Haystack
Production-ready open-source framework for RAG pipelines and AI agents.
About
deepset's open-source Python framework for building production-ready LLM applications around composable, typed-component pipelines. Its core abstraction is a pipeline DAG (embedders, retrievers, rankers, routers, generators, agents) with 100+ components, vendor-agnostic model integrations, and a built-in evaluation framework.
Hayhooks can expose pipelines as REST or MCP endpoints (verified in README); deepset sells an Enterprise Platform for managed deployments. Apache-2.0 licensed.
What it can do
- Modular pipeline DAGs with typed sockets, branching, loops, and conditional routing
- 24 component categories incl. 9 retriever variants; built-in in-memory BM25/embedding stores
- Model- and vendor-agnostic: OpenAI, Anthropic, Mistral, Cohere, Hugging Face, Google, Azure, Bedrock, local models
- Built-in RAG evaluation framework; agent lifecycle hooks and token/step tracking for cost control
- Tool calling agents (Tool/Toolset/ComponentTool), memory, human-in-the-loop package
- Hayhooks: expose pipelines/agents as REST APIs, MCP servers, or OpenAI-compatible endpoints
Setup
- Run
pip install haystack-ai, plus integration packages for your stack (e.g.chroma-haystack,openai-haystack). - Choose a document store: built-in
InMemoryDocumentStorefor dev, or a vector DB integration for production. - Build a pipeline by connecting typed components (embedder → retriever → ranker → generator) into a DAG.
- Set provider API keys for your generators/embedders.
- Run the pipeline (sync or async with token streaming); evaluate quality with the built-in evaluators.
- (Optional) Wrap the pipeline with Hayhooks to serve it as a REST API or MCP server.
Prerequisites
Python 3.x; model-provider API keys; a document store (in-memory built-in for dev).
Use cases
Works with
Trust score — 9/10
Official deepset project, Apache-2.0, 26.7k+ stars, 6.5k+ commits with ongoing releases, strong docs, CI, and OpenSSF best-practice badges. Vendor-agnostic by design and backed by an enterprise company, so lock-in and abandonment risk are low. Minor caveats: it collects anonymous component-init telemetry (opt-out documented), and the ecosystem is smaller than LangChain's. The vendor's customer-logo list is provider-claimed.
★ 26,725 GitHub stars
How the trust score is built
Full methodology →- Adoption · stars/downloads, log-scaled vs peers
- 8.3/10
- Maintenance · recency, releases, issue load
- 9.8/10
- Openness · license + docs
- 10.0/10
- Manual review · sanity read + red-flag check
- 9.0/10
- · 26,725 GitHub stars (log-scaled vs catalog peers)
- · blended with ~566,454 monthly package downloads
- · last push 0d ago; 55 releases/12mo; 158 open issues
- · manual review: telemetry opt-out documented; smaller ecosystem
Sources
Every fact above was checked against these sources. Where a claim comes from the provider and couldn't be independently verified, the text says so.