# MapReduceChain

> **Class** in `langchain_classic`

📖 [View in docs](https://reference.langchain.com/python/langchain-classic/chains/mapreduce/MapReduceChain)

Map-reduce chain.

## Signature

```python
MapReduceChain()
```

## Extends

- `Chain`

## Properties

- `combine_documents_chain`
- `text_splitter`
- `input_key`
- `output_key`
- `model_config`
- `input_keys`
- `output_keys`

## Methods

- [`from_params()`](https://reference.langchain.com/python/langchain-classic/chains/mapreduce/MapReduceChain/from_params)

## ⚠️ Deprecated

Deprecated since version 0.2.13.

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[View source on GitHub](https://github.com/langchain-ai/langchain/blob/6fb37dba71da807af60aa7b909f71f0625a666bf/libs/langchain/langchain_classic/chains/mapreduce.py#L30)