IERC721 {
    /**
     * @dev Returns the total amount of tokens stored by the contract.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns a token ID owned by `owner` at a given `index` of its token list.
     * Use along with {balanceOf} to enumerate all of ``owner``'s tokens.
     */
    function tokenOfOwnerByIndex(address owner, uint256 index) external view returns (uint256);

    /**
     * @dev Returns a token ID at a given `index` of all the tokens stored by the contract.
     * Use along with {totalSupply} to enumerate all tokens.
     */
    function tokenByIndex(uint256 index) external view returns (uint256);
}

File 6 of 27 : IERC721.sol
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (token/ERC721/IERC721.sol)

pragma solidity ^0.8.0;

import "../../utils/introspection/IERC165.sol";

/**
 * @dev Required interface of an ERC721 compliant contract.
 */
interface IERC721 is IERC165 {
    /**
     * @dev Emitted when `tokenId` token is transferred from `from` to `to`.
     */
    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);

    /**
     * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
     */
    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);

    /**
     * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
     */
    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);

    /**
     * @dev Returns the number of tokens in ``owner``'s account.
     */
    function balanceOf(address owner) external view returns (uint256 balance);

    /**
     * @dev Returns the owner of the `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function ownerOf(uint256 tokenId) external view returns (address owner);

    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        bytes calldata data
    ) external;

    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
     * are aware of the ERC721 protocol to prevent tokens from being forever locked.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If the caller is not `from`, it must have been allowed to move this token by either {approve} or {setApprovalForAll}.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external;

    /**
     * @dev Transfers `tokenId` token from `from` to `to`.
     *
     * WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must be owned by `from`.
     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external;

    /**
     * @dev Gives permission to `to` to transfer `tokenId` token to another account.
     * The approval is cleared when the token is transferred.
     *
     * Only a single account can be approved at a time, so approving the zero address clears previous approvals.
     *
     * Requirements:
     *
     * - The caller must own the token or be an approved operator.
     * - `tokenId` must exist.
     *
     * Emits an {Approval} event.
     */
    function approve(address to, uint256 tokenId) external;

    /**
     * @dev Approve or remove `operator` as an operator for the caller.
     * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
     *
     * Requirements:
     *
     * - The `operator` cannot be the caller.
     *
     * Emits an {ApprovalForAll} event.
     */
    function setApprovalForAll(address operator, bool _approved) external;

    /**
     * @dev Returns the account approved for `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function getApproved(uint256 tokenId) external view returns (address operator);

    /**
     * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
     *
     * See {setApprovalForAll}
     */
    function isApprovedForAll(address owner, address operator) external view returns (bool);
}

File 7 of 27 : Address.sol
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (utils/Address.sol)

pragma solidity ^0.8.1;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.

        return account.code.length > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCall(target, data, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");

        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");

        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");

        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly
                /// @solidity memory-safe-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

File 8 of 27 : ERC165Checker.sol
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.2) (utils/introspection/ERC165Checker.sol)

pragma solidity ^0.8.0;

import "./IERC165.sol";

/**
 * @dev Library used to query support of an interface declared via {IERC165}.
 *
 * Note that these functions return the actual result of the query: they do not
 * `revert` if an interface is not supported. It is up to the caller to decide
 * what to do in these cases.
 */
library ERC165Checker {
    // As per the EIP-165 spec, no interface should ever match 0xffffffff
    bytes4 private constant _INTERFACE_ID_INVALID = 0xffffffff;

    /**
     * @dev Returns true if `account` supports the {IERC165} interface,
     */
    function supportsERC165(address account) internal view returns (bool) {
        // Any contract that implements ERC165 must explicitly indicate support of
        // InterfaceId_ERC165 and explicitly indicate non-support of InterfaceId_Invalid
        return
            _supportsERC165Interface(account, type(IERC165).interfaceId) &&
            !_supportsERC165Interface(account, _INTERFACE_ID_INVALID);
    }

    /**
     * @dev Returns true if `account` supports the interface defined by
     * `interfaceId`. Support for {IERC165} itself is queried automatically.
     *
     * See {IERC165-supportsInterface}.
     */
    function supportsInterface(address account, bytes4 interfaceId) internal view returns (bool) {
        // query support of both ERC165 as per the spec and support of _interfaceId
        return supportsERC165(account) && _supportsERC165Interface(account, interfaceId);
    }

    /**
     * @dev Returns a boolean array where each value corresponds to the
     * interfaces passed in and whether they're supported or not. This allows
     * you to batch check interfaces for a contract where your expectation
     * is that some interfaces may not be supported.
     *
     * See {IERC165-supportsInterface}.
     *
     * _Available since v3.4._
     */
    function getSupportedInterfaces(address account, bytes4[] memory interfaceIds)
        internal
        view
        returns (bool[] memory)
    {
        // an array of booleans corresponding to interfaceIds and whether they're supported or not
        bool[] memory interfaceIdsSupported = new bool[](interfaceIds.length);

        // query support of ERC165 itself
        if (supportsERC165(account)) {
            // query support of each interface in interfaceIds
            for (uint256 i = 0; i < interfaceIds.length; i++) {
                interfaceIdsSupported[i] = _supportsERC165Interface(account, interfaceIds[i]);
            }
        }

        return interfaceIdsSupported;
    }

    /**
     * @dev Returns true if `account` supports all the interfaces defined in
     * `interfaceIds`. Support for {IERC165} itself is queried automatically.
     *
     * Batch-querying can lead to gas savings by skipping repeated checks for
     * {IERC165} support.
     *
     * See {IERC165-supportsInterface}.
     */
    function supportsAllInterfaces(address account, bytes4[] memory interfaceIds) internal view returns (bool) {
        // query support of ERC165 itself
        if (!supportsERC165(account)) {
            return false;
        }

        // query support of each interface in _interfaceIds
        for (uint256 i = 0; i < interfaceIds.length; i++) {
            if (!_supportsERC165Interface(account, interfaceIds[i])) {
                return false;
            }
        }

        // all interfaces supported
        return true;
    }

    /**
     * @notice Query if a contract implements an interface, does not check ERC165 support
     * @param account The address of the contract to query for support of an interface
     * @param interfaceId The interface identifier, as specified in ERC-165
     * @return true if the contract at account indicates support of the interface with
     * identifier interfaceId, false otherwise
     * @dev Assumes that account contains a contract that supports ERC165, otherwise
     * the behavior of this method is undefined. This precondition can be checked
     * with {supportsERC165}.
     * Interface identification is specified in ERC-165.
     */
    function _supportsERC165Interface(address account, bytes4 interfaceId) private view returns (bool) {
        // prepare call
        bytes memory encodedParams = abi.encodeWithSelector(IERC165.supportsInterface.selector, interfaceId);

        // perform static call
        bool success;
        uint256 returnSize;
        uint256 returnValue;
        assembly {
            success := staticcall(30000, account, add(encodedParams, 0x20), mload(encodedParams), 0x00, 0x20)
            returnSize := returndatasize()
            returnValue := mload(0x00)
        }

        return success && returnSize >= 0x20 && returnValue > 0;
    }
}

File 9 of 27 : IERC165.sol
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC165 standard, as defined in the
 * https://eips.ethereum.org/EIPS/eip-165[EIP].
 *
 * Implementers can declare support of contract interfaces, which can then be
 * queried by others ({ERC165Checker}).
 *
 * For an implementation, see {ERC165}.
 */
interface IERC165 {
    /**
     * @dev Returns true if this contract implements the interface defined by
     * `interfaceId`. See the corresponding
     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
     * to learn more about how these ids are created.
     *
     * This function call must use less than 30 000 gas.
     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}

File 10 of 27 : Math.sol
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (utils/math/Math.sol)

pragma solidity ^0.8.0;

/**
 * @dev Standard math utilities missing in the Solidity language.
 */
library Math {
    enum Rounding {
        Down, // Toward negative infinity
        Up, // Toward infinity
        Zero // Toward zero
    }

    /**
     * @dev Returns the largest of two numbers.
     */
    function max(uint256 a, uint256 b) internal pure returns (uint256) {
        return a >= b ? a : b;
    }

    /**
     * @dev Returns the smallest of two numbers.
     */
    function min(uint256 a, uint256 b) internal pure returns (uint256) {
        return a < b ? a : b;
    }

    /**
     * @dev Returns the average of two numbers. The result is rounded towards
     * zero.
     */
    function average(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b) / 2 can overflow.
        return (a & b) + (a ^ b) / 2;
    }

    /**
     * @dev Returns the ceiling of the division of two numbers.
     *
     * This differs from standard division with `/` in that it rounds up instead
     * of rounding down.
     */
    function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b - 1) / b can overflow on addition, so we distribute.
        return a == 0 ? 0 : (a - 1) / b + 1;
    }

    /**
     * @notice Calculates floor(x * y / denominator) with full precision. Throws if result overflows a uint256 or denominator == 0
     * @dev Original credit to Remco Bloemen under MIT license (https://xn--2-umb.com/21/muldiv)
     * with further edits by Uniswap Labs also under MIT license.
     */
    function mulDiv(
        uint256 x,
        uint256 y,
        uint256 denominator
    ) internal pure returns (uint256 result) {
        unchecked {
            // 512-bit multiply [prod1 prod0] = x * y. Compute the product mod 2^256 and mod 2^256 - 1, then use
            // use the Chinese Remainder Theorem to reconstruct the 512 bit result. The result is stored in two 256
            // variables such that product = prod1 * 2^256 + prod0.
            uint256 prod0; // Least significant 256 bits of the product
            uint256 prod1; // Most significant 256 bits of the product
            assembly {
                let mm := mulmod(x, y, not(0))
                prod0 := mul(x, y)
                prod1 := sub(sub(mm, prod0), lt(mm, prod0))
            }

            // Handle non-overflow cases, 256 by 256 division.
            if (prod1 == 0) {
                return prod0 / denominator;
            }

            // Make sure the result is less than 2^256. Also prevents denominator == 0.
            require(denominator > prod1);

            ///////////////////////////////////////////////
            // 512 by 256 division.
            ///////////////////////////////////////////////

            // Make division exact by subtracting the remainder from [prod1 prod0].
            uint256 remainder;
            assembly {
                // Compute remainder using mulmod.
                remainder := mulmod(x, y, denominator)

                // Subtract 256 bit number from 512 bit number.
                prod1 := sub(prod1, gt(remainder, prod0))
                prod0 := sub(prod0, remainder)
            }

            // Factor powers of two out of denominator and compute largest power of two divisor of denominator. Always >= 1.
            // See https://cs.stackexchange.com/q/138556/92363.

            // Does not overflow because the denominator cannot be zero at this stage in the function.
            uint256 twos = denominator & (~denominator + 1);
            assembly {
                // Divide denominator by twos.
                denominator := div(denominator, twos)

                // Divide [prod1 prod0] by twos.
                prod0 := div(prod0, twos)

                // Flip twos such that it is 2^256 / twos. If twos is zero, then it becomes one.
                twos := add(div(sub(0, twos), twos), 1)
            }

            // Shift in bits from prod1 into prod0.
            prod0 |= prod1 * twos;

            // Invert denominator mod 2^256. Now that denominator is an odd number, it has an inverse modulo 2^256 such
            // that denominator * inv = 1 mod 2^256. Compute the inverse by starting with a seed that is correct for
            // four bits. That is, denominator * inv = 1 mod 2^4.
            uint256 inverse = (3 * denominator) ^ 2;

            // Use the Newton-Raphson iteration to improve the precision. Thanks to Hensel's lifting lemma, this also works
            // in modular arithmetic, doubling the correct bits in each step.
            inverse *= 2 - denominator * inverse; // inverse mod 2^8
            inverse *= 2 - denominator * inverse; // inverse mod 2^16
            inverse *= 2 - denominator * inverse; // inverse mod 2^32
            inverse *= 2 - denominator * inverse; // inverse mod 2^64
            inverse *= 2 - denominator * inverse; // inverse mod 2^128
            inverse *= 2 - denominator * inverse; // inverse mod 2^256

            // Because the division is now exact we can divide by multiplying with the modular inverse of denominator.
            // This will give us the correct result modulo 2^256. Since the preconditions guarantee that the outcome is
            // less than 2^256, this is the final result. We don't need to compute the high bits of the result and prod1
            // is no longer required.
            result = prod0 * inverse;
            return result;
        }
    }

    /**
     * @notice Calculates x * y / denominator with full precision, following the selected rounding direction.
     */
    function mulDiv(
        uint256 x,
        uint256 y,
        uint256 denominator,
        Rounding rounding
    ) internal pure returns (uint256) {
        uint256 result = mulDiv(x, y, denominator);
        if (rounding == Rounding.Up && mulmod(x, y, denominator) > 0) {
            result += 1;
        }
        return result;
    }

