> For the complete documentation index, see [llms.txt](https://docs.yield.fi/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.yield.fi/earn-with-yieldfi/integration-sdk/contracts/ytoken-legacy.md).

# YToken (Legacy)

> **Note**: This page documents legacy YToken contracts. For v3 contracts, see Vault Contract.

YToken contracts are yield-bearing ERC-4626 vault tokens (yUSD, yBTC, yETH, etc.) from earlier versions.

### Connecting to YToken

#### Using Wagmi

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

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

  const connectYTokenContract = 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 yUSD = connectYToken(
      contracts.yUSD,
      yTokenAbi, // Your YToken ABI
      signer
    );

    return yUSD;
  };
}
```

#### Using Browser Provider

```typescript
import { connectYToken, 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 yUSD = connectYToken(
  contracts.yUSD,
  yTokenAbi, // Your YToken ABI
  signer
);
```

### ERC-20 Operations

```typescript
// Get balance
const balance = await yUSD.balanceOf(userAddress);

// Transfer
await yUSD.transfer(recipient, amount);

// Approve
await yUSD.approve(spender, amount);
```

### ERC-4626 Operations

```typescript
// Deposit assets
const shares = await yUSD.deposit(amount, receiver);

// Redeem shares
await yUSD.redeem(shares, receiver, owner);

// Get conversion rates
const assetsPerShare = await yUSD.convertToAssets(shares);
const sharesPerAsset = await yUSD.convertToShares(amount);
```

### View Methods

```typescript
// Get total assets
const totalAssets = await yUSD.totalAssets();

// Get total supply
const totalSupply = await yUSD.totalSupply();

// Get asset address
const asset = await yUSD.asset();
```

### Migration to V3

For new integrations, use v3 contracts:

* **Manager V3** - See Manager Contract
* **Vault Contract** - See Vault Contract