Haystack by deepset

Haystack by deepset is an open-source AI orchestration framework for Python that enables developers to build production-ready LLM (Large Language Model) applications and RAG (Retrieval-Augmented Generation) pipelines. It features modular, customizable pipelines and agent workflows, integrates with a wide array of LLM vendors and models, and supports deploying applications as REST APIs or MCP servers. Haystack is ideal for users building search, semantic search, question answering, RAG-based systems, and autonomous AI agents—ranging from enterprise teams to individual developers who require transparency, extensibility, and production robustness.