# Verify ERC20 token on Etherscan that was deployed through Remix: Step by Step Guide

All my problems are solved thank you very much @Skyge.

1 Like

Error

EDIT

I fixed the issue by compiling without optimization and chosing that as well on the verify proccess

@Skyge sorry for the messages i managed to do it myself i just disabled optimization and it worked

1 Like

I have th same question, can you tell me how to solve? this is code ,the contract is 0x0B0bf29464f6c01472aFBe0a5081a7b8250Dfbc6

``````/**
*Submitted for verification at BscScan.com on 2022-02-17
*/

pragma solidity ^0.6.2;

library SafeMathUint {
function toInt256Safe(uint256 a) internal pure returns (int256) {
int256 b = int256(a);
require(b >= 0);
return b;
}
}

library SafeMathInt {
int256 private constant MIN_INT256 = int256(1) << 255;
int256 private constant MAX_INT256 = ~(int256(1) << 255);

/**
* @dev Multiplies two int256 variables and fails on overflow.
*/
function mul(int256 a, int256 b) internal pure returns (int256) {
int256 c = a * b;

// Detect overflow when multiplying MIN_INT256 with -1
require(c != MIN_INT256 || (a & MIN_INT256) != (b & MIN_INT256));
require((b == 0) || (c / b == a));
return c;
}

/**
* @dev Division of two int256 variables and fails on overflow.
*/
function div(int256 a, int256 b) internal pure returns (int256) {
// Prevent overflow when dividing MIN_INT256 by -1
require(b != -1 || a != MIN_INT256);

// Solidity already throws when dividing by 0.
return a / b;
}

/**
* @dev Subtracts two int256 variables and fails on overflow.
*/
function sub(int256 a, int256 b) internal pure returns (int256) {
int256 c = a - b;
require((b >= 0 && c <= a) || (b < 0 && c > a));
return c;
}

/**
* @dev Adds two int256 variables and fails on overflow.
*/
function add(int256 a, int256 b) internal pure returns (int256) {
int256 c = a + b;
require((b >= 0 && c >= a) || (b < 0 && c < a));
return c;
}

/**
* @dev Converts to absolute value, and fails on overflow.
*/
function abs(int256 a) internal pure returns (int256) {
require(a != MIN_INT256);
return a < 0 ? -a : a;
}

function toUint256Safe(int256 a) internal pure returns (uint256) {
require(a >= 0);
return uint256(a);
}
}

library SafeMath {
/**
* @dev Returns the addition of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's `+` operator.
*
* Requirements:
*
*/
function add(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a + b;
require(c >= a, "SafeMath: addition overflow");

return c;
}

/**
* @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 sub(a, b, "SafeMath: subtraction overflow");
}

/**
* @dev Returns the subtraction of two unsigned integers, reverting with custom message on
* overflow (when the result is negative).
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
*
* - Subtraction cannot overflow.
*/
function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b <= a, errorMessage);
uint256 c = a - b;

return c;
}

/**
* @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) {
// 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 0;
}

uint256 c = a * b;
require(c / a == b, "SafeMath: multiplication overflow");

return c;
}

/**
* @dev Returns the integer division of two unsigned integers. Reverts 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) internal pure returns (uint256) {
return div(a, b, "SafeMath: division by zero");
}

/**
* @dev Returns the integer division of two unsigned integers. Reverts 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) {
require(b > 0, errorMessage);
uint256 c = a / b;
// assert(a == b * c + a % b); // There is no case in which this doesn't hold

return c;
}

/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* Reverts 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 mod(a, b, "SafeMath: modulo by zero");
}

/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* Reverts with custom message 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, string memory errorMessage) internal pure returns (uint256) {
require(b != 0, errorMessage);
return a % b;
}
}

library IterableMapping {
// Iterable mapping from address to uint;
struct Map {
}

function get(Map storage map, address key) public view returns (uint) {
return map.values[key];
}

function getIndexOfKey(Map storage map, address key) public view returns (int) {
if(!map.inserted[key]) {
return -1;
}
return int(map.indexOf[key]);
}

function getKeyAtIndex(Map storage map, uint index) public view returns (address) {
return map.keys[index];
}

function size(Map storage map) public view returns (uint) {
return map.keys.length;
}

function set(Map storage map, address key, uint val) public {
if (map.inserted[key]) {
map.values[key] = val;
} else {
map.inserted[key] = true;
map.values[key] = val;
map.indexOf[key] = map.keys.length;
map.keys.push(key);
}
}

function remove(Map storage map, address key) public {
if (!map.inserted[key]) {
return;
}

delete map.inserted[key];
delete map.values[key];

uint index = map.indexOf[key];
uint lastIndex = map.keys.length - 1;

map.indexOf[lastKey] = index;
delete map.indexOf[key];

map.keys[index] = lastKey;
map.keys.pop();
}
}

abstract contract Context {
function _msgSender() internal view virtual returns (address) {
return msg.sender;
}

function _msgData() internal view virtual returns (bytes calldata) {
this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
return msg.data;
}
}

contract Ownable is Context {

/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/
constructor () public {
_owner = msgSender;
}

/**
* @dev Returns the address of the current owner.
*/
function owner() public view returns (address) {
return _owner;
}

/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
require(_owner == _msgSender(), "Ownable: caller is not the owner");
_;
}

/**
* @dev Leaves the contract without owner. It will not be possible to call
* `onlyOwner` functions anymore. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby removing any functionality that is only available to the owner.
*/
function renounceOwnership() public virtual onlyOwner {
}

/**
* @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 {
emit OwnershipTransferred(_owner, newOwner);
_owner = newOwner;
}
}

interface IUniswapV2Router01 {
function factory() external pure returns (address);
function WETH() external pure returns (address);

uint amountBDesired,
uint amountAMin,
uint amountBMin,
) external returns (uint amountA, uint amountB, uint liquidity);
uint amountTokenDesired,
uint amountTokenMin,
uint amountETHMin,
) external payable returns (uint amountToken, uint amountETH, uint liquidity);
function removeLiquidity(
uint liquidity,
uint amountAMin,
uint amountBMin,
) external returns (uint amountA, uint amountB);
function removeLiquidityETH(
uint liquidity,
uint amountTokenMin,
uint amountETHMin,
) external returns (uint amountToken, uint amountETH);
function removeLiquidityWithPermit(
uint liquidity,
uint amountAMin,
uint amountBMin,
bool approveMax, uint8 v, bytes32 r, bytes32 s
) external returns (uint amountA, uint amountB);
function removeLiquidityETHWithPermit(
uint liquidity,
uint amountTokenMin,
uint amountETHMin,
bool approveMax, uint8 v, bytes32 r, bytes32 s
) external returns (uint amountToken, uint amountETH);
function swapExactTokensForTokens(
uint amountIn,
uint amountOutMin,
) external returns (uint[] memory amounts);
function swapTokensForExactTokens(
uint amountOut,
uint amountInMax,
) external returns (uint[] memory amounts);
external
payable
returns (uint[] memory amounts);
external
returns (uint[] memory amounts);
external
returns (uint[] memory amounts);
external
payable
returns (uint[] memory amounts);

function quote(uint amountA, uint reserveA, uint reserveB) external pure returns (uint amountB);
function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut) external pure returns (uint amountOut);
function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut) external pure returns (uint amountIn);
function getAmountsOut(uint amountIn, address[] calldata path) external view returns (uint[] memory amounts);
function getAmountsIn(uint amountOut, address[] calldata path) external view returns (uint[] memory amounts);
}

// pragma solidity >=0.6.2;

interface IUniswapV2Router02 is IUniswapV2Router01 {
function removeLiquidityETHSupportingFeeOnTransferTokens(
uint liquidity,
uint amountTokenMin,
uint amountETHMin,
) external returns (uint amountETH);
function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens(
uint liquidity,
uint amountTokenMin,
uint amountETHMin,
bool approveMax, uint8 v, bytes32 r, bytes32 s
) external returns (uint amountETH);

function swapExactTokensForTokensSupportingFeeOnTransferTokens(
uint amountIn,
uint amountOutMin,
) external;
function swapExactETHForTokensSupportingFeeOnTransferTokens(
uint amountOutMin,
) external payable;
function swapExactTokensForETHSupportingFeeOnTransferTokens(
uint amountIn,
uint amountOutMin,
) external;
}

interface IUniswapV2Pair {

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 (uint);
function balanceOf(address owner) external view returns (uint);

function approve(address spender, uint value) external returns (bool);
function transfer(address to, uint 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 (uint);

event Mint(address indexed sender, uint amount0, uint amount1);
event Swap(
uint amount0In,
uint amount1In,
uint amount0Out,
uint amount1Out,
);
event Sync(uint112 reserve0, uint112 reserve1);

function MINIMUM_LIQUIDITY() external pure returns (uint);
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 (uint);
