# SummarizerMixin

> **Class** in `langchain_classic`

📖 [View in docs](https://reference.langchain.com/python/langchain-classic/memory/summary/SummarizerMixin)

Mixin for summarizer.

## Signature

```python
SummarizerMixin()
```

## Extends

- `BaseModel`

## Properties

- `human_prefix`
- `ai_prefix`
- `llm`
- `prompt`
- `summary_message_cls`

## Methods

- [`predict_new_summary()`](https://reference.langchain.com/python/langchain-classic/memory/summary/SummarizerMixin/predict_new_summary)
- [`apredict_new_summary()`](https://reference.langchain.com/python/langchain-classic/memory/summary/SummarizerMixin/apredict_new_summary)

## ⚠️ Deprecated

Deprecated since version 0.2.12. Will be removed in version 2.0.0. For agents, summarize conversation history with `create_agent` and summarization middleware. See https://docs.langchain.com/oss/python/langchain/short-term-memory and https://docs.langchain.com/oss/python/langgraph/add-memory#summarize-messages

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[View source on GitHub](https://github.com/langchain-ai/langchain/blob/79cab2dc7f58be720cac43db3677b4c1fd971f91/libs/langchain/langchain_classic/memory/summary.py#L19)