Tavily

// process.env.LANGSMITH_API_KEY = "<YOUR API KEY HERE>";
// process.env.LANGSMITH_TRACING = "true";

import IntegrationInstallTooltip from "@mdx_components/integration_install_tooltip.mdx";
<IntegrationInstallTooltip></IntegrationInstallTooltip>

<Npm2Yarn>
  @langchain/community @langchain/core
</Npm2Yarn>

import { TavilySearchAPIRetriever } from "@langchain/community/retrievers/tavily_search_api";

const retriever = new TavilySearchAPIRetriever({
  k: 3,
});

const query = "what is the current weather in SF?";

await retriever.invoke(query);

[
  Document {
    pageContent: "{'location': {'name': 'San Francisco', 'region': 'California', 'country': 'United States of America', 'lat': 37.78, 'lon': -122.42, 'tz_id': 'America/Los_Angeles', 'localtime_epoch': 1722900266, 'localtime': '2024-08-05 16:24'}, 'current': {'last_updated_epoch': 1