# XRBG Source Code (Ethereum)

{% code overflow="wrap" lineNumbers="true" fullWidth="true" %}

```solidity
// SPDX-License-Identifier: GPL-3.0

pragma solidity 0.8.17;

import { ERC20 } from "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import { Ownable } from "@openzeppelin/contracts/access/Ownable.sol";
import { ERC20Burnable } from "@openzeppelin/contracts/token/ERC20/extensions/ERC20Burnable.sol";
import { ERC20Pausable } from "@openzeppelin/contracts/token/ERC20/extensions/ERC20Pausable.sol";
import { LibCommon } from "./lib/LibCommon.sol";

contract CompliantXRBGoldEthereumXRBDAO is ERC20, ERC20Burnable, ERC20Pausable, Ownable {
  uint256 private constant MAX_BPS_AMOUNT = 10_000;
  uint256 private constant MAX_ALLOWED_BPS = 5_000;
  string public constant VERSION = "security_v_1";
  string public constant CONTRACT_NAME = "CompliantXRBGoldEthereumXRBDAO";
  bytes32 public constant CONTRACT_HASH = 0x75b373a0db468cf626d56ef839aad6921667ebcbbe5b48f0e578b602069adbbe;
  /// @notice mapping of blacklisted addresses to a boolean
  mapping(address => bool) private _isBlacklisted;
  /// @notice mapping of whitelisted addresses to a boolean
  mapping(address => bool) public whitelist;
  /// @notice array holding all whitelisted addresses
  address[] public whitelistedAddresses;
  /// @notice support for attaching of documentation for security tokens
  string public initialDocumentUri;
  /// @notice the security token documentation
  string public documentUri;
  /// @notice initial number of tokens which will be minted during initialization
  uint256 public immutable initialSupply;
  /// @notice initial max amount of tokens allowed per wallet
  uint256 public immutable initialMaxTokenAmountPerAddress;
  /// @notice max amount of tokens allowed per wallet
  uint256 public maxTokenAmountPerAddress;
  /// @notice set of features supported by the token
  struct ERC20ConfigProps {
    bool _isMintable;
    bool _isBurnable;
    bool _isPausable;
    bool _isBlacklistEnabled;
    bool _isDocumentAllowed;
    bool _isWhitelistEnabled;
    bool _isMaxAmountOfTokensSet;
    bool _isForceTransferAllowed;
    bool _isTaxable;
    bool _isDeflationary;
  }
  /// @notice features of the token
  ERC20ConfigProps private configProps;
  /// @notice owner of the contract
  address public immutable initialTokenOwner;
  /// @notice number of decimals of the token
  uint8 private immutable _decimals;
  address public taxAddress;
  uint256 public taxBPS;
  uint256 public deflationBPS;

  /// @notice emitted when an address is blacklisted
  event UserBlacklisted(address indexed addr);
  /// @notice emitted when an address is unblacklisted
  event UserUnBlacklisted(address indexed addr);
  /// @notice emitted when a new document is set for the security token
  event DocumentUriSet(string newDocUri);
  /// @notice emitted when a new max amount of tokens per wallet is set
  event MaxTokenAmountPerSet(uint256 newMaxTokenAmount);
  /// @notice emitted when a new whitelist is set
  event UsersWhitelisted(address[] updatedAddresses);
  /// @notice emitted when a new tax address or taxBPS is set
  event TaxConfigSet(address indexed _taxAddress, uint256 indexed _taxBPS);
  /// @notice emitted when a new deflationBPS is set
  event DeflationConfigSet(uint256 indexed _deflationBPS);

  /// @notice raised when the amount sent is zero
  error InvalidMaxTokenAmount(uint256 maxTokenAmount);
  /// @notice raised when the decimals are not in the range 0 - 18
  error InvalidDecimals(uint8 decimals);
  /// @notice raised when setting maxTokenAmount less than current
  error MaxTokenAmountPerAddrLtPrevious();
  /// @notice raised when blacklisting is not enabled
  error BlacklistNotEnabled();
  /// @notice raised when the address is already blacklisted
  error AddrAlreadyBlacklisted(address addr);
  /// @notice raised when the address is already unblacklisted
  error AddrAlreadyUnblacklisted(address addr);
  /// @notice raised when attempting to blacklist a whitelisted address
