> ## Documentation Index
> Fetch the complete documentation index at: https://docs.ostium.com/llms.txt
> Use this file to discover all available pages before exploring further.

# getVaultBalance

> Protocol vault balance in USDC — the liquidity backing trader PnL on Ostium.

`getVaultBalance()` returns the protocol vault balance in USDC: the liquidity backing trader PnL. It is the input to the exposure-limit check, which is why the SDK exposes it.

```ts theme={null}
const vault = await client.getVaultBalance();
console.log(vault);   // 12_480_331.42
```

The value is cached for 60 seconds, so calling it per-keystroke in an order ticket costs nothing after the first read.

## Response

`Promise<number>` — USDC, as a plain number.

## Why it matters

A pair group can only hold a share of vault liquidity as collateral. That ceiling is what `withinExposureLimit` on [`previewOpenTrade()`](/developer/reference/preview-open-trade) and `limits.groupCollateral` on [`getMaxCollateral()`](/developer/reference/get-max-collateral) are measured against. Both read the vault for you — call this directly only if you are computing exposure yourself.