All functionality related to Anthropic models.. Anthropic is an AI safety and research company, and is the creator of Claude. This page covers all integrations between Anthropic models and LangChain.

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Prompting Best Practices

Anthropic models have several prompting best practices compared to OpenAI models. System Messages may only be the first message Anthropic models require any system messages to be the first one in your prompts.

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ChatAnthropic

ChatAnthropic is a subclass of LangChain’s ChatModel, meaning it works best with ChatPromptTemplate. You can import this wrapper with the following code:
See this section for general instructions on installing integration packages.
npm
npm install @langchain/anthropic @langchain/core

import { ChatAnthropic } from "@langchain/anthropic";
const model = new ChatAnthropic({});
When working with ChatModels, it is preferred that you design your prompts as ChatPromptTemplates. Here is an example below of doing that: 
import { ChatPromptTemplate } from "langchain/prompts";

const prompt = ChatPromptTemplate.fromMessages([
  ["system", "You are a helpful chatbot"],
  ["human", "Tell me a joke about {topic}"],
]);
You can then use this in a chain as follows: 
const chain = prompt.pipe(model);
await chain.invoke({ topic: "bears" });
See the chat model integration page for more examples, including multimodal inputs.