haystack MCP Client: Production-Ready LLM Orchestration & Agent Control
haystack MCP Client: Production-Ready LLM Orchestration & Agent Control
haystack is an open-source AI orchestration framework in Python, designed for developers building production-ready LLM applications. It enables the creation of context-engineered systems through modular pipelines and agent workflows, offering explicit control over how information is retrieved, routed, and generated before it reaches the model.
Granular Control for Context Engineering
One of haystack's core strengths lies in its explicit control over context engineering. Developers can design flexible systems that dictate precisely how information is retrieved, ranked, filtered, combined, structured, and routed. This transparency extends to pipelines and agent workflows, where retrieval, memory, tools, and generation are all traceable components. The framework supports adding loops, branches, and conditional logic to manage context flow, ensuring that LLM applications behave predictably and efficiently.
Production-Ready Agents with Lifecycle Hooks
haystack provides agents built specifically for production environments. These agents offer lifecycle hooks such such as before_llm, before_tool, and on_exit, allowing developers to integrate guardrails and custom logic at critical points. For monitoring and cost control, agents track step_count, token_usage, and tool calls out of the box. To accelerate development, haystack includes ready-made agents from its Agent Pack, such as a deep research agent or an advanced RAG agent. Agents can also be given progressive skill discovery via SkillToolset, which ensures skill descriptions are only introduced into context when relevant.
Native Asynchronous Operations
The framework features native asynchronous support, enhancing performance and responsiveness. A single Pipeline can execute synchronously or asynchronously, streaming tokens as they are generated. Furthermore, Agent instances are capable of running concurrent tool calls, which can significantly improve the efficiency of complex workflows involving multiple external interactions.
Modular and Vendor-Agnostic Design
haystack is built for modularity and customization. It includes a suite of built-in components for common tasks like retrieval, indexing, tool calling, memory management, and evaluation. Developers also have the flexibility to create their own custom components. The framework maintains a model- and vendor-agnostic approach, allowing integration with a variety of LLMs and services without being locked into a specific provider.