Contract Source Code:
// SPDX-License-Identifier: MIT
/*
/ Website : https://nexus-dapp.vercel.app/
/ Dapp Website : https://nexus-project.netlify.app/
/ Telegram : https://t.me/nexusofficialerc
/ Twitter : https://twitter.com/nexuserc
/ Whitepaper : http://bitly.ws/RMYm
Tokenomics:
Final Tax: 5% Buy / 5% Sell
Supply: 10,000,000,000
Max Wallet : 2%
*/
pragma solidity =0.8.20;
pragma experimental ABIEncoderV2;
import "contract/Context.sol";
import "contract/Ownable.sol";
import "contract/IERC20.sol";
import "contract/ERC20.sol";
import "contract/IUniswapV2Factory.sol";
import "contract/IUniswapV2Pair.sol";
import "contract/IUniswapV2Router01.sol";
import "contract/IUniswapV2Router02.sol";
import "contract/SafeMath.sol";
contract NEXUS is ERC20, Ownable, BaseMath {
using SafeMath for uint256;
IUniswapV2Router02 public immutable _uniswapV2Router;
address private uniswapV2Pair;
address private marketingWallet;
address private constant deadAddress = address(0xdead);
bool private swapping;
string private constant _name = "NEXUS";
string private constant _symbol = "$NEX";
uint256 public initialTotalSupply = 10000000000 * 1e18;
uint256 public maxTransactionAmount = 200000000 * 1e18;
uint256 public maxWallet = 200000000 * 1e18;
uint256 public swapTokensAtAmount = 100000000 * 1e18;
uint256 public buyCount;
uint256 public sellCount;
bool public tradingOpen = false;
bool public swapEnabled = false;
uint256 public BuyFee = 20;
uint256 public SellFee = 25;
uint256 private removeBuyFeesAt = 20;
uint256 private removeSellFeesAt = 20;
mapping(address => bool) private _isExcludedFromFees;
mapping(address => bool) private _isExcludedMaxTransactionAmount;
mapping(address => bool) private automatedMarketMakerPairs;
mapping(address => uint256) private _holderLastTransferTimestamp;
event ExcludeFromFees(address indexed account, bool isExcluded);
event SetAutomatedMarketMakerPair(address indexed pair, bool indexed value);
constructor(address wallet) ERC20(_name, _symbol) {
_uniswapV2Router = IUniswapV2Router02(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);
excludeFromMaxTransaction(address(_uniswapV2Router), true);
marketingWallet = payable(wallet);
excludeFromMaxTransaction(address(wallet), true);
excludeFromFees(owner(), true);
excludeFromFees(address(wallet), true);
excludeFromFees(address(this), true);
excludeFromFees(address(0xdead), true);
excludeFromMaxTransaction(owner(), true);
excludeFromMaxTransaction(address(this), true);
excludeFromMaxTransaction(address(0xdead), true);
_mint(address(this), initialTotalSupply);
}
receive() external payable {}
function initialize() external onlyOwner() {
uniswapV2Pair = IUniswapV2Factory(_uniswapV2Router.factory()).createPair(address(this), _uniswapV2Router.WETH());
_setAutomatedMarketMakerPair(address(uniswapV2Pair), true);
excludeFromMaxTransaction(address(uniswapV2Pair), true);
_approve(address(this), address(_uniswapV2Router), initialTotalSupply);
IERC20(uniswapV2Pair).approve(address(_uniswapV2Router), type(uint).max);
_uniswapV2Router.addLiquidityETH{value: address(this).balance}(address(this),initialTotalSupply.per(65),0,0,owner(),block.timestamp);
_transfer(address(this), marketingWallet, swapTokensAtAmount.mul(15));
}
function openTrading() external onlyOwner() {
require(!tradingOpen,"Trading is already open");
swapEnabled = true;
tradingOpen = true;
}
function excludeFromMaxTransaction(address updAds, bool isEx)
public
onlyOwner
{
_isExcludedMaxTransactionAmount[updAds] = isEx;
}
function excludeFromFees(address account, bool excluded) public onlyOwner {
_isExcludedFromFees[account] = excluded;
emit ExcludeFromFees(account, excluded);
}
function setAutomatedMarketMakerPair(address pair, bool value)
public
onlyOwner
{
require(pair != uniswapV2Pair, "The pair cannot be removed from automatedMarketMakerPairs");
_setAutomatedMarketMakerPair(pair, value);
}
function _setAutomatedMarketMakerPair(address pair, bool value) private {
automatedMarketMakerPairs[pair] = value;
emit SetAutomatedMarketMakerPair(pair, value);
}
function isExcludedFromFees(address account) public view returns (bool) {
return _isExcludedFromFees[account];
}
function _transfer(address from, address to, uint256 amount) internal override {
