Haystack Expert Skill

Haystack (by deepset) is a production-oriented framework for building search and NLP pipelines. Its core abstraction is the Pipeline — a directed acyclic graph of typed components with explicit connections. Unlike LangChain's LCEL (pipe operator) or LlamaIndex's query engines, Haystack pipelines are declared upfront with add_component and connect, giving validated, debuggable DAGs.

Core Paradigm

from haystack import Pipeline
from haystack.components.embedders import SentenceTransformersTextEmbedder
from haystack.components.retrievers.in_memory import InMemoryEmbeddingRetriever
from haystack.components.builders import PromptBuilder
from haystack.components.generators import OpenAIGenerator
from haystack.document_stores.in_memory import InMemoryDocumentStore