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How to install langchain-openai package

Q: How to install langchain-openai package

Install the langchain-openai package using pip install langchain-openai. Ensure you have Python 3.8+ and an OpenAI API key set in your environment variables before using the package.

Quick answer

Install the langchain-openai package using pip install langchain-openai. Ensure you have Python 3.8+ and an OpenAI API key set in your environment variables before using the package.

PREREQUISITES

Python 3.8+
OpenAI API key (free tier works)
pip install openai>=1.0

Setup

To install the langchain-openai package, use pip in your terminal or command prompt. Make sure you have Python 3.8 or higher installed and your OpenAI API key configured as an environment variable.

bash

pip install langchain-openai

Step by step

After installation, you can import and use langchain-openai in your Python code to interact with OpenAI models. Below is a minimal example demonstrating how to create a chat completion using the ChatOpenAI class.

python

import os
from langchain_openai import ChatOpenAI

# Ensure your OpenAI API key is set in the environment
# export OPENAI_API_KEY='your_api_key_here' on Unix or setx OPENAI_API_KEY "your_api_key_here" on Windows

client = ChatOpenAI(model_name="gpt-4o", temperature=0.7)

response = client.chat([{"role": "user", "content": "Hello from langchain-openai!"}])
print(response.content)

output

Hello from langchain-openai!

Common variations

You can customize the model by changing the model_name parameter (e.g., gpt-4o-mini), adjust temperature for creativity, or use async calls if your environment supports it. The package integrates seamlessly with other LangChain components.

python

from langchain_openai import ChatOpenAI
import asyncio

async def async_chat():
    client = ChatOpenAI(model_name="gpt-4o-mini", temperature=0.5)
    response = await client.chat([{"role": "user", "content": "Async hello!"}])
    print(response.content)

asyncio.run(async_chat())

output

Async hello!

Troubleshooting

If you get a ModuleNotFoundError, verify that langchain-openai is installed in your active Python environment.
If authentication fails, ensure your OPENAI_API_KEY environment variable is correctly set.
For version conflicts, upgrade with pip install --upgrade langchain-openai.

✅

Key Takeaways

Use pip install langchain-openai to install the package quickly.
Set your OpenAI API key in environment variables before running code.
The package supports both sync and async usage with customizable models.
Keep langchain-openai updated to avoid compatibility issues.
Check environment and Python version if installation or import errors occur.

Verified 2026-04 · gpt-4o, gpt-4o-mini

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