# Does code comply with OpenZeppelin license and copyright terms?

**URL:** <https://forum.openzeppelin.com/t/does-code-comply-with-openzeppelin-license-and-copyright-terms/4749>\
**Category:** Contracts\
**Tags:** erc20\
**Created:** [November 24, 2020, 3:54pm UTC](https://forum.openzeppelin.com/t/does-code-comply-with-openzeppelin-license-and-copyright-terms/4749 "2020-11-24T15:54:33Z")\
**Posts on this page:** 1\
**Showing post:** 3

<div class="post-metadata">

**Author:** ![abcoathup](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.openzeppelin.com/abcoathup/32/415_2.png) [@abcoathup](https://forum.openzeppelin.com/u/abcoathup)\
**Post date:** [November 25, 2020, 3:51am UTC](https://forum.openzeppelin.com/t/does-code-comply-with-openzeppelin-license-and-copyright-terms/4749/3 "2020-11-25T03:51:22Z")

</div>

Hi @kanedaaaa,

Welcome to the community 👋

> To keep your system secure, you should **always** use the installed code as-is, and neither copy-paste it from online sources, nor modify it yourself.

\_From: [https://docs.openzeppelin.com/contracts/3.x/#usage\_](https://docs.openzeppelin.com/contracts/3.x/#usage_)

You should install OpenZeppelin Contracts (`npm install @openzeppelin/contracts`) and then import.

Your contract could then look as follows (and you wouldn't need to clone the other contracts from OpenZeppelin Contracts):

## Kata.sol

```auto
// contracts/Kata.sol
// SPDX-License-Identifier: MIT
pragma solidity ^0.6.0;

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

contract Kata is ERC20 {
    constructor() public ERC20("Kata", "KATA") {
        _mint(msg.sender, 700 * (10 ** uint256(decimals())));
    }
}

```

Please note, in the OpenZeppelin Contracts ERC20 implementation, the default decimals is 18, whilst you were doing `10**9`. If you want to use a different number of decimals you can call [`_setupDecimals`](https://docs.openzeppelin.com/contracts/3.x/api/token/erc20#ERC20-_setupDecimals-uint8-) in your constructor.

* * *

As for the OpenZeppelin Contracts license and copyright, as long as you are compliant with the MIT license (e.g. don't try to change to a non-compliant license) and don't remove OpenZeppelin copyright then you should be compliant.

I recommend when you verify your contract on Etherscan, that you do multi-file verification to maintain imports and SPDX License identifiers: [How to verify with Hardhat or Truffle a smart contract using OpenZeppelin Contracts](https://forum.openzeppelin.com/t/verify-smart-contract-inheriting-from-openzeppelin-contracts/4119)

You could add a Built with OpenZeppelin badge: [https://docs.openzeppelin.com/openzeppelin/#share\_the\_love](https://docs.openzeppelin.com/openzeppelin/#share_the_love)

* * *

I recommend creating some tests to ensure that your contract functions as expected. See: [https://docs.openzeppelin.com/learn/writing-automated-tests](https://docs.openzeppelin.com/learn/writing-automated-tests)

* * *

I also suggest looking at: [Points to consider when creating a fungible token (ERC20, ERC777)](https://forum.openzeppelin.com/t/points-to-consider-when-creating-a-fungible-token-erc20-erc777/2915)

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_[View the full topic](https://forum.openzeppelin.com/t/does-code-comply-with-openzeppelin-license-and-copyright-terms/4749)._