    /**
     * @dev Returns the square root of a number. It the number is not a perfect square, the value is rounded down.
     *
     * Inspired by Henry S. Warren, Jr.'s "Hacker's Delight" (Chapter 11).
     */
    function sqrt(uint256 a) internal pure returns (uint256) {
        if (a == 0) {
            return 0;
        }

        // For our first guess, we get the biggest power of 2 which is smaller than the square root of the target.
        // We know that the "msb" (most significant bit) of our target number `a` is a power of 2 such that we have
        // `msb(a) <= a < 2*msb(a)`.
        // We also know that `k`, the position of the most significant bit, is such that `msb(a) = 2**k`.
        // This gives `2**k < a <= 2**(k+1)` → `2**(k/2) <= sqrt(a) < 2 ** (k/2+1)`.
        // Using an algorithm similar to the msb conmputation, we are able to compute `result = 2**(k/2)` which is a
        // good first aproximation of `sqrt(a)` with at least 1 correct bit.
        uint256 result = 1;
        uint256 x = a;
        if (x >> 128 > 0) {
            x >>= 128;
            result <<= 64;
        }
        if (x >> 64 > 0) {
            x >>= 64;
            result <<= 32;
        }
        if (x >> 32 > 0) {
            x >>= 32;
            result <<= 16;
        }
        if (x >> 16 > 0) {
            x >>= 16;
            result <<= 8;
        }
        if (x >> 8 > 0) {
            x >>= 8;
            result <<= 4;
        }
        if (x >> 4 > 0) {
            x >>= 4;
            result <<= 2;
        }
        if (x >> 2 > 0) {
            result <<= 1;
        }

        // At this point `result` is an estimation with one bit of precision. We know the true value is a uint128,
        // since it is the square root of a uint256. Newton's method converges quadratically (precision doubles at
        // every iteration). We thus need at most 7 iteration to turn our partial result with one bit of precision
        // into the expected uint128 result.
        unchecked {
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            return min(result, a / result);
        }
    }

    /**
     * @notice Calculates sqrt(a), following the selected rounding direction.
     */
    function sqrt(uint256 a, Rounding rounding) internal pure returns (uint256) {
        uint256 result = sqrt(a);
        if (rounding == Rounding.Up && result * result < a) {
            result += 1;
        }
        return result;
    }
}

File 11 of 27 : SignedMath.sol
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (utils/math/SignedMath.sol)

pragma solidity ^0.8.0;

/**
 * @dev Standard signed math utilities missing in the Solidity language.
 */
library SignedMath {
    /**
     * @dev Returns the largest of two signed numbers.
     */
    function max(int256 a, int256 b) internal pure returns (int256) {
        return a >= b ? a : b;
    }

    /**
     * @dev Returns the smallest of two signed numbers.
     */
    function min(int256 a, int256 b) internal pure returns (int256) {
        return a < b ? a : b;
    }

    /**
     * @dev Returns the average of two signed numbers without overflow.
     * The result is rounded towards zero.
     */
    function average(int256 a, int256 b) internal pure returns (int256) {
        // Formula from the book "Hacker's Delight"
        int256 x = (a & b) + ((a ^ b) >> 1);
        return x + (int256(uint256(x) >> 255) & (a ^ b));
    }

    /**
     * @dev Returns the absolute unsigned value of a signed value.
     */
    function abs(int256 n) internal pure returns (uint256) {
        unchecked {
            // must be unchecked in order to support `n = type(int256).min`
            return uint256(n >= 0 ? n : -n);
        }
    }
}

File 12 of 27 : Strings.sol
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (utils/Strings.sol)

pragma solidity ^0.8.0;

/**
 * @dev String operations.
 */
library Strings {
    bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";
    uint8 private constant _ADDRESS_LENGTH = 20;

    /**
     * @dev Converts a `uint256` to its ASCII `string` decimal representation.
     */
    function toString(uint256 value) internal pure returns (string memory) {
        // Inspired by OraclizeAPI's implementation - MIT licence
        // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol

        if (value == 0) {
            return "0";
        }
        uint256 temp = value;
        uint256 digits;
        while (temp != 0) {
            digits++;
            temp /= 10;
        }
        bytes memory buffer = new bytes(digits);
        while (value != 0) {
            digits -= 1;
            buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
            value /= 10;
        }
        return string(buffer);
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
     */
    function toHexString(uint256 value) internal pure returns (string memory) {
        if (value == 0) {
            return "0x00";
        }
        uint256 temp = value;
        uint256 length = 0;
        while (temp != 0) {
            length++;
            temp >>= 8;
        }
        return toHexString(value, length);
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
     */
    function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
        bytes memory buffer = new bytes(2 * length + 2);
        buffer[0] = "0";
        buffer[1] = "x";
        for (uint256 i = 2 * length + 1; i > 1; --i) {
            buffer[i] = _HEX_SYMBOLS[value & 0xf];
            value >>= 4;
        }
        require(value == 0, "Strings: hex length insufficient");
        return string(buffer);
    }

    /**
     * @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal representation.
     */
    function toHexString(address addr) internal pure returns (string memory) {
        return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH);
    }
}

File 13 of 27 : FixedPointMathLib.sol
// SPDX-License-Identifier: MIT
pragma solidity >=0.8.0;

/// @notice Arithmetic library with operations for fixed-point numbers.
/// @author Solmate (https://github.com/Rari-Capital/solmate/blob/main/src/utils/FixedPointMathLib.sol)
library FixedPointMathLib {
    /*//////////////////////////////////////////////////////////////
                    SIMPLIFIED FIXED POINT OPERATIONS
    //////////////////////////////////////////////////////////////*/

    uint256 internal constant WAD = 1e18; // The scalar of ETH and most ERC20s.

    function mulWadDown(uint256 x, uint256 y) internal pure returns (uint256) {
        return mulDivDown(x, y, WAD); // Equivalent to (x * y) / WAD rounded down.
    }

    function mulWadUp(uint256 x, uint256 y) internal pure returns (uint256) {
        return mulDivUp(x, y, WAD); // Equivalent to (x * y) / WAD rounded up.
    }

    function divWadDown(uint256 x, uint256 y) internal pure returns (uint256) {
        return mulDivDown(x, WAD, y); // Equivalent to (x * WAD) / y rounded down.
    }

    function divWadUp(uint256 x, uint256 y) internal pure returns (uint256) {
        return mulDivUp(x, WAD, y); // Equivalent to (x * WAD) / y rounded up.
    }

    function powWad(int256 x, int256 y) internal pure returns (int256) {
        // Equivalent to x to the power of y because x ** y = (e ** ln(x)) ** y = e ** (ln(x) * y)
        return expWad((lnWad(x) * y) / int256(WAD)); // Using ln(x) means x must be greater than 0.
    }

    function expWad(int256 x) internal pure returns (int256 r) {
        unchecked {
            // When the result is < 0.5 we return zero. This happens when
            // x <= floor(log(0.5e18) * 1e18) ~ -42e18
            if (x <= -42139678854452767551) return 0;

            // When the result is > (2**255 - 1) / 1e18 we can not represent it as an
            // int. This happens when x >= floor(log((2**255 - 1) / 1e18) * 1e18) ~ 135.
            if (x >= 135305999368893231589) revert("EXP_OVERFLOW");

            // x is now in the range (-42, 136) * 1e18. Convert to (-42, 136) * 2**96
            // for more intermediate precision and a binary basis. This base conversion
            // is a multiplication by 1e18 / 2**96 = 5**18 / 2**78.
            x = (x << 78) / 5**18;

            // Reduce range of x to (-½ ln 2, ½ ln 2) * 2**96 by factoring out powers
            // of two such that exp(x) = exp(x') * 2**k, where k is an integer.
            // Solving this gives k = round(x / log(2)) and x' = x - k * log(2).
            int256 k = ((x << 96) / 54916777467707473351141471128 + 2**95) >> 96;
            x = x - k * 54916777467707473351141471128;

            // k is in the range [-61, 195].

            // Evaluate using a (6, 7)-term rational approximation.
            // p is made monic, we'll multiply by a scale factor later.
            int256 y = x + 1346386616545796478920950773328;
            y = ((y * x) >> 96) + 57155421227552351082224309758442;
            int256 p = y + x - 94201549194550492254356042504812;
            p = ((p * y) >> 96) + 28719021644029726153956944680412240;
            p = p * x + (4385272521454847904659076985693276 << 96);

            // We leave p in 2**192 basis so we don't need to scale it back up for the division.
            int256 q = x - 2855989394907223263936484059900;
            q = ((q * x) >> 96) + 50020603652535783019961831881945;
            q = ((q * x) >> 96) - 533845033583426703283633433725380;
            q = ((q * x) >> 96) + 3604857256930695427073651918091429;
            q = ((q * x) >> 96) - 14423608567350463180887372962807573;
            q = ((q * x) >> 96) + 26449188498355588339934803723976023;

            assembly {
                // Div in assembly because solidity adds a zero check despite the unchecked.
                // The q polynomial won't have zeros in the domain as all its roots are complex.
                // No scaling is necessary because p is already 2**96 too large.
                r := sdiv(p, q)
            }

            // r should be in the range (0.09, 0.25) * 2**96.

            // We now need to multiply r by:
            // * the scale factor s = ~6.031367120.
            // * the 2**k factor from the range reduction.
            // * the 1e18 / 2**96 factor for base conversion.
            // We do this all at once, with an intermediate result in 2**213
            // basis, so the final right shift is always by a positive amount.
            r = int256((uint256(r) * 3822833074963236453042738258902158003155416615667) >> uint256(195 - k));
        }
    }

    function lnWad(int256 x) internal pure returns (int256 r) {
        unchecked {
            require(x > 0, "UNDEFINED");

            // We want to convert x from 10**18 fixed point to 2**96 fixed point.
            // We do this by multiplying by 2**96 / 10**18. But since
            // ln(x * C) = ln(x) + ln(C), we can simply do nothing here
            // and add ln(2**96 / 10**18) at the end.

            // Reduce range of x to (1, 2) * 2**96
            // ln(2^k * x) = k * ln(2) + ln(x)
            int256 k = int256(log2(uint256(x))) - 96;
            x <<= uint256(159 - k);
            x = int256(uint256(x) >> 159);

            // Evaluate using a (8, 8)-term rational approximation.
            // p is made monic, we will multiply by a scale factor later.
            int256 p = x + 3273285459638523848632254066296;
            p = ((p * x) >> 96) + 24828157081833163892658089445524;
            p = ((p * x) >> 96) + 43456485725739037958740375743393;
            p = ((p * x) >> 96) - 11111509109440967052023855526967;
            p = ((p * x) >> 96) - 45023709667254063763336534515857;
            p = ((p * x) >> 96) - 14706773417378608786704636184526;
            p = p * x - (795164235651350426258249787498 << 96);

            // We leave p in 2**192 basis so we don't need to scale it back up for the division.
            // q is monic by convention.
            int256 q = x + 5573035233440673466300451813936;
            q = ((q * x) >> 96) + 71694874799317883764090561454958;
            q = ((q * x) >> 96) + 283447036172924575727196451306956;
            q = ((q * x) >> 96) + 401686690394027663651624208769553;
            q = ((q * x) >> 96) + 204048457590392012362485061816622;
            q = ((q * x) >> 96) + 31853899698501571402653359427138;
            q = ((q * x) >> 96) + 909429971244387300277376558375;
            assembly {
                // Div in assembly because solidity adds a zero check despite the unchecked.
                // The q polynomial is known not to have zeros in the domain.
                // No scaling required because p is already 2**96 too large.
                r := sdiv(p, q)
            }

            // r is in the range (0, 0.125) * 2**96

            // Finalization, we need to:
            // * multiply by the scale factor s = 5.549…
            // * add ln(2**96 / 10**18)
            // * add k * ln(2)
            // * multiply by 10**18 / 2**96 = 5**18 >> 78

            // mul s * 5e18 * 2**96, base is now 5**18 * 2**192
            r *= 1677202110996718588342820967067443963516166;
            // add ln(2) * k * 5e18 * 2**192
            r += 16597577552685614221487285958193947469193820559219878177908093499208371 * k;
            // add ln(2**96 / 10**18) * 5e18 * 2**192
            r += 600920179829731861736702779321621459595472258049074101567377883020018308;
            // base conversion: mul 2**18 / 2**192
            r >>= 174;
        }
    }

    /*//////////////////////////////////////////////////////////////
                    LOW LEVEL FIXED POINT OPERATIONS
    //////////////////////////////////////////////////////////////*/

    function mulDivDown(
        uint256 x,
        uint256 y,
        uint256 denominator
    ) internal pure returns (uint256 z) {
        assembly {
            // Store x * y in z for now.
            z := mul(x, y)

            // Equivalent to require(denominator != 0 && (x == 0 || (x * y) / x == y))
            if iszero(and(iszero(iszero(denominator)), or(iszero(x), eq(div(z, x), y)))) {
                revert(0, 0)
            }

