# is_pydantic_v1_subclass

> **Function** in `langchain_core`

📖 [View in docs](https://reference.langchain.com/python/langchain-core/utils/pydantic/is_pydantic_v1_subclass)

Check if the given class is Pydantic v1-like.

## Signature

```python
is_pydantic_v1_subclass(
    cls: type,
) -> bool
```

## Returns

`bool`

`True` if the given class is a subclass of Pydantic `BaseModel` 1.x.

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[View source on GitHub](https://github.com/langchain-ai/langchain/blob/9f232caa7a8fe1ca042a401942d5d90d54ceb1a6/libs/core/langchain_core/utils/pydantic.py#L78)