# UsageBreakdownRow

One group of a `UsageBreakdown`.

**Kind:** an object, used in responses.

## Fields

Every field is present in a response; empty ones are `null`.

| Field | Type | Description |
|---|---|---|
| `key` | `string \| null` | The value to pass to the dimension's filter to drill into this row; null means "no value" (`~none`). |
| `label` | `string \| null` | A display name where the key is an id (definition, root, trigger) or a namespace; otherwise null. |
| `detail` | `string \| null` | The kind of run for definition, version and root rows; what started the runs for trigger rows. |
| `totals` | [`UsageTotals`](https://docs.maitento.com/reference/types/usage-totals.md) | The group's usage. |

## Example

```json
{
  "key": "...",
  "label": "...",
  "detail": "...",
  "totals": {
    "runs": 0,
    "runtimeMs": 0,
    "executionMs": 0,
    "steps": 0,
    "stepRuntimeMs": 0,
    "toolCalls": 0,
    "tokens": {
      "input": 0,
      "output": 0,
      "cacheRead": 0,
      "cacheWrite": 0,
      "reasoning": 0,
      "total": 0
    },
    "webSearches": 0,
    "webPages": 0,
    "webDownloads": 0,
    "imageDescriptions": 0,
    "webCredits": 0,
    "webBytes": 0
  }
}
```

## Where it's used

- Inside [`UsageBreakdown`](https://docs.maitento.com/reference/types/usage-breakdown.md)