function price1CumulativeLast() external view returns (uint);
function kLast() external view returns (uint);

function mint(address to) external returns (uint liquidity);
function burn(address to) external returns (uint amount0, uint amount1);
function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external;
function sync() external;

}

interface IUniswapV2Factory {

function feeTo() external view returns (address);
function feeToSetter() external view returns (address);

function allPairs(uint) external view returns (address pair);
function allPairsLength() external view returns (uint);

}

interface IERC20 {

function totalSupply() external view returns (uint256);
function balanceOf(address account) external view returns (uint256);
function transfer(address recipient, uint256 amount) external returns (bool);

function approve(address spender, uint256 amount) external returns (bool);

function transferFrom(
uint256 amount
) external returns (bool);

}

function name() external view returns (string memory);

function symbol() external view returns (string memory);

function decimals() external view returns (uint8);
}

contract ERC20 is Context, IERC20, IERC20Metadata {
using SafeMath for uint256;

uint256 private _totalSupply;

string private _name;
string private _symbol;

constructor(string memory name_, string memory symbol_) public {
_name = name_;
_symbol = symbol_;
}

function name() public view virtual override returns (string memory) {
return _name;
}

function symbol() public view virtual override returns (string memory) {
return _symbol;
}

function decimals() public view virtual override returns (uint8) {
return 18;
}

function totalSupply() public view virtual override returns (uint256) {
return _totalSupply;
}

function balanceOf(address account) public view virtual override returns (uint256) {
return _balances[account];
}

function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
_transfer(_msgSender(), recipient, amount);
return true;
}

function allowance(address owner, address spender) public view virtual override returns (uint256) {
return _allowances[owner][spender];
}

function approve(address spender, uint256 amount) public virtual override returns (bool) {
_approve(_msgSender(), spender, amount);
return true;
}

function transferFrom(
uint256 amount
) public virtual override returns (bool) {
_transfer(sender, recipient, amount);
_approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
return true;
}

return true;
}

function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
_approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
return true;
}

function _transfer(
uint256 amount
) internal virtual {

_beforeTokenTransfer(sender, recipient, amount);

_balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance");
emit Transfer(sender, recipient, amount);
}

function _mint(address account, uint256 amount) internal virtual {

}

function _burn(address account, uint256 amount) internal virtual {

_balances[account] = _balances[account].sub(amount, "ERC20: burn amount exceeds balance");
_totalSupply = _totalSupply.sub(amount);
}

function _approve(
uint256 amount
) internal virtual {

_allowances[owner][spender] = amount;
emit Approval(owner, spender, amount);
}

function _beforeTokenTransfer(
uint256 amount
) internal virtual {}
}

contract RichCoin is ERC20, Ownable {
using SafeMath for uint256;

IUniswapV2Router02 public uniswapV2Router;

bool private swapping;

uint256 public swapTokensAtAmount = 1 * (10**18);

uint256 public _maxTxAmount = 4044000000 * (10**18);
uint256 public _maxHavAmount = 8088000000 * (10**18);

uint256 public _startTimeForSwap;

uint256 public liquidityFee = 4;
uint256 public marketingFee = 4;

mapping (address => bool) private _isExcludedFromFees;

mapping (address => bool) public automatedMarketMakerPairs;

event ExcludeFromFees(address indexed account, bool isExcluded);

event SetAutomatedMarketMakerPair(address indexed pair, bool indexed value);

event GasForProcessingUpdated(uint256 indexed newValue, uint256 indexed oldValue);

event SwapAndLiquify(
uint256 tokensSwapped,
uint256 tokensIntoLiqudity
);

event SendDividends(
uint256 tokensSwapped,
uint256 amount
);

event ProcessedDividendTracker(
uint256 iterations,
uint256 claims,
uint256 lastProcessedIndex,
bool indexed automatic,
uint256 gas,
);

constructor() public ERC20("Hope2022", "Hope2022") {

IUniswapV2Router02 _uniswapV2Router = IUniswapV2Router02(0x10ED43C718714eb63d5aA57B78B54704E256024E);

uniswapV2Router = _uniswapV2Router;
uniswapV2Pair = _uniswapV2Pair;

_setAutomatedMarketMakerPair(_uniswapV2Pair, true);

excludeFromFees(owner(), true);

_mint(owner(), 202200000000 * (10**18));
}

}

uniswapV2Pair = _uniswapV2Pair;
}

function excludeFromFees(address account, bool excluded) public onlyOwner {
