> ## 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.

# PricingSource

Who bills the engine's calls beyond the model's tokens: `openrouter` (the `pricing` rows, from the caller's credits), `provider` (a per-call tool fee from the model's provider on the inference call, at its own rates), `byok` (the engine's vendor, against the caller's own key), or `none` (no charge)

## Example Usage

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

value := components.PricingSourceOpenrouter

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

## Values

| Name | Value |
| - | - |
| `PricingSourceOpenrouter` | openrouter |
| `PricingSourceProvider` | provider |
| `PricingSourceBYOK` | byok |
| `PricingSourceNone` | none |