rag-implementation

# RAG Implementation Master Retrieval-Augmented Generation (RAG) to build LLM applications that provide accurate, grounded responses using external knowledge sources. ## When to Use This Skill - Building Q&A systems over proprietary documents - Creating chatbots with current, factual information - Implementing semantic search with natural language queries - Reducing hallucinations with grounded responses - Enabling LLMs to access domain-specific knowledge - Building documentation assistants - Creating research tools with source citation ## Core Components ### 1. Vector Databases **Purpose**: Store and retrieve document embeddings efficiently **Options:** - **Pinecone**: Managed, scalable, serverless - **Weaviate**: Open-source, hybrid search, GraphQL - **Milvus**: High performance, on-premise - **Chroma**: Lightweight, easy to use, local development - **Qdrant**: Fast, filtered search, Rust-based - **pgvector**: PostgreSQL extension, SQL integration ### 2. Embeddings **Purpose**: Convert text to numerical vectors for similarity search **Models (2026):** | Model | Dimensions | Best For | |-------|------------|----------| | **voyage-3-large** | 1024 | Claude apps (Anthropic recommended) | | **voyage-code-3** | 1024 | Code search | | **text-embedding-3-large** | 3072 | OpenAI apps, high accuracy | | **text-embedding-3-small** | 1536 | OpenAI apps, cost-effective | | **bge-large-en-v1.5** | 1024 | Open source, local deployment | | **multilingual-e5-large** | 1024 | Multi-language support | ### 3. Retrieval Strategies **Approaches:** - **Dense Retrieval**: Semantic similarity via embeddings - **Sparse Retrieval**: Keyword matching (BM25, TF-IDF) - **Hybrid Search**: Combine dense + sparse with weighted fusion - **Multi-Query**: Generate multiple query variations - **HyDE**: Generate hypothetical documents for better retrieval ### 4. Reranking **Purpose**: Improve retrieval quality by reordering results **Methods:** - **Cross-Encoders**: BERT-based reranking (ms-marco-MiniLM) - **Cohere Rerank**: API-based reranking - **Maximal Marginal Relevance (MMR)**: Diversity + relevance - **LLM-based**: Use LLM to score relevance ## Quick Start with LangGraph ```python from langgraph.graph import StateGraph, START, END from langchain_anthropic import ChatAnthropic from langchain_voyageai import VoyageAIEmbeddings from langchain_pinecone import PineconeVectorStore from langchain_core.documents import Document from langchain_core.prompts import ChatPromptTemplate from langchain_text_splitters import RecursiveCharacterTextSplitter from typing import TypedDict, Annotated class RAGState(TypedDict): question: str context: list[Document] answer: str # Initialize components llm = ChatAnthropic(model="claude-sonnet-5") embeddings = VoyageAIEmbeddings(model="voyage-3-large") vectorstore = PineconeVectorStore(index_name="docs", embedding=embeddings) retriever = vectorstore.as_retriever(search_kwargs={"k": 4}) # RAG prompt rag_prompt = ChatPromptTemplate.from_template( """Answer based on the context below. If you cannot answer, say so. Context: {context} Question: {question} Answer:""" ) async def retrieve(state: RAGState) -> RAGState: """Retrieve relevant documents.""" docs = await retriever.ainvoke(state["question"]) return {"context": docs} async def generate(state: RAGState) -> RAGState: """Generate answer from context.""" context_text = "\n\n".join(doc.page_content for doc in state["context"]) messages = rag_prompt.format_messages( context=context_text, question=state["question"] ) response = await llm.ainvoke(messages) return {"answer": response.content} # Build RAG graph builder = StateGraph(RAGState) builder.add_node("retrieve", retrieve) builder.add_node("generate", generate) builder.add_edge(START, "retrieve") builder.add_edge("retrieve", "generate") builder.add_edge("generate", END) rag_chain = builder.compile() # Use result = await rag_chain.ainvoke({"question": "What are the main features?"}) print(result["answer"]) ``` ## Detailed patterns and worked examples Detailed pattern documentation lives in `references/details.md`. Read that file when the navigation tier above is insufficient.