Traces every model call in your app, and turns the interesting ones into test cases. Built by LangChain.
Others in observability
Common questions
Is LangSmith free to use?
LangSmith is open source and free to run yourself. You still pay whichever model provider you point it at, and this tutorial is free with no signup.
Do I need to know Python to use LangSmith?
Basic Python is enough. Functions, dictionaries and imports cover most of what LangSmith asks of you.
When should I not use LangSmith?
When something else in observability fits the job better. The others in that group are listed below.
Lessons for LangSmith are being written. Meanwhile the APIs for AI tutorial covers the same ground: state, tools, loops, memory and human approval. Most of it carries straight over.
Start the APIs for AI tutorial →