> ## 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.

# CostDetails

Breakdown of upstream inference costs

## Fields

| Field                                 | Type                       | Required             | Description                                                                                                                                                                                                                                                               |
| ------------------------------------- | -------------------------- | -------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `server_tool_cost`                    | *OptionalNullable\[float]* | :heavy\_minus\_sign: | Metered server-tool execution cost (for example, shell sandbox time) billed for this request, in USD. Matches the billed checkpoint and settlement amounts exactly. 0 when a metered server tool ran but settled at zero dollars; absent when no metered server tool ran. |
| `upstream_inference_completions_cost` | *float*                    | :heavy\_check\_mark: | N/A                                                                                                                                                                                                                                                                       |
| `upstream_inference_cost`             | *OptionalNullable\[float]* | :heavy\_minus\_sign: | N/A                                                                                                                                                                                                                                                                       |
| `upstream_inference_prompt_cost`      | *float*                    | :heavy\_check\_mark: | N/A                                                                                                                                                                                                                                                                       |