pyusd-payments-sdk

Utilities for interacting with Arx HaLo–secured wallets from the browser. The SDK wraps the @arx-research/libhalo web API to perform PYUSD transfers.

Installation

npm install pyusd-payments-sdk

Quick Start

import { HaloClient } from "pyusd-payments-sdk";

const client = new HaloClient({
  rpcUrl: "https://ethereum-sepolia-rpc.publicnode.com",
  network: "testnet", // or "mainnet", "arbitrum", "arbitrum-testnet"
  recipient: "0xRecipientAddressHere",
});

// listen for status updates from the HaLo chip
const onStatusChange = (state) => console.log("HaLo status:", state);

async function run() {
  const senderAddress = await client.getWalletAddress({ onStatusChange });
  console.log("HaLo wallet address:", senderAddress);

  const balance = await client.getPyusdBalance(senderAddress);
  console.log(`PYUSD balance: ${balance}`);

  const signedTx = await client.makePayment(senderAddress, {
    amount: "5.0", // PYUSD amount in human-readable units
    onStatusChange,
  });

  const broadcast = await client.broadcastTransaction(signedTx);
  console.log("Broadcast hash:", broadcast.hash);
}

run().catch(console.error);

Initialization

• rpcUrl: HTTPS JSON-RPC endpoint for the target network.
• network: "mainnet", "testnet", "arbitrum", or "arbitrum-testnet"; determines which PYUSD contract is used.
• recipient: destination address for payments; makePayment always targets this account.

Reading the HaLo Wallet Address

const address = await client.getWalletAddress({ onStatusChange });

• onStatusChange (optional) receives status transitions (prompt, reading, success, error).

Checking PYUSD Balance

const balance = await client.getPyusdBalance(address);

Returns the formatted PYUSD balance in human-readable units (defaults to 6 decimals if the contract call fails).

Making a PYUSD Payment

const signedTx = await client.makePayment(address, {
  amount: "10.5", // PYUSD amount
  onStatusChange,
});

const broadcast = await client.broadcastTransaction(signedTx);

• amount: string/number/bigint in PYUSD units (e.g., "10" for 10 PYUSD).
• Optionally override gas parameters with transactionOverrides.
• After signing, use signedTx.serialized or broadcastTransaction to submit the payload.