# get_usage_callback

> **Function** in `langchain_nvidia_ai_endpoints`

📖 [View in docs](https://reference.langchain.com/python/langchain-nvidia-ai-endpoints/callbacks/get_usage_callback)

Get the OpenAI callback handler in a context manager.

Exposes token and cost information.

## Signature

```python
get_usage_callback(
    price_map: dict = {},
    callback: Optional[UsageCallbackHandler] = None,
) -> Generator[UsageCallbackHandler, None, None]
```

## Description

**Example:**

```python
with get_openai_callback() as cb:
    # Use the OpenAI callback handler
```

## Returns

`None`

The OpenAI callback handler.

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[View source on GitHub](https://github.com/langchain-ai/langchain-nvidia/blob/5bfb68d5b10aa0330a6b79a36375b9bc0c6acef7/libs/ai-endpoints/langchain_nvidia_ai_endpoints/callbacks.py#L282)