Haystack by deepset

Haystack by deepset is an open-source framework for building production-ready LLM (Large Language Model) applications in Python. It allows developers to design modular pipelines and advanced agent workflows for retrieval-augmented generation (RAG), semantic search, contextual question answering, document intelligence, and autonomous agent orchestration. Haystack supports deep customization, explicit context engineering, integration with various model vendors, and deploying applications as REST APIs or MCP servers. It is ideal for AI engineers, researchers, and enterprises looking to create scalable multimodal AI solutions or agentic applications.