Haystack

Open-source LLM framework for RAG and NLP pipelines — production-ready by deepset

Haystack is an open-source Python framework for building production-grade NLP and LLM applications, developed by deepset. It provides a pipeline-based architecture for RAG systems, question answering, semantic search, and document intelligence. Haystack 2.0 introduced a composable component system supporting any LLM provider — used by 15,000+ teams including Airbus, Netflix, and Nvidia.

Key specs

16,000 GitHub stars source

as of 2026-03-27