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LangSmith is a platform for building production-grade LLM applications.

It lets you debug, test, evaluate, and monitor chains and intelligent agents built on any LLM framework and seamlessly integrates with LangChain, the go-to open source framework for building with LLMs.

LangSmith is developed by LangChain, the company behind the open source LangChain framework.


LangSmith is currently in private beta. If you'd like to be added to the waitlist, please sign up for an account here.

Active Development

LangSmith is an early product in beta. If you run into any urgent issues or bugs, please reach out to us at

We appreciate your patience.

Quick Start

Interactive Tutorial

If following along with code is more your thing, we've set up a Jupyter notebook at this link to help you get started with LangSmith.

If you already use LangChain, you can connect to LangSmith in a few steps:

  1. Create a LangSmith account using one of the supported login methods.
  2. Create an API Key by navigating to the settings page.
  3. Install the latest version LangChain for your target environment and programming language.
    pip install -U langchain
  4. Configure runtime environment:
    1. Replace "<your-api-key>" with the API key generated in step 1
    2. Replace "<your-openai-api-key>" with an OpenAI API Key from here
    export LANGCHAIN_TRACING_V2=true
    export LANGCHAIN_API_KEY=<your-api-key>
    export LANGCHAIN_PROJECT=<your-project> # if not specified, defaults to "default"

    # The below examples use the OpenAI API, so you will need
    export OPENAI_API_KEY=<your-openai-api-key>
  5. Run the example code below.
    from langchain.chat_models import ChatOpenAI

    llm = ChatOpenAI()
    llm.invoke("Hello, world!")

Congratulations! Your first run is now visible in LangSmith! Navigate to the projects page to view your "Hello, world!" trace.

Next Steps

Read the LangSmith Overview to learn more about what LangSmith has to offer.

To learn how to best take advantage of the visualization and replay capabilities within LangSmith, check out the tracing documentation.

To start testing and evaluating your LLMs, chains, and agents, check out the testing & evaluation quickstart and related documentation.

Additional Resources

Contact Sales

If you're interested in enterprise support and LangSmith access for larger team, fill out this form to speak with sales.