---
title: LanguageModelSession.Usage
framework: foundationmodels
role: symbol
role_heading: Structure
path: foundationmodels/languagemodelsession/usage-swift.struct
---

# LanguageModelSession.Usage

Information about how many tokens were used by a response.

## Declaration

```swift
struct Usage
```

## Topics

### Creating a token usage instance

- [init(input:output:metadata:)](foundationmodels/languagemodelsession/usage-swift.struct/init(input:output:metadata:).md)

### Updating the usage

- [input](foundationmodels/languagemodelsession/usage-swift.struct/input-swift.property.md)
- [LanguageModelSession.Usage.Input](foundationmodels/languagemodelsession/usage-swift.struct/input-swift.struct.md)
- [output](foundationmodels/languagemodelsession/usage-swift.struct/output-swift.property.md)
- [LanguageModelSession.Usage.Output](foundationmodels/languagemodelsession/usage-swift.struct/output-swift.struct.md)
- [metadata](foundationmodels/languagemodelsession/usage-swift.struct/metadata.md)
- [totalTokenCount](foundationmodels/languagemodelsession/usage-swift.struct/totaltokencount.md)

## Relationships

### Conforms To

- [Sendable](swift/sendable.md)
- [SendableMetatype](swift/sendablemetatype.md)

## See Also

### Inspecting a session

- [usage](foundationmodels/languagemodelsession/usage-swift.property.md)
- [properties](foundationmodels/languagemodelsession/properties.md)
- [transcriptErrorHandlingPolicy](foundationmodels/languagemodelsession/transcripterrorhandlingpolicy.md)