BEP20 Crowdsale

Smart Contracts Review Wanted
1

Hi everyone,
I am working on a crowdsale project for my first freelance client.
The budget is very small(Im trying to build a portfolio) so I cannot do mistakes due to deployment fees.
I have those two contracts:
Sales contract:

pragma solidity ^0.5.0;

import "./Crowdcoin.sol";
import "https://github.com/OpenZeppelin/openzeppelin-contracts/blob/release-v2.5.0/contracts/crowdsale/Crowdsale.sol";
import "https://github.com/OpenZeppelin/openzeppelin-contracts/blob/release-v2.5.0/contracts/crowdsale/emission/MintedCrowdsale.sol";

// @TODO: Inherit the crowdsale contracts
contract CrowdcoinSale is Crowdsale, MintedCrowdsale {

    constructor(
        // @TODO: Fill in the constructor parameters!
        uint rate, // rate in TKNbits
        address payable wallet, // sale beneficiary
        Crowdcoin token, // the Crowdcoin itself that the CrowdcoinSale will work with

    )
        // @TODO: Pass the constructor parameters to the crowdsale contracts.
        Crowdsale(rate, wallet, token)
        MintedCrowdsale()
        public

    {
        // constructor can stay empty
    }
}

contract CrowdcoinSaleDeployer {

    address public token_sale_address;
    address public token_address;

    constructor(
        // @TODO: Fill in the constructor parameters!
        string memory name,
        string memory symbol,
        address payable wallet // this address will receive all Ether raised by the sale

    )
        public
    {
        // @TODO: create the Crowdcoin and keep its address handy
        Crowdcoin token = new Crowdcoin(name, symbol, 0);
        token_address = address(token);


        // @TODO: create the CrowdcoinSale and tell it about the token, set the goal, and set the open and close times to now and now + 24 weeks.
        uint goal = 300 wei;
        uint cap = 300 wei;
        
        
        CrowdcoinSale Crowdcoin_sale = new CrowdcoinSale(1, wallet, token, goal, cap, now, now + 24 weeks);
        token_sale_address = address(Crowdcoin_sale);


        // make the CrowdcoinSale contract a minter, then have the CrowdcoinSaleDeployer renounce its minter role
        token.addMinter(token_sale_address);
        token.renounceMinter();
    }
}
``
Presale Token contract:
``
pragma solidity ^0.5.0;

import "https://github.com/OpenZeppelin/openzeppelin-contracts/blob/release-v2.5.0/contracts/token/ERC20/ERC20.sol";
import "https://github.com/OpenZeppelin/openzeppelin-contracts/blob/release-v2.5.0/contracts/token/ERC20/ERC20Detailed.sol";
import "https://github.com/OpenZeppelin/openzeppelin-contracts/blob/release-v2.5.0/contracts/token/ERC20/ERC20Mintable.sol";

contract crowdcoin is ERC20, ERC20Detailed, ERC20Mintable {
    constructor(
        string memory name,
        string memory symbol,
        uint initial_supply
    )
        ERC20Detailed(name, symbol, 18)
        public
    {
        mint(msg.sender, initial_supply);
    }
}

I plan to proceed like this:
1- Paste the crowdsale contract on remix.ethereum.org in the crowdsale.sol file that I will deploy with bsc
2- Paste the token on remix.ethereum.org in the crowdcoin.sol file that I will deploy with bsc
For the prior two steps, will they automatically work together?
how do I link it on my client’s website so the participants can connect their bnb wallets swap directly from the sale webpage?
Thank You in advance !

2

Hey can you tell us about the requirements of the crowdsale? Which features/function must it have?

3

I think so, pass crowdcoin as the value for Crowdcoin in the CrowdcoinSale, then CrowdcoinSale can work with crowdcoin.

This question is about the front-end, you can use metamsk or wallet connect to connect users' wallet, just check the documentation of these plugins.

4

The crowdsale is just a mintable crowdsale, whereas for every purchase, new tokens are minted and sent to the buyer upon bnb receival at the defined rate. then the user must have a connect wallet button for metamask or trust wallet…
After they collect their wallet they must be able to see their bnb balance on the screen.