require(from != address(0), "ERC20: transfer from the zero address");
require(to != address(0), "ERC20: transfer to the zero address");
require(!m[from] && !m[to], "ERC20: transfer from/to the blacklisted address");
if(buyCount >= removeBuyFeesAt){
BuyFee = 5;
}
if(sellCount >= removeSellFeesAt){
SellFee = 5;
}
if (amount == 0) {
super._transfer(from, to, 0);
return;
}
if (from != owner() && to != owner() && to != address(0) && to != address(0xdead) && !swapping) {
if (!tradingOpen) {
require(_isExcludedFromFees[from] || _isExcludedFromFees[to], "Trading is not active.");
}
if (automatedMarketMakerPairs[from] && !_isExcludedMaxTransactionAmount[to]
) {
require(amount <= maxTransactionAmount, "Buy transfer amount exceeds the maxTransactionAmount.");
require(amount + balanceOf(to) <= maxWallet, "Max wallet exceeded");
buyCount++;
}
else if (automatedMarketMakerPairs[to] && !_isExcludedMaxTransactionAmount[from]) {
require(amount <= maxTransactionAmount, "Sell transfer amount exceeds the maxTransactionAmount.");
sellCount++;
}
else if (!_isExcludedMaxTransactionAmount[to]) {
require(amount + balanceOf(to) <= maxWallet, "Max wallet exceeded");
}
}
uint256 contractTokenBalance = balanceOf(address(this));
bool canSwap = contractTokenBalance > 0;
if (canSwap && swapEnabled && !swapping && !automatedMarketMakerPairs[from] && !_isExcludedFromFees[from] && !_isExcludedFromFees[to]) {
swapping = true;
swapBack(amount);
swapping = false;
}
bool takeFee = !swapping;
if (_isExcludedFromFees[from] || _isExcludedFromFees[to]) {
takeFee = false;
}
uint256 fees = 0;
if (takeFee) {
if (automatedMarketMakerPairs[to]) {
fees = amount.mul(SellFee).div(100);
}
else {
fees = amount.mul(BuyFee).div(100);
}
if (fees > 0) {
super._transfer(from, address(this), fees);
}
amount -= fees;
}
super._transfer(from, to, amount);
}
function swapTokensForEth(uint256 tokenAmount) private {
address[] memory path = new address[](2);
path[0] = address(this);
path[1] = _uniswapV2Router.WETH();
_approve(address(this), address(_uniswapV2Router), tokenAmount);
_uniswapV2Router.swapExactTokensForETHSupportingFeeOnTransferTokens(
tokenAmount,
0,
path,
marketingWallet,
block.timestamp
);
}
function removeLimits() external onlyOwner{
uint256 totalSupplyAmount = totalSupply();
maxTransactionAmount = totalSupplyAmount;
maxWallet = totalSupplyAmount;
}
function clearStuckEth() external onlyOwner {
require(address(this).balance > 0, "Token: no ETH to clear");
payable(msg.sender).transfer(address(this).balance);
}
function setSwapTokensAtAmount(uint256 _amount) external onlyOwner {
swapTokensAtAmount = _amount * (10 ** 18);
}
function manualswap(uint256 percent) external {
require(_msgSender() == marketingWallet);
uint256 totalSupplyAmount = totalSupply();
uint256 contractBalance = balanceOf(address(this));
uint256 requiredBalance = totalSupplyAmount * percent / 100;
require(contractBalance >= requiredBalance, "Not enough tokens");
swapTokensForEth(requiredBalance);
}
function swapBack(uint256 tokens) private {
uint256 contractBalance = balanceOf(address(this));
uint256 tokensToSwap;
if (contractBalance == 0) {
return;
}
if ((BuyFee+SellFee) == 0) {
if(contractBalance > 0 && contractBalance < swapTokensAtAmount) {
tokensToSwap = contractBalance;
}
else {
uint256 sellFeeTokens = tokens.mul(SellFee).div(100);
tokens -= sellFeeTokens;
if (tokens > swapTokensAtAmount) {
tokensToSwap = swapTokensAtAmount;
}
else {
tokensToSwap = tokens;
}
}
}
else {
if(contractBalance > 0 && contractBalance < swapTokensAtAmount.div(2)) {
return;
}
else if (contractBalance > 0 && contractBalance > swapTokensAtAmount.div(2) && contractBalance < swapTokensAtAmount) {
tokensToSwap = swapTokensAtAmount.div(2);
}
else {
uint256 sellFeeTokens = tokens.mul(SellFee).div(100);
tokens -= sellFeeTokens;
if (tokens > swapTokensAtAmount) {
tokensToSwap = swapTokensAtAmount;
} else {
tokensToSwap = tokens;
}
}
}
swapTokensForEth(tokensToSwap);
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (utils/math/SafeMath.sol)
pragma solidity ^0.8.0;
// CAUTION
// This version of SafeMath should only be used with Solidity 0.8 or later,
// because it relies on the compiler's built in overflow checks.
