# NotGiven

> **Class** in `langsmith`

📖 [View in docs](https://reference.langchain.com/python/langsmith/_openapi_client/_types/NotGiven)

For parameters with a meaningful None value, we need to distinguish between
the user explicitly passing None, and the user not passing the parameter at
all.

User code shouldn't need to use not_given directly.

For example:

```py
def create(timeout: Timeout | None | NotGiven = not_given): ...

create(timeout=1)  # 1s timeout
create(timeout=None)  # No timeout
create()  # Default timeout behavior
```

## Signature

```python
NotGiven()
```

---

[View source on GitHub](https://github.com/langchain-ai/langsmith-sdk/blob/d6cd6082f09e7826a2d6afe444ae6119e61b82a6/python/langsmith/_openapi_client/_types.py#L130)