  error CannotBlacklistWhitelistedAddr(address addr);
  /// @notice raised when a recipient address is blacklisted
  error RecipientBlacklisted(address addr);
  /// @notice raised when a sender address is blacklisted
  error SenderBlacklisted(address addr);
  /// @notice raised when a recipient address is not whitelisted
  error RecipientNotWhitelisted(address addr);
  /// @notice raised when a sender address is not whitelisted
  error SenderNotWhitelisted(address addr);
  /// @notice raised when recipient balance exceeds maxTokenAmountPerAddress
  error DestBalanceExceedsMaxAllowed(address addr);
  /// @notice raised minting is not enabled
  error MintingNotEnabled();
  /// @notice raised when burning is not enabled
  error BurningNotEnabled();
  /// @notice raised when pause is not enabled
  error PausingNotEnabled();
  /// @notice raised when whitelist is not enabled
  error WhitelistNotEnabled();
  /// @notice raised when attempting to whitelist a blacklisted address
  error CannotWhitelistBlacklistedAddr(address addr);
  /// @notice raised when trying to set a document URI when not allowed
  error DocumentUriNotAllowed();
  /// @notice raised when trying to set a max amount of tokens when not allowed
  error MaxTokenAmountNotAllowed();
  /// @notice raised when trying to set a tax address or taxBPS when not allowed
  error TokenIsNotTaxable();
  /// @notice raised when trying to set a deflationBPS when not allowed
  error TokenIsNotDeflationary();
  /// @notice raised when trying to set an invalid taxBPS
  error InvalidTaxBPS(uint256 bps);
  /// @notice raised when trying to set and invalid deflationBPS
  error InvalidDeflationBPS(uint256 bps);

  /**
   * @notice modifier for validating if transfer is possible and valid
   * @param sender the sender of the transaction
   * @param recipient the recipient of the transaction
   */
  modifier validateTransfer(address sender, address recipient) {
    if (isWhitelistEnabled()) {
      if (!whitelist[sender]) {
        revert SenderNotWhitelisted(sender);
      }
      if (!whitelist[recipient]) {
        revert RecipientNotWhitelisted(recipient);
      }
      if (
        sender != msg.sender && msg.sender != owner() && !whitelist[msg.sender]
      ) {
        revert SenderNotWhitelisted(msg.sender);
      }
    }
    if (isBlacklistEnabled()) {
      if (_isBlacklisted[sender]) {
        revert SenderBlacklisted(sender);
      }
      if (_isBlacklisted[recipient]) {
        revert RecipientBlacklisted(recipient);
      }
      if (
        sender != msg.sender &&
        msg.sender != owner() &&
        _isBlacklisted[msg.sender]
      ) {
        revert SenderBlacklisted(msg.sender);
      }
    }
    _;
  }

  constructor(
    string memory name_,
    string memory symbol_,
    uint256 initialSupplyToSet,
    uint8 decimalsToSet,
    address tokenOwner,
    ERC20ConfigProps memory customConfigProps,
    uint256 maxTokenAmount,
    string memory newDocumentUri,
    address _taxAddress,
    uint256 _taxBPS,
    uint256 _deflationBPS
  ) ERC20(name_, symbol_) {
    if (customConfigProps._isMaxAmountOfTokensSet) {
      if (maxTokenAmount == 0) {
        revert InvalidMaxTokenAmount(maxTokenAmount);
      }
    }
    if (decimalsToSet > 18) {
      revert InvalidDecimals(decimalsToSet);
    }
    if (customConfigProps._isTaxable) {
      if (_taxBPS > MAX_ALLOWED_BPS) {
        revert InvalidTaxBPS(_taxBPS);
      }
      LibCommon.validateAddress(_taxAddress);
      taxAddress = _taxAddress;
      taxBPS = _taxBPS;
    }
    if (customConfigProps._isDeflationary) {
      if (_deflationBPS > MAX_ALLOWED_BPS) {
        revert InvalidDeflationBPS(_deflationBPS);
      }
      deflationBPS = _deflationBPS;
    }
    LibCommon.validateAddress(tokenOwner);

    initialSupply = initialSupplyToSet;
    initialMaxTokenAmountPerAddress = maxTokenAmount;
    initialDocumentUri = newDocumentUri;
    initialTokenOwner = tokenOwner;
    _decimals = decimalsToSet;
