Paper QA
FreeLLM Chain for answering questions from documents with citations 
FreeFree tier
About Paper QA
Paper QA is an open-source Python library that enables answering questions from documents by leveraging large language models (LLMs) and providing citations. It uses a retrieval-augmented generation approach to find relevant passages and generate answers with source references, making it useful for research, academic, and document-based Q&A tasks.
Key Features
LLM-based question answering over documents
Citation generation for transparency and verifiability
Integration with LangChain workflows
Open source (MIT license) and free to use
Pros & Cons
Pros
- Provides citations for every answer, enhancing trustworthiness
- Open source and free, with no licensing costs
- Easy to integrate into existing LangChain pipelines
Cons
- Requires local setup and API keys for underlying LLMs
- May not optimize for extremely large or complex document collections without further tuning
Best For
Answering questions from research papersDocument-based Q&A for knowledge managementSupporting literature reviews with cited answers