            // Divide z by the denominator.
            z := div(z, denominator)
        }
    }

    function mulDivUp(
        uint256 x,
        uint256 y,
        uint256 denominator
    ) internal pure returns (uint256 z) {
        assembly {
            // Store x * y in z for now.
            z := mul(x, y)

            // Equivalent to require(denominator != 0 && (x == 0 || (x * y) / x == y))
            if iszero(and(iszero(iszero(denominator)), or(iszero(x), eq(div(z, x), y)))) {
                revert(0, 0)
            }

            // First, divide z - 1 by the denominator and add 1.
            // We allow z - 1 to underflow if z is 0, because we multiply the
            // end result by 0 if z is zero, ensuring we return 0 if z is zero.
            z := mul(iszero(iszero(z)), add(div(sub(z, 1), denominator), 1))
        }
    }

    function rpow(
        uint256 x,
        uint256 n,
        uint256 scalar
    ) internal pure returns (uint256 z) {
        assembly {
            switch x
            case 0 {
                switch n
                case 0 {
                    // 0 ** 0 = 1
                    z := scalar
                }
                default {
                    // 0 ** n = 0
                    z := 0
                }
            }
            default {
                switch mod(n, 2)
                case 0 {
                    // If n is even, store scalar in z for now.
                    z := scalar
                }
                default {
                    // If n is odd, store x in z for now.
                    z := x
                }

                // Shifting right by 1 is like dividing by 2.
                let half := shr(1, scalar)

                for {
                    // Shift n right by 1 before looping to halve it.
                    n := shr(1, n)
                } n {
                    // Shift n right by 1 each iteration to halve it.
                    n := shr(1, n)
                } {
                    // Revert immediately if x ** 2 would overflow.
                    // Equivalent to iszero(eq(div(xx, x), x)) here.
                    if shr(128, x) {
                        revert(0, 0)
                    }

                    // Store x squared.
                    let xx := mul(x, x)

                    // Round to the nearest number.
                    let xxRound := add(xx, half)

                    // Revert if xx + half overflowed.
                    if lt(xxRound, xx) {
                        revert(0, 0)
                    }

                    // Set x to scaled xxRound.
                    x := div(xxRound, scalar)

                    // If n is even:
                    if mod(n, 2) {
                        // Compute z * x.
                        let zx := mul(z, x)

                        // If z * x overflowed:
                        if iszero(eq(div(zx, x), z)) {
                            // Revert if x is non-zero.
                            if iszero(iszero(x)) {
                                revert(0, 0)
                            }
                        }

                        // Round to the nearest number.
                        let zxRound := add(zx, half)

                        // Revert if zx + half overflowed.
                        if lt(zxRound, zx) {
                            revert(0, 0)
                        }

                        // Return properly scaled zxRound.
                        z := div(zxRound, scalar)
                    }
                }
            }
        }
    }

    /*//////////////////////////////////////////////////////////////
                        GENERAL NUMBER UTILITIES
    //////////////////////////////////////////////////////////////*/

    function sqrt(uint256 x) internal pure returns (uint256 z) {
        assembly {
            let y := x // We start y at x, which will help us make our initial estimate.

            z := 181 // The "correct" value is 1, but this saves a multiplication later.

            // This segment is to get a reasonable initial estimate for the Babylonian method. With a bad
            // start, the correct # of bits increases ~linearly each iteration instead of ~quadratically.

            // We check y >= 2^(k + 8) but shift right by k bits
            // each branch to ensure that if x >= 256, then y >= 256.
            if iszero(lt(y, 0x10000000000000000000000000000000000)) {
                y := shr(128, y)
                z := shl(64, z)
            }
            if iszero(lt(y, 0x1000000000000000000)) {
                y := shr(64, y)
                z := shl(32, z)
            }
            if iszero(lt(y, 0x10000000000)) {
                y := shr(32, y)
                z := shl(16, z)
            }
            if iszero(lt(y, 0x1000000)) {
                y := shr(16, y)
                z := shl(8, z)
            }

            // Goal was to get z*z*y within a small factor of x. More iterations could
            // get y in a tighter range. Currently, we will have y in [256, 256*2^16).
            // We ensured y >= 256 so that the relative difference between y and y+1 is small.
            // That's not possible if x < 256 but we can just verify those cases exhaustively.

            // Now, z*z*y <= x < z*z*(y+1), and y <= 2^(16+8), and either y >= 256, or x < 256.
            // Correctness can be checked exhaustively for x < 256, so we assume y >= 256.
            // Then z*sqrt(y) is within sqrt(257)/sqrt(256) of sqrt(x), or about 20bps.

            // For s in the range [1/256, 256], the estimate f(s) = (181/1024) * (s+1) is in the range
            // (1/2.84 * sqrt(s), 2.84 * sqrt(s)), with largest error when s = 1 and when s = 256 or 1/256.

            // Since y is in [256, 256*2^16), let a = y/65536, so that a is in [1/256, 256). Then we can estimate
            // sqrt(y) using sqrt(65536) * 181/1024 * (a + 1) = 181/4 * (y + 65536)/65536 = 181 * (y + 65536)/2^18.

            // There is no overflow risk here since y < 2^136 after the first branch above.
            z := shr(18, mul(z, add(y, 65536))) // A mul() is saved from starting z at 181.

            // Given the worst case multiplicative error of 2.84 above, 7 iterations should be enough.
            z := shr(1, add(z, div(x, z)))
            z := shr(1, add(z, div(x, z)))
            z := shr(1, add(z, div(x, z)))
            z := shr(1, add(z, div(x, z)))
            z := shr(1, add(z, div(x, z)))
            z := shr(1, add(z, div(x, z)))
            z := shr(1, add(z, div(x, z)))

            // If x+1 is a perfect square, the Babylonian method cycles between
            // floor(sqrt(x)) and ceil(sqrt(x)). This statement ensures we return floor.
            // See: https://en.wikipedia.org/wiki/Integer_square_root#Using_only_integer_division
            // Since the ceil is rare, we save gas on the assignment and repeat division in the rare case.
            // If you don't care whether the floor or ceil square root is returned, you can remove this statement.
            z := sub(z, lt(div(x, z), z))
        }
    }

    function log2(uint256 x) internal pure returns (uint256 r) {
        require(x > 0, "UNDEFINED");

        assembly {
            r := shl(7, lt(0xffffffffffffffffffffffffffffffff, x))
            r := or(r, shl(6, lt(0xffffffffffffffff, shr(r, x))))
            r := or(r, shl(5, lt(0xffffffff, shr(r, x))))
            r := or(r, shl(4, lt(0xffff, shr(r, x))))
            r := or(r, shl(3, lt(0xff, shr(r, x))))
            r := or(r, shl(2, lt(0xf, shr(r, x))))
            r := or(r, shl(1, lt(0x3, shr(r, x))))
            r := or(r, lt(0x1, shr(r, x)))
        }
    }
}

File 14 of 27 : ResourceMetering.sol
// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;

import { Initializable } from "@openzeppelin/contracts/proxy/utils/Initializable.sol";
import { Math } from "@openzeppelin/contracts/utils/math/Math.sol";
import { Burn } from "../libraries/Burn.sol";
import { Arithmetic } from "../libraries/Arithmetic.sol";

/**
 * @custom:upgradeable
 * @title ResourceMetering
 * @notice ResourceMetering implements an EIP-1559 style resource metering system where pricing
 *         updates automatically based on current demand.
 */
abstract contract ResourceMetering is Initializable {
    /**
     * @notice Represents the various parameters that control the way in which resources are
     *         metered. Corresponds to the EIP-1559 resource metering system.
     *
     * @custom:field prevBaseFee   Base fee from the previous block(s).
     * @custom:field prevBoughtGas Amount of gas bought so far in the current block.
     * @custom:field prevBlockNum  Last block number that the base fee was updated.
     */
    struct ResourceParams {
        uint128 prevBaseFee;
        uint64 prevBoughtGas;
        uint64 prevBlockNum;
    }

    /**
     * @notice Represents the configuration for the EIP-1559 based curve for the deposit gas
     *         market. These values should be set with care as it is possible to set them in
     *         a way that breaks the deposit gas market. The target resource limit is defined as
     *         maxResourceLimit / elasticityMultiplier. This struct was designed to fit within a
     *         single word. There is additional space for additions in the future.
     *
     * @custom:field maxResourceLimit             Represents the maximum amount of deposit gas that
     *                                            can be purchased per block.
     * @custom:field elasticityMultiplier         Determines the target resource limit along with
     *                                            the resource limit.
     * @custom:field baseFeeMaxChangeDenominator  Determines max change on fee per block.
     * @custom:field minimumBaseFee               The min deposit base fee, it is clamped to this
     *                                            value.
     * @custom:field systemTxMaxGas               The amount of gas supplied to the system
     *                                            transaction. This should be set to the same number
     *                                            that the op-node sets as the gas limit for the
     *                                            system transaction.
     * @custom:field maximumBaseFee               The max deposit base fee, it is clamped to this
     *                                            value.
     */
    struct ResourceConfig {
        uint32 maxResourceLimit;
        uint8 elasticityMultiplier;
        uint8 baseFeeMaxChangeDenominator;
        uint32 minimumBaseFee;
        uint32 systemTxMaxGas;
        uint128 maximumBaseFee;
    }

    /**
     * @notice EIP-1559 style gas parameters.
     */
    ResourceParams public params;

    /**
     * @notice Reserve extra slots (to a total of 50) in the storage layout for future upgrades.
     */
    uint256[48] private __gap;

    /**
     * @notice Meters access to a function based an amount of a requested resource.
     *
     * @param _amount Amount of the resource requested.
     */
    modifier metered(uint64 _amount) {
        // Record initial gas amount so we can refund for it later.
        uint256 initialGas = gasleft();

        // Run the underlying function.
        _;

        // Run the metering function.
        _metered(_amount, initialGas);
    }

    /**
     * @notice An internal function that holds all of the logic for metering a resource.
     *
     * @param _amount     Amount of the resource requested.
     * @param _initialGas The amount of gas before any modifier execution.
     */
    function _metered(uint64 _amount, uint256 _initialGas) internal {
        // Update block number and base fee if necessary.
        uint256 blockDiff = block.number - params.prevBlockNum;

        ResourceConfig memory config = _resourceConfig();
        int256 targetResourceLimit = int256(uint256(config.maxResourceLimit)) /
            int256(uint256(config.elasticityMultiplier));

        if (blockDiff > 0) {
            // Handle updating EIP-1559 style gas parameters. We use EIP-1559 to restrict the rate
            // at which deposits can be created and therefore limit the potential for deposits to
            // spam the L2 system. Fee scheme is very similar to EIP-1559 with minor changes.
            int256 gasUsedDelta = int256(uint256(params.prevBoughtGas)) - targetResourceLimit;
            int256 baseFeeDelta = (int256(uint256(params.prevBaseFee)) * gasUsedDelta) /
                (targetResourceLimit * int256(uint256(config.baseFeeMaxChangeDenominator)));

            // Update base fee by adding the base fee delta and clamp the resulting value between
            // min and max.
            int256 newBaseFee = Arithmetic.clamp({
                _value: int256(uint256(params.prevBaseFee)) + baseFeeDelta,
                _min: int256(uint256(config.minimumBaseFee)),
                _max: int256(uint256(config.maximumBaseFee))
            });

            // If we skipped more than one block, we also need to account for every empty block.
            // Empty block means there was no demand for deposits in that block, so we should
            // reflect this lack of demand in the fee.
            if (blockDiff > 1) {
                // Update the base fee by repeatedly applying the exponent 1-(1/change_denominator)
                // blockDiff - 1 times. Simulates multiple empty blocks. Clamp the resulting value
                // between min and max.
                newBaseFee = Arithmetic.clamp({
                    _value: Arithmetic.cdexp({
                        _coefficient: newBaseFee,
                        _denominator: int256(uint256(config.baseFeeMaxChangeDenominator)),
                        _exponent: int256(blockDiff - 1)
                    }),
                    _min: int256(uint256(config.minimumBaseFee)),
                    _max: int256(uint256(config.maximumBaseFee))
                });
            }

            // Update new base fee, reset bought gas, and update block number.
            params.prevBaseFee = uint128(uint256(newBaseFee));
            params.prevBoughtGas = 0;
            params.prevBlockNum = uint64(block.number);
        }

        // Make sure we can actually buy the resource amount requested by the user.
        params.prevBoughtGas += _amount;
        require(
            int256(uint256(params.prevBoughtGas)) <= int256(uint256(config.maxResourceLimit)),
            "ResourceMetering: cannot buy more gas than available gas limit"
        );

        // Determine the amount of ETH to be paid.
        uint256 resourceCost = uint256(_amount) * uint256(params.prevBaseFee);

