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

# ResponseFormat

The response format. "json" (default) returns \{ text, usage }; "verbose\_json" additionally returns task, language, duration, and segment-level timestamps (OpenAI-compatible providers only).

## Example Usage

```go theme={null}
import (
	"github.com/OpenRouterTeam/go-sdk/models/operations"
)

value := operations.ResponseFormatJSON

// Open enum: custom values can be created with a direct type cast
custom := operations.ResponseFormat("custom_value")
```

## Values

| Name                        | Value         |
| --------------------------- | ------------- |
| `ResponseFormatJSON`        | json          |
| `ResponseFormatVerboseJSON` | verbose\_json |