# ExperimentRunStats

> **Class** in `langsmith`

📖 [View in docs](https://reference.langchain.com/python/langsmith/schemas/ExperimentRunStats)

Run statistics for an experiment.

## Signature

```python
ExperimentRunStats()
```

## Extends

- `TypedDict`

## Constructors

```python
__init__(
    run_count: Optional[int],
    latency_p50: Optional[timedelta],
    latency_p99: Optional[timedelta],
    total_tokens: Optional[int],
    prompt_tokens: Optional[int],
    completion_tokens: Optional[int],
    last_run_start_time: Optional[datetime],
    run_facets: Optional[list[dict[str, Any]]],
    total_cost: Optional[Decimal],
    prompt_cost: Optional[Decimal],
    completion_cost: Optional[Decimal],
    first_token_p50: Optional[timedelta],
    first_token_p99: Optional[timedelta],
    error_rate: Optional[float],
)
```

| Name | Type |
|------|------|
| `run_count` | `Optional[int]` |
| `latency_p50` | `Optional[timedelta]` |
| `latency_p99` | `Optional[timedelta]` |
| `total_tokens` | `Optional[int]` |
| `prompt_tokens` | `Optional[int]` |
| `completion_tokens` | `Optional[int]` |
| `last_run_start_time` | `Optional[datetime]` |
| `run_facets` | `Optional[list[dict[str, Any]]]` |
| `total_cost` | `Optional[Decimal]` |
| `prompt_cost` | `Optional[Decimal]` |
| `completion_cost` | `Optional[Decimal]` |
| `first_token_p50` | `Optional[timedelta]` |
| `first_token_p99` | `Optional[timedelta]` |
| `error_rate` | `Optional[float]` |


## Properties

- `run_count`
- `latency_p50`
- `latency_p99`
- `total_tokens`
- `prompt_tokens`
- `completion_tokens`
- `last_run_start_time`
- `run_facets`
- `total_cost`
- `prompt_cost`
- `completion_cost`
- `first_token_p50`
- `first_token_p99`
- `error_rate`

---

[View source on GitHub](https://github.com/langchain-ai/langsmith-sdk/blob/fcda9320ff067c3d3857e9e3d088fc1eb0643fc4/python/langsmith/schemas.py#L1282)