# ChatModelInput

> **Class** in `langchain_classic`

📖 [View in docs](https://reference.langchain.com/python/langchain-classic/smith/evaluation/runner_utils/ChatModelInput)

Input for a chat model.

## Signature

```python
ChatModelInput()
```

## Extends

- `TypedDict`

## Constructors

```python
__init__(
    messages: list[BaseMessage],
)
```

| Name | Type |
|------|------|
| `messages` | `list[BaseMessage]` |


## Properties

- `messages`

---

[View source on GitHub](https://github.com/langchain-ai/langchain/blob/42f8f79293cfb7589e5bc1d74a8ae4dfd0bf15e3/libs/langchain/langchain_classic/smith/evaluation/runner_utils.py#L297)