EVM

Quick start

git checkout dev
git pull # make sure you have the latest changes
git checkout -b my-custom-world # create a new branch for your customized world
npx hypkg apply drama-haus/evm
npm install # install the EVM dependencies (wagmi and viem)

You can check what this patch adds here

Environment Configuration

The EVM integration requires the following environment variables to be added to your .env file:

# Required for all modes
PUBLIC_EVM=mainnet  # EVM chain to use (defaults to 'mainnet')

# For server wallet operations
EVM_SEED_PHRASE=   # Required for server wallet operations

Using in scripts

The integration exposes player.evm and world.evm to scripts:

• player.evm contains the connected wallet address of that player
• world.evm provides access to EVM functionality and utilities

Player Properties

// Get the current player's wallet address
const player = world.getPlayer()
console.log(player.evm) // Returns the player's wallet address

World Properties

The world.evm object provides the following structure:

world.evm = {
  actions: {}, // wagmi actions
  utils: {}, // viem utilities
  abis: {
    erc20: erc20Abi,
    erc721: null
  }
}

Client-Side Actions

On the client side, all wagmi actions are automatically bound to the world object and available through world.evm.actions. These actions are pre-configured with the current wagmi config and can be used directly:

// Example of using client-side actions
const result = await world.evm.actions.readContract({
  address: '0x...',
  abi: world.evm.abis.erc20,
  functionName: 'balanceOf',
  args: [player.evm]
})

// Write operations are also available
const tx = await world.evm.actions.writeContract({
  address: '0x...',
  abi: world.evm.abis.erc20,
  functionName: 'transfer',
  args: [recipientAddress, amount]
})

Note

Client-side actions are automatically bound when the client initializes and the wallet is connected. They use the current wagmi configuration and wallet connection.

Contract Interactions

The EVM integration provides access to contract interactions through world.evm.actions and world.evm.getContract().

Basic Usage

// Access a contract by its address
const contract = world.evm.getContract({
  address: '0x...',
  abi: world.evm.abis.erc20
})

// Read from a contract
const balance = await world.evm.actions.readContract({
  address: '0x...',
  abi: world.evm.abis.erc20,
  functionName: 'balanceOf',
  args: [player.evm]
})

Common Contract Methods

These methods are available in both server and client contexts:

// Get a wallet's token balance
const balance = await world.evm.actions.readContract({
  address: tokenAddress,
  abi: world.evm.abis.erc20,
  functionName: 'balanceOf',
  args: [walletAddress]
})

// Transfer tokens
const transferResult = await world.evm.actions.writeContract({
  address: tokenAddress,
  abi: world.evm.abis.erc20,
  functionName: 'transfer',
  args: [recipientAddress, amount]
})

Example

app.on('update', () => {
  const player = world.getPlayer()
  if (player.evm) {
    // Player has a connected wallet
    const contract = world.evm.getContract({
      address: '0x...',
      abi: world.evm.abis.erc20
    })

    // Use wagmi actions
    const balance = await world.evm.actions.readContract({
      address: '0x...',
      abi: world.evm.abis.erc20,
      functionName: 'balanceOf',
      args: [player.evm]
    })

    if (balance > 0) {
      app.send('client:balance', [balance, player.evm])
    }
  }
})