# get_required_header

> **Function** in `langsmith`

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

## Signature

```python
get_required_header(
    headers: HeadersLike,
    header: str,
) -> str
```

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[View source on GitHub](https://github.com/langchain-ai/langsmith-sdk/blob/d6cd6082f09e7826a2d6afe444ae6119e61b82a6/python/langsmith/_openapi_client/_utils/_utils.py#L384)