VyToken (Legacy)

Note: This page documents legacy VyToken contracts. For v3 contracts, see Vault Contract.

VyToken contracts are volatile yield token contracts (vyUSD, vyBTC, vyETH) with enhanced yield optimization from earlier versions.

Connecting to VyToken

Using Wagmi

import { connectVyToken, getContractAddresses, Chain } from "yieldfi-sdk";
import { ethers } from "ethers";
import { useAccount, useWalletClient } from "wagmi";

function VyTokenExample() {
  const { address } = useAccount();
  const { data: walletClient } = useWalletClient();

  const connectVyTokenContract = async () => {
    if (!walletClient || !address) {
      throw new Error("Wallet not connected");
    }

    const provider = new ethers.BrowserProvider(walletClient);
    const signer = await provider.getSigner();

    const contracts = getContractAddresses(Chain.ETHEREUM);
    const vyUSD = connectVyToken(
      contracts.vyUSD,
      vyTokenAbi, // Your VyToken ABI
      signer
    );

    return vyUSD;
  };
}

Using Browser Provider

import { connectVyToken, getContractAddresses, Chain } from "yieldfi-sdk";
import { ethers } from "ethers";

if (!window.ethereum) {
  throw new Error("No wallet found");
}

const provider = new ethers.BrowserProvider(window.ethereum);
const signer = await provider.getSigner();

const contracts = getContractAddresses(Chain.ETHEREUM);

const vyUSD = connectVyToken(
  contracts.vyUSD,
  vyTokenAbi, // Your VyToken ABI
  signer
);

VyToken-Specific Operations

Deposit YToken

// Approve yToken spending
await yUSD.approve(vyUSD.target, amount);

// Deposit yToken directly
await vyUSD.depositYToken(receiver, amount);

View Methods

// Get underlying yToken
const yToken = await vyUSD.yToken();

// Get guardrail multiplier
const guardrail = await vyUSD.guardrailMultiplier();

// Get total yToken deposited
const totalYToken = await vyUSD.totalYToken();

Inherited Operations

VyToken inherits all YToken operations (ERC-20 and ERC-4626):

// ERC-20
const balance = await vyUSD.balanceOf(userAddress);
await vyUSD.transfer(recipient, amount);

// ERC-4626
const shares = await vyUSD.deposit(amount, receiver);
await vyUSD.redeem(shares, receiver, owner);

Migration to V3

For new integrations, use v3 contracts:

• Manager V3 - See Manager Contract

• Vault Contract - See Vault Contract