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Chat models are language models that use a sequence of messages as inputs and return messages as outputs .

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Install and use

See this section for general instructions on installing LangChain packages.
Install:
npm i @langchain/openai
Add environment variables:
OPENAI_API_KEY=your-api-key
Instantiate the model:
import { ChatOpenAI } from "@langchain/openai";

const model = new ChatOpenAI({ model: "gpt-4o-mini" });

await model.invoke("Hello, world!")
Install:
npm i @langchain/anthropic
Add environment variables:
ANTHROPIC_API_KEY=your-api-key
Instantiate the model:
import { ChatAnthropic } from "@langchain/anthropic";

const model = new ChatAnthropic({
model: "claude-3-sonnet-20240620",
temperature: 0
});

await model.invoke("Hello, world!")
Install:
npm i @langchain/google-genai
Add environment variables:
GOOGLE_API_KEY=your-api-key
Instantiate the model:
import { ChatGoogleGenerativeAI } from "@langchain/google-genai";

const model = new ChatGoogleGenerativeAI({
modelName: "gemini-2.5-flash-lite",
temperature: 0
});

await model.invoke("Hello, world!")
Install:
npm i @langchain/google-vertexai
Add environment variables:
GOOGLE_APPLICATION_CREDENTIALS=credentials.json
Instantiate the model:
import { ChatVertexAI } from "@langchain/google-vertexai";

const model = new ChatVertexAI({
model: "gemini-1.5-flash",
temperature: 0
});

await model.invoke("Hello, world!")
Install:
npm i @langchain/mistralai
Add environment variables:
MISTRAL_API_KEY=your-api-key
Instantiate the model:
import { ChatMistralAI } from "@langchain/mistralai";

const model = new ChatMistralAI({
model: "mistral-large-latest",
temperature: 0
});

await model.invoke("Hello, world!")
Install:
npm i @langchain/community
Add environment variables:
FIREWORKS_API_KEY=your-api-key
Instantiate the model:
import { ChatFireworks } from "@langchain/community/chat_models/fireworks";

const model = new ChatFireworks({
model: "accounts/fireworks/models/llama-v3p1-70b-instruct",
temperature: 0
});

await model.invoke("Hello, world!")
Install:
npm i @langchain/groq
Add environment variables:
GROQ_API_KEY=your-api-key
Instantiate the model:
import { ChatGroq } from "@langchain/groq";

const model = new ChatGroq({
model: "llama-3.3-70b-versatile",
temperature: 0
});

await model.invoke("Hello, world!")
ModelStreamJSON modeTool CallingwithStructuredOutput()Multimodal
BedrockChat✅❌🟡 (Bedrock Anthropic only)🟡 (Bedrock Anthropic only)🟡 (Bedrock Anthropic only)
ChatBedrockConverse✅❌✅✅✅
ChatAnthropic✅❌✅✅✅
ChatCloudflareWorkersAI✅❌❌❌❌
ChatCohere✅❌✅✅✅
ChatFireworks✅✅✅✅✅
ChatGoogleGenerativeAI✅❌✅✅✅
ChatVertexAI✅❌✅✅✅
ChatGroq✅✅✅✅✅
ChatMistralAI✅✅✅✅✅
ChatOllama✅✅✅✅✅
ChatOpenAI✅✅✅✅✅
ChatTogetherAI✅✅✅✅✅
ChatXAI✅✅✅✅❌

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Chat Completions API

Certain model providers offer endpoints that are compatible with OpenAI’s (legacy) Chat Completions API. In such case, you can use ChatOpenAI with a custom base_url to connect to these endpoints.
To use OpenRouter, you will need to sign up for an account and obtain an API key.
import { ChatOpenAI } from "@langchain/openai";

const model = new ChatOpenAI({
    model: "...", // Specify a model available on OpenRouter
    configuration: {
    apiKey: "OPENROUTER_API_KEY",
    baseURL: "https://openrouter.ai/api/v1",
    }
});
Refer to the OpenRouter documentation for more details.

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All chat models

Alibaba Tongyi

Anthropic

Arcjet Redact

Azure OpenAI

Baidu Qianfan

Amazon Bedrock

Amazon Bedrock Converse

Cerebras

Cloudflare Workers AI

Cohere

Deep Infra

DeepSeek

Fake LLM

Fireworks

Friendli

Google GenAI

Google Vertex AI

Groq

IBM watsonx.ai

Llama CPP

Minimax

MistralAI

Moonshot

Novita AI

Ollama

OpenAI

Perplexity

PremAI

Tencent Hunyuan

Together

WebLLM

xAI

YandexGPT

ZhipuAI

If you’d like to contribute an integration, see Contributing integrations.
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