# VertexAI

> **Class** in `langchain_google_vertexai`

📖 [View in docs](https://reference.langchain.com/python/langchain-google-vertexai/llms/VertexAI)

Google Vertex AI text completion large language models (legacy LLM).

!!! version-added "Vertex AI Platform Support"

    Added in `langchain-google-genai` 4.0.0.

    `ChatGoogleGenerativeAI` now supports both the **Gemini Developer API** and
    **Vertex AI Platform** as backend options.

## Signature

```python
VertexAI(
    self,
    *,
    model_name: str | None = None,
    **kwargs: Any = {},
)
```

## Extends

- `_VertexAICommon`
- `BaseLLM`

## Constructors

```python
__init__(
    self,
    *,
    model_name: str | None = None,
    **kwargs: Any = {},
) -> None
```

| Name | Type |
|------|------|
| `model_name` | `str \| None` |


## Properties

- `model_name`
- `tuned_model_name`
- `response_mime_type`
- `response_schema`
- `model_config`

## Methods

- [`is_lc_serializable()`](https://reference.langchain.com/python/langchain-google-vertexai/llms/VertexAI/is_lc_serializable)
- [`get_lc_namespace()`](https://reference.langchain.com/python/langchain-google-vertexai/llms/VertexAI/get_lc_namespace)
- [`validate_environment()`](https://reference.langchain.com/python/langchain-google-vertexai/llms/VertexAI/validate_environment)
- [`get_num_tokens()`](https://reference.langchain.com/python/langchain-google-vertexai/llms/VertexAI/get_num_tokens)

## ⚠️ Deprecated

Use [`GoogleGenerativeAI`][langchain_google_genai.GoogleGenerativeAI] instead.

---

[View source on GitHub](https://github.com/langchain-ai/langchain-google/blob/a3f016b2a6c4af535df275545f76fa7424aa39e5/libs/vertexai/langchain_google_vertexai/llms.py#L26)