# ModelAuthenticationError

> **Class** in `langchain_core`

📖 [View in docs](https://reference.langchain.com/python/langchain-core/exceptions/ModelAuthenticationError)

Exception raised when model provider authentication fails (HTTP 401).

## Signature

```python
ModelAuthenticationError()
```

## Extends

- `ModelError`

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[View source on GitHub](https://github.com/langchain-ai/langchain/blob/fc7dc7757a46ebb444be1ead0efdeab5ca7ad8ce/libs/core/langchain_core/exceptions.py#L83)