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

# Interface: Usage

Token usage for a request.

## Properties

<a id="sdk-input_tokens" />

### input\_tokens

```ts theme={null}
readonly input_tokens: number | null;
```

Number of input tokens used, or `null` when the API did not report it.

***

<a id="sdk-output_tokens" />

### output\_tokens

```ts theme={null}
readonly output_tokens: number | null;
```

Number of output tokens used, or `null` when the API did not report it.


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