    configProps = customConfigProps;
    documentUri = newDocumentUri;
    maxTokenAmountPerAddress = maxTokenAmount;

    if (initialSupplyToSet != 0) {
      _mint(tokenOwner, initialSupplyToSet * 10 ** decimalsToSet);
    }

    if (tokenOwner != msg.sender) {
      transferOwnership(tokenOwner);
    }
  }

  /**
   * @notice hook called before any transfer of tokens. This includes minting and burning
   * imposed by the ERC20 standard
   * @param from - address of the sender
   * @param to - address of the recipient
   * @param amount - amount of tokens to transfer
   */
  function _beforeTokenTransfer(
    address from,
    address to,
    uint256 amount
  ) internal virtual override(ERC20, ERC20Pausable) {
    super._beforeTokenTransfer(from, to, amount);
  }

  /// @notice method which checks if the token is pausable
  function isPausable() public view returns (bool) {
    return configProps._isPausable;
  }

  /// @notice method which checks if the token is mintable
  function isMintable() public view returns (bool) {
    return configProps._isMintable;
  }

  /// @notice method which checks if the token is burnable
  function isBurnable() public view returns (bool) {
    return configProps._isBurnable;
  }

  /// @notice method which checks if the token supports blacklisting
  function isBlacklistEnabled() public view returns (bool) {
    return configProps._isBlacklistEnabled;
  }

  /// @notice method which checks if the token supports whitelisting
  function isWhitelistEnabled() public view returns (bool) {
    return configProps._isWhitelistEnabled;
  }

  /// @notice method which checks if the token supports max amount of tokens per wallet
  function isMaxAmountOfTokensSet() public view returns (bool) {
    return configProps._isMaxAmountOfTokensSet;
  }

  /// @notice method which checks if the token supports documentUris
  function isDocumentUriAllowed() public view returns (bool) {
    return configProps._isDocumentAllowed;
  }

  /// @notice method which checks if the token supports force transfers
  function isForceTransferAllowed() public view returns (bool) {
    return configProps._isForceTransferAllowed;
  }

  /// @notice method which returns the number of decimals for the token
  function decimals() public view virtual override returns (uint8) {
    return _decimals;
  }

  /// @notice method which checks if the token is taxable
  function isTaxable() public view returns (bool) {
    return configProps._isTaxable;
  }

  /// @notice method which checks if the token is deflationary
  function isDeflationary() public view returns (bool) {
    return configProps._isDeflationary;
  }

  /**
   * @notice which returns an array of all the whitelisted addresses
   * @return whitelistedAddresses array of all the whitelisted addresses
   */
  function getWhitelistedAddresses() external view returns (address[] memory) {
    return whitelistedAddresses;
  }

  /**
   * @notice method which allows the owner to set a documentUri
   * @param newDocumentUri - the new documentUri
   * @dev only callable by the owner
   */
  function setDocumentUri(
    string memory newDocumentUri
  ) external onlyOwner whenNotPaused {
    if (!isDocumentUriAllowed()) {
      revert DocumentUriNotAllowed();
    }
    documentUri = newDocumentUri;
    emit DocumentUriSet(newDocumentUri);
  }

  /**
   * @notice method which allows the owner to set a max amount of tokens per wallet
   * @param newMaxTokenAmount - the new max amount of tokens per wallet
   * @dev only callable by the owner
   */
  function setMaxTokenAmountPerAddress(
    uint256 newMaxTokenAmount
  ) external onlyOwner whenNotPaused {
    if (!isMaxAmountOfTokensSet()) {
      revert MaxTokenAmountNotAllowed();
    }
    if (newMaxTokenAmount <= maxTokenAmountPerAddress) {
      revert MaxTokenAmountPerAddrLtPrevious();
    }

    maxTokenAmountPerAddress = newMaxTokenAmount;
    emit MaxTokenAmountPerSet(newMaxTokenAmount);
  }

  /**