        // We currently charge for this ETH amount as an L1 gas burn, so we convert the ETH amount
        // into gas by dividing by the L1 base fee. We assume a minimum base fee of 1 gwei to avoid
        // division by zero for L1s that don't support 1559 or to avoid excessive gas burns during
        // periods of extremely low L1 demand. One-day average gas fee hasn't dipped below 1 gwei
        // during any 1 day period in the last 5 years, so should be fine.
        uint256 gasCost = resourceCost / Math.max(block.basefee, 1 gwei);

        // Give the user a refund based on the amount of gas they used to do all of the work up to
        // this point. Since we're at the end of the modifier, this should be pretty accurate. Acts
        // effectively like a dynamic stipend (with a minimum value).
        uint256 usedGas = _initialGas - gasleft();
        if (gasCost > usedGas) {
            Burn.gas(gasCost - usedGas);
        }
    }

    /**
     * @notice Virtual function that returns the resource config. Contracts that inherit this
     *         contract must implement this function.
     *
     * @return ResourceConfig
     */
    function _resourceConfig() internal virtual returns (ResourceConfig memory);

    /**
     * @notice Sets initial resource parameter values. This function must either be called by the
     *         initializer function of an upgradeable child contract.
     */
    // solhint-disable-next-line func-name-mixedcase
    function __ResourceMetering_init() internal onlyInitializing {
        params = ResourceParams({
            prevBaseFee: 1 gwei,
            prevBoughtGas: 0,
            prevBlockNum: uint64(block.number)
        });
    }
}

File 15 of 27 : L2ERC721Bridge.sol
// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;

import { ERC721Bridge } from "../universal/ERC721Bridge.sol";
import { ERC165Checker } from "@openzeppelin/contracts/utils/introspection/ERC165Checker.sol";
import { L1ERC721Bridge } from "../L1/L1ERC721Bridge.sol";
import { IOptimismMintableERC721 } from "../universal/IOptimismMintableERC721.sol";
import { Semver } from "../universal/Semver.sol";

/**
 * @title L2ERC721Bridge
 * @notice The L2 ERC721 bridge is a contract which works together with the L1 ERC721 bridge to
 *         make it possible to transfer ERC721 tokens from Ethereum to Optimism. This contract
 *         acts as a minter for new tokens when it hears about deposits into the L1 ERC721 bridge.
 *         This contract also acts as a burner for tokens being withdrawn.
 *         **WARNING**: Do not bridge an ERC721 that was originally deployed on Optimism. This
 *         bridge ONLY supports ERC721s originally deployed on Ethereum. Users will need to
 *         wait for the one-week challenge period to elapse before their Optimism-native NFT
 *         can be refunded on L2.
 */
contract L2ERC721Bridge is ERC721Bridge, Semver {
    /**
     * @custom:semver 1.1.0
     *
     * @param _messenger   Address of the CrossDomainMessenger on this network.
     * @param _otherBridge Address of the ERC721 bridge on the other network.
     */
    constructor(address _messenger, address _otherBridge)
        Semver(1, 1, 0)
        ERC721Bridge(_messenger, _otherBridge)
    {}

    /**
     * @notice Completes an ERC721 bridge from the other domain and sends the ERC721 token to the
     *         recipient on this domain.
     *
     * @param _localToken  Address of the ERC721 token on this domain.
     * @param _remoteToken Address of the ERC721 token on the other domain.
     * @param _from        Address that triggered the bridge on the other domain.
     * @param _to          Address to receive the token on this domain.
     * @param _tokenId     ID of the token being deposited.
     * @param _extraData   Optional data to forward to L1. Data supplied here will not be used to
     *                     execute any code on L1 and is only emitted as extra data for the
     *                     convenience of off-chain tooling.
     */
    function finalizeBridgeERC721(
        address _localToken,
        address _remoteToken,
        address _from,
        address _to,
        uint256 _tokenId,
        bytes calldata _extraData
    ) external onlyOtherBridge {
        require(_localToken != address(this), "L2ERC721Bridge: local token cannot be self");

        // Note that supportsInterface makes a callback to the _localToken address which is user
        // provided.
        require(
            ERC165Checker.supportsInterface(_localToken, type(IOptimismMintableERC721).interfaceId),
            "L2ERC721Bridge: local token interface is not compliant"
        );

        require(
            _remoteToken == IOptimismMintableERC721(_localToken).remoteToken(),
            "L2ERC721Bridge: wrong remote token for Optimism Mintable ERC721 local token"
        );

        // When a deposit is finalized, we give the NFT with the same tokenId to the account
        // on L2. Note that safeMint makes a callback to the _to address which is user provided.
        IOptimismMintableERC721(_localToken).safeMint(_to, _tokenId);

        // slither-disable-next-line reentrancy-events
        emit ERC721BridgeFinalized(_localToken, _remoteToken, _from, _to, _tokenId, _extraData);
    }

    /**
     * @inheritdoc ERC721Bridge
     */
    function _initiateBridgeERC721(
        address _localToken,
        address _remoteToken,
        address _from,
        address _to,
        uint256 _tokenId,
        uint32 _minGasLimit,
        bytes calldata _extraData
    ) internal override {
        require(_remoteToken != address(0), "L2ERC721Bridge: remote token cannot be address(0)");

        // Check that the withdrawal is being initiated by the NFT owner
        require(
            _from == IOptimismMintableERC721(_localToken).ownerOf(_tokenId),
            "L2ERC721Bridge: Withdrawal is not being initiated by NFT owner"
        );

        // Construct calldata for l1ERC721Bridge.finalizeBridgeERC721(_to, _tokenId)
        // slither-disable-next-line reentrancy-events
        address remoteToken = IOptimismMintableERC721(_localToken).remoteToken();
        require(
            remoteToken == _remoteToken,
            "L2ERC721Bridge: remote token does not match given value"
        );

        // When a withdrawal is initiated, we burn the withdrawer's NFT to prevent subsequent L2
        // usage
        // slither-disable-next-line reentrancy-events
        IOptimismMintableERC721(_localToken).burn(_from, _tokenId);

        bytes memory message = abi.encodeWithSelector(
            L1ERC721Bridge.finalizeBridgeERC721.selector,
            remoteToken,
            _localToken,
            _from,
            _to,
            _tokenId,
            _extraData
        );

        // Send message to L1 bridge
        // slither-disable-next-line reentrancy-events
        MESSENGER.sendMessage(OTHER_BRIDGE, message, _minGasLimit);

        // slither-disable-next-line reentrancy-events
        emit ERC721BridgeInitiated(_localToken, remoteToken, _from, _to, _tokenId, _extraData);
    }
}

File 16 of 27 : Arithmetic.sol
// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;

import { SignedMath } from "@openzeppelin/contracts/utils/math/SignedMath.sol";
import { FixedPointMathLib } from "@rari-capital/solmate/src/utils/FixedPointMathLib.sol";

/**
 * @title Arithmetic
 * @notice Even more math than before.
 */
library Arithmetic {
    /**
     * @notice Clamps a value between a minimum and maximum.
     *
     * @param _value The value to clamp.
     * @param _min   The minimum value.
     * @param _max   The maximum value.
     *
     * @return The clamped value.
     */
    function clamp(
        int256 _value,
        int256 _min,
        int256 _max
    ) internal pure returns (int256) {
        return SignedMath.min(SignedMath.max(_value, _min), _max);
    }

    /**
     * @notice (c)oefficient (d)enominator (exp)onentiation function.
     *         Returns the result of: c * (1 - 1/d)^exp.
     *
     * @param _coefficient Coefficient of the function.
     * @param _denominator Fractional denominator.
     * @param _exponent    Power function exponent.
     *
     * @return Result of c * (1 - 1/d)^exp.
     */
    function cdexp(
        int256 _coefficient,
        int256 _denominator,
        int256 _exponent
    ) internal pure returns (int256) {
        return
            (_coefficient *
                (FixedPointMathLib.powWad(1e18 - (1e18 / _denominator), _exponent * 1e18))) / 1e18;
    }
}

File 17 of 27 : Burn.sol
// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;

/**
 * @title Burn
 * @notice Utilities for burning stuff.
 */
library Burn {
    /**
     * Burns a given amount of ETH.
     *
     * @param _amount Amount of ETH to burn.
     */
    function eth(uint256 _amount) internal {
        new Burner{ value: _amount }();
    }

    /**
     * Burns a given amount of gas.
     *
     * @param _amount Amount of gas to burn.
     */
    function gas(uint256 _amount) internal view {
        uint256 i = 0;
        uint256 initialGas = gasleft();
        while (initialGas - gasleft() < _amount) {
            ++i;
        }
    }
}

/**
 * @title Burner
 * @notice Burner self-destructs on creation and sends all ETH to itself, removing all ETH given to
 *         the contract from the circulating supply. Self-destructing is the only way to remove ETH
 *         from the circulating supply.
 */
contract Burner {
    constructor() payable {
        selfdestruct(payable(address(this)));
    }
}

File 18 of 27 : Constants.sol
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import { ResourceMetering } from "../L1/ResourceMetering.sol";

/**
 * @title Constants
 * @notice Constants is a library for storing constants. Simple! Don't put everything in here, just
 *         the stuff used in multiple contracts. Constants that only apply to a single contract
 *         should be defined in that contract instead.
 */
library Constants {
    /**
     * @notice Special address to be used as the tx origin for gas estimation calls in the
     *         OptimismPortal and CrossDomainMessenger calls. You only need to use this address if
     *         the minimum gas limit specified by the user is not actually enough to execute the
     *         given message and you're attempting to estimate the actual necessary gas limit. We
     *         use address(1) because it's the ecrecover precompile and therefore guaranteed to
     *         never have any code on any EVM chain.
     */
    address internal constant ESTIMATION_ADDRESS = address(1);

    /**
     * @notice Value used for the L2 sender storage slot in both the OptimismPortal and the
     *         CrossDomainMessenger contracts before an actual sender is set. This value is
     *         non-zero to reduce the gas cost of message passing transactions.
     */
    address internal constant DEFAULT_L2_SENDER = 0x000000000000000000000000000000000000dEaD;

    /**
     * @notice Returns the default values for the ResourceConfig. These are the recommended values
     *         for a production network.
     */
    function DEFAULT_RESOURCE_CONFIG()
        internal
        pure
        returns (ResourceMetering.ResourceConfig memory)
    {
        ResourceMetering.ResourceConfig memory config = ResourceMetering.ResourceConfig({
            maxResourceLimit: 20_000_000,
            elasticityMultiplier: 10,
            baseFeeMaxChangeDenominator: 8,
            minimumBaseFee: 1 gwei,
            systemTxMaxGas: 1_000_000,
            maximumBaseFee: type(uint128).max
        });
        return config;
    }
}

File 19 of 27 : Encoding.sol
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import { Types } from "./Types.sol";
import { Hashing } from "./Hashing.sol";
import { RLPWriter } from "./rlp/RLPWriter.sol";

/**
 * @title Encoding
 * @notice Encoding handles Optimism's various different encoding schemes.
 */
library Encoding {
    /**
     * @notice RLP encodes the L2 transaction that would be generated when a given deposit is sent
     *         to the L2 system. Useful for searching for a deposit in the L2 system. The
     *         transaction is prefixed with 0x7e to identify its EIP-2718 type.
     *
     * @param _tx User deposit transaction to encode.
     *
     * @return RLP encoded L2 deposit transaction.
     */
    function encodeDepositTransaction(Types.UserDepositTransaction memory _tx)
        internal
        pure
        returns (bytes memory)
    {
        bytes32 source = Hashing.hashDepositSource(_tx.l1BlockHash, _tx.logIndex);
        bytes[] memory raw = new bytes[](8);
        raw[0] = RLPWriter.writeBytes(abi.encodePacked(source));
        raw[1] = RLPWriter.writeAddress(_tx.from);
        raw[2] = _tx.isCreation ? RLPWriter.writeBytes("") : RLPWriter.writeAddress(_tx.to);
        raw[3] = RLPWriter.writeUint(_tx.mint);
        raw[4] = RLPWriter.writeUint(_tx.value);
        raw[5] = RLPWriter.writeUint(uint256(_tx.gasLimit));
        raw[6] = RLPWriter.writeBool(false);
        raw[7] = RLPWriter.writeBytes(_tx.data);
        return abi.encodePacked(uint8(0x7e), RLPWriter.writeList(raw));
    }

    /**
     * @notice Encodes the cross domain message based on the version that is encoded into the
     *         message nonce.
     *
     * @param _nonce    Message nonce with version encoded into the first two bytes.
     * @param _sender   Address of the sender of the message.
     * @param _target   Address of the target of the message.
     * @param _value    ETH value to send to the target.
     * @param _gasLimit Gas limit to use for the message.
     * @param _data     Data to send with the message.
     *
     * @return Encoded cross domain message.
     */
    function encodeCrossDomainMessage(
        uint256 _nonce,
        address _sender,
        address _target,
        uint256 _value,
        uint256 _gasLimit,
        bytes memory _data
    ) internal pure returns (bytes memory) {
        (, uint16 version) = decodeVersionedNonce(_nonce);
        if (version == 0) {
            return encodeCrossDomainMessageV0(_target, _sender, _data, _nonce);
        } else if (version == 1) {
            return encodeCrossDomainMessageV1(_nonce, _sender, _target, _value, _gasLimit, _data);
        } else {
            revert("Encoding: unknown cross domain message version");
        }
    }