require(_isExcludedFromFees[account] != excluded, "BABYBUSD: Account is already the value of 'excluded'");
_isExcludedFromFees[account] = excluded;

emit ExcludeFromFees(account, excluded);
}

function excludeMultipleAccountsFromFees(address[] calldata accounts, bool excluded) public onlyOwner {
for(uint256 i = 0; i < accounts.length; i++) {
_isExcludedFromFees[accounts[i]] = excluded;
}

emit ExcludeMultipleAccountsFromFees(accounts, excluded);
}

function setMarketingWallet(address payable wallet) external onlyOwner{
}

function setMaxTxAmount(uint256 maxTxAmount) external onlyOwner {
_maxTxAmount = maxTxAmount;
}

function setMaxHavAmount(uint256 maxHavAmount) external onlyOwner {
_maxHavAmount = maxHavAmount;
}

function setSwapTokensAtAmount(uint256 value) external onlyOwner{
swapTokensAtAmount = value;
}

function setStartTimeForSwap() external onlyOwner {
if (_startTimeForSwap == 0) {
_startTimeForSwap = block.timestamp;
}
}

function setLiquiditFee(uint256 value) external onlyOwner{
liquidityFee = value;
}

function setMarketingFee(uint256 value) external onlyOwner{
marketingFee = value;

}

function setAutomatedMarketMakerPair(address pair, bool value) public onlyOwner {
require(pair != uniswapV2Pair, "BABYBUSD: The PancakeSwap pair cannot be removed from automatedMarketMakerPairs");

_setAutomatedMarketMakerPair(pair, value);
}

function _setAutomatedMarketMakerPair(address pair, bool value) private {
require(automatedMarketMakerPairs[pair] != value, "BABYBUSD: Automated market maker pair is already set to that value");
automatedMarketMakerPairs[pair] = value;

emit SetAutomatedMarketMakerPair(pair, value);
}

function isExcludedFromFees(address account) public view returns(bool) {
return _isExcludedFromFees[account];
}

function _transfer(
uint256 amount
) internal override {
require(amount > 0, "Transfer amount must be greater than zero");

uint256 balance;
if (!_isExcludedFromFees[from] && !_isExcludedFromFees[to] ) {
require(
amount <= _maxTxAmount,
"Transfer amount exceeds the maxTxAmount."
);

if (
!automatedMarketMakerPairs[from] &&
!automatedMarketMakerPairs[to]
) {
balance = balanceOf(to);

if(balance<=_maxHavAmount){
require(
amount + balance <= _maxHavAmount,
"Transfer amount exceeds the maxHavAmount."
);
}

}

}

if (
_startTimeForSwap == 0 &&
!_isExcludedFromFees[from] &&
!_isExcludedFromFees[to]
) {
revert("Not open sale");
}

if (automatedMarketMakerPairs[from] && !_isExcludedFromFees[to]) {
balance = balanceOf(to);
if (amount + balance > _maxHavAmount) {
revert("tranfer to balance > max");
}
}

bool canSwap = contractTokenBalance >= swapTokensAtAmount;

if( canSwap &&
!swapping &&
!automatedMarketMakerPairs[from] &&
from != owner() &&
to != owner()
) {
swapping = true;

uint256 marketingTokens = contractTokenBalance.mul(marketingFee).div(totalFees);
swapAndSendToFee(marketingTokens);

uint256 swapTokens = contractTokenBalance.mul(liquidityFee).div(totalFees);
swapAndLiquify(swapTokens);

swapping = false;
}

bool takeFee = !swapping;

if(_isExcludedFromFees[from] || _isExcludedFromFees[to]) {
takeFee = false;
}

if(takeFee) {
uint256 fees = amount.mul(totalFees).div(100);
if(automatedMarketMakerPairs[to]){
fees += amount.mul(1).div(100);
}
amount = amount.sub(fees);

}

super._transfer(from, to, amount);

}

function swapAndSendToFee(uint256 tokens) private  {

swapTokensForCake(tokens);
}

function swapAndLiquify(uint256 tokens) private {
// split the contract balance into halves
uint256 half = tokens.div(2);
uint256 otherHalf = tokens.sub(half);

// capture the contract's current ETH balance.
// this is so that we can capture exactly the amount of ETH that the
// swap creates, and not make the liquidity event include any ETH that
// has been manually sent to the contract

// swap tokens for ETH
swapTokensForEth(half); // <- this breaks the ETH -> HATE swap when swap+liquify is triggered

// how much ETH did we just swap into?

emit SwapAndLiquify(half, newBalance, otherHalf);
}

function swapTokensForEth(uint256 tokenAmount) private {

// generate the uniswap pair path of token -> weth
path[1] = uniswapV2Router.WETH();

// make the swap
uniswapV2Router.swapExactTokensForETHSupportingFeeOnTransferTokens(
tokenAmount,
0, // accept any amount of ETH
path,
block.timestamp
);

}

function swapTokensForCake(uint256 tokenAmount) private {

path[1] = uniswapV2Router.WETH();
path[2] = BUSD;

// make the swap
uniswapV2Router.swapExactTokensForTokensSupportingFeeOnTransferTokens(
tokenAmount,
0,
path,
block.timestamp
);
}

function addLiquidity(uint256 tokenAmount, uint256 ethAmount) private {

// approve token transfer to cover all possible scenarios

tokenAmount,
0, // slippage is unavoidable
0, // slippage is unavoidable
block.timestamp
);

}

}
``````