   * @notice method which allows the owner to blacklist an address
   * @param addr - the address to blacklist
   * @dev only callable by the owner
   * @dev only callable if the token is not paused
   * @dev only callable if the token supports blacklisting
   * @dev only callable if the address is not already blacklisted
   * @dev only callable if the address is not whitelisted
   */
  function blackList(address addr) external onlyOwner whenNotPaused {
    LibCommon.validateAddress(addr);
    if (!isBlacklistEnabled()) {
      revert BlacklistNotEnabled();
    }
    if (_isBlacklisted[addr]) {
      revert AddrAlreadyBlacklisted(addr);
    }
    if (isWhitelistEnabled() && whitelist[addr]) {
      revert CannotBlacklistWhitelistedAddr(addr);
    }

    _isBlacklisted[addr] = true;
    emit UserBlacklisted(addr);
  }

  /**
   * @notice method which allows the owner to unblacklist an address
   * @param addr - the address to unblacklist
   * @dev only callable by the owner
   * @dev only callable if the token is not paused
   * @dev only callable if the token supports blacklisting
   * @dev only callable if the address is blacklisted
   */
  function removeFromBlacklist(address addr) external onlyOwner whenNotPaused {
    LibCommon.validateAddress(addr);
    if (!isBlacklistEnabled()) {
      revert BlacklistNotEnabled();
    }
    if (!_isBlacklisted[addr]) {
      revert AddrAlreadyUnblacklisted(addr);
    }
    delete _isBlacklisted[addr];
    emit UserUnBlacklisted(addr);
  }

  /**
   * @notice method which allows the owner to set the tax config
   * @param _taxAddress - the new taxAddress
   * @param _taxBPS - the new taxBPS
   */
  function setTaxConfig(
    address _taxAddress,
    uint256 _taxBPS
  ) external onlyOwner whenNotPaused {
    if (!isTaxable()) {
      revert TokenIsNotTaxable();
    }
    if (_taxBPS > MAX_ALLOWED_BPS) {
      revert InvalidTaxBPS(_taxBPS);
    }
    LibCommon.validateAddress(_taxAddress);
    taxAddress = _taxAddress;
    taxBPS = _taxBPS;
    emit TaxConfigSet(_taxAddress, _taxBPS);
  }

  /**
   * @notice method which allows the owner to set the deflation config
   * @param _deflationBPS - the new deflationBPS
   */
  function setDeflationConfig(
    uint256 _deflationBPS
  ) external onlyOwner whenNotPaused {
    if (!isDeflationary()) {
      revert TokenIsNotDeflationary();
    }
    if (_deflationBPS > MAX_ALLOWED_BPS) {
      revert InvalidDeflationBPS(_deflationBPS);
    }
    deflationBPS = _deflationBPS;
    emit DeflationConfigSet(_deflationBPS);
  }

  /**
   * @notice method which allows to transfer a predefined amount of tokens to a predefined address
   * @param to - the address to transfer the tokens to
   * @param amount - the amount of tokens to transfer
   * @return true if the transfer was successful
   * @dev only callable if the token is not paused
   * @dev only callable if the balance of the receiver is lower than the max amount of tokens per wallet
   * @dev checks if blacklisting is enabled and if the sender and receiver are not blacklisted
   * @dev checks if whitelisting is enabled and if the sender and receiver are whitelisted
   * @dev captures the tax during the transfer if tax is enabvled
   * @dev burns the deflationary amount during the transfer if deflation is enabled
   */
  function transfer(
    address to,
    uint256 amount
  )
    public
    virtual
    override
    whenNotPaused
    validateTransfer(msg.sender, to)
    returns (bool)
  {
    uint256 taxAmount = _taxAmount(msg.sender, amount);
    uint256 deflationAmount = _deflationAmount(amount);
    uint256 amountToTransfer = amount - taxAmount - deflationAmount;

    if (isMaxAmountOfTokensSet()) {
      if (balanceOf(to) + amountToTransfer > maxTokenAmountPerAddress) {
        revert DestBalanceExceedsMaxAllowed(to);
      }
    }

    if (taxAmount != 0) {
      _transfer(msg.sender, taxAddress, taxAmount);
    }
    if (deflationAmount != 0) {
      _burn(msg.sender, deflationAmount);
    }
