LangSmith
Observability & evalsLangChain's platform for tracing, testing, and evaluating LLM and agent applications.
LangSmith is the observability and evaluation product from the LangChain team. It traces runs in detail, supports datasets and evaluations, and integrates tightly with LangChain and LangGraph — though it works with any stack.
For teams already building on LangChain tools, that integration makes it the path of least resistance.
Where it's ideally used
A natural fit when a project is built on LangChain or LangGraph and you want tracing and evals from the same ecosystem.
Where it doesn't fit
Primarily a hosted product, so it needs review when traces must stay self-hosted within your own environment.