pip install --upgrade langchain
langchain plus start
Option 2 (Hosted):
After making an account an grabbing a LangChainPlus API Key, set the LANGCHAIN_ENDPOINT and LANGCHAIN_API_KEY environment variables
import os
os.environ["LANGCHAIN_TRACING_V2"] = "true"
# os.environ["LANGCHAIN_ENDPOINT"] = "https://langchainpro-api-gateway-12bfv6cf.uc.gateway.dev"  # Uncomment this line if you want to use the hosted version
# os.environ["LANGCHAIN_API_KEY"] = "<YOUR-LANGCHAINPLUS-API-KEY>"  # Uncomment this line if you want to use the hosted version.
import langchain
from langchain.agents import Tool, initialize_agent, load_tools
from langchain.agents import AgentType
from langchain.callbacks import tracing_enabled
from langchain.chat_models import ChatOpenAI
from langchain.llms import OpenAI
# Agent run with tracing. Ensure that OPENAI_API_KEY is set appropriately to run this example.
llm = OpenAI(temperature=0)
tools = load_tools(["llm-math"], llm=llm)
agent = initialize_agent(
    tools, llm, agent=AgentType.ZERO_SHOT_REACT_DESCRIPTION, verbose=True
)
agent.run("What is 2 raised to .123243 power?")
> Entering new AgentExecutor chain...
 I need to use a calculator to solve this.
Action: Calculator
Action Input: 2^.123243
Observation: Answer: 1.0891804557407723
Thought: I now know the final answer.
Final Answer: 1.0891804557407723
> Finished chain.
'1.0891804557407723'
 Contents

[Beta] Tracing V2
By Harrison Chase


Contents

[Beta] Tracing V2
By Harrison Chase

      © Copyright 2023, Harrison Chase.

  Last updated on May 18, 2023.


.md
.pdf
Cloud Hosted Setup
 Contents
Installation
Environment Setup
Cloud Hosted Setup#
We offer a hosted version of tracing at langchainplus.vercel.app. You can use this to view traces from your run without having to run the server locally.
Note: we are currently only offering this to a limited number of users. The hosted platform is VERY alpha, in active development, and data might be dropped at any time. Don’t depend on data being persisted in the system long term and don’t log traces that may contain sensitive information. If you’re interested in using the hosted platform, please fill out the form here.
Installation#
Login to the system and click “API Key” in the top right corner. Generate a new key and keep it safe. You will need it to authenticate with the system.
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"
You will also need to set an environment variable to specify the endpoint and your API key. This can be done with the following environment variables:
LANGCHAIN_ENDPOINT = “https://langchain-api-gateway-57eoxz8z.uc.gateway.dev”
LANGCHAIN_API_KEY - set this to the API key you generated during installation.
An example of adding all relevant environment variables is below:
import os
os.environ["LANGCHAIN_HANDLER"] = "langchain"
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! Better to set it in your terminal.
 Contents

Installation
Environment Setup
By Harrison Chase

      © Copyright 2023, Harrison Chase.

  Last updated on May 18, 2023.


.md
.pdf
Locally Hosted Setup
 Contents
Installation
Environment Setup
Locally Hosted Setup#
This page contains instructions for installing and then setting up the environment to use the locally hosted version of tracing.
Installation#
Ensure you have Docker installed (see Get Docker) and that it’s running.
Install the latest version of langchain: pip install langchain or pip install langchain -U to upgrade your
existing version.
Run langchain-server. This command was installed automatically when you ran the above command (pip install langchain).
This will spin up the server in the terminal, hosted on port 4137 by default.
Once you see the terminal
output langchain-langchain-frontend-1 | ➜ Local: [http://localhost:4173/](http://localhost:4173/), navigate
to http://localhost:4173/
You should see a page with your tracing sessions. See the overview page for a walkthrough of the UI.
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.
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"
 Contents

Installation
Environment Setup
By Harrison Chase

      © Copyright 2023, Harrison Chase.


By Harrison Chase

      © Copyright 2023, Harrison Chase.

  Last updated on May 18, 2023.