langchain/docs/tracing/hosted_installation.md

Cloud Hosted Tracing Setup

This guide provides instructions for setting up your environment to use the cloud-hosted version of the LangChain Plus tracing server. For instructions on locally hosted tracing, please reference the Locally Hosted Tracing Setup guide.

We offer a hosted version of tracing at the LangChain Plus website. You can use this to interact with your traces and evaluation datasets without having to install the local server.

Note: We are currently only offering this to a limited number of users. The hosted platform is in the alpha stage, actively under development, and data might be dropped at any time. Do not depend on data being persisted in the system long term and refrain from logging traces that may contain sensitive information. If you're interested in using the hosted platform, please fill out the form here.

Setup

Follow these steps to set up your environment to use the cloud-hosted tracing server:

1. Log in to the system and click "API Key" in the top right corner. Generate a new key and assign it to the LANGCHAIN_API_KEY environment variable.

export LANGCHAIN_API_KEY="your api key"

Environment Configuration

Once you've set up your account, configure your LangChain application's environment to use tracing. This can be done by setting an environment variable in your terminal by running:

export LANGCHAIN_TRACING_V2=true

You can also add the following snippet to the top of every script:

import os
os.environ["LANGCHAIN_TRACING_V2"] = "true"

Additionally, you need to set an environment variables to specify the endpoint. You can do this with the following environment variable:

export LANGCHAIN_ENDPOINT="https://api.langchain.plus"

Here's an example of adding all relevant environment variables:

export LANGCHAIN_TRACING_V2="true"
export LANGCHAIN_ENDPOINT="https://api.langchain.plus"
export LANGCHAIN_API_KEY="my api key"
# export LANGCHAIN_SESSION="My Session Name" # Optional, otherwise, traces are logged to the "default" session 

Or in python:

import os
os.environ["LANGCHAIN_TRACING_V2"] = "true"
os.environ["LANGCHAIN_ENDPOINT"] = "https://langchain-api-gateway-57eoxz8z.uc.gateway.dev"
os.environ["LANGCHAIN_API_KEY"] = "my_api_key"  # Don't commit this to your repo! Set it in your terminal instead.
# os.environ["LANGCHAIN_SESSION"] = "My Session Name" # Optional, otherwise, traces are logged to the "default" session 

Tracing Context Manager

Although using environment variables is recommended for most tracing use cases, you can also configure runs to be sent to a specific session using the context manager:

from langchain.callbacks.manager import tracing_v2_enabled

with tracing_v2_enabled("My Session Name"):
    ...

Congratulations!

Now that you've signed in, you can use the server to help debug, monitor, and evaluate your LangChain applications. What's next?

• For an overview of the LangChain Plus UI check out the LangChain Tracing guide.
• For information on how to use your traces as datasets for testing and evaluation, check out the Datasets guide.