    /**
     * @notice Encodes a cross domain message based on the V0 (legacy) encoding.
     *
     * @param _target Address of the target of the message.
     * @param _sender Address of the sender of the message.
     * @param _data   Data to send with the message.
     * @param _nonce  Message nonce.
     *
     * @return Encoded cross domain message.
     */
    function encodeCrossDomainMessageV0(
        address _target,
        address _sender,
        bytes memory _data,
        uint256 _nonce
    ) internal pure returns (bytes memory) {
        return
            abi.encodeWithSignature(
                "relayMessage(address,address,bytes,uint256)",
                _target,
                _sender,
                _data,
                _nonce
            );
    }

    /**
     * @notice Encodes a cross domain message based on the V1 (current) encoding.
     *
     * @param _nonce    Message nonce.
     * @param _sender   Address of the sender of the message.
     * @param _target   Address of the target of the message.
     * @param _value    ETH value to send to the target.
     * @param _gasLimit Gas limit to use for the message.
     * @param _data     Data to send with the message.
     *
     * @return Encoded cross domain message.
     */
    function encodeCrossDomainMessageV1(
        uint256 _nonce,
        address _sender,
        address _target,
        uint256 _value,
        uint256 _gasLimit,
        bytes memory _data
    ) internal pure returns (bytes memory) {
        return
            abi.encodeWithSignature(
                "relayMessage(uint256,address,address,uint256,uint256,bytes)",
                _nonce,
                _sender,
                _target,
                _value,
                _gasLimit,
                _data
            );
    }

    /**
     * @notice Adds a version number into the first two bytes of a message nonce.
     *
     * @param _nonce   Message nonce to encode into.
     * @param _version Version number to encode into the message nonce.
     *
     * @return Message nonce with version encoded into the first two bytes.
     */
    function encodeVersionedNonce(uint240 _nonce, uint16 _version) internal pure returns (uint256) {
        uint256 nonce;
        assembly {
            nonce := or(shl(240, _version), _nonce)
        }
        return nonce;
    }

    /**
     * @notice Pulls the version out of a version-encoded nonce.
     *
     * @param _nonce Message nonce with version encoded into the first two bytes.
     *
     * @return Nonce without encoded version.
     * @return Version of the message.
     */
    function decodeVersionedNonce(uint256 _nonce) internal pure returns (uint240, uint16) {
        uint240 nonce;
        uint16 version;
        assembly {
            nonce := and(_nonce, 0x0000ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff)
            version := shr(240, _nonce)
        }
        return (nonce, version);
    }
}

File 20 of 27 : Hashing.sol
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import { Types } from "./Types.sol";
import { Encoding } from "./Encoding.sol";

/**
 * @title Hashing
 * @notice Hashing handles Optimism's various different hashing schemes.
 */
library Hashing {
    /**
     * @notice Computes the hash of the RLP encoded L2 transaction that would be generated when a
     *         given deposit is sent to the L2 system. Useful for searching for a deposit in the L2
     *         system.
     *
     * @param _tx User deposit transaction to hash.
     *
     * @return Hash of the RLP encoded L2 deposit transaction.
     */
    function hashDepositTransaction(Types.UserDepositTransaction memory _tx)
        internal
        pure
        returns (bytes32)
    {
        return keccak256(Encoding.encodeDepositTransaction(_tx));
    }

    /**
     * @notice Computes the deposit transaction's "source hash", a value that guarantees the hash
     *         of the L2 transaction that corresponds to a deposit is unique and is
     *         deterministically generated from L1 transaction data.
     *
     * @param _l1BlockHash Hash of the L1 block where the deposit was included.
     * @param _logIndex    The index of the log that created the deposit transaction.
     *
     * @return Hash of the deposit transaction's "source hash".
     */
    function hashDepositSource(bytes32 _l1BlockHash, uint256 _logIndex)
        internal
        pure
        returns (bytes32)
    {
        bytes32 depositId = keccak256(abi.encode(_l1BlockHash, _logIndex));
        return keccak256(abi.encode(bytes32(0), depositId));
    }

    /**
     * @notice Hashes the cross domain message based on the version that is encoded into the
     *         message nonce.
     *
     * @param _nonce    Message nonce with version encoded into the first two bytes.
     * @param _sender   Address of the sender of the message.
     * @param _target   Address of the target of the message.
     * @param _value    ETH value to send to the target.
     * @param _gasLimit Gas limit to use for the message.
     * @param _data     Data to send with the message.
     *
     * @return Hashed cross domain message.
     */
    function hashCrossDomainMessage(
        uint256 _nonce,
        address _sender,
        address _target,
        uint256 _value,
        uint256 _gasLimit,
        bytes memory _data
    ) internal pure returns (bytes32) {
        (, uint16 version) = Encoding.decodeVersionedNonce(_nonce);
        if (version == 0) {
            return hashCrossDomainMessageV0(_target, _sender, _data, _nonce);
        } else if (version == 1) {
            return hashCrossDomainMessageV1(_nonce, _sender, _target, _value, _gasLimit, _data);
        } else {
            revert("Hashing: unknown cross domain message version");
        }
    }

    /**
     * @notice Hashes a cross domain message based on the V0 (legacy) encoding.
     *
     * @param _target Address of the target of the message.
     * @param _sender Address of the sender of the message.
     * @param _data   Data to send with the message.
     * @param _nonce  Message nonce.
     *
     * @return Hashed cross domain message.
     */
    function hashCrossDomainMessageV0(
        address _target,
        address _sender,
        bytes memory _data,
        uint256 _nonce
    ) internal pure returns (bytes32) {
        return keccak256(Encoding.encodeCrossDomainMessageV0(_target, _sender, _data, _nonce));
    }

    /**
     * @notice Hashes a cross domain message based on the V1 (current) encoding.
     *
     * @param _nonce    Message nonce.
     * @param _sender   Address of the sender of the message.
     * @param _target   Address of the target of the message.
     * @param _value    ETH value to send to the target.
     * @param _gasLimit Gas limit to use for the message.
     * @param _data     Data to send with the message.
     *
     * @return Hashed cross domain message.
     */
    function hashCrossDomainMessageV1(
        uint256 _nonce,
        address _sender,
        address _target,
        uint256 _value,
        uint256 _gasLimit,
        bytes memory _data
    ) internal pure returns (bytes32) {
        return
            keccak256(
                Encoding.encodeCrossDomainMessageV1(
                    _nonce,
                    _sender,
                    _target,
                    _value,
                    _gasLimit,
                    _data
                )
            );
    }

    /**
     * @notice Derives the withdrawal hash according to the encoding in the L2 Withdrawer contract
     *
     * @param _tx Withdrawal transaction to hash.
     *
     * @return Hashed withdrawal transaction.
     */
    function hashWithdrawal(Types.WithdrawalTransaction memory _tx)
        internal
        pure
        returns (bytes32)
    {
        return
            keccak256(
                abi.encode(_tx.nonce, _tx.sender, _tx.target, _tx.value, _tx.gasLimit, _tx.data)
            );
    }

    /**
     * @notice Hashes the various elements of an output root proof into an output root hash which
     *         can be used to check if the proof is valid.
     *
     * @param _outputRootProof Output root proof which should hash to an output root.
     *
     * @return Hashed output root proof.
     */
    function hashOutputRootProof(Types.OutputRootProof memory _outputRootProof)
        internal
        pure
        returns (bytes32)
    {
        return
            keccak256(
                abi.encode(
                    _outputRootProof.version,
                    _outputRootProof.stateRoot,
                    _outputRootProof.messagePasserStorageRoot,
                    _outputRootProof.latestBlockhash
                )
            );
    }
}

File 21 of 27 : RLPWriter.sol
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

/**
 * @custom:attribution https://github.com/bakaoh/solidity-rlp-encode
 * @title RLPWriter
 * @author RLPWriter is a library for encoding Solidity types to RLP bytes. Adapted from Bakaoh's
 *         RLPEncode library (https://github.com/bakaoh/solidity-rlp-encode) with minor
 *         modifications to improve legibility.
 */
library RLPWriter {
    /**
     * @notice RLP encodes a byte string.
     *
     * @param _in The byte string to encode.
     *
     * @return The RLP encoded string in bytes.
     */
    function writeBytes(bytes memory _in) internal pure returns (bytes memory) {
        bytes memory encoded;

        if (_in.length == 1 && uint8(_in[0]) < 128) {
            encoded = _in;
        } else {
            encoded = abi.encodePacked(_writeLength(_in.length, 128), _in);
        }

        return encoded;
    }

    /**
     * @notice RLP encodes a list of RLP encoded byte byte strings.
     *
     * @param _in The list of RLP encoded byte strings.
     *
     * @return The RLP encoded list of items in bytes.
     */
    function writeList(bytes[] memory _in) internal pure returns (bytes memory) {
        bytes memory list = _flatten(_in);
        return abi.encodePacked(_writeLength(list.length, 192), list);
    }

    /**
     * @notice RLP encodes a string.
     *
     * @param _in The string to encode.
     *
     * @return The RLP encoded string in bytes.
     */
    function writeString(string memory _in) internal pure returns (bytes memory) {
        return writeBytes(bytes(_in));
    }

    /**
     * @notice RLP encodes an address.
     *
     * @param _in The address to encode.
     *
     * @return The RLP encoded address in bytes.
     */
    function writeAddress(address _in) internal pure returns (bytes memory) {
        return writeBytes(abi.encodePacked(_in));
    }

    /**
     * @notice RLP encodes a uint.
     *
     * @param _in The uint256 to encode.
     *
     * @return The RLP encoded uint256 in bytes.
     */
    function writeUint(uint256 _in) internal pure returns (bytes memory) {
        return writeBytes(_toBinary(_in));
    }

    /**
     * @notice RLP encodes a bool.
     *
     * @param _in The bool to encode.
     *
     * @return The RLP encoded bool in bytes.
     */
    function writeBool(bool _in) internal pure returns (bytes memory) {
        bytes memory encoded = new bytes(1);
        encoded[0] = (_in ? bytes1(0x01) : bytes1(0x80));
        return encoded;
    }

    /**
     * @notice Encode the first byte and then the `len` in binary form if `length` is more than 55.
     *
     * @param _len    The length of the string or the payload.
     * @param _offset 128 if item is string, 192 if item is list.
     *
     * @return RLP encoded bytes.
     */
    function _writeLength(uint256 _len, uint256 _offset) private pure returns (bytes memory) {
        bytes memory encoded;

        if (_len < 56) {
            encoded = new bytes(1);
            encoded[0] = bytes1(uint8(_len) + uint8(_offset));
        } else {
            uint256 lenLen;
            uint256 i = 1;
            while (_len / i != 0) {
                lenLen++;
                i *= 256;
            }

            encoded = new bytes(lenLen + 1);
            encoded[0] = bytes1(uint8(lenLen) + uint8(_offset) + 55);
            for (i = 1; i <= lenLen; i++) {
                encoded[i] = bytes1(uint8((_len / (256**(lenLen - i))) % 256));
            }
        }

        return encoded;
    }

    /**
     * @notice Encode integer in big endian binary form with no leading zeroes.
     *
     * @param _x The integer to encode.
     *
     * @return RLP encoded bytes.
     */
    function _toBinary(uint256 _x) private pure returns (bytes memory) {
        bytes memory b = abi.encodePacked(_x);

        uint256 i = 0;
        for (; i < 32; i++) {
            if (b[i] != 0) {
                break;
            }
        }

        bytes memory res = new bytes(32 - i);
        for (uint256 j = 0; j < res.length; j++) {
            res[j] = b[i++];
        }

        return res;
    }

    /**
     * @custom:attribution https://github.com/Arachnid/solidity-stringutils
     * @notice Copies a piece of memory to another location.
     *
     * @param _dest Destination location.
     * @param _src  Source location.
     * @param _len  Length of memory to copy.
     */
    function _memcpy(
        uint256 _dest,
        uint256 _src,
        uint256 _len
    ) private pure {
        uint256 dest = _dest;
        uint256 src = _src;
        uint256 len = _len;

        for (; len >= 32; len -= 32) {
            assembly {
                mstore(dest, mload(src))
            }
            dest += 32;
            src += 32;
        }

        uint256 mask;
        unchecked {
            mask = 256**(32 - len) - 1;
        }
        assembly {
            let srcpart := and(mload(src), not(mask))
            let destpart := and(mload(dest), mask)
            mstore(dest, or(destpart, srcpart))
        }
    }

