Haystack

Haystack is an open-source Python framework from deepset for building production-ready AI agents, RAG pipelines and LLM apps from modular components, with optional enterprise support and a visual orchestration platform.

Haystack is an open-source AI orchestration framework for building LLM-powered agents and applications. It is installed as a Python package (haystack-ai) and gives developers modular, composable building blocks for each stage of an AI system: retrieval, reasoning, memory and tool use. The project is maintained by deepset and has a large community following, with more than 26 thousand GitHub stars and an active Discord server. In practice, work is organised around pipelines. A pipeline connects components such as retrievers, generators and tools, and it can branch and loop, which makes multi-step decision flows and self-correction patterns possible. Prompts can be built with Jinja-2 templates, and generators share a standardized interface, so swapping one model provider for another does not require rewriting the surrounding logic. Pipelines are serializable, cloud-agnostic and Kubernetes-ready, and the documentation includes logging, monitoring and deployment guides. The framework stresses transparency: every step can be inspected, debugged and tuned. The homepage lists use cases including advanced RAG with hybrid retrieval, conversational bots, content generation engines, multimodal apps that handle images and audio transcription, and tool-calling agents. It names connections to OpenAI, Anthropic, Mistral, Hugging Face, Weaviate, Pinecone and Elasticsearch, framed as an open architecture without vendor lock-in. The audience is software and ML engineers who want code-level control rather than a no-code builder. Beyond the free framework, deepset offers two paid-adjacent tiers: Enterprise Support, with private engineering help, deployment templates and pricing based on company size, and an AI Orchestration Platform with visual pipeline design, testing workflows, access controls and cloud or on-prem deployment. Compared with other agent and RAG frameworks, Haystack leans toward explicit, inspectable pipelines and production operations over rapid, opinionated abstractions. Teams that prefer a hosted visual tool will find the platform tier more relevant than the library alone.