langchain/docs/getting_started/environment.md

Setting up your environment

Using LangChain will usually require integrations with one or more model providers, data stores, apis, etc. There are two components to setting this up, installing the correct python packages and setting the right environment variables.

Python packages

The python package needed varies based on the integration. See the list of integrations for details. There should also be helpful error messages raised if you try to run an integration and are missing any required python packages.

Environment Variables

The environment variable needed varies based on the integration. See the list of integrations for details. There should also be helpful error messages raised if you try to run an integration and are missing any required environment variables.

You can set the environment variable in a few ways. If you are trying to set the environment variable FOO to value bar, here are the ways you could do so:

• From the command line:

export FOO=bar

• From the python notebook/script:

import os
os.environ["FOO"] = "bar"

For the Getting Started example, we will be using OpenAI's APIs, so we will first need to install their SDK:

pip install openai

We will then need to set the environment variable. Let's do this from inside the Jupyter notebook (or Python script).

import os
os.environ["OPENAI_API_KEY"] = "..."