Hi
Deployed using Remix
I already check manually and hardhat verification but i had no luck
Could you check this contract verification?
I have another contracts signed with the same code and I would like to know about it.

BSC Mainnet

complied using 0.8.12
optimization enabled 200

arguments:

``````"0x3C2423AE99dd4e0c736d580A19a4aC603B7262E6,
0x7Ec487482aF4781190CdB0fF68FF2501a9613e57,
1666236600"
``````

--------------Code---------------

``````// contracts/Timelock.sol

pragma solidity ^0.8.0;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC20/utils/TokenTimelock.sol";

contract TokenTimeLock is TokenTimelock {
constructor(IERC20 token, address payable beneficiary, uint256 releaseTime) TokenTimelock(token, beneficiary,releaseTime) {}
}
``````

1 Like

A post was merged into an existing topic: Before verifying the contract, I sent a token to other wallets, now I cannot verify, it asks me for the ABI. Should I add the constructs to the other wallets?

Thank you so much! It works perfectly!

1 Like

So how do I verify a token that has already been deployed and is on the ETH Mainnet

Hi, welcome to the community!

I think you can follow the tutorial that wrote above.

I followed these instructions and I am still getting an error message when I try to verify my token contract on the Etherscan website. The error message says, "Error! Unable to generate Contract ByteCode and ABI"

Below is the original code for I used for my token as well as the flattened code.
Thank you so much for your help!!

``````// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;

import "@openzeppelin/contracts/token/ERC20/ERC20.sol";

contract Token is ERC20 {

constructor () ERC20("Intrinsic", "INC") {
_mint(msg.sender, 1000000 * (10 ** uint256(decimals())));
}
}
``````

Here is the flattened code.

``````
// File: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/v3.4.0-solc-0.7/contracts/math/SafeMath.sol

pragma solidity ^0.7.0;

/**
* @dev Wrappers over Solidity's arithmetic operations with added overflow
* checks.
*
* Arithmetic operations in Solidity wrap on overflow. This can easily result
* in bugs, because programmers usually assume that an overflow raises an
* error, which is the standard behavior in high level programming languages.
* `SafeMath` restores this intuition by reverting the transaction when an
* operation overflows.
*
* Using this library instead of the unchecked operations eliminates an entire
* class of bugs, so it's recommended to use it always.
*/
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) {
uint256 c = a + b;
if (c < a) return (false, 0);
return (true, c);
}

/**
* @dev Returns the substraction of two unsigned integers, with an overflow flag.
*
* _Available since v3.4._
*/
function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
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) {
// 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) {
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) {
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:
*
*/
function add(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a + b;
require(c >= a, "SafeMath: addition overflow");
return c;
}

/**
* @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) {
require(b <= a, "SafeMath: subtraction overflow");
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) {
if (a == 0) return 0;
uint256 c = a * b;
require(c / a == b, "SafeMath: multiplication overflow");
return c;
}

/**
* @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. 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) internal pure returns (uint256) {
require(b > 0, "SafeMath: division by zero");
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) {
require(b > 0, "SafeMath: modulo by zero");
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) {
require(b <= a, errorMessage);
return a - b;
}

/**
* @dev Returns the integer division of two unsigned integers, reverting with custom message on
* division by zero. The result is rounded towards zero.
*
* CAUTION: This function is deprecated because it requires allocating memory for the error
* message unnecessarily. For custom revert reasons use {tryDiv}.
*
* 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) {
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) {
require(b > 0, errorMessage);
return a % b;
}
}

// File: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/v3.4.0-solc-0.7/contracts/token/ERC20/IERC20.sol

pragma solidity ^0.7.0;

/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/
interface IERC20 {
/**
* @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 `recipient`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transfer(address recipient, 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.
*/

/**
* @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 `sender` to `recipient` 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.
*/

/**
