# QAWithSourcesChain

> **Class** in `langchain_classic`

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

Question answering with sources over documents.

## Signature

```python
QAWithSourcesChain()
```

## Extends

- `BaseQAWithSourcesChain`

## Properties

- `input_docs_key`
- `input_keys`

## ⚠️ Deprecated

Deprecated since version 0.2.13.

---

[View source on GitHub](https://github.com/langchain-ai/langchain/blob/6fb37dba71da807af60aa7b909f71f0625a666bf/libs/langchain/langchain_classic/chains/qa_with_sources/base.py#L218)