> ## Documentation Index
> Fetch the complete documentation index at: https://openrouter-d02e98a0-mintlify-7021d5f4.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Usage - Go SDK

> Usage type definition

<Warning>
  The Go SDK and docs are currently in beta.
  Report issues on [GitHub](https://github.com/OpenRouterTeam/go-sdk/issues).
</Warning>

Token usage information for the response

## Fields

| Field                 | Type                                                                                       | Required             | Description                                                         |
| --------------------- | ------------------------------------------------------------------------------------------ | -------------------- | ------------------------------------------------------------------- |
| `InputTokens`         | `int64`                                                                                    | :heavy\_check\_mark: | N/A                                                                 |
| `InputTokensDetails`  | [components.InputTokensDetails](/client-sdks/go/api-reference/models/inputtokensdetails)   | :heavy\_check\_mark: | N/A                                                                 |
| `OutputTokens`        | `int64`                                                                                    | :heavy\_check\_mark: | N/A                                                                 |
| `OutputTokensDetails` | [components.OutputTokensDetails](/client-sdks/go/api-reference/models/outputtokensdetails) | :heavy\_check\_mark: | N/A                                                                 |
| `TotalTokens`         | `int64`                                                                                    | :heavy\_check\_mark: | N/A                                                                 |
| `Cost`                | optionalnullable.OptionalNullable\[`float64`]                                              | :heavy\_minus\_sign: | Cost of the completion                                              |
| `CostDetails`         | [\*components.UsageCostDetails](/client-sdks/go/api-reference/models/usagecostdetails)     | :heavy\_minus\_sign: | N/A                                                                 |
| `IsByok`              | `*bool`                                                                                    | :heavy\_minus\_sign: | Whether a request was made using a Bring Your Own Key configuration |