Haystack: Open-Source AI Orchestration Framework

Haystack is an open-source AI orchestration framework that helps AI engineers, developers, data scientists, and enterprise teams build production-ready AI agents, powerful RAG applications, and scalable multimodal search systems. It offers standardized tool calling, scalable context engineering, and branching and looping pipelines that give you full control over complex, multi-step decision flows. All generators provide a standardized interface for building conversational AI. Haystack uses a freemium model: the open-source framework is free to use, with options to add consulting hours and service packages or upgrade to the Haystack Enterprise Platform. Enterprise support includes up to 4 hours of remote technical consultation and an email support channel with direct access to core engineers. The learning curve is medium.