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EVM And Cosmos API's

Overview​

Helios provides dual API compatibility, supporting both EVM JSON-RPC and Cosmos gRPC endpoints. This allows developers to interact with the blockchain using familiar tools from both ecosystems.

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EVM JSON-RPC Support​

Helios is fully EVM-compatible, exposing standard Ethereum JSON-RPC endpoints. This means you can use popular Ethereum libraries like Web3.js or ethers.js to interact with the network.

Available Endpoints​

  • Mainnet: https://dataseed.helioschain.network
  • Testnet: https://dataseed-testnet.helioschain.network

Example: Querying Balance with ethers.js​

const { ethers } = require("ethers");
// Connect to Helios RPC
const provider = new ethers.JsonRpcProvider("https://dataseed-testnet.helioschain.network");
async function getBalance(address) {
    const balance = await provider.getBalance(address);
    console.log(`Balance: ${ethers.formatEther(balance)} HELIOS`);
}
getBalance("0x742d35Cc6634C0532925a3b844Bc454e4438f44e");

Supported EVM Methods​

  • eth_getBalance
  • eth_sendTransaction
  • eth_call
  • eth_estimateGas
  • eth_getBlockByNumber
  • And all other standard Ethereum JSON-RPC methods
  • Helios Featured Methods:
  • eth_getAccountTransactionsByPageAndSize
  • eth_getBlocksByPageAndSize
  • eth_getCosmosAddress
  • eth_getCosmosValoperAddress
  • eth_getDelegation
  • eth_getDelegations
  • eth_getProposal
  • eth_getProposalsByPageAndSize
  • eth_getTokenBalance
  • eth_getTokensBalance
  • eth_getTokensByPageAndSize
  • eth_getTransactionsByPageAndSize
  • eth_getValidatorsByPageAndSize
  • eth_getAllWhitelistedAssets
  • And all other methods available in the section Supported EVM Methods

TODO: section dedicated Supported EVM Methods

Cosmos gRPC Support​

Helios also implements Cosmos SDK's gRPC endpoints, enabling direct interaction with Cosmos-specific features like staking, governance, and IBC transfers.

Available Endpoints​

  • Mainnet gRPC: grpc.helioschain.network:9090
  • Testnet gRPC: grpc-testnet.helioschain.network:9090

Example: Querying Validators using Cosmos gRPC​

const { createWallet } = require("@helios-chain-labs/helios-ts-wallet");
const { QueryClient } = require("@cosmjs/stargate");
async function getValidators() {
    const client = await QueryClient.connect("grpc-testnet.helioschain.network:9090");
    const response = await client.staking.validators({
        status: "BOND_STATUS_BONDED",
        pagination: {
            key: new Uint8Array(),
            offset: Long.fromNumber(0),
            limit: Long.fromNumber(100),
            countTotal: true
        }
        }
    );
    console.log("Active Validators:", response.validators);
}
getValidators();

Supported Cosmos Modules​

  • x/auth: Account management
  • x/bank: Token transfers
  • x/staking: Validator operations
  • x/gov: Governance proposals
  • x/ibc: Inter-blockchain communication

Using Both APIs Together​

Helios's dual API support allows developers to leverage the best of both worlds. For example, you can:

  • Use EVM APIs for smart contract interactions
  • Use Cosmos APIs for staking and governance
  • Combine both for cross-chain applications

Example: Combined API Usage​

const { ethers } = require("ethers");
const { createWallet } = require("@helios-chain-labs/helios-ts-wallet");
async function crossChainInteraction() {
    // EVM interaction
    const evmProvider = new ethers.JsonRpcProvider("https://dataseed-testnet.helioschain.network");
    const evmBalance = await evmProvider.getBalance(address);
    // Cosmos interaction
    const cosmosWallet = await createWallet();
    const stakingInfo = await cosmosWallet.getStakingInfo();

    console.log("EVM Balance:", ethers.formatEther(evmBalance));
    console.log("Staking Info:", stakingInfo);
}

Best Practices​

  1. RPC Node Selection

    • Use dedicated RPC nodes for production applications
    • Implement fallback RPC endpoints for reliability

  2. Error Handling

    • Always implement proper error handling for both API types
    • Monitor for chain-specific errors and handle them appropriately

  3. Rate Limiting

    • Respect API rate limits
    • Implement request caching when appropriate

  4. Security

    • Never expose private keys in your code
    • Use environment variables for sensitive configuration
    • Validate all responses before processing

For more detailed information about specific API endpoints and methods, refer to the Helios API Reference.

References:

  1. https://docs.ethers.org/v5/ - Ethers Typescript Library
  2. @helios-chain-labs/helios-ts-wallet - Helios Typescript Library