Datetime parser

This OutputParser can be used to parse LLM output into datetime format.

tip

See this section for general instructions on installing integration packages.

npm

npm install @langchain/openai

Yarn

yarn add @langchain/openai

pnpm

pnpm add @langchain/openai

import { ChatOpenAI } from "@langchain/openai";
import { ChatPromptTemplate } from "@langchain/core/prompts";
import { DatetimeOutputParser } from "langchain/output_parsers";

const parser = new DatetimeOutputParser();

const prompt = ChatPromptTemplate.fromTemplate(`Answer the users question:

{question}

{format_instructions}`);

const promptWithInstructions = await prompt.partial({
  format_instructions: parser.getFormatInstructions(),
});

const model = new ChatOpenAI({ temperature: 0 });

const chain = promptWithInstructions.pipe(model).pipe(parser);

const response = await chain.invoke({
  question: "When was Chicago incorporated?",
});

console.log(response, response instanceof Date);

/*
  1837-03-04T00:00:00.000Z, true
*/

API Reference:

• ChatOpenAI from @langchain/openai
• ChatPromptTemplate from @langchain/core/prompts
• DatetimeOutputParser from langchain/output_parsers