> For the complete documentation index, see [llms.txt](https://docs.yo.xyz/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.yo.xyz/integrations/integration-guides/sdk/core/vault-reads.md).

# Vault Reads

On-chain read functions for querying vault state, balances, and allowances.

## Vault State

```ts
const state = await client.getVaultState(vaultAddress)
```

Returns a `VaultState` object:

| Field           | Type      | Description                              |
| --------------- | --------- | ---------------------------------------- |
| `address`       | `Address` | Vault contract address                   |
| `name`          | `string`  | Vault name (e.g., "YO ETH Vault")        |
| `symbol`        | `string`  | Vault symbol (e.g., "yoETH")             |
| `decimals`      | `number`  | Vault share decimals                     |
| `totalAssets`   | `bigint`  | Total assets under management            |
| `totalSupply`   | `bigint`  | Total shares issued                      |
| `asset`         | `Address` | Underlying asset address                 |
| `assetDecimals` | `number`  | Underlying asset decimals                |
| `exchangeRate`  | `bigint`  | Current exchange rate (shares per asset) |

## Preview Functions

```ts
// How many shares will I get for 1 ETH?
const shares = await client.previewDeposit(vault, parseEther('1'))

// How many assets will I get for 100 shares?
const assets = await client.previewRedeem(vault, 100n)

// Conversion helpers
const assetsFromShares = await client.convertToAssets(vault, shares)
const sharesFromAssets = await client.convertToShares(vault, parseEther('1'))
```

## Gateway Quote Functions

Quote functions read from the Yo Gateway contract and account for fees and routing.

```ts
// Gateway-aware previews
const shares = await client.quotePreviewDeposit(vault, parseEther('1'))
const assets = await client.quotePreviewRedeem(vault, shares)
const sharesNeeded = await client.quotePreviewWithdraw(vault, parseEther('1'))

// Gateway-aware conversions
const assetsOut = await client.quoteConvertToAssets(vault, shares)
const sharesOut = await client.quoteConvertToShares(vault, parseEther('1'))
```

## Balance Queries

```ts
// ERC-20 token balance
const { balance, decimals } = await client.getTokenBalance(tokenAddress, account)

// Vault share balance
const shares = await client.getShareBalance(vaultAddress, account)

// Full user position
const position = await client.getUserPosition(vaultAddress, account)
// position.shares, position.assets
```

## Allowance Queries

```ts
// ERC-20 allowance
const allowance = await client.getAllowance(token, owner, spender)
const sufficient = await client.hasEnoughAllowance(token, owner, spender, amount)

// Gateway-specific allowance helpers
const shareAllowance = await client.getShareAllowance(vault, owner)
const assetAllowance = await client.getAssetAllowance(vault, owner)
```


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