Haystack

Haystack by deepset is an end-to-end framework for building production-ready LLM applications. It orchestrates embedding models, LLMs, vector search, and more into flexible pipelines with branching and looping for complex agent workflows. Features include RAG, question answering, semantic search, multimodal support (image processing, generation, audio transcription), function calling with tools, and resilient fallback patterns. Package migrated from farm-haystack to haystack-ai in 2025.