# ServiceAuth

> **Class** in `langsmith`

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

Service-to-service JWT authentication for write replicas.

## Signature

```python
ServiceAuth()
```

## Extends

- `TypedDict`

## Constructors

```python
__init__(
    service_key: str,
    tenant_id: NotRequired[str],
)
```

| Name | Type |
|------|------|
| `service_key` | `str` |
| `tenant_id` | `NotRequired[str]` |


## Properties

- `service_key`
- `tenant_id`

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[View source on GitHub](https://github.com/langchain-ai/langsmith-sdk/blob/19dc497a3d89638e4cc35db72ea1c29cad35cbbf/python/langsmith/run_trees.py#L36)