    /**
     * @custom:attribution https://github.com/sammayo/solidity-rlp-encoder
     * @notice Flattens a list of byte strings into one byte string.
     *
     * @param _list List of byte strings to flatten.
     *
     * @return The flattened byte string.
     */
    function _flatten(bytes[] memory _list) private pure returns (bytes memory) {
        if (_list.length == 0) {
            return new bytes(0);
        }

        uint256 len;
        uint256 i = 0;
        for (; i < _list.length; i++) {
            len += _list[i].length;
        }

        bytes memory flattened = new bytes(len);
        uint256 flattenedPtr;
        assembly {
            flattenedPtr := add(flattened, 0x20)
        }

        for (i = 0; i < _list.length; i++) {
            bytes memory item = _list[i];

            uint256 listPtr;
            assembly {
                listPtr := add(item, 0x20)
            }

            _memcpy(flattenedPtr, listPtr, item.length);
            flattenedPtr += _list[i].length;
        }

        return flattened;
    }
}

File 22 of 27 : SafeCall.sol
// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;

/**
 * @title SafeCall
 * @notice Perform low level safe calls
 */
library SafeCall {
    /**
     * @notice Performs a low level call without copying any returndata.
     * @dev Passes no calldata to the call context.
     *
     * @param _target   Address to call
     * @param _gas      Amount of gas to pass to the call
     * @param _value    Amount of value to pass to the call
     */
    function send(
        address _target,
        uint256 _gas,
        uint256 _value
    ) internal returns (bool) {
        bool _success;
        assembly {
            _success := call(
                _gas, // gas
                _target, // recipient
                _value, // ether value
                0, // inloc
                0, // inlen
                0, // outloc
                0 // outlen
            )
        }
        return _success;
    }

    /**
     * @notice Perform a low level call without copying any returndata
     *
     * @param _target   Address to call
     * @param _gas      Amount of gas to pass to the call
     * @param _value    Amount of value to pass to the call
     * @param _calldata Calldata to pass to the call
     */
    function call(
        address _target,
        uint256 _gas,
        uint256 _value,
        bytes memory _calldata
    ) internal returns (bool) {
        bool _success;
        assembly {
            _success := call(
                _gas, // gas
                _target, // recipient
                _value, // ether value
                add(_calldata, 32), // inloc
                mload(_calldata), // inlen
                0, // outloc
                0 // outlen
            )
        }
        return _success;
    }

    /**
     * @notice Helper function to determine if there is sufficient gas remaining within the context
     *         to guarantee that the minimum gas requirement for a call will be met as well as
     *         optionally reserving a specified amount of gas for after the call has concluded.
     * @param _minGas      The minimum amount of gas that may be passed to the target context.
     * @param _reservedGas Optional amount of gas to reserve for the caller after the execution
     *                     of the target context.
     * @return `true` if there is enough gas remaining to safely supply `_minGas` to the target
     *         context as well as reserve `_reservedGas` for the caller after the execution of
     *         the target context.
     * @dev !!!!! FOOTGUN ALERT !!!!!
     *      1.) The 40_000 base buffer is to account for the worst case of the dynamic cost of the
     *          `CALL` opcode's `address_access_cost`, `positive_value_cost`, and
     *          `value_to_empty_account_cost` factors with an added buffer of 5,700 gas. It is
     *          still possible to self-rekt by initiating a withdrawal with a minimum gas limit
     *          that does not account for the `memory_expansion_cost` & `code_execution_cost`
     *          factors of the dynamic cost of the `CALL` opcode.
     *      2.) This function should *directly* precede the external call if possible. There is an
     *          added buffer to account for gas consumed between this check and the call, but it
     *          is only 5,700 gas.
     *      3.) Because EIP-150 ensures that a maximum of 63/64ths of the remaining gas in the call
     *          frame may be passed to a subcontext, we need to ensure that the gas will not be
     *          truncated.
     *      4.) Use wisely. This function is not a silver bullet.
     */
    function hasMinGas(uint256 _minGas, uint256 _reservedGas) internal view returns (bool) {
        bool _hasMinGas;
        assembly {
            // Equation: gas × 63 ≥ minGas × 64 + 63(40_000 + reservedGas)
            _hasMinGas := iszero(
                lt(mul(gas(), 63), add(mul(_minGas, 64), mul(add(40000, _reservedGas), 63)))
            )
        }
        return _hasMinGas;
    }

    /**
     * @notice Perform a low level call without copying any returndata. This function
     *         will revert if the call cannot be performed with the specified minimum
     *         gas.
     *
     * @param _target   Address to call
     * @param _minGas   The minimum amount of gas that may be passed to the call
     * @param _value    Amount of value to pass to the call
     * @param _calldata Calldata to pass to the call
     */
    function callWithMinGas(
        address _target,
        uint256 _minGas,
        uint256 _value,
        bytes memory _calldata
    ) internal returns (bool) {
        bool _success;
        bool _hasMinGas = hasMinGas(_minGas, 0);
        assembly {
            // Assertion: gasleft() >= (_minGas * 64) / 63 + 40_000
            if iszero(_hasMinGas) {
                // Store the "Error(string)" selector in scratch space.
                mstore(0, 0x08c379a0)
                // Store the pointer to the string length in scratch space.
                mstore(32, 32)
                // Store the string.
                //
                // SAFETY:
                // - We pad the beginning of the string with two zero bytes as well as the
                // length (24) to ensure that we override the free memory pointer at offset
                // 0x40. This is necessary because the free memory pointer is likely to
                // be greater than 1 byte when this function is called, but it is incredibly
                // unlikely that it will be greater than 3 bytes. As for the data within
                // 0x60, it is ensured that it is 0 due to 0x60 being the zero offset.
                // - It's fine to clobber the free memory pointer, we're reverting.
                mstore(88, 0x0000185361666543616c6c3a204e6f7420656e6f75676820676173)

                // Revert with 'Error("SafeCall: Not enough gas")'
                revert(28, 100)
            }

            // The call will be supplied at least ((_minGas * 64) / 63) gas due to the
            // above assertion. This ensures that, in all circumstances (except for when the
            // `_minGas` does not account for the `memory_expansion_cost` and `code_execution_cost`
            // factors of the dynamic cost of the `CALL` opcode), the call will receive at least
            // the minimum amount of gas specified.
            _success := call(
                gas(), // gas
                _target, // recipient
                _value, // ether value
                add(_calldata, 32), // inloc
                mload(_calldata), // inlen
                0x00, // outloc
                0x00 // outlen
            )
        }
        return _success;
    }
}

File 23 of 27 : Types.sol
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

/**
 * @title Types
 * @notice Contains various types used throughout the Optimism contract system.
 */
library Types {
    /**
     * @notice OutputProposal represents a commitment to the L2 state. The timestamp is the L1
     *         timestamp that the output root is posted. This timestamp is used to verify that the
     *         finalization period has passed since the output root was submitted.
     *
     * @custom:field outputRoot    Hash of the L2 output.
     * @custom:field timestamp     Timestamp of the L1 block that the output root was submitted in.
     * @custom:field l2BlockNumber L2 block number that the output corresponds to.
     */
    struct OutputProposal {
        bytes32 outputRoot;
        uint128 timestamp;
        uint128 l2BlockNumber;
    }

    /**
     * @notice Struct representing the elements that are hashed together to generate an output root
     *         which itself represents a snapshot of the L2 state.
     *
     * @custom:field version                  Version of the output root.
     * @custom:field stateRoot                Root of the state trie at the block of this output.
     * @custom:field messagePasserStorageRoot Root of the message passer storage trie.
     * @custom:field latestBlockhash          Hash of the block this output was generated from.
     */
    struct OutputRootProof {
        bytes32 version;
        bytes32 stateRoot;
        bytes32 messagePasserStorageRoot;
        bytes32 latestBlockhash;
    }

    /**
     * @notice Struct representing a deposit transaction (L1 => L2 transaction) created by an end
     *         user (as opposed to a system deposit transaction generated by the system).
     *
     * @custom:field from        Address of the sender of the transaction.
     * @custom:field to          Address of the recipient of the transaction.
     * @custom:field isCreation  True if the transaction is a contract creation.
     * @custom:field value       Value to send to the recipient.
     * @custom:field mint        Amount of ETH to mint.
     * @custom:field gasLimit    Gas limit of the transaction.
     * @custom:field data        Data of the transaction.
     * @custom:field l1BlockHash Hash of the block the transaction was submitted in.
     * @custom:field logIndex    Index of the log in the block the transaction was submitted in.
     */
    struct UserDepositTransaction {
        address from;
        address to;
        bool isCreation;
        uint256 value;
        uint256 mint;
        uint64 gasLimit;
        bytes data;
        bytes32 l1BlockHash;
        uint256 logIndex;
    }

    /**
     * @notice Struct representing a withdrawal transaction.
     *
     * @custom:field nonce    Nonce of the withdrawal transaction
     * @custom:field sender   Address of the sender of the transaction.
     * @custom:field target   Address of the recipient of the transaction.
     * @custom:field value    Value to send to the recipient.
     * @custom:field gasLimit Gas limit of the transaction.
     * @custom:field data     Data of the transaction.
     */
    struct WithdrawalTransaction {
        uint256 nonce;
        address sender;
        address target;
        uint256 value;
        uint256 gasLimit;
        bytes data;
    }
}

File 24 of 27 : CrossDomainMessenger.sol
// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;

import { Initializable } from "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
import { SafeCall } from "../libraries/SafeCall.sol";
import { Hashing } from "../libraries/Hashing.sol";
import { Encoding } from "../libraries/Encoding.sol";
import { Constants } from "../libraries/Constants.sol";

/**
 * @custom:legacy
 * @title CrossDomainMessengerLegacySpacer0
 * @notice Contract only exists to add a spacer to the CrossDomainMessenger where the
 *         libAddressManager variable used to exist. Must be the first contract in the inheritance
 *         tree of the CrossDomainMessenger.
 */
contract CrossDomainMessengerLegacySpacer0 {
    /**
     * @custom:legacy
     * @custom:spacer libAddressManager
     * @notice Spacer for backwards compatibility.
     */
    address private spacer_0_0_20;
}

/**
 * @custom:legacy
 * @title CrossDomainMessengerLegacySpacer1
 * @notice Contract only exists to add a spacer to the CrossDomainMessenger where the
 *         PausableUpgradable and OwnableUpgradeable variables used to exist. Must be
 *         the third contract in the inheritance tree of the CrossDomainMessenger.
 */
contract CrossDomainMessengerLegacySpacer1 {
    /**
     * @custom:legacy
     * @custom:spacer ContextUpgradable's __gap
     * @notice Spacer for backwards compatibility. Comes from OpenZeppelin
     *         ContextUpgradable.
     *
     */
    uint256[50] private spacer_1_0_1600;

    /**
     * @custom:legacy
     * @custom:spacer OwnableUpgradeable's _owner
     * @notice Spacer for backwards compatibility.
     *         Come from OpenZeppelin OwnableUpgradeable.
     */
    address private spacer_51_0_20;

    /**
     * @custom:legacy
     * @custom:spacer OwnableUpgradeable's __gap
     * @notice Spacer for backwards compatibility. Comes from OpenZeppelin
     *         OwnableUpgradeable.
     */
    uint256[49] private spacer_52_0_1568;

    /**
     * @custom:legacy
     * @custom:spacer PausableUpgradable's _paused
     * @notice Spacer for backwards compatibility. Comes from OpenZeppelin
     *         PausableUpgradable.
     */
    bool private spacer_101_0_1;

    /**
     * @custom:legacy
     * @custom:spacer PausableUpgradable's __gap
     * @notice Spacer for backwards compatibility. Comes from OpenZeppelin
     *         PausableUpgradable.
     */
    uint256[49] private spacer_102_0_1568;

    /**
     * @custom:legacy
     * @custom:spacer ReentrancyGuardUpgradeable's `_status` field.
     * @notice Spacer for backwards compatibility.
     */
    uint256 private spacer_151_0_32;

    /**
     * @custom:legacy
     * @custom:spacer ReentrancyGuardUpgradeable's __gap
     * @notice Spacer for backwards compatibility.
     */
    uint256[49] private spacer_152_0_1568;

    /**
     * @custom:legacy
     * @custom:spacer blockedMessages
     * @notice Spacer for backwards compatibility.
     */
    mapping(bytes32 => bool) private spacer_201_0_32;

    /**
     * @custom:legacy
     * @custom:spacer relayedMessages
     * @notice Spacer for backwards compatibility.
     */
    mapping(bytes32 => bool) private spacer_202_0_32;
}