* @dev Emitted when `value` tokens are moved from one account (`from`) to
* another (`to`).
*
* Note that `value` may be zero.
*/

/**
* @dev Emitted when the allowance of a `spender` for an `owner` is set by
* a call to {approve}. `value` is the new allowance.
*/
}

// File: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/v3.4.0-solc-0.7/contracts/utils/Context.sol

pragma solidity >=0.6.0 <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 GSN 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 payable) {
return msg.sender;
}

function _msgData() internal view virtual returns (bytes memory) {
this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
return msg.data;
}
}

// File: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/v3.4.0-solc-0.7/contracts/token/ERC20/ERC20.sol

pragma solidity ^0.7.0;

/**
* @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.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
* to implement supply mechanisms].
*
* We have followed general OpenZeppelin guidelines: functions revert instead
* of 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 {
using SafeMath for uint256;

mapping (address => uint256) private _balances;

uint256 private _totalSupply;

string private _name;
string private _symbol;
uint8 private _decimals;

/**
* @dev Sets the values for {name} and {symbol}, initializes {decimals} with
* a default value of 18.
*
* To select a different value for {decimals}, use {_setupDecimals}.
*
* All three of these values are immutable: they can only be set once during
* construction.
*/
constructor (string memory name_, string memory symbol_) {
_name = name_;
_symbol = symbol_;
_decimals = 18;
}

/**
* @dev Returns the name of the token.
*/
function name() public view virtual returns (string memory) {
return _name;
}

/**
* @dev Returns the symbol of the token, usually a shorter version of the
* name.
*/
function symbol() public view virtual 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 value {ERC20} uses, unless {_setupDecimals} is
* called.
*
* 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 returns (uint8) {
return _decimals;
}

/**
* @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:
*
* - `recipient` cannot be the zero address.
* - the caller must have a balance of at least `amount`.
*/
function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
_transfer(_msgSender(), recipient, 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}.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function approve(address spender, uint256 amount) public virtual override returns (bool) {
_approve(_msgSender(), 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}.
*
* Requirements:
*
* - `sender` and `recipient` cannot be the zero address.
* - `sender` must have a balance of at least `amount`.
* - the caller must have allowance for ``sender``'s tokens of at least
* `amount`.
*/
function transferFrom(address sender, address recipient, uint256 amount) public virtual override returns (bool) {
_transfer(sender, recipient, amount);
_approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
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.
*/
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) {
_approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
return true;
}

/**
* @dev Moves tokens `amount` from `sender` to `recipient`.
*
* This is 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:
*
* - `sender` cannot be the zero address.
* - `recipient` cannot be the zero address.
* - `sender` must have a balance of at least `amount`.
*/

_beforeTokenTransfer(sender, recipient, amount);

_balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance");
emit Transfer(sender, recipient, 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:
*
* - `to` cannot be the zero address.
*/
function _mint(address account, uint256 amount) internal virtual {

}

/**
* @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 {

_balances[account] = _balances[account].sub(amount, "ERC20: burn amount exceeds balance");
_totalSupply = _totalSupply.sub(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.
*/

_allowances[owner][spender] = amount;
emit Approval(owner, spender, amount);
}

/**
* @dev Sets {decimals} to a value other than the default one of 18.
*
* WARNING: This function should only be called from the constructor. Most
* applications that interact with token contracts will not expect
* {decimals} to ever change, and may work incorrectly if it does.
*/
function _setupDecimals(uint8 decimals_) internal virtual {
_decimals = decimals_;
}

/**
* @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 to 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.
*
*/
}

// File: contracts/Token.sol

pragma solidity ^0.7.0;

contract Token is ERC20 {

constructor () ERC20("Intrinsic", "INC") {
_mint(msg.sender, 1000000 * (10 ** uint256(decimals())));
}
}
``````

