> ## 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

```typescript theme={null}
import { PricingSource } from "@openrouter/sdk/models";

let value: PricingSource = "openrouter";

// Open enum: unrecognized values are captured as Unrecognized<string>
```

## Values

```typescript theme={null}
"openrouter" | "provider" | "byok" | "none" | Unrecognized<string>
```