> ## 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.

# SessionCostItem

## Fields

| Field                     | Type                                                | Required             | Description                           | Example                   |
| ------------------------- | --------------------------------------------------- | -------------------- | ------------------------------------- | ------------------------- |
| `app_name`                | *str*                                               | :heavy\_check\_mark: | Published harness display label.      | Hermes Agent              |
| `app_slug`                | *str*                                               | :heavy\_check\_mark: | Stable public slug of the harness.    | hermes-agent              |
| `median_session_cost_usd` | *float*                                             | :heavy\_check\_mark: | Median USD spend per sampled session. | 1.74                      |
| `model_permaslug`         | *str*                                               | :heavy\_check\_mark: | Exact model permaslug.                | anthropic/claude-4.8-opus |
| `turn_range`              | [components.TurnRange](../components/turnrange.mdx) | :heavy\_check\_mark: | Inclusive session turn-count range.   | 10-49-turns               |