I did not optimize and flatten my contract prior to deployment.

Is it not verifiable now?

its is still verifiable

Hi I have been trying to verify a contract I created on remix for weeks but getting know where.
Any Ideas

1 Like

@Skyge I have flattened the contract and checked in remix, everything ok,

I have followed the guide accordingly

but at the time of verify and publish in the ropsten network deployed I get the following error

Hii I am importing the open zeppelin contract and creating a token. It has been successfully compiled and deployed but I am not able to verify and publish the same. Here is the error.

Hi, welcome to the community!

When you verify your contracts, you can use a single file: flatten all dependencies contracts into a file, you can follow this tutorial to do this. Or use the multi-files, but I really recommend you to use plugin to verify contracts, such as `truffle` or `hardhat`.

1 Like

@Skyge
A pleasure to greet you, I have followed your steps to verify the contract this time in the BSCScan before uploading to production I did a test in the Tesnet network and everything worked perfectly, now I try to verify the contract by the main BSCScan network and I get the error that I send you in capture, I have seen that the same thing happens a lot here I would like to know what it can be and if it is possible your help.

I have done it through the IDE of remix ethereum with flattener

Hello all,

I have followed stricly the step by step but I am not able to verify my contract. The contract use 3 interfaces so I flattened the file but even with this it does not work. Here is the error:

Thanks for anyone who can help !

Hi, welcome to the community!

I am not sure why you can not verify your contracts, all steps have been listed at above. Maybe you can paste your source code, contract address and compiler version at here.

Hi, welcome to the community!

I am not sure why you can not verify your contracts, all steps have been listed at above. Maybe you can paste your source code, contract address and compiler version at here.