EVM

The Ethereum Virtual Machine (EVM) is the runtime environment for smart contracts in Ethereum. It’s a fundamental part of the Ethereum network and is used by many other blockchain platforms that aim to provide Ethereum-like functionality. Our EVM SDK provides a simple interface to interact with EVM-compatible blockchains.

Supported Networks

The EVM SDK supports multiple EVM-compatible networks:

Network	Mainnet	Testnet	Chain ID
Ethereum	`https://rpc.ankr.com/eth`	Sepolia: `https://ethereum-sepolia-rpc.publicnode.com`	1 / 11155111
Polygon	`https://polygon-rpc.com`	Amoy: `https://rpc-amoy.polygon.technology`	137 / 80002
Arbitrum	`https://arbitrum.llamarpc.com`	Sepolia: `https://sepolia-rollup.arbitrum.io/rpc`	42161 / 421614
Base	`https://base.llamarpc.com`	Sepolia: `https://sepolia.base.org`	8453 / 84532
Avalanche	`https://api.avax.network/ext/bc/C/rpc`	Fuji: `https://avalanche-fuji-c-chain.publicnode.com`	43114 / 43113
BSC	`https://bsc-dataseed1.defibit.io`	Testnet: `https://data-seed-prebsc-2-s2.bnbchain.org:8545`	56 / 97
Linea	`https://rpc.linea.build`	Goerli: `https://rpc.goerli.linea.build`	59144 / 59140

Core Concepts

Accounts: Ethereum addresses that can hold balance and send transactions
Transactions: Signed data packages that store a message to be sent from an externally owned account
Gas: The fee required to execute operations on the Ethereum network
Smart Contracts: Programs that run on the Ethereum blockchain

Setting up your wallet

To interact with EVM-compatible chains, you’ll need a wallet with a private key. You can use tools like MetaMask or hardware wallets to generate and manage your keys securely. For testing purposes, you can use faucets to get testnet tokens: Ethereum Sepolia:

Polygon Amoy:

Polygon Faucet

Arbitrum Sepolia:

Arbitrum Faucet

Base Sepolia:

Base Faucet

Initialization

Import the SDK and create a new instance:

import { EVM } from "@kynesyslabs/demosdk/xm-websdk"

const rpc_url = "https://sepolia.infura.io/v3/YOUR-PROJECT-ID"
const instance = await EVM.create(rpc_url)

Connecting your wallet

To create signed transaction payloads, you need to connect your wallet to the SDK:

const privateKey = "0x1234567890abcdef..." // Your private key
await instance.connectWallet(privateKey)

You can view the address of your connected wallet using the getAddress method:

const address = instance.getAddress()
console.log(`Address: ${address}`)

Creating a token transfer payload

To create a signed transaction payload to transfer ETH, you can use the preparePay method:

const recipientAddress = "0x742d35Cc6634C0532925a3b844Bc454e4438f44e"
const amount = "0.1" // Amount in ETH
const signedTx = await instance.preparePay(recipientAddress, amount)

The signedTx is a signed transaction that can be used a DEMOS transaction.

Creating multiple transfer payload

You can prepare multiple signed transaction payloads at once using the preparePays method:

const transfers = [
    { address: "0x742d35Cc6634C0532925a3b844Bc454e4438f44e", amount: "0.1" },
    { address: "0x742d35Cc6634C0532925a3b844Bc454e4438f44e", amount: "0.2" },
]
const signedTxs = await instance.preparePays(transfers)

The signedTxs is an array of signed transaction payloads that can be used in a DEMOS transaction.

Checking balance

You can check the balance of an address using the getBalance method:

const balance = await instance.getBalance(
    "0x742d35Cc6634C0532925a3b844Bc454e4438f44e",
)
console.log(`Balance: ${balance} ETH`)

Signing messages

const message = "Hello, world!"

// signing
const signature = await instance.signMessage(message)

// verifying signature
const verified = await instance.verifyMessage(
    message,
    signature,
    instance.getAddress(),
)

expect(verified).toBe(true)

Working with smart contracts

The SDK provides methods to interact with smart contracts. Note that abi must be passed as a JSON string, not a JavaScript array — pass it through JSON.stringify(abi) if you have it as an array.

const contractAddress = "0x..."
const abi = JSON.stringify([/* contract ABI */])

const contract = await instance.getContractInstance(contractAddress, abi)

// Read from contract
const result = await instance.readFromContract(contract, "functionName", [arg1, arg2])

// Write to contract — returns the signed-and-broadcast tx hash as a string
const txHash = await instance.writeToContract(
    contract,
    "functionName",
    [arg1, arg2],
    { gasLimit: 200_000, value: "0.01" }, // optional; value is in ETH (parsed via parseEther)
)

readFromContract(contract, fnName, args) calls a view/pure function and returns the raw return value. writeToContract(contract, fnName, args, options?) builds, signs, and broadcasts a state-changing transaction. The optional fourth argument accepts { gasLimit?: number; value?: string } — value is the ETH amount as a decimal string and is parsed via parseEther.

Listening for events

You can listen for specific events or all events from a contract:

// Listen for a specific event (contract, abi, event, timeout?)
const eventData = await instance.listenForEvent(contractAddress, abi, "EventName", 5000)

// Listen for all events (returns a function to remove the listener)
const unsubscribe = instance.listenForAllEvents(contractAddress, abi, (...args) => {
    console.log("event", args)
})

Cleaning up

To disconnect your wallet and clean up resources, you can use the disconnect method:

await instance.disconnect()

Advanced usage

For more advanced use cases, you can access underlying properties and methods of the EVM instance:

Property/Method	Description	API Reference
`instance.provider`	The JsonRpcProvider instance for interacting with the Ethereum network	JsonRpcProvider
`instance.wallet`	The Wallet instance representing the connected account	Wallet
`instance.contracts`	A Map of Contract instances for interacting with smart contracts	Contract
`instance.signTransaction(s)`	Method(s) to sign one or multiple transactions	-

You can use these properties and methods to perform custom operations:

const blockNumber = await instance.provider.getBlockNumber()

API Reference

https://kynesyslabs.github.io/demosdk-api-ref/classes/xmwebsdk.EVM.html

Getting Started

WebSDK

Cross Chain

Utilities

Storage Programs

Code Examples

Web2 Integration

Bridges

Advanced

Wallet Integration

Evm

EVM

Supported Networks

Core Concepts

Setting up your wallet

Initialization

Connecting your wallet

Creating a token transfer payload

Creating multiple transfer payload

Checking balance

Signing messages

Working with smart contracts

Listening for events

Cleaning up

Advanced usage

API Reference

Resources

​EVM

​Supported Networks

​Core Concepts

​Setting up your wallet

​Initialization

​Connecting your wallet

​Creating a token transfer payload

​Creating multiple transfer payload

​Checking balance

​Signing messages

​Working with smart contracts

​Listening for events

​Cleaning up

​Advanced usage

​API Reference

​Resources

EVM

Supported Networks

Core Concepts

Setting up your wallet

Initialization

Connecting your wallet

Creating a token transfer payload

Creating multiple transfer payload

Checking balance

Signing messages

Working with smart contracts

Listening for events

Cleaning up

Advanced usage

API Reference

Resources