What problem does it solve? Building LLM-powered applications requires wiring together model providers, tools, memory, and retrieval pipelines, which involves significant boilerplate and provider-specific code. This Skill provides guidance and code patterns for using LangChain to assemble agents, chains, and RAG systems with swappable LLM providers. ## Core Features & Use Cases - Agent Creation: Build ReAct and tool-calling agents with create_agent, custom tools, parallel tool execution, and streaming output. - RAG Pipelines: Load documents from web, PDF, GitHub, or CSV, split them into chunks, embed them into vector stores like Chroma, Pinecone, or FAISS, and run retrieval QA chains with conversation memory. - Provider Flexibility: Swap between OpenAI, Anthropic, and Google models with a single line change, plus structured output via Pydantic schemas and LangSmith tracing for observability. - Use Case: Build a chatbot that answers questions about your documentation by loading web pages, indexing them in Chroma, and running a conversational retrieval chain that remembers prior turns. ## Quick Start Ask the AI to create a LangChain agent with a weather tool and a web search tool using the Anthropic Claude model, then run it on a sample question.