    return super.transfer(to, amountToTransfer);
  }

  /**
   * @notice method which allows to transfer a predefined amount of tokens from a predefined address to a predefined address
   * @param from - the address to transfer the tokens from
   * @param to - the address to transfer the tokens to
   * @param amount - the amount of tokens to transfer
   * @return true if the transfer was successful
   * @dev only callable if the token is not paused
   * @dev only callable if the balance of the receiver is lower than the max amount of tokens per wallet
   * @dev checks if blacklisting is enabled and if the sender and receiver are not blacklisted
   * @dev checks if whitelisting is enabled and if the sender and receiver are whitelisted
   * @dev captures the tax during the transfer if tax is enabvled
   * @dev burns the deflationary amount during the transfer if deflation is enabled
   */
  function transferFrom(
    address from,
    address to,
    uint256 amount
  )
    public
    virtual
    override
    whenNotPaused
    validateTransfer(from, to)
    returns (bool)
  {
    uint256 taxAmount = _taxAmount(from, amount);
    uint256 deflationAmount = _deflationAmount(amount);
    uint256 amountToTransfer = amount - taxAmount - deflationAmount;

    if (isMaxAmountOfTokensSet()) {
      if (balanceOf(to) + amountToTransfer > maxTokenAmountPerAddress) {
        revert DestBalanceExceedsMaxAllowed(to);
      }
    }

    if (taxAmount != 0) {
      _transfer(from, taxAddress, taxAmount);
    }
    if (deflationAmount != 0) {
      _burn(from, deflationAmount);
    }

    if (isForceTransferAllowed() && owner() == msg.sender) {
      _transfer(from, to, amountToTransfer);
      return true;
    } else {
      return super.transferFrom(from, to, amountToTransfer);
    }
  }

  /**
   * @notice method which allows to mint a predefined amount of tokens to a predefined address
   * @param to - the address to mint the tokens to
   * @param amount - the amount of tokens to mint
   * @dev only callable by the owner
   * @dev only callable if the token is not paused
   * @dev only callable if the token supports additional minting
   * @dev only callable if the balance of the receiver is lower than the max amount of tokens per wallet
   * @dev checks if blacklisting is enabled and if the receiver is not blacklisted
   * @dev checks if whitelisting is enabled and if the receiver is whitelisted
   */
  function mint(address to, uint256 amount) external onlyOwner whenNotPaused {
    if (!isMintable()) {
      revert MintingNotEnabled();
    }
    if (isMaxAmountOfTokensSet()) {
      if (balanceOf(to) + amount > maxTokenAmountPerAddress) {
        revert DestBalanceExceedsMaxAllowed(to);
      }
    }
    if (isBlacklistEnabled()) {
      if (_isBlacklisted[to]) {
        revert RecipientBlacklisted(to);
      }
    }
    if (isWhitelistEnabled()) {
      if (!whitelist[to]) {
        revert RecipientNotWhitelisted(to);
      }
    }

    super._mint(to, amount);
  }

  /**
   * @notice method which allows to burn a predefined amount of tokens
   * @param amount - the amount of tokens to burn
   * @dev only callable by the owner
   * @dev only callable if the token is not paused
   * @dev only callable if the token supports burning
   */
  function burn(uint256 amount) public override onlyOwner whenNotPaused {
    if (!isBurnable()) {
      revert BurningNotEnabled();
    }
    super.burn(amount);
  }

  /**
   * @notice method which allows to burn a predefined amount of tokens from a predefined address
   * @param from - the address to burn the tokens from
   * @param amount - the amount of tokens to burn
   * @dev only callable by the owner
   * @dev only callable if the token is not paused
   * @dev only callable if the token supports burning
   */
  function burnFrom(
    address from,
    uint256 amount
  ) public override onlyOwner whenNotPaused {
    if (!isBurnable()) {
      revert BurningNotEnabled();
    }