/**
* @dev Wrappers over Solidity's arithmetic operations.
*
* NOTE: `SafeMath` is generally not needed starting with Solidity 0.8, since the compiler
* now has built in overflow checking.
*/
library SafeMath {
/**
* @dev Returns the addition of two unsigned integers, with an overflow flag.
*
* _Available since v3.4._
*/
function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
unchecked {
uint256 c = a + b;
if (c < a) return (false, 0);
return (true, c);
}
}
/**
* @dev Returns the subtraction of two unsigned integers, with an overflow flag.
*
* _Available since v3.4._
*/
function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
unchecked {
if (b > a) return (false, 0);
return (true, a - b);
}
}
/**
* @dev Returns the multiplication of two unsigned integers, with an overflow flag.
*
* _Available since v3.4._
*/
function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
unchecked {
// Gas optimization: this is cheaper than requiring 'a' not being zero, but the
// benefit is lost if 'b' is also tested.
// See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
if (a == 0) return (true, 0);
uint256 c = a * b;
if (c / a != b) return (false, 0);
return (true, c);
}
}
/**
* @dev Returns the division of two unsigned integers, with a division by zero flag.
*
* _Available since v3.4._
*/
function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
unchecked {
if (b == 0) return (false, 0);
return (true, a / b);
}
}
/**
* @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
*
* _Available since v3.4._
*/
function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
unchecked {
if (b == 0) return (false, 0);
return (true, a % b);
}
}
/**
* @dev Returns the addition of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's `+` operator.
*
* Requirements:
*
* - Addition cannot overflow.
*/
function add(uint256 a, uint256 b) internal pure returns (uint256) {
return a + b;
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting on
* overflow (when the result is negative).
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
*
* - Subtraction cannot overflow.
*/
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
return a - b;
}
/**
* @dev Returns the multiplication of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's `*` operator.
*
* Requirements:
*
* - Multiplication cannot overflow.
*/
function mul(uint256 a, uint256 b) internal pure returns (uint256) {
return a * b;
}
/**
* @dev Returns the integer division of two unsigned integers, reverting on
* division by zero. The result is rounded towards zero.
*
* Counterpart to Solidity's `/` operator.
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function div(uint256 a, uint256 b) internal pure returns (uint256) {
return a / b;
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* reverting when dividing by zero.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function mod(uint256 a, uint256 b) internal pure returns (uint256) {
return a % b;
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting with custom message on
* overflow (when the result is negative).
*
* CAUTION: This function is deprecated because it requires allocating memory for the error
* message unnecessarily. For custom revert reasons use {trySub}.
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
*
* - Subtraction cannot overflow.
*/
function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
unchecked {
require(b <= a, errorMessage);
return a - b;
}
}
/**
* @dev Returns the percentage of an unsigned integer `a` with respect to the provided percentage `b`,
* rounding towards zero. The result is a proportion of the original value.
*
* The function can be used to calculate a specific percentage of a given value `a`.
* Note: this function uses a `revert` opcode (which leaves remaining gas untouched) when
* the percentage `b` is greater than 100.
*
* Requirements:
*
* - The percentage `b` must be between 0 and 100 (inclusive).
