# pytest_addoption

> **Function** in `langsmith`

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

Set a boolean flag for LangSmith output.

Skip if --langsmith-output is already defined.

## Signature

```python
pytest_addoption(
    parser,
)
```

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[View source on GitHub](https://github.com/langchain-ai/langsmith-sdk/blob/791701a304a72495d108669ef11c194983fd0e95/python/langsmith/pytest_plugin.py#L20)