    super.burnFrom(from, amount);
  }

  /**
   * @notice method which allows to pause the token
   * @dev only callable by the owner
   */
  function pause() external onlyOwner {
    if (!isPausable()) {
      revert PausingNotEnabled();
    }
    _pause();
  }

  /**
   * @notice method which allows to unpause the token
   * @dev only callable by the owner
   */
  function unpause() external onlyOwner {
    if (!isPausable()) {
      revert PausingNotEnabled();
    }
    _unpause();
  }

  /**
   * @notice method which allows to removing the owner of the token
   * @dev methods which are only callable by the owner will not be callable anymore
   * @dev only callable by the owner
   * @dev only callable if the token is not paused
   */
  function renounceOwnership() public override onlyOwner whenNotPaused {
    super.renounceOwnership();
  }

  /**
   * @notice method which allows to transfer the ownership of the token
   * @param newOwner - the address of the new owner
   * @dev only callable by the owner
   * @dev only callable if the token is not paused
   */
  function transferOwnership(
    address newOwner
  ) public override onlyOwner whenNotPaused {
    super.transferOwnership(newOwner);
  }

  /**
   * @notice method which allows to update the whitelist of the token
   * @param updatedAddresses - the new set of addresses
   * @dev only callable by the owner
   * @dev only callable if the token supports whitelisting
   */
  function updateWhitelist(
    address[] calldata updatedAddresses
  ) external onlyOwner whenNotPaused {
    if (!isWhitelistEnabled()) {
      revert WhitelistNotEnabled();
    }
    _clearWhitelist();
    _addManyToWhitelist(updatedAddresses);
    whitelistedAddresses = updatedAddresses;
    emit UsersWhitelisted(updatedAddresses);
  }

  /**
   * @notice method which allows for adding a new set of addresses to the whitelist
   * @param addresses - the addresses to add to the whitelist
   * @dev called internally by the contract
   * @dev only callable if any of the addresses are not already whitelisted
   */
  function _addManyToWhitelist(address[] calldata addresses) private {
    for (uint256 i; i < addresses.length; ) {
      LibCommon.validateAddress(addresses[i]);
      if (configProps._isBlacklistEnabled && _isBlacklisted[addresses[i]]) {
        revert CannotWhitelistBlacklistedAddr(addresses[i]);
      }
      whitelist[addresses[i]] = true;
      unchecked {
        ++i;
      }
    }
  }

  /**
   * @notice method which allows for removing a set of addresses from the whitelist
   */
  function _clearWhitelist() private {
    unchecked {
      address[] memory addresses = whitelistedAddresses;
      for (uint256 i; i < addresses.length; i++) {
        delete whitelist[addresses[i]];
      }
    }
  }

  /**
   * @notice method which returns the amount of tokens to be taxed during a transfer
   * @param sender - the address of the originating account
   * @param amount - the total amount of tokens sent in the transfer
   * @dev if the tax address is the same as the originating account performing the transfer, no tax is applied
   */
  function _taxAmount(
    address sender,
    uint256 amount
  ) internal view returns (uint256 taxAmount) {
    taxAmount = 0;
    if (taxBPS != 0 && sender != taxAddress) {
      taxAmount = (amount * taxBPS) / MAX_BPS_AMOUNT;
    }
  }

  /**
   * @notice method which returns the amount of tokens to be burned during a transfer
   * @param amount - the total amount of tokens sent in the transfer
   */
  function _deflationAmount(
    uint256 amount
  ) internal view returns (uint256 deflationAmount) {
    deflationAmount = 0;
    if (deflationBPS != 0) {
      deflationAmount = (amount * deflationBPS) / MAX_BPS_AMOUNT;
    }
  }
}
```

{% endcode %}


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://whitepaper.xrb.gold/the-design-of-xrbg/smart-contract-and-technology/xrbg-source-code-ethereum.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.