/**
 * @custom:upgradeable
 * @title CrossDomainMessenger
 * @notice CrossDomainMessenger is a base contract that provides the core logic for the L1 and L2
 *         cross-chain messenger contracts. It's designed to be a universal interface that only
 *         needs to be extended slightly to provide low-level message passing functionality on each
 *         chain it's deployed on. Currently only designed for message passing between two paired
 *         chains and does not support one-to-many interactions.
 *
 *         Any changes to this contract MUST result in a semver bump for contracts that inherit it.
 */
abstract contract CrossDomainMessenger is
    CrossDomainMessengerLegacySpacer0,
    Initializable,
    CrossDomainMessengerLegacySpacer1
{
    /**
     * @notice Current message version identifier.
     */
    uint16 public constant MESSAGE_VERSION = 1;

    /**
     * @notice Constant overhead added to the base gas for a message.
     */
    uint64 public constant RELAY_CONSTANT_OVERHEAD = 200_000;

    /**
     * @notice Numerator for dynamic overhead added to the base gas for a message.
     */
    uint64 public constant MIN_GAS_DYNAMIC_OVERHEAD_NUMERATOR = 64;

    /**
     * @notice Denominator for dynamic overhead added to the base gas for a message.
     */
    uint64 public constant MIN_GAS_DYNAMIC_OVERHEAD_DENOMINATOR = 63;

    /**
     * @notice Extra gas added to base gas for each byte of calldata in a message.
     */
    uint64 public constant MIN_GAS_CALLDATA_OVERHEAD = 16;

    /**
     * @notice Gas reserved for performing the external call in `relayMessage`.
     */
    uint64 public constant RELAY_CALL_OVERHEAD = 40_000;

    /**
     * @notice Gas reserved for finalizing the execution of `relayMessage` after the safe call.
     */
    uint64 public constant RELAY_RESERVED_GAS = 40_000;

    /**
     * @notice Gas reserved for the execution between the `hasMinGas` check and the external
     *         call in `relayMessage`.
     */
    uint64 public constant RELAY_GAS_CHECK_BUFFER = 5_000;

    /**
     * @notice Address of the paired CrossDomainMessenger contract on the other chain.
     */
    address public immutable OTHER_MESSENGER;

    /**
     * @notice Mapping of message hashes to boolean receipt values. Note that a message will only
     *         be present in this mapping if it has successfully been relayed on this chain, and
     *         can therefore not be relayed again.
     */
    mapping(bytes32 => bool) public successfulMessages;

    /**
     * @notice Address of the sender of the currently executing message on the other chain. If the
     *         value of this variable is the default value (0x00000000...dead) then no message is
     *         currently being executed. Use the xDomainMessageSender getter which will throw an
     *         error if this is the case.
     */
    address internal xDomainMsgSender;

    /**
     * @notice Nonce for the next message to be sent, without the message version applied. Use the
     *         messageNonce getter which will insert the message version into the nonce to give you
     *         the actual nonce to be used for the message.
     */
    uint240 internal msgNonce;

    /**
     * @notice Mapping of message hashes to a boolean if and only if the message has failed to be
     *         executed at least once. A message will not be present in this mapping if it
     *         successfully executed on the first attempt.
     */
    mapping(bytes32 => bool) public failedMessages;

    /**
     * @notice Reserve extra slots in the storage layout for future upgrades.
     *         A gap size of 41 was chosen here, so that the first slot used in a child contract
     *         would be a multiple of 50.
     */
    uint256[42] private __gap;

    /**
     * @notice Emitted whenever a message is sent to the other chain.
     *
     * @param target       Address of the recipient of the message.
     * @param sender       Address of the sender of the message.
     * @param message      Message to trigger the recipient address with.
     * @param messageNonce Unique nonce attached to the message.
     * @param gasLimit     Minimum gas limit that the message can be executed with.
     */
    event SentMessage(
        address indexed target,
        address sender,
        bytes message,
        uint256 messageNonce,
        uint256 gasLimit
    );

    /**
     * @notice Additional event data to emit, required as of Bedrock. Cannot be merged with the
     *         SentMessage event without breaking the ABI of this contract, this is good enough.
     *
     * @param sender Address of the sender of the message.
     * @param value  ETH value sent along with the message to the recipient.
     */
    event SentMessageExtension1(address indexed sender, uint256 value);

    /**
     * @notice Emitted whenever a message is successfully relayed on this chain.
     *
     * @param msgHash Hash of the message that was relayed.
     */
    event RelayedMessage(bytes32 indexed msgHash);

    /**
     * @notice Emitted whenever a message fails to be relayed on this chain.
     *
     * @param msgHash Hash of the message that failed to be relayed.
     */
    event FailedRelayedMessage(bytes32 indexed msgHash);

    /**
     * @param _otherMessenger Address of the messenger on the paired chain.
     */
    constructor(address _otherMessenger) {
        OTHER_MESSENGER = _otherMessenger;
    }

    /**
     * @notice Sends a message to some target address on the other chain. Note that if the call
     *         always reverts, then the message will be unrelayable, and any ETH sent will be
     *         permanently locked. The same will occur if the target on the other chain is
     *         considered unsafe (see the _isUnsafeTarget() function).
     *
     * @param _target      Target contract or wallet address.
     * @param _message     Message to trigger the target address with.
     * @param _minGasLimit Minimum gas limit that the message can be executed with.
     */
    function sendMessage(
        address _target,
        bytes calldata _message,
        uint32 _minGasLimit
    ) external payable {
        // Triggers a message to the other messenger. Note that the amount of gas provided to the
        // message is the amount of gas requested by the user PLUS the base gas value. We want to
        // guarantee the property that the call to the target contract will always have at least
        // the minimum gas limit specified by the user.
        _sendMessage(
            OTHER_MESSENGER,
            baseGas(_message, _minGasLimit),
            msg.value,
            abi.encodeWithSelector(
                this.relayMessage.selector,
                messageNonce(),
                msg.sender,
                _target,
                msg.value,
                _minGasLimit,
                _message
            )
        );

        emit SentMessage(_target, msg.sender, _message, messageNonce(), _minGasLimit);
        emit SentMessageExtension1(msg.sender, msg.value);

        unchecked {
            ++msgNonce;
        }
    }

    /**
     * @notice Relays a message that was sent by the other CrossDomainMessenger contract. Can only
     *         be executed via cross-chain call from the other messenger OR if the message was
     *         already received once and is currently being replayed.
     *
     * @param _nonce       Nonce of the message being relayed.
     * @param _sender      Address of the user who sent the message.
     * @param _target      Address that the message is targeted at.
     * @param _value       ETH value to send with the message.
     * @param _minGasLimit Minimum amount of gas that the message can be executed with.
     * @param _message     Message to send to the target.
     */
    function relayMessage(
        uint256 _nonce,
        address _sender,
        address _target,
        uint256 _value,
        uint256 _minGasLimit,
        bytes calldata _message
    ) external payable {
        (, uint16 version) = Encoding.decodeVersionedNonce(_nonce);
        require(
            version < 2,
            "CrossDomainMessenger: only version 0 or 1 messages are supported at this time"
        );

        // If the message is version 0, then it's a migrated legacy withdrawal. We therefore need
        // to check that the legacy version of the message has not already been relayed.
        if (version == 0) {
            bytes32 oldHash = Hashing.hashCrossDomainMessageV0(_target, _sender, _message, _nonce);
            require(
                successfulMessages[oldHash] == false,
                "CrossDomainMessenger: legacy withdrawal already relayed"
            );
        }

        // We use the v1 message hash as the unique identifier for the message because it commits
        // to the value and minimum gas limit of the message.
        bytes32 versionedHash = Hashing.hashCrossDomainMessageV1(
            _nonce,
            _sender,
            _target,
            _value,
            _minGasLimit,
            _message
        );

        if (_isOtherMessenger()) {
            // These properties should always hold when the message is first submitted (as
            // opposed to being replayed).
            assert(msg.value == _value);
            assert(!failedMessages[versionedHash]);
        } else {
            require(
                msg.value == 0,
                "CrossDomainMessenger: value must be zero unless message is from a system address"
            );

            require(
                failedMessages[versionedHash],
                "CrossDomainMessenger: message cannot be replayed"
            );
        }

        require(
            _isUnsafeTarget(_target) == false,
            "CrossDomainMessenger: cannot send message to blocked system address"
        );

        require(
            successfulMessages[versionedHash] == false,
            "CrossDomainMessenger: message has already been relayed"
        );

        // If there is not enough gas left to perform the external call and finish the execution,
        // return early and assign the message to the failedMessages mapping.
        // We are asserting that we have enough gas to:
        // 1. Call the target contract (_minGasLimit + RELAY_CALL_OVERHEAD + RELAY_GAS_CHECK_BUFFER)
        //   1.a. The RELAY_CALL_OVERHEAD is included in `hasMinGas`.
        // 2. Finish the execution after the external call (RELAY_RESERVED_GAS).
        //
        // If `xDomainMsgSender` is not the default L2 sender, this function
        // is being re-entered. This marks the message as failed to allow it to be replayed.
        if (
            !SafeCall.hasMinGas(_minGasLimit, RELAY_RESERVED_GAS + RELAY_GAS_CHECK_BUFFER) ||
            xDomainMsgSender != Constants.DEFAULT_L2_SENDER
        ) {
            failedMessages[versionedHash] = true;
            emit FailedRelayedMessage(versionedHash);

            // Revert in this case if the transaction was triggered by the estimation address. This
            // should only be possible during gas estimation or we have bigger problems. Reverting
            // here will make the behavior of gas estimation change such that the gas limit
            // computed will be the amount required to relay the message, even if that amount is
            // greater than the minimum gas limit specified by the user.
            if (tx.origin == Constants.ESTIMATION_ADDRESS) {
                revert("CrossDomainMessenger: failed to relay message");
            }

            return;
        }

        xDomainMsgSender = _sender;
        bool success = SafeCall.call(_target, gasleft() - RELAY_RESERVED_GAS, _value, _message);
        xDomainMsgSender = Constants.DEFAULT_L2_SENDER;

        if (success) {
            successfulMessages[versionedHash] = true;
            emit RelayedMessage(versionedHash);
        } else {
            failedMessages[versionedHash] = true;
            emit FailedRelayedMessage(versionedHash);

            // Revert in this case if the transaction was triggered by the estimation address. This
            // should only be possible during gas estimation or we have bigger problems. Reverting
            // here will make the behavior of gas estimation change such that the gas limit
            // computed will be the amount required to relay the message, even if that amount is
            // greater than the minimum gas limit specified by the user.
            if (tx.origin == Constants.ESTIMATION_ADDRESS) {
                revert("CrossDomainMessenger: failed to relay message");
            }
        }
    }

    /**
     * @notice Retrieves the address of the contract or wallet that initiated the currently
     *         executing message on the other chain. Will throw an error if there is no message
     *         currently being executed. Allows the recipient of a call to see who triggered it.
     *
     * @return Address of the sender of the currently executing message on the other chain.
     */
    function xDomainMessageSender() external view returns (address) {
        require(
            xDomainMsgSender != Constants.DEFAULT_L2_SENDER,
            "CrossDomainMessenger: xDomainMessageSender is not set"
        );

        return xDomainMsgSender;
    }

    /**
     * @notice Retrieves the next message nonce. Message version will be added to the upper two
     *         bytes of the message nonce. Message version allows us to treat messages as having
     *         different structures.
     *
     * @return Nonce of the next message to be sent, with added message version.
     */
    function messageNonce() public view returns (uint256) {
        return Encoding.encodeVersionedNonce(msgNonce, MESSAGE_VERSION);
    }

    /**
     * @notice Computes the amount of gas required to guarantee that a given message will be
     *         received on the other chain without running out of gas. Guaranteeing that a message
     *         will not run out of gas is important because this ensures that a message can always
     *         be replayed on the other chain if it fails to execute completely.
     *
     * @param _message     Message to compute the amount of required gas for.
     * @param _minGasLimit Minimum desired gas limit when message goes to target.
     *
     * @return Amount of gas required to guarantee message receipt.
     */
    function baseGas(bytes calldata _message, uint32 _minGasLimit) public pure returns (uint64) {
        return
            // Constant overhead
            RELAY_CONSTANT_OVERHEAD +
            // Calldata overhead
            (uint64(_message.length) * MIN_GAS_CALLDATA_OVERHEAD) +
            // Dynamic overhead (EIP-150)
            ((_minGasLimit * MIN_GAS_DYNAMIC_OVERHEAD_NUMERATOR) /
                MIN_GAS_DYNAMIC_OVERHEAD_DENOMINATOR) +
            // Gas reserved for the worst-case cost of 3/5 of the `CALL` opcode's dynamic gas
            // factors. (Conservative)
            RELAY_CALL_OVERHEAD +
            // Relay reserved gas (to ensure execution of `relayMessage` completes after the
            // subcontext finishes executing) (Conservative)
            RELAY_RESERVED_GAS +
            // Gas reserved for the execution between the `hasMinGas` check and the `CALL`
            // opcode. (Conservative)
            RELAY_GAS_CHECK_BUFFER;
    }

