laconicd/docs/guides/tools/remix.md

Remix: Deploying a Smart Contract

Learn how to deploy a simple Solidity-based smart contract to Ethermint using the Remix in-browser IDE {synopsis}

Pre-requisite Readings

• Installation {prereq}
• Run a node {prereq}
• MetaMask {prereq}

Remix is an in-browser IDE for Solidity smart contracts. In this guide, we will learn how to deploy a contract to a running Ethermint network through Remix and interact with it.

Connect Ethermint account to Remix

::: tip If you haven’t already, follow the steps in the Metamask guide to import your Ethermint private key into Metamask. Start the Ethermint daemon and REST server. :::

Go to Remix. There are some contracts in the File Explorer. Replace these with the source code to Counter.sol below. On the left-most bar, select the Solidity Compiler and compile the contract.

pragma solidity >=0.7.0 <0.9.0;

contract Counter {
  uint256 counter = 0;

  function add() public {
    counter++;
  }

  function subtract() public {
    counter--;
  }

  function getCounter() public view returns (uint256) {
    return counter;
  }
}

Next, select the Deploy and Run option. Select Injected Web3 as the Environment. This will open a metamask popup for you to connect your Metamask to Remix. Select Connect to confirm.

You should see your account show up in the left-hand panel.

Deploy and Interact

Now that your account is connected, you are able to deploy the contract. Press the Deploy button. A metamask pop-up will appear asking you to confirm. Confirm the transaction. You should see a log for the deployment transaction in the Ethermint daemon logs:

I[2020-07-15|17:26:43.155] Added good transaction                       module=mempool tx=877A8E6600FA27EC2B2362719274314977B243671DC4E5F8796ED97FFC0CBE42 res="&{CheckTx:log:\"[]\" gas_wanted:121193 }" height=31 total=1

Once the contract has been successfully deployed, you will see it show up in the Deployed Contracts section in the left-hand side, as well as a green check in the Remix console showing the transaction details.

Now, you are able to interact with the contract through Remix. For Counter.sol, click add. This will open a Metamask pop-up asking you to confirm. Confirm the transaction. Then, click getCounter to get the count, which should be 1.