LangGraph TypeScript quickstart Follow the live docs — do not invent an alternate API from memory: https://docs.langchain.com/oss/javascript/langgraph/quickstart Fetch that page (Docs MCP or HTTP) and implement what it shows (calculator / math agent with the Graph API). Prefer the Graph API path over the Functional API unless the user asks otherwise. Skip graph visualization. Local setup constraints Apply these on top of the quickstart (they keep setup minimal and model-agnostic): 1. Ask which provider/model to use. Showcase that LangGraph works with any LangChain chat model. Suggested prompt…