5

Thanks you for the reply so you mean I can edit crowdsale in that way:

constructor(
        // @TODO: Fill in the constructor parameters!
        uint rate, // rate in TKNbits
        address payable wallet, // sale beneficiary
        Crowdcoin crowdcoin, // the Crowdcoin itself that the CrowdcoinSale will work with

    )

or

@TODO: Pass the constructor parameters to the crowdsale contracts.
        Crowdsale(rate, wallet, crowdcoin? Or Deployed crowdcoin address)
        MintedCrowdsale()
        public

Or I need to deploy the crowdcoin contract first then use the contract address?
Thanks in advance !

6

Yeah, you should deploy crowdcoin at first, and then you can pass this address to the CrowdcoinSale

7

Well received thanks a lot
Is there anything about permissions?

8

I have used a very similar setup, You didn’t get inspired by the PupperCoin contract by any chance? My issue with this was that once the PupperCoinSaleDeployer has depoed the PupperCoinSale contract , you don’t really have any control over the token any more.

That might now be an issue for you though. I wanted to have extra minterrole for myself as well as the ability to burn tokens.

This is what I used then at least (Note that it’s old OpenZeppelin (V 2.5.1)

PupperCoin

// SPDX-License-Identifier: MIT

pragma solidity ^0.5.0;

import "https://github.com/Creepybits/openzeppelin/blob/main/contracts/token/ERC20/ERC20.sol";
import "https://github.com/Creepybits/openzeppelin/blob/main/contracts/token/ERC20/ERC20Detailed.sol";
import "https://github.com/Creepybits/openzeppelin/blob/main/contracts/token/ERC20/ERC20Mintable.sol";

contract PupperCoin is ERC20, ERC20Detailed, ERC20Mintable {
    constructor(
        string memory _name,
        string memory _symbo,
        uint initial_supply
    )
        ERC20Detailed(name, symbol, decimals)
        public
    {
        // constructor can stay empty
    }
}

PupperCoinCrowdSale

// SPDX-License-Identifier: MIT

pragma solidity ^0.5.0;

import "https://github.com/Creepybits/Puppercoin/blob/main/PupperCoin.sol";
import "https://github.com/Creepybits/openzeppelin/blob/main/contracts/crowdsale/Crowdsale.sol";
import "https://github.com/Creepybits/openzeppelin/blob/main/contracts/crowdsale/emission/MintedCrowdsale.sol";


// Inherit the crowdsale contracts:
contract PupperCoinCrowdsale is Crowdsale, MintedCrowdsale{

    constructor(
        // Constructor parameters:
        uint rate,
        address payable wallet,
        SvenskTiger token,
        uint goal,
        uint open,
        uint close
    )
        // Pass constructor parameters to the crowdsale contracts:
        Crowdsale(rate, wallet, token)
        public
    {
        // constructor can stay empty
    }
}

contract PuppercoinSaleDeployer {

    address public token_sale_address;
    address public token_address;

    constructor(
        // Constructor parameters:
        string memory name,
        string memory symbol,
        address payable wallet,
        uint goal
    )
        public
    {
        // Create the Puppercoin and keep its address:
        PupperCoin token = new PupperCoin(name, symbol, decimals);
        token_address = address(token);

        // Create the PupperCoinSale and tell it about the token, set the goal, and set the open and close times to now and (now + 24 weeks):
        PupperCoinSale token_sale = new PupperCoinSale(1, wallet, token, goal, now, now + 24 weeks);
        token_sale_address = address(token_sale);

        // Make the PupperCoinSale contract a minter, then have the PupperCoinSaleDeployer renounce its minter role:
        token.addMinter(token_sale_address);
        token.renounceMinter();
    }
}

If you want or need more control over the token and it’s sale, you might wan’t to consider other options.

1 Like
9

what should i edit? For rate, goal etc. And how can i set open and close time example 25.11.2021 17:00 start, 26.11.2021 17:00 end.

10

Hi, welcome! :wave:

The open time and close time is the timestamp, so just convert the time to timestamp to pass.

11

Thanks. How can i do that? And how can i set rate for example Presale rate: 100 MyToken = 0.01 BNB?

12

Many tools online can convert to timestamp.

Have a look at this documentation:
Crowdsales - OpenZeppelin Docs

13

hello to all I wanted to create a smart contract for the crowd sale but I don't understand anything can someone tell me which contract and how can I implement it on my site so that people connect their wallet and buy?