Using Remix to Deploy to Moonbeam

Introduction

Remix is one of the commonly used development environments for smart contracts on Ethereum. Given Moonbeam’s Ethereum compatibility features, Remix can be used directly with any of the Moonbeam networks.

This guide walks through the process of creating and deploying a Solidity-based smart contract to a Moonbeam development node using the Remix IDE. This guide can be adapted for Moonbeam, Moonriver, or Moonbase Alpha.

Checking Prerequisites

For the purposes of this guide, you'll need to have the following:

• A locally running Moonbeam development node
• MetaMask installed and configured to use your development node

If you followed the guides above, you should have a local Moonbeam node which will begin to author blocks as transactions arrive.

Your development node comes with 10 pre-funded accounts. You should have MetaMask connected to your Moonbeam development node and have imported at least one of the pre-funded accounts.

If you're adapting this guide for Moonbeam, Moonriver, or Moonbase Alpha make sure you are connected to the correct network and have an account with funds.
You can get DEV tokens for testing on Moonbase Alpha once every 24 hours from the Moonbase Alpha Faucet.

Getting Started with Remix

Now, you can head to Remix to get started. In the main screen, under Featured Plugins, select SOLIDITY to configure Remix for Solidity development, then navigate to the File Explorers view.

You will create a new file to save the Solidity smart contract. Hit the + button under File Explorers and enter the name MyToken.sol in the pop-up.

Next, paste the following smart contract into the editor tab:

pragma solidity ^0.7.0;

import 'https://github.com/OpenZeppelin/openzeppelin-contracts/blob/release-v3.2.0-solc-0.7/contracts/token/ERC20/ERC20.sol';

// This ERC-20 contract mints the specified amount of tokens to the contract creator.
contract MyToken is ERC20 {
  constructor(uint256 initialSupply) ERC20("MyToken", "MYTOK") {
    _mint(msg.sender, initialSupply);
  }
}

This is a simple ERC-20 contract based on the current OpenZeppelin ERC-20 template. It creates MyToken with symbol MYTOK and mints the entirety of the initial supply to the creator of the contract.

Now, navigate to the Compile sidebar option and press the Compile MyToken.sol button.

Note

With the release of Solidity v0.8.20, support for the Shanghai hard fork has been introduced, which includes PUSH0 opcodes in the generated bytecode. Support for the PUSH0 opcode on Moonbeam hasn't been rolled out yet. As such, if you'd like to use Solidity v0.8.20, you'll need to modify some configurations. From the Advanced Configurations dropdown, you can set the EVM VERSION to london.

If you attempt to use the default compiler of Solidity v0.8.20, you will see the following error:

{'code': -32603, 'message': 'evm error: InvalidCode(Opcode(95))', 'data': '0x'}

You will see Remix download all of the OpenZeppelin dependencies and compile the contract.

Deploying a Contract to Moonbeam Using Remix

Now you can deploy the contract by navigating to the Deployment sidebar option. You need to change the topmost ENVIRONMENT dropdown from JavaScript VM to Injected Web3. This tells Remix to use the MetaMask injected provider, which will point it to your Moonbeam development node. If you wanted to try this using another Moonbeam network, you would have to connect MetaMask to the correct network instead of your local development node.

As soon as you select Injected Web3, you will be prompted to allow Remix to connect to your MetaMask account.

Press Next in MetaMask to allow Remix to access the selected account.

Back on Remix, you should see that the account you wish to use for deployment is now managed by MetaMask. Next to the Deploy button, specify an initial supply of 8M tokens. Since this contract uses the default of 18 decimals, the value to put in the box is 8000000000000000000000000.

Once you have entered this value, select Deploy.

You will be prompted in MetaMask to confirm the contract deployment transaction.

Note

If you have problems deploying any specific contract, you can try manually increasing the gas limit in MetaMask. Select the colored circle in the top right corner and select Settings from the menu. Then click on Advanced and toggle the Advanced Gas Controls setting to ON.

After you press Confirm and the deployment is complete, you will see the transaction listed in MetaMask. The contract will appear under Deployed Contracts in Remix.

Once the contract is deployed, you can interact with it from within Remix.

Drill down on the contract under Deployed Contracts. Clicking on name, symbol, and totalSupply should return MyToken, MYTOK, and 8000000000000000000000000 respectively. If you copy the address from which you deployed the contract and paste it into the balanceOf field, you should see the entirety of the balance of the ERC-20 as belonging to that user. Copy the contract address by clicking the button next to the contract name and address.

Interacting with a Moonbeam-based ERC-20 from MetaMask

Now, open MetaMask to add the newly deployed ERC-20 tokens. Before doing so, make sure you have copied the contract's address from Remix. Back in MetaMask, click on Add Token as shown below. Make sure you are connected to the account that deployed the token contract.

Paste the copied contract address into the Custom Token field. The Token Symbol and Decimals of Precision fields should be automatically populated.

After hitting Next, you will need to confirm that you want to add these tokens to your MetaMask account. Hit Add Token and you should see a balance of 8M MyTokens in MetaMask:

Now you can send some of these ERC-20 tokens to the other account that you have set up in MetaMask. Hit Send to initiate the transfer of 500 MyTokens and select the destination account.

After hitting Next, you will be asked to confirm (similar to what is pictured below).

Hit Confirm and, after the transaction is complete, you will see a confirmation and a reduction of the MyToken account balance from the sender account in MetaMask:

If you own the account that you sent the tokens to, you can add the token asset to verify that the transfer arrived.

Using the Moonbeam Remix Plugin

The Moonbeam team has built a Remix plugin that makes it even easier to develop and deploy your Ethereum smart contracts on Moonbeam. The Moonbeam Remix plugin combines all of the important functions needed to compile, deploy, and interact with your smart contracts from one place - no switching tabs needed. The Moonbeam Remix plugin supports Moonbeam, Moonriver, and the Moonbase Alpha TestNet.

Installing the Moonbeam Remix Plugin

To install the Moonbeam Remix plugin, take the following steps:

1. Head to the Plugin manager tab
2. Search for Moonbeam
3. Press Activate and the Moonbeam Remix plugin will be added directly above the plugin manager tab

Once you've added the plugin, a Moonbeam logo will appear on the left hand side, representing the Moonbeam Remix plugin tab.

Getting Started with the Moonbeam Remix Plugin

Click on the Moonbeam logo in your Remix IDE to open the Moonbeam plugin. This part assumes you already have a contract in Remix ready to be compiled. You can generate an ERC-20 contract here. To deploy an ERC-20 Token to Moonbase Alpha using the Moonbeam Remix plugin, you can take the following steps:

1. Press Connect to connect MetaMask to Remix
2. Ensure you're on the correct network. For this example, you should be on Moonbase Alpha
3. Press Compile or choose Auto-Compile if you prefer
4. Press Deploy and Confirm the transaction in MetaMask

It's that easy! Once the contract is deployed, you'll see the address and all available read/write methods to interact with it.

The Moonbeam Remix plugin works seamlessly with Remix so you can freely switch between using the traditional Remix compile and deploy tabs and the Moonbeam Remix plugin.

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Last update: May 12, 2023
| Created: March 1, 2022