Developing dApps

Helios provides a robust EVM-compatible and Cosmos SDK-based environment for developers to build decentralized applications (dApps) with enhanced interoperability, governance, and security features. Whether you’re building a DeFi platform, AI-driven dApp, or a cross-chain solution, Helios enables integration with multiple ecosystems.

Why Build on Helios?

EVM & Cosmos SDK Support – Deploy smart contracts using Solidity (EVM) or leverage Cosmos modules for advanced blockchain functionalities.
Interchain Compatibility – Directly interact with multiple chains through Hyperion Modules and I-PoSR staking consensus.
Built-in Governance & Reputation System – Smart contract execution can be influenced by on-chain governance and validator reputation.
Optimized Staking & Economic Model – dApps can integrate weighted staking models, benefiting from multi-asset security.

Helios Development Environment Setup

1. Install Required Dependencies

To start developing, ensure you have the following tools installed:

# Node.js & Yarn (for dApp development)
curl -fsSL https://deb.nodesource.com/setup_18.x | sudo -E bash -
sudo apt install -y nodejs
npm install --global yarn

# Hardhat (for EVM smart contract deployment)
npm install --global hardhat

# Helios SDK (JS/TS Packages)
npm install @helios-chain-labs/proto @helios-chain-labs/transactions @helios-chain-labs/helios-ts-wallet

2. Connecting to Helios Testnet

Before deploying smart contracts or interacting with Helios APIs, connect to the Helios Testnet:

EVM Connection (Web3.js / ethers.js)

const { ethers } = require("ethers");

// Connect to Helios Testnet RPC
const provider = new ethers.JsonRpcProvider("https://dataseed-testnet.helioschain.network");

// Load Wallet (Using Private Key)
const wallet = new ethers.Wallet("YOUR_PRIVATE_KEY", provider);

console.log(`Connected to Helios as ${wallet.address}`);

Cosmos SDK Connection Example (Helios SDK)

const { createWallet, signAndBroadcastTx } = require("@helios-chain-labs/helios-ts-wallet");

const LOCALNET_CHAIN = {
  chainId: 4141,
  cosmosChainId: '4141',
  rpcEndpoint: 'https://dataseed-testnet.helioschain.network',
  bech32Prefix: 'helios',
  currency: {
    coinDenom: 'HELIOS',
    coinMinimalDenom: 'ahelios',
    coinDecimals: 18,
  },
};

// Generate a new Helios Wallet
const wallet = await createWallet();

// Get address and fund it via testnet faucet
console.log("Your Helios Address:", wallet.address);

// Create the vote transaction
const txVote = createTxMsgVote(
  LOCALNET_CHAIN,
  sender,
  LOCALNET_FEE,
  '', // Optional memo
  {
    proposalId: proposalId,
    voter: sender.accountAddress,
    option: voteOption
  }
);

💡 Testnet tokens can be requested from the official Helios Faucet.

Deploying Smart Contracts on Helios (EVM)

Helios is fully EVM-compatible, meaning you can deploy Solidity smart contracts using Hardhat or Foundry.

1. Create a New Hardhat Project

npx hardhat init
cd my-helios-project

2. Configure Hardhat for Helios

Modify hardhat.config.js:

require("@nomicfoundation/hardhat-toolbox");

module.exports = {
  solidity: "0.8.20",
  networks: {
    heliosTestnet: {
      url: "https://dataseed-testnet.helioschain.network",
      accounts: ["YOUR_PRIVATE_KEY"],
    },
  },
};

3. Write a Sample Smart Contract

Create contracts/MyContract.sol:

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

contract MyContract {
    string public message;

    constructor(string memory _message) {
        message = _message;
    }

    function updateMessage(string memory _newMessage) public {
        message = _newMessage;
    }
}

4. Compile & Deploy

npx hardhat compile
npx hardhat run --network heliosTestnet scripts/deploy.js

Interacting with Helios Smart Contracts (EVM)

Once deployed, you can interact with smart contracts via ethers.js:

const contract = new ethers.Contract(
  "YOUR_CONTRACT_ADDRESS",
  ["function updateMessage(string _newMessage) external"],
  wallet
);

await contract.updateMessage("Hello from Helios!");