Locally Hosted Setup#

This page contains instructions for installing and then setting up the environment to use the locally hosted version of tracing.

Installation#

  1. Ensure you have Docker installed (see Get Docker) and that it’s running.

  2. Install the latest version of langchain: pip install langchain or pip install langchain -U to upgrade your existing version.

  3. Run langchain-server

    1. This will spin up the server in the terminal.

    2. Once you see the terminal output langchain-langchain-frontend-1 | ➜ Local: [http://localhost:4173/](http://localhost:4173/), navigate to http://localhost:4173/

  4. You should see a page with your tracing sessions. See the overview page for a walkthrough of the UI.

  5. Currently, trace data is not guaranteed to be persisted between runs of langchain-server. If you want to persist your data, you can mount a volume to the Docker container. See the Docker docs for more info.

  6. To stop the server, press Ctrl+C in the terminal where you ran langchain-server.

Environment Setup#

After installation, you must now set up your environment to use tracing.

This can be done by setting an environment variable in your terminal by running export LANGCHAIN_HANDLER=langchain.

You can also do this by adding the below snippet to the top of every script. IMPORTANT: this must go at the VERY TOP of your script, before you import anything from langchain.

import os
os.environ["LANGCHAIN_HANDLER"] = "langchain"