# chains

> **Module** in `langchain_classic`

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

**Chains** are easily reusable components linked together.

Chains encode a sequence of calls to components like models, document retrievers,
other Chains, etc., and provide a simple interface to this sequence.

The Chain interface makes it easy to create apps that are:

    - **Stateful:** add Memory to any Chain to give it state,
    - **Observable:** pass Callbacks to a Chain to execute additional functionality,
        like logging, outside the main sequence of component calls,
    - **Composable:** combine Chains with other components, including other Chains.

## Properties

- `importer`

## Methods

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

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[View source on GitHub](https://github.com/langchain-ai/langchain/blob/8fec4e7ceee2c368b068c49f9fed453276e210e7/libs/langchain/langchain_classic/chains/__init__.py)