    /**
     * @notice Intializer.
     */
    // solhint-disable-next-line func-name-mixedcase
    function __CrossDomainMessenger_init() internal onlyInitializing {
        xDomainMsgSender = Constants.DEFAULT_L2_SENDER;
    }

    /**
     * @notice Sends a low-level message to the other messenger. Needs to be implemented by child
     *         contracts because the logic for this depends on the network where the messenger is
     *         being deployed.
     *
     * @param _to       Recipient of the message on the other chain.
     * @param _gasLimit Minimum gas limit the message can be executed with.
     * @param _value    Amount of ETH to send with the message.
     * @param _data     Message data.
     */
    function _sendMessage(
        address _to,
        uint64 _gasLimit,
        uint256 _value,
        bytes memory _data
    ) internal virtual;

    /**
     * @notice Checks whether the message is coming from the other messenger. Implemented by child
     *         contracts because the logic for this depends on the network where the messenger is
     *         being deployed.
     *
     * @return Whether the message is coming from the other messenger.
     */
    function _isOtherMessenger() internal view virtual returns (bool);

    /**
     * @notice Checks whether a given call target is a system address that could cause the
     *         messenger to peform an unsafe action. This is NOT a mechanism for blocking user
     *         addresses. This is ONLY used to prevent the execution of messages to specific
     *         system addresses that could cause security issues, e.g., having the
     *         CrossDomainMessenger send messages to itself.
     *
     * @param _target Address of the contract to check.
     *
     * @return Whether or not the address is an unsafe system address.
     */
    function _isUnsafeTarget(address _target) internal view virtual returns (bool);
}

File 25 of 27 : ERC721Bridge.sol
// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;

import { CrossDomainMessenger } from "./CrossDomainMessenger.sol";
import { Address } from "@openzeppelin/contracts/utils/Address.sol";

/**
 * @title ERC721Bridge
 * @notice ERC721Bridge is a base contract for the L1 and L2 ERC721 bridges.
 */
abstract contract ERC721Bridge {
    /**
     * @notice Messenger contract on this domain.
     */
    CrossDomainMessenger public immutable MESSENGER;

    /**
     * @notice Address of the bridge on the other network.
     */
    address public immutable OTHER_BRIDGE;

    /**
     * @notice Reserve extra slots (to a total of 50) in the storage layout for future upgrades.
     */
    uint256[49] private __gap;

    /**
     * @notice Emitted when an ERC721 bridge to the other network is initiated.
     *
     * @param localToken  Address of the token on this domain.
     * @param remoteToken Address of the token on the remote domain.
     * @param from        Address that initiated bridging action.
     * @param to          Address to receive the token.
     * @param tokenId     ID of the specific token deposited.
     * @param extraData   Extra data for use on the client-side.
     */
    event ERC721BridgeInitiated(
        address indexed localToken,
        address indexed remoteToken,
        address indexed from,
        address to,
        uint256 tokenId,
        bytes extraData
    );

    /**
     * @notice Emitted when an ERC721 bridge from the other network is finalized.
     *
     * @param localToken  Address of the token on this domain.
     * @param remoteToken Address of the token on the remote domain.
     * @param from        Address that initiated bridging action.
     * @param to          Address to receive the token.
     * @param tokenId     ID of the specific token deposited.
     * @param extraData   Extra data for use on the client-side.
     */
    event ERC721BridgeFinalized(
        address indexed localToken,
        address indexed remoteToken,
        address indexed from,
        address to,
        uint256 tokenId,
        bytes extraData
    );

    /**
     * @notice Ensures that the caller is a cross-chain message from the other bridge.
     */
    modifier onlyOtherBridge() {
        require(
            msg.sender == address(MESSENGER) && MESSENGER.xDomainMessageSender() == OTHER_BRIDGE,
            "ERC721Bridge: function can only be called from the other bridge"
        );
        _;
    }

    /**
     * @param _messenger   Address of the CrossDomainMessenger on this network.
     * @param _otherBridge Address of the ERC721 bridge on the other network.
     */
    constructor(address _messenger, address _otherBridge) {
        require(_messenger != address(0), "ERC721Bridge: messenger cannot be address(0)");
        require(_otherBridge != address(0), "ERC721Bridge: other bridge cannot be address(0)");

        MESSENGER = CrossDomainMessenger(_messenger);
        OTHER_BRIDGE = _otherBridge;
    }

    /**
     * @custom:legacy
     * @notice Legacy getter for messenger contract.
     *
     * @return Messenger contract on this domain.
     */
    function messenger() external view returns (CrossDomainMessenger) {
        return MESSENGER;
    }

    /**
     * @custom:legacy
     * @notice Legacy getter for other bridge address.
     *
     * @return Address of the bridge on the other network.
     */
    function otherBridge() external view returns (address) {
        return OTHER_BRIDGE;
    }

    /**
     * @notice Initiates a bridge of an NFT to the caller's account on the other chain. Note that
     *         this function can only be called by EOAs. Smart contract wallets should use the
     *         `bridgeERC721To` function after ensuring that the recipient address on the remote
     *         chain exists. Also note that the current owner of the token on this chain must
     *         approve this contract to operate the NFT before it can be bridged.
     *         **WARNING**: Do not bridge an ERC721 that was originally deployed on Optimism. This
     *         bridge only supports ERC721s originally deployed on Ethereum. Users will need to
     *         wait for the one-week challenge period to elapse before their Optimism-native NFT
     *         can be refunded on L2.
     *
     * @param _localToken  Address of the ERC721 on this domain.
     * @param _remoteToken Address of the ERC721 on the remote domain.
     * @param _tokenId     Token ID to bridge.
     * @param _minGasLimit Minimum gas limit for the bridge message on the other domain.
     * @param _extraData   Optional data to forward to the other chain. Data supplied here will not
     *                     be used to execute any code on the other chain and is only emitted as
     *                     extra data for the convenience of off-chain tooling.
     */
    function bridgeERC721(
        address _localToken,
        address _remoteToken,
        uint256 _tokenId,
        uint32 _minGasLimit,
        bytes calldata _extraData
    ) external {
        // Modifier requiring sender to be EOA. This prevents against a user error that would occur
        // if the sender is a smart contract wallet that has a different address on the remote chain
        // (or doesn't have an address on the remote chain at all). The user would fail to receive
        // the NFT if they use this function because it sends the NFT to the same address as the
        // caller. This check could be bypassed by a malicious contract via initcode, but it takes
        // care of the user error we want to avoid.
        require(!Address.isContract(msg.sender), "ERC721Bridge: account is not externally owned");

        _initiateBridgeERC721(
            _localToken,
            _remoteToken,
            msg.sender,
            msg.sender,
            _tokenId,
            _minGasLimit,
            _extraData
        );
    }

    /**
     * @notice Initiates a bridge of an NFT to some recipient's account on the other chain. Note
     *         that the current owner of the token on this chain must approve this contract to
     *         operate the NFT before it can be bridged.
     *         **WARNING**: Do not bridge an ERC721 that was originally deployed on Optimism. This
     *         bridge only supports ERC721s originally deployed on Ethereum. Users will need to
     *         wait for the one-week challenge period to elapse before their Optimism-native NFT
     *         can be refunded on L2.
     *
     * @param _localToken  Address of the ERC721 on this domain.
     * @param _remoteToken Address of the ERC721 on the remote domain.
     * @param _to          Address to receive the token on the other domain.
     * @param _tokenId     Token ID to bridge.
     * @param _minGasLimit Minimum gas limit for the bridge message on the other domain.
     * @param _extraData   Optional data to forward to the other chain. Data supplied here will not
     *                     be used to execute any code on the other chain and is only emitted as
     *                     extra data for the convenience of off-chain tooling.
     */
    function bridgeERC721To(
        address _localToken,
        address _remoteToken,
        address _to,
        uint256 _tokenId,
        uint32 _minGasLimit,
        bytes calldata _extraData
    ) external {
        require(_to != address(0), "ERC721Bridge: nft recipient cannot be address(0)");

        _initiateBridgeERC721(
            _localToken,
            _remoteToken,
            msg.sender,
            _to,
            _tokenId,
            _minGasLimit,
            _extraData
        );
    }

    /**
     * @notice Internal function for initiating a token bridge to the other domain.
     *
     * @param _localToken  Address of the ERC721 on this domain.
     * @param _remoteToken Address of the ERC721 on the remote domain.
     * @param _from        Address of the sender on this domain.
     * @param _to          Address to receive the token on the other domain.
     * @param _tokenId     Token ID to bridge.
     * @param _minGasLimit Minimum gas limit for the bridge message on the other domain.
     * @param _extraData   Optional data to forward to the other domain. Data supplied here will
     *                     not be used to execute any code on the other domain and is only emitted
     *                     as extra data for the convenience of off-chain tooling.
     */
    function _initiateBridgeERC721(
        address _localToken,
        address _remoteToken,
        address _from,
        address _to,
        uint256 _tokenId,
        uint32 _minGasLimit,
        bytes calldata _extraData
    ) internal virtual;
}

File 26 of 27 : IOptimismMintableERC721.sol
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import {
    IERC721Enumerable
} from "@openzeppelin/contracts/token/ERC721/extensions/IERC721Enumerable.sol";

/**
 * @title IOptimismMintableERC721
 * @notice Interface for contracts that are compatible with the OptimismMintableERC721 standard.
 *         Tokens that follow this standard can be easily transferred across the ERC721 bridge.
 */
interface IOptimismMintableERC721 is IERC721Enumerable {
    /**
     * @notice Emitted when a token is minted.
     *
     * @param account Address of the account the token was minted to.
     * @param tokenId Token ID of the minted token.
     */
    event Mint(address indexed account, uint256 tokenId);

    /**
     * @notice Emitted when a token is burned.
     *
     * @param account Address of the account the token was burned from.
     * @param tokenId Token ID of the burned token.
     */
    event Burn(address indexed account, uint256 tokenId);

    /**
     * @notice Mints some token ID for a user, checking first that contract recipients
     *         are aware of the ERC721 protocol to prevent tokens from being forever locked.
     *
     * @param _to      Address of the user to mint the token for.
     * @param _tokenId Token ID to mint.
     */
    function safeMint(address _to, uint256 _tokenId) external;

    /**
     * @notice Burns a token ID from a user.
     *
     * @param _from    Address of the user to burn the token from.
     * @param _tokenId Token ID to burn.
     */
    function burn(address _from, uint256 _tokenId) external;

    /**
     * @notice Chain ID of the chain where the remote token is deployed.
     */
    function REMOTE_CHAIN_ID() external view returns (uint256);

    /**
     * @notice Address of the token on the remote domain.
     */
    function REMOTE_TOKEN() external view returns (address);

    /**
     * @notice Address of the ERC721 bridge on this network.
     */
    function BRIDGE() external view returns (address);

    /**
     * @notice Chain ID of the chain where the remote token is deployed.
     */
    function remoteChainId() external view returns (uint256);

    /**
     * @notice Address of the token on the remote domain.
     */
    function remoteToken() external view returns (address);

    /**
     * @notice Address of the ERC721 bridge on this network.
     */
    function bridge() external view returns (address);
}

File 27 of 27 : Semver.sol
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import { Strings } from "@openzeppelin/contracts/utils/Strings.sol";

/**
 * @title Semver
 * @notice Semver is a simple contract for managing contract versions.
 */
contract Semver {
    /**
     * @notice Contract version number (major).
     */
    uint256 private immutable MAJOR_VERSION;

    /**
     * @notice Contract version number (minor).
     */
    uint256 private immutable MINOR_VERSION;

    /**
     * @notice Contract version number (patch).
     */
    uint256 private immutable PATCH_VERSION;

    /**
     * @param _major Version number (major).
     * @param _minor Version number (minor).
     * @param _patch Version number (patch).
     */
    constructor(
        uint256 _major,
        uint256 _minor,
        uint256 _patch
    ) {
        MAJOR_VERSION = _major;
        MINOR_VERSION = _minor;
        PATCH_VERSION = _patch;
    }

    /**
     * @notice Returns the full semver contract version.
     *
     * @return Semver contract version as a string.
     */
    function version() public view returns (string memory) {
        return
            string(
                abi.encodePacked(
                    Strings.toString(MAJOR_VERSION),
                    ".",
                    Strings.toString(MINOR_VERSION),
                    ".",
                    Strings.toString(PATCH_VERSION)
                )
            );
    }
}

Settings
{
  "optimizer": {
    "enabled": true,
    "runs": 999999
  },
  "outputSelection": {
    "*": {
      "*": [
        "evm.bytecode",
        "evm.deployedBytecode",
        "devdoc",
        "userdoc",
        "metadata",
        "abi"
      ]
    }
  },
  "metadata": {
    "bytecodeHash": "none"
  },
  "libraries": {}
}

Contract ABI

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A contract address hosts a smart contract, which is a set of code stored on the blockchain that runs when predetermined conditions are met. Learn more about addresses in our Knowledge Base.