Home Original page

What is Haystack? | Haystack

Haystack is an open-source AI orchestration framework built by deepset, enabling Python developers to build production-ready AI agents, multimodal applications, and advanced RAG systems.

Built for scalable context engineering, Haystack gives you control over how information moves through your system, from retrieval and tool use to memory and model execution. Haystack structures agents and applications as explicit, modular pipelines composed of retrievers, routers, memory layers, tools, evaluators, and generators. This modular architecture allows each component to be tested, replaced, and improved independently. As a result, you can ship faster and continuously evolve applications in production.

Backed by a global developer community and enterprise customer adoption, Haystack has become a trusted framework for building AI applications that operate reliably in complex, mission-critical environments.

pip install -U haystack-ai

📘 Want to learn more how to use Haystack? Check out the docs

Who is Haystack For?

Haystack is built for AI developers and engineers creating AI systems that need to be accurate, modular, and transparent. It supports everything from agent workflows to advanced RAG and multimodal applications.

It’s designed for AI systems running in real-world enterprise environments. Haystack integrates with existing architectures, supports governance and compliance requirements, and lets you keep evolving your application as models, techniques, and user needs change.

Run Haystack in your own environment, get dedicated support or extend it with a cloud or self-hosted platform to test, deploy, and operate pipelines at scale.

Why Developers Love Haystack

Built for production from day one, Haystack is the leading open-source framework for building reliable, flexible, and composable LLM applications from first prototype to full-scale deployment.

Modern AI systems don’t fail because of the model. They fail because context is not well managed. Haystack gives developers full control over how context is retrieved, structured, routed, evaluated, and improved over time.

Here’s why developers choose Haystack:

Engineer context, not just prompts
Design explicit pipelines that control retrieval, ranking, memory, tools, and generation so every token sent to the model is intentional and traceable.

Build flexible, composable systems
Use built-in components like retrievers, generators, rankers, and agents or create your own. Add loops, branches, and conditional logic to tailor context flow to your exact use case.

Swap models and components without rewriting your system
Integrate smoothly with model providers, vector databases, and AI tools in a modular architecture built for change and continual improvement.

Deploy into real environments
Serve pipelines as REST APIs or MCP servers with Hayhooks. Run in your own infrastructure and integrate with enterprise architectures.

Observe and improve continuously
Use tracing, logging, and evaluation tools to monitor retrieval quality, latency, tool usage, and outputs and iteratively refine your system.

Build on stable engineering foundations
Clean architecture, careful dependency management, and a breaking change policy that avoids surprises in production.

Whether you’re building agent workflows, retrieval over millions of docs, text-to-SQL pipelines, or document processing flows, Haystack lets you scale capabilities without increasing system complexity by giving you explicit control over context flow.

The Haystack Ecosystem

We build tools that make LLM applications usable in production, from open-source foundations to full-scale operational platforms.

  • Haystack → Our open-source Python framework for AI orchestration, launched in 2020. Build modular pipelines that control retrieval, agents, tools, and generation with full transparency and flexibility.
  • Haystack Enterprise Starter → Expert guidance, advanced pipeline templates, deployment playbooks, and early access features for teams that want to move faster with experienced support.
  • Haystack Enterprise Platform → A production platform for running Gen AI applications at scale with governance, testing, observability, security controls, and infrastructure flexibility designed for real-world enterprise environments. Try it for free.

Recognized as a Gartner Cool Vendor in AI Engineering, we’re proud to support both the global open-source community and enterprises building mission-critical AI systems.

Behind Haystack is a global community of developers, researchers, and AI builders who care about making LLM systems reliable in the real world.

From first-time contributors to core maintainers, the community brings deep expertise across retrieval, agents, evaluation, infrastructure, and applied AI. Together, we test ideas, bring them to production-readiness, share implementation patterns, and push the boundaries of what open-source AI systems can do.

Haystack grows through practical collaboration, not just experimentation, but building systems that work.

We’d love to have you involved:

Enter the Haystack Open Source Universe

There are so many ways to start building: