d-hackmt/Langsmith-Tracing ? reverse-engineered prompt

Build me a small LangSmith demo app that shows how LLM tracing and observability work in practice.

I want a Streamlit chat app that answers questions using a local document knowledge base about LLM security and deployment, and it should be wired so every model call, retriever call, and agent step shows up in LangSmith automatically. Please also include a few simple notebook examples that demonstrate auto tracing, a traced custom function, a RAG flow, and a multi tool agent so I can compare the traces in the dashboard.

Make the app feel like a simple production style document assistant, with clear chat output and visible thinking steps where it makes sense. If you need to look up current LangChain or LangSmith docs online, go ahead. Keep the code clean and easy to run from the README, with clear setup for the three LangSmith environment variables and a straightforward way to test it locally.