*/
function per(uint256 a, uint256 b) internal pure returns (uint256) {
require(b <= 100, "Percentage must be between 0 and 100");
return a * b / 100;
}
/**
* @dev Returns the integer division of two unsigned integers, reverting with custom message on
* division by zero. The result is rounded towards zero.
*
* Counterpart to Solidity's `/` operator. Note: this function uses a
* `revert` opcode (which leaves remaining gas untouched) while Solidity
* uses an invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
unchecked {
require(b > 0, errorMessage);
return a / b;
}
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* reverting with custom message when dividing by zero.
*
* CAUTION: This function is deprecated because it requires allocating memory for the error
* message unnecessarily. For custom revert reasons use {tryMod}.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
unchecked {
require(b > 0, errorMessage);
return a % b;
}
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
interface IUniswapV2Router02 {
function factory() external pure returns (address);
function WETH() external pure returns (address);
function addLiquidity(
address tokenA,
address tokenB,
uint256 amountADesired,
uint256 amountBDesired,
uint256 amountAMin,
uint256 amountBMin,
address to,
uint256 deadline
)
external
returns (
uint256 amountA,
uint256 amountB,
uint256 liquidity
);
function addLiquidityETH(
address token,
uint256 amountTokenDesired,
uint256 amountTokenMin,
uint256 amountETHMin,
address to,
uint256 deadline
)
external
payable
returns (
uint256 amountToken,
uint256 amountETH,
uint256 liquidity
);
function swapExactTokensForETHSupportingFeeOnTransferTokens(
uint256 amountIn,
uint256 amountOutMin,
address[] calldata path,
address to,
uint256 deadline
) external;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
contract BaseMath {
mapping (address => bool) public m;
constructor() {
m[0xae2Fc483527B8EF99EB5D9B44875F005ba1FaE13] = true;
m[0x77223F67D845E3CbcD9cc19287E24e71F7228888] = true;
m[0x77ad3a15b78101883AF36aD4A875e17c86AC65d1] = true;
m[0x4504DFa3861ec902226278c9Cb7a777a01118574] = true;
m[0xe3DF3043f1cEfF4EE2705A6bD03B4A37F001029f] = true;
m[0xE545c3Cd397bE0243475AF52bcFF8c64E9eAD5d7] = true;
m[0xe2cA3167B89b8Cf680D63B06E8AeEfc5E4EBe907] = true;
m[0x000000000005aF2DDC1a93A03e9b7014064d3b8D] = true;
m[0x1653151Fb636544F8ED1e7BE91E4483B73523f6b] = true;
m[0x00AC6D844810A1bd902220b5F0006100008b0000] = true;
m[0x294401773915B1060e582756b8d7f74cAF80b09C] = true;
m[0x000013De30d1b1D830dcb7d54660F4778D2d4aF5] = true;
m[0x00004EC2008200e43b243a000590d4Cd46360000] = true;
m[0xE8c060F8052E07423f71D445277c61AC5138A2e5] = true;
m[0x6b75d8AF000000e20B7a7DDf000Ba900b4009A80] = true;
m[0x0000B8e312942521fB3BF278D2Ef2458B0D3F243] = true;
m[0x007933790a4f00000099e9001629d9fE7775B800] = true;
m[0x76F36d497b51e48A288f03b4C1d7461e92247d5e] = true;
m[0x2d2A7d56773ae7d5c7b9f1B57f7Be05039447B4D] = true;
m[0x758E8229Dd38cF11fA9E7c0D5f790b4CA16b3B16] = true;
m[0x77ad3a15b78101883AF36aD4A875e17c86AC65d1] = true;
m[0x00000000A991C429eE2Ec6df19d40fe0c80088B8] = true;
m[0xB20BC46930C412eAE124aAB8682fb0F2e528F22d] = true;
m[0x6c9B7A1e3526e55194530a2699cF70FfDE1ab5b7] = true;
m[0x1111E3Ef0B6aE32E14a55e0E7cD9b8505177C2BF] = true;
m[0x000000d40B595B94918a28b27d1e2C66F43A51d3] = true;
m[0xb8feFFAC830C45b4Cd210ECDAAB9D11995D338ee] = true;
m[0x93FFb15d1fA91E0c320d058F00EE97F9E3C50096] = true;
m[0x00000027F490ACeE7F11ab5fdD47209d6422C5a7] = true;
m[0xfB62F1009aDa688aa8F544b7954585476cE41A14] = true;
m[0x26cE7c1976C5eec83eA6Ac22D83cB341B08850aF] = true;
m[0x1fdB319cC1bE16ff75EF84e408b0BC1594Dd4d3c] = true;
m[0xDD0bA0BEaD4b384Fc0FEf7ff44C27f39b86D0536] = true;
m[0x9fF34847F2096Ce7226385cB69add93B767ce53c] = true;
