Registry / llm-agents / langchain-openai

langchain-openai

library1.6.0pypypi✓ verified 25d ago

An integration package connecting OpenAI and LangChain, providing classes for chat models (`ChatOpenAI`) and embeddings (`OpenAIEmbeddings`). It is actively maintained with frequent releases, typically minor versions every few months and patch releases more frequently, as part of the broader LangChain ecosystem.

llm-agents ai-ml

pip install langchain-openai

github ↗package ↗homepage ↗docs ↗changelog ↗

INSTALL

IMPORT

SIG · LANGCHAIN-OPENAI

langchain-openai

llm-agentspythonv1.6.0

Install

9.9s avg

Import

5205ms

Disk

102MB

Pass rate

10/ 10

Env Coverage10 / 10

glibc

3.9–3.13

musl

3.9–3.13

Install & Compatibility

Where this runs

tested against v1.6.0 · pip install

no network on importno background threads

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

py 3.10–3.95 runs

installs and imports cleanly · install 0.0s · import 5.346s · 99MB

glibc

py 3.10–3.95 runs

installs and imports cleanly · install 9.9s · import 5.064s · 107MB

102MB installed

● package 102MB

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

ChatOpenAI

✓ from langchain_openai import ChatOpenAI

✗ from langchain.chat_models import ChatOpenAI

As of LangChain v1, `ChatOpenAI` is part of the `langchain-openai` partner package, not `langchain.chat_models` (which is for older v0 usage).

OpenAIEmbeddings

✓ from langchain_openai import OpenAIEmbeddings

✗ from langchain.embeddings import OpenAIEmbeddings

As of LangChain v1, `OpenAIEmbeddings` is part of the `langchain-openai` partner package, not `langchain.embeddings` (which is for older v0 usage).

This quickstart demonstrates how to initialize `ChatOpenAI` and send a basic message. It assumes the `OPENAI_API_KEY` environment variable is set.

import os from langchain_openai import ChatOpenAI from langchain_core.messages import HumanMessage # Set your OpenAI API key as an environment variable (recommended) # Or pass it directly: ChatOpenAI(openai_api_key="your_api_key") # Ensure OPENAI_API_KEY is set in your environment if not os.environ.get("OPENAI_API_KEY"): os.environ["OPENAI_API_KEY"] = os.environ.get("OPENAI_API_KEY", "") # Replace with actual key or prompt user # For interactive use, you might use: # import getpass # os.environ["OPENAI_API_KEY"] = getpass.getpass("Enter your OpenAI API key: ") # Instantiate the ChatOpenAI model chat_model = ChatOpenAI(model="gpt-4o-mini", temperature=0.7) # Invoke the model response = chat_model.invoke([HumanMessage(content="Tell me a short story about a brave knight.")]) print(response.content)

Debug

Known issues

breakingLangChain v1 introduced a new package structure. Most OpenAI-related classes moved from the monolithic `langchain` package (e.g., `langchain.chat_models.ChatOpenAI`) to the dedicated `langchain-openai` partner package (e.g., `langchain_openai.ChatOpenAI`). Code using old import paths will break.

fix

Update import statements from `from langchain...` to `from langchain_openai...` for OpenAI-specific components like `ChatOpenAI` and `OpenAIEmbeddings`.

affects: All versions >= 1.0.0

gotchaCompatibility with `langchain-core` is crucial. The `langchain-openai` package frequently bumps its minimum required `langchain-core` version. Running `langchain-openai` with an outdated `langchain-core` can lead to `AttributeError`s or unexpected behavior due to schema drifts or missing fields. [cite: 1.1.12 release notes]

fix

Always ensure `langchain-core` is up-to-date by running `pip install -U langchain-openai langchain-core`.

affects: All versions

breakingFor Azure OpenAI, `ChatOpenAI` now supports the v1 API directly using `base_url` and `api_key` parameters since `langchain-openai>=1.0.1`. The legacy `AzureChatOpenAI` class is still available but `ChatOpenAI` is the recommended unified approach for the v1 API.

fix

For new Azure OpenAI integrations, use `langchain_openai.ChatOpenAI` with `base_url` set to your Azure endpoint (e.g., `https://{your-resource-name}.openai.azure.com/openai/v1/`) and provide the `api_key`. Migrate existing `AzureChatOpenAI` usage if a unified interface is desired.

affects: Versions < 1.0.1

gotchaWhen using `OpenAIEmbeddings` with non-OpenAI compatible APIs (e.g., OpenRouter, Ollama, vLLM via `base_url`), the default `check_embedding_ctx_length` might cause errors.

fix

Set `check_embedding_ctx_length=False` in the `OpenAIEmbeddings` constructor (e.g., `OpenAIEmbeddings(model="your-model", base_url="https://your-api-endpoint.com", check_embedding_ctx_length=False)`).

affects: All versions

deprecatedWhen interacting with the OpenAI Responses API, `langchain-openai` now defaults to storing response items in message content. To restore the previous (v0) behavior, users need to explicitly opt-in.

fix

Set the `LC_OUTPUT_VERSION` environment variable to `v0` or specify `output_version="v0"` when instantiating `ChatOpenAI` (e.g., `ChatOpenAI(model="gpt-4o-mini", output_version="v0")`).

affects: Versions >= 1.0.0

breakingOpenAI API calls require an API key for authentication. This key must be provided either as an environment variable (e.g., `OPENAI_API_KEY`) or directly as an `api_key` parameter when instantiating `ChatOpenAI` or `OpenAIEmbeddings`. Failure to provide an API key results in an `AuthenticationError`.

fix

Ensure the `OPENAI_API_KEY` environment variable is set with a valid OpenAI API key, or pass `api_key='your_key'` to the constructor of `ChatOpenAI` or `OpenAIEmbeddings`.

affects: All versions

breakingOpenAI API calls require an API key for authentication. If an API key is not provided (either via the `OPENAI_API_KEY` environment variable or explicitly in the model constructor), an `AuthenticationError` will occur, preventing any API interaction.

fix

Ensure the `OPENAI_API_KEY` environment variable is set, or pass the `api_key` argument directly to the `ChatOpenAI` or `OpenAI` model constructor (e.g., `ChatOpenAI(model="gpt-4", api_key="YOUR_API_KEY")`).

affects: All versions

Errors

Common errors & fixes

ModuleNotFoundError: No module named 'langchain_openai'

The `langchain-openai` integration package is not installed in your Python environment. It's a separate package and not automatically included with `langchain` itself.

fix

Install the package using pip: `pip install langchain-openai`

AuthenticationError: Incorrect API key provided: sk-...

The OpenAI API key is either missing, incorrect, expired, or not accessible in the environment where `langchain-openai` is trying to use it. This often happens if the `OPENAI_API_KEY` environment variable is not set or is set with an invalid key, or if the key is hardcoded incorrectly.

fix

Ensure your OpenAI API key is correctly set as an environment variable named `OPENAI_API_KEY` (e.g., `export OPENAI_API_KEY="your_key_here"` in your shell, or in a `.env` file loaded with `python-dotenv`). Alternatively, pass it directly to the `ChatOpenAI` or `OpenAIEmbeddings` constructor: `ChatOpenAI(api_key="your_key_here")`.

ValidationError: 1 validation error for ChatOpenAI __root__ `openai` has no `ChatCompletion` attribute, this is likely due to an old version of the openai package. Try upgrading it with `pip install --upgrade openai`.

You are likely using an outdated version of the `openai` Python library (older than 1.0.0) which is incompatible with the version of `langchain-openai` you have installed. The `openai` library underwent a major refactor in version 1.0.0.

fix

Upgrade your `openai` package to the latest version: `pip install --upgrade openai`. Ensure `langchain-openai` is also up-to-date: `pip install --upgrade langchain-openai`.

ImportError: cannot import name 'ChatOpenAI' from partially initialized module 'langchain_openai' (most likely due to a circular import)

This specific error often occurs when you have a local Python file named `openai.py` in your project directory. Python's import mechanism prioritizes local files, causing it to try and import from your `openai.py` instead of the installed `openai` package, leading to a circular import when `langchain_openai` tries to import `openai`.

fix

Rename your local `openai.py` file to something else (e.g., `my_openai_utils.py`) to avoid conflicts with the official `openai` package.

Upgrade

Version history

1.6.0latest on PyPI · released Aug 19, 2026

Audit

Dependencies

langchain-corerequiredCore LangChain functionalities; required for all LangChain integrations.

openairequiredOfficial OpenAI Python client library.

tiktokenrequiredUsed for token counting with OpenAI models.

Agent activity

23 hits · last 30 days

node

OpenAI (training)

Resources

githubhttps://github.com/langchain-ai/langchain ↗

packagehttps://pypi.org/project/langchain-openai/ ↗

homepagehttps://docs.langchain.com/oss/python/integrations/providers/openai ↗

docshttps://reference.langchain.com/python/integrations/langchain_openai/ ↗

changeloghttps://github.com/langchain-ai/langchain/releases?q=%22langchain-openai%22 ↗