
Haystack
A framework for building NLP applications (e.g. agents, semantic search, question-answering) with language models.
- Freemium
- API, Python library
- DesignAI Tools for PythonAI Tools for Natural Language Processing
- Free plan available
- No credit card

What is Haystack?
Key features
Modular pipeline architecture
connect components like retrievers, readers, and language models in different configurations without rewriting core logic
Language model flexibility
works with multiple LLM providers and can use open-source or proprietary models
Document retrieval and indexing
built-in support for storing, indexing, and searching through documents to provide context to language models
Question-answering pipelines
pre-configured workflows for extracting answers from documents using retrieval-augmented generation
Agent building
tools for creating autonomous systems that can plan and execute tasks using language models
Production-ready
designed to handle real applications with features for monitoring, error handling, and scalability
Pros & cons
Advantages
- Flexible and modular design means you're not locked into a specific approach or vendor
- Active open-source community with documentation and examples for common use cases
- Works with both commercial and open-source language models, giving you cost and privacy options
- Particularly strong for retrieval-augmented generation tasks, which often produce better results than using language models alone
Limitations
- Requires Python knowledge and software engineering skills; not a visual no-code tool
- Steeper learning curve compared to API-only tools since you need to understand how to assemble components
- Community support rather than dedicated commercial support in the free tier
Use cases
Building search systems that understand natural language queries and return relevant documents
Creating question-answering systems that pull answers from your own knowledge base or documents
Developing AI agents that can retrieve information and make decisions based on that context
Prototyping natural language processing features before building custom solutions
Processing and indexing large document collections to make them searchable by language models
Ready to try Haystack?
Pricing
Free
Free
Full access to the open-source framework, community support, suitable for development and small deployments
Haystack Cloud
Varies
Managed hosting and deployment options for production applications, with pricing based on usage
Get started with Haystack
Click through to Haystack and start using it now.
- Free plan available
- No credit card