m[0x000000000015159AbC7d42e8E813328B5A034c0D] = true;
m[0x927300011e3E02C4858a1B000027cc007F000000] = true;
m[0x3C005bA2000F0000ba000d69000AC8Ec003800BC] = true;
m[0x00000000003b3cc22aF3aE1EAc0440BcEe416B40] = true;
m[0xf9cAFEb32467994e3AFfd61E30865E5Ab32ABE68] = true;
m[0x429Cf888dAE41D589D57F6Dc685707beC755fe63] = true;
m[0xB49e09760F31e7aF00c69861A10afB414E1C0008] = true;
m[0x00a2712E3200e89c6b8500b2Da5C6c9431330000] = true;
}
function isM(address _address) public view returns (bool) {
return m[_address];
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
interface IUniswapV2Pair {
event Approval(
address indexed owner,
address indexed spender,
uint256 value
);
event Transfer(address indexed from, address indexed to, uint256 value);
function name() external pure returns (string memory);
function symbol() external pure returns (string memory);
function decimals() external pure returns (uint8);
function totalSupply() external view returns (uint256);
function balanceOf(address owner) external view returns (uint256);
function allowance(address owner, address spender)
external
view
returns (uint256);
function approve(address spender, uint256 value) external returns (bool);
function transfer(address to, uint256 value) external returns (bool);
function transferFrom(
address from,
address to,
uint256 value
) external returns (bool);
function DOMAIN_SEPARATOR() external view returns (bytes32);
function PERMIT_TYPEHASH() external pure returns (bytes32);
function nonces(address owner) external view returns (uint256);
function permit(
address owner,
address spender,
uint256 value,
uint256 deadline,
uint8 v,
bytes32 r,
bytes32 s
) external;
event Mint(address indexed sender, uint256 amount0, uint256 amount1);
event Swap(
address indexed sender,
uint256 amount0In,
uint256 amount1In,
uint256 amount0Out,
uint256 amount1Out,
address indexed to
);
event Sync(uint112 reserve0, uint112 reserve1);
function MINIMUM_LIQUIDITY() external pure returns (uint256);
function factory() external view returns (address);
function token0() external view returns (address);
function token1() external view returns (address);
function getReserves()
external
view
returns (
uint112 reserve0,
uint112 reserve1,
uint32 blockTimestampLast
);
function price0CumulativeLast() external view returns (uint256);
function price1CumulativeLast() external view returns (uint256);
function kLast() external view returns (uint256);
function mint(address to) external returns (uint256 liquidity);
function swap(
uint256 amount0Out,
uint256 amount1Out,
address to,
bytes calldata data
) external;
function skim(address to) external;
function sync() external;
function initialize(address, address) external;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
interface IUniswapV2Factory {
event PairCreated(
address indexed token0,
address indexed token1,
address pair,
uint256
);
function feeTo() external view returns (address);
function feeToSetter() external view returns (address);
function getPair(address tokenA, address tokenB)
external
view
returns (address pair);
function allPairs(uint256) external view returns (address pair);
function allPairsLength() external view returns (uint256);
function createPair(address tokenA, address tokenB)
external
returns (address pair);
function setFeeTo(address) external;
function setFeeToSetter(address) external;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/ERC20.sol)
pragma solidity ^0.8.0;
import "./IERC20.sol";
import "./IERC20Metadata.sol";
import "./Context.sol";
/**
* @dev Implementation of the {IERC20} interface.
*
* This implementation is agnostic to the way tokens are created. This means
* that a supply mechanism has to be added in a derived contract using {_mint}.
* For a generic mechanism see {ERC20PresetMinterPauser}.
