Quickstart Guide

This guide walks you through executing your first transaction with Helios.
By the end, you’ll have simulated and executed a basic DeFi operation using the Helios API.

Prerequisites

• A Helios API key

• Node.js 18+

• A wallet or signer you control (Helios is non-custodial)

Installation

Install the Helios SDK using your package manager of choice.

npm install @helios/sdk

Initialize the Client

Create a Helios client and configure the environment.

import { Helios } from "@helios/sdk";
const helios = new Helios({
  apiKey: process.env.HELIOS_API_KEY,
  environment: "mainnet", // or "testnet"
});

The client handles routing, simulation, and execution coordination.
Signing and custody remain external to Helios.

Simulate an Execution

Before executing on-chain, you can simulate routes to inspect cost, slippage, and risk signals.

const simulation = await helios.simulate({
  asset: "USDC",
  amount: "4500",
  fromChain: "ethereum",
  toChain: "arbitrum",
});

console.log(simulation.routes);

Simulation returns candidate routes along with estimated gas, fees, and execution constraints.
No transactions are sent at this stage.

Execute a Transaction

Once satisfied with the simulation, execute the transaction.

const execution = await helios.execute({
  asset: "USDC",
  amount: "4500",
  fromChain: "ethereum",
  toChain: "arbitrum",
  options: {
    slippage: 0.5,
    riskLevel: "balanced",
  },
});

Helios coordinates routing and execution, but the transaction must be signed by your wallet or signing service.

Execution Result

Executions return structured, machine-readable responses.

console.log(execution.status);
// "executed"
console.log(execution.txHash);