# fromSpecTokenUsage

# Function: fromSpecTokenUsage()

```ts
function fromSpecTokenUsage(usage, leftover?): TokenUsage<ProviderUsageDetails> | undefined;
```

Defined in: [packages/ai/src/utilities/ag-ui-usage.ts:110](https://github.com/TanStack/ai/blob/main/packages/ai/src/utilities/ag-ui-usage.ts#L110)

## Parameters

### usage

  \| readonly [`SpecTokenUsage`](../interfaces/SpecTokenUsage.md)[]
  \| `undefined`

### leftover?

`TokenUsageLeftover`

## Returns

`TokenUsage`\<`ProviderUsageDetails`\> \| `undefined`