# 2. Deploying Smart Contract

You can use Remix Online IDE or use Truffle to deploy `MyERC20` smart contract.

## 2.1 Deploying smart contract using Remix Online IDE <a href="#id-2-1-deploying-smart-contract-using-klaytn-ide" id="id-2-1-deploying-smart-contract-using-klaytn-ide"></a>

* Please visit [Klaytn Plugin for Remix](https://ide.klaytn.foundation) and create a `MyERC20` contract. The complete source code was given at [Writing ERC-20 Smart Contract](https://archive-docs.klaytn.foundation/content/smart-contract/sample-contracts/erc-20/1-erc20).
* Prepare your account which will be used to deploy the contract.
  * If you do not have an account yet, create one at <https://baobab.wallet.klaytn.foundation/create> or <https://toolkit.klaytn.foundation/account/accountKeyLegacy>.
  * Get some test KLAY from the faucet - <https://baobab.wallet.klaytn.foundation/faucet>
* Let's deploy `MyERC20.sol` with the deploy parameters of `BAOBABTOKEN`, `BAO` and `8`.

![ERC20-1-deploy](https://2361259531-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fo8dCjygb765jszAbMUcT%2Fuploads%2Fgit-blob-72da314e3b5217d1fa79f279a2c2636f869e9524%2Ferc20-1-deploy.png?alt=media\&token=8be6b968-625a-473a-928e-9f7f05cfe851)

After deploying, you can invoke `balanceOf` with your account, which was used to deploy the contract. You will find there are `10000000000000` tokens available in your account as below. Because you set `decimal` as `8` when deploying the contract above, it minted a fixed number of `100000` tokens in the constructor, with one token having a decimal value of `10^8`. `totalSupply` method will return the total supply of tokens minted which should be also `10000000000000`.

![ERC20-2-owner-token](https://2361259531-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fo8dCjygb765jszAbMUcT%2Fuploads%2Fgit-blob-9e0612f0d48b68ec28db082537749ca92b7dfe07%2Ferc20-2-owner_token.png?alt=media\&token=31c31352-a9f5-4913-b06d-b41f471f2da8)

`MyERC20` is now live !

## 2.2 Deploying smart contract using truffle <a href="#id-2-2-deploying-smart-contract-using-truffle" id="id-2-2-deploying-smart-contract-using-truffle"></a>

You should have installed [node.js](https://nodejs.org/) in your environment. Please take a look at [Installing Node.js via package manager](https://nodejs.org/en/download/package-manager/) to install node.js using package manager in various environment.

```
$ mkdir klaytn
$ cd klaytn
$ npm init # initialize npm at the erc20token directory
$ npm install truffle@4.1.15
$ npm install caver-js@latest # installing caver-js
$ ln -s node_modules/truffle/build/cli.bundled.js truffle
$ export PATH=`pwd`:$PATH
```

Now you have installed truffle and caver-js which are required to deploy smart contract.

Let's prepare `truffle` and a smart contract `MyERC20.sol`.

```
$ mkdir myerc20
$ cd myerc20
$ truffle init
```

Now you will have following directory structures.

```
.
├── contracts
│   ├── Migrations.sol
├── migrations
│   └── 1_initial_migration.js
└── truffle-config.js
```

Now write `MyERC20.sol` and locate it to `contracts` directory.

Also edit `1_initial_migration.js` as below to deploys `MyERC20` contract with initial parameters of `BAOBABTOKEN`, `BAO` and `8`. The token name is set to `BAOBABTOKEN` and the token symbol to `BAO`. Token has decimal value `10^8`. Note that when you query the `totalSupply` of `BAOBABTOKEN` for example, it returns `10^13`, not `10^5`, because solidity does not support floating point, the number of tokens always represented as a natural number in the smallest denomination.

```javascript
const Migrations = artifacts.require("./Migrations.sol");
const MyERC20 = artifacts.require("./MyERC20.sol");
module.exports = function(deployer) {
  deployer.deploy(Migrations);
  deployer.deploy(MyERC20, 'BAOBABTOKEN', 'BAO', 8);
};
```

You also have to edit `truffle-config.js` as shown below to deploy a smart contract to Klaytn network. This is the same step described in [Deploying a Smart Contract using Truffle](https://archive-docs.klaytn.foundation/getting-started/quick-start/deploy-a-smart-contract#deploying-a-smart-contract-using-truffle).

```
// truffle-config.js
module.exports = {
    networks: {
        baobab: {
            host: '127.0.0.1',
            port: 8551,
            from: '0xabcdabcdabcdabcdabcdabcdabcdabcdabcdabcd', // enter your account address
            network_id: '1001', // Baobab network id
            gas: 20000000, // transaction gas limit
            gasPrice: 250000000000, // gasPrice of Baobab is 250 ston
        },
    },
    compilers: {
      solc: {
        version: "0.5.12"    // Specify compiler's version to 0.5.12
      }
  }
};
```

Now you are all ready and can deploy `MyERC20.sol` as below.

```
$ truffle deploy --network baobab --reset
Compiling ./contracts/MyERC20.sol...
Writing artifacts to ./build/contracts

Using network 'baobab'.

Running migration: 1_initial_migration.js
  Replacing Migrations...
  ... 0x5a947f076f4570dff8ff18b1ae3557e27dd69c92ce38a3c97fad8f5355914066
  Migrations: 0x0d737e9865e5fc4c1ff53744fd2c13c52a44b9bc
  Deploying MyERC20...
  ... 0x1571e80552dab1d67260e8914e06d9b16ccae16fb698c750f6a09aab12517bc1
  MyERC20: 0xc4c8257ED9B4eB6422fDe29B1eCe5Ce301e637e1
Saving successful migration to network...
  ... 0x5b984b3f79c425d80470a96d5badb857fc05e7f31d94423044ae3119c639aa77
Saving artifacts...
```

It shows that the transaction hash for deploying `MyERC20` is `0x1571e80552dab1d67260e8914e06d9b16ccae16fb698c750f6a09aab12517bc1` and the address of `MyERC20` is `0xc4c8257ED9B4eB6422fDe29B1eCe5Ce301e637e1`.

Now `MyERC20` is live !