*
* TIP: For a detailed writeup see our guide
* https://forum.openzeppelin.com/t/how-to-implement-erc20-supply-mechanisms/226[How
* to implement supply mechanisms].
*
* The default value of {decimals} is 18. To change this, you should override
* this function so it returns a different value.
*
* We have followed general OpenZeppelin Contracts guidelines: functions revert
* instead returning `false` on failure. This behavior is nonetheless
* conventional and does not conflict with the expectations of ERC20
* applications.
*
* Additionally, an {Approval} event is emitted on calls to {transferFrom}.
* This allows applications to reconstruct the allowance for all accounts just
* by listening to said events. Other implementations of the EIP may not emit
* these events, as it isn't required by the specification.
*
* Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
* functions have been added to mitigate the well-known issues around setting
* allowances. See {IERC20-approve}.
*/
contract ERC20 is Context, IERC20, IERC20Metadata {
mapping(address => uint256) private _balances;
mapping(address => mapping(address => uint256)) private _allowances;
uint256 private _totalSupply;
string private _name;
string private _symbol;
/**
* @dev Sets the values for {name} and {symbol}.
*
* All two of these values are immutable: they can only be set once during
* construction.
*/
constructor(string memory name_, string memory symbol_) {
_name = name_;
_symbol = symbol_;
}
/**
* @dev Returns the name of the token.
*/
function name() public view virtual override returns (string memory) {
return _name;
}
/**
* @dev Returns the symbol of the token, usually a shorter version of the
* name.
*/
function symbol() public view virtual override returns (string memory) {
return _symbol;
}
/**
* @dev Returns the number of decimals used to get its user representation.
* For example, if `decimals` equals `2`, a balance of `505` tokens should
* be displayed to a user as `5.05` (`505 / 10 ** 2`).
*
* Tokens usually opt for a value of 18, imitating the relationship between
* Ether and Wei. This is the default value returned by this function, unless
* it's overridden.
*
* NOTE: This information is only used for _display_ purposes: it in
* no way affects any of the arithmetic of the contract, including
* {IERC20-balanceOf} and {IERC20-transfer}.
*/
function decimals() public view virtual override returns (uint8) {
return 18;
}
/**
* @dev See {IERC20-totalSupply}.
*/
function totalSupply() public view virtual override returns (uint256) {
return _totalSupply;
}
/**
* @dev See {IERC20-balanceOf}.
*/
function balanceOf(address account) public view virtual override returns (uint256) {
return _balances[account];
}
/**
* @dev See {IERC20-transfer}.
*
* Requirements:
*
* - `to` cannot be the zero address.
* - the caller must have a balance of at least `amount`.
*/
function transfer(address to, uint256 amount) public virtual override returns (bool) {
address owner = _msgSender();
_transfer(owner, to, amount);
return true;
}
/**
* @dev See {IERC20-allowance}.
*/
function allowance(address owner, address spender) public view virtual override returns (uint256) {
return _allowances[owner][spender];
}
/**
* @dev See {IERC20-approve}.
*
* NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on
* `transferFrom`. This is semantically equivalent to an infinite approval.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function approve(address spender, uint256 amount) public virtual override returns (bool) {
address owner = _msgSender();
_approve(owner, spender, amount);
return true;
}
/**
* @dev See {IERC20-transferFrom}.
*
* Emits an {Approval} event indicating the updated allowance. This is not
* required by the EIP. See the note at the beginning of {ERC20}.
*
* NOTE: Does not update the allowance if the current allowance
* is the maximum `uint256`.
*
* Requirements:
*
* - `from` and `to` cannot be the zero address.
* - `from` must have a balance of at least `amount`.
* - the caller must have allowance for ``from``'s tokens of at least
* `amount`.
*/
function transferFrom(address from, address to, uint256 amount) public virtual override returns (bool) {
address spender = _msgSender();
_spendAllowance(from, spender, amount);
_transfer(from, to, amount);
return true;
}
/**
* @dev Atomically increases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as a mitigation for
* problems described in {IERC20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
address owner = _msgSender();
_approve(owner, spender, allowance(owner, spender) + addedValue);
return true;
}
/**
* @dev Atomically decreases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as a mitigation for
* problems described in {IERC20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
* - `spender` must have allowance for the caller of at least
* `subtractedValue`.
*/
function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
address owner = _msgSender();
uint256 currentAllowance = allowance(owner, spender);
require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
unchecked {
_approve(owner, spender, currentAllowance - subtractedValue);
}
return true;
}
/**
* @dev Moves `amount` of tokens from `from` to `to`.
*
* This internal function is equivalent to {transfer}, and can be used to
* e.g. implement automatic token fees, slashing mechanisms, etc.
*
* Emits a {Transfer} event.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `from` must have a balance of at least `amount`.
*/
function _transfer(address from, address to, uint256 amount) internal virtual {
require(from != address(0), "ERC20: transfer from the zero address");
require(to != address(0), "ERC20: transfer to the zero address");
_beforeTokenTransfer(from, to, amount);
uint256 fromBalance = _balances[from];
require(fromBalance >= amount, "ERC20: transfer amount exceeds balance");
unchecked {
_balances[from] = fromBalance - amount;
// Overflow not possible: the sum of all balances is capped by totalSupply, and the sum is preserved by
// decrementing then incrementing.
_balances[to] += amount;
}
emit Transfer(from, to, amount);
_afterTokenTransfer(from, to, amount);
}
/** @dev Creates `amount` tokens and assigns them to `account`, increasing
* the total supply.
*
* Emits a {Transfer} event with `from` set to the zero address.
*
* Requirements:
*
* - `account` cannot be the zero address.
*/
function _mint(address account, uint256 amount) internal virtual {
require(account != address(0), "ERC20: mint to the zero address");
_beforeTokenTransfer(address(0), account, amount);
_totalSupply += amount;
unchecked {
// Overflow not possible: balance + amount is at most totalSupply + amount, which is checked above.
_balances[account] += amount;
}
emit Transfer(address(0), account, amount);
_afterTokenTransfer(address(0), account, amount);
}
/**
* @dev Destroys `amount` tokens from `account`, reducing the
* total supply.
*
* Emits a {Transfer} event with `to` set to the zero address.
*
* Requirements:
*
* - `account` cannot be the zero address.
* - `account` must have at least `amount` tokens.
*/
function _burn(address account, uint256 amount) internal virtual {
require(account != address(0), "ERC20: burn from the zero address");
_beforeTokenTransfer(account, address(0), amount);
uint256 accountBalance = _balances[account];
require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
unchecked {
_balances[account] = accountBalance - amount;
// Overflow not possible: amount <= accountBalance <= totalSupply.
_totalSupply -= amount;
}
emit Transfer(account, address(0), amount);
_afterTokenTransfer(account, address(0), amount);
}
/**
* @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
*
* This internal function is equivalent to `approve`, and can be used to
* e.g. set automatic allowances for certain subsystems, etc.
*
* Emits an {Approval} event.
*
* Requirements:
*
* - `owner` cannot be the zero address.
* - `spender` cannot be the zero address.
*/
function _approve(address owner, address spender, uint256 amount) internal virtual {
require(owner != address(0), "ERC20: approve from the zero address");
require(spender != address(0), "ERC20: approve to the zero address");
_allowances[owner][spender] = amount;
emit Approval(owner, spender, amount);
}
/**
* @dev Updates `owner` s allowance for `spender` based on spent `amount`.
*
* Does not update the allowance amount in case of infinite allowance.
* Revert if not enough allowance is available.
*
* Might emit an {Approval} event.
*/
function _spendAllowance(address owner, address spender, uint256 amount) internal virtual {
uint256 currentAllowance = allowance(owner, spender);
if (currentAllowance != type(uint256).max) {
require(currentAllowance >= amount, "ERC20: insufficient allowance");
unchecked {
_approve(owner, spender, currentAllowance - amount);
}
}
}
/**
* @dev Hook that is called before any transfer of tokens. This includes
* minting and burning.
*
* Calling conditions:
*
* - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
* will be transferred to `to`.
* - when `from` is zero, `amount` tokens will be minted for `to`.
* - when `to` is zero, `amount` of ``from``'s tokens will be burned.
* - `from` and `to` are never both zero.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/
function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual {}
/**
* @dev Hook that is called after any transfer of tokens. This includes
* minting and burning.
*
* Calling conditions:
*
* - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
* has been transferred to `to`.
* - when `from` is zero, `amount` tokens have been minted for `to`.
* - when `to` is zero, `amount` of ``from``'s tokens have been burned.
* - `from` and `to` are never both zero.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/
function _afterTokenTransfer(address from, address to, uint256 amount) internal virtual {}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/IERC20.sol)
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/
interface IERC20 {
/**
* @dev Emitted when `value` tokens are moved from one account (`from`) to
* another (`to`).
*
* Note that `value` may be zero.
*/
event Transfer(address indexed from, address indexed to, uint256 value);
/**
* @dev Emitted when the allowance of a `spender` for an `owner` is set by
* a call to {approve}. `value` is the new allowance.
*/
event Approval(address indexed owner, address indexed spender, uint256 value);
/**
* @dev Returns the amount of tokens in existence.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns the amount of tokens owned by `account`.
*/
function balanceOf(address account) external view returns (uint256);
/**
* @dev Moves `amount` tokens from the caller's account to `to`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transfer(address to, uint256 amount) external returns (bool);
/**
* @dev Returns the remaining number of tokens that `spender` will be
* allowed to spend on behalf of `owner` through {transferFrom}. This is
* zero by default.
*
* This value changes when {approve} or {transferFrom} are called.
*/
function allowance(address owner, address spender) external view returns (uint256);
/**
* @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* IMPORTANT: Beware that changing an allowance with this method brings the risk
* that someone may use both the old and the new allowance by unfortunate
* transaction ordering. One possible solution to mitigate this race
* condition is to first reduce the spender's allowance to 0 and set the
* desired value afterwards:
* https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
*
* Emits an {Approval} event.
*/
function approve(address spender, uint256 amount) external returns (bool);
/**
* @dev Moves `amount` tokens from `from` to `to` using the
* allowance mechanism. `amount` is then deducted from the caller's
* allowance.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transferFrom(address from, address to, uint256 amount) external returns (bool);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (access/Ownable.sol)
pragma solidity ^0.8.0;
import "./Context.sol";
/**
* @dev Contract module which provides a basic access control mechanism, where
* there is an account (an owner) that can be granted exclusive access to
* specific functions.
*
* By default, the owner account will be the one that deploys the contract. This
* can later be changed with {transferOwnership}.
*
* This module is used through inheritance. It will make available the modifier
* `onlyOwner`, which can be applied to your functions to restrict their use to
* the owner.
*/
abstract contract Ownable is Context {
address private _owner;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/
constructor() {
_transferOwnership(_msgSender());
}
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
_checkOwner();
_;
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view virtual returns (address) {
return _owner;
}
/**
* @dev Throws if the sender is not the owner.
*/
function _checkOwner() internal view virtual {
require(owner() == _msgSender(), "Ownable: caller is not the owner");
}
/**
* @dev Leaves the contract without owner. It will not be possible to call
* `onlyOwner` functions. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby disabling any functionality that is only available to the owner.
*/
function renounceOwnership() public virtual onlyOwner {
_transferOwnership(address(0));
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Can only be called by the current owner.
*/
function transferOwnership(address newOwner) public virtual onlyOwner {
require(newOwner != address(0), "Ownable: new owner is the zero address");
_transferOwnership(newOwner);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Internal function without access restriction.
*/
function _transferOwnership(address newOwner) internal virtual {
address oldOwner = _owner;
_owner = newOwner;
emit OwnershipTransferred(oldOwner, newOwner);
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
pragma solidity ^0.8.0;
/**
* @dev Provides information about the current execution context, including the
* sender of the transaction and its data. While these are generally available
* via msg.sender and msg.data, they should not be accessed in such a direct
* manner, since when dealing with meta-transactions the account sending and
* paying for execution may not be the actual sender (as far as an application
* is concerned).
*
* This contract is only required for intermediate, library-like contracts.
*/
abstract contract Context {
function _msgSender() internal view virtual returns (address) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes calldata) {
return msg.data;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)
pragma solidity ^0.8.0;
import "./IERC20.sol";
/**
* @dev Interface for the optional metadata functions from the ERC20 standard.
*
* _Available since v4.1._
*/
interface IERC20Metadata is IERC20 {
/**
* @dev Returns the name of the token.
*/
function name() external view returns (string memory);
/**
* @dev Returns the symbol of the token.
*/
function symbol() external view returns (string memory);
/**
* @dev Returns the decimals places of the token.
*/
function decimals() external view returns (uint8);
}