Using LangChain.js

Setting up langchain.js

If you don't have it installed already, install the LangChain OpenAI package using npm:

npm install @langchain/openai

Setting up the AI Router

Set the openai base url to the AI Router base url https://api.airouter.io in your code and api key to the one you generated. Then proceed to call the OpenAI methods as you would normally do:

import { ChatOpenAI } from '@langchain/openai';
import { PromptTemplate } from '@langchain/core/prompts';

const llm = new ChatOpenAI(
  {
    model: 'auto',
    apiKey: '<THE-API-KEY-YOU-GENERATED>'
    configuration: {
      baseURL: "https://api.airouter.io",
    },
  },
);
const prompt = PromptTemplate.fromTemplate(
    'What is the capital of France?',
);
const chain = prompt.pipe(llm);
const result = await chain.invoke({});

The above example lets the AI Router select the most appropriate model for each request. It is possible to also supply a list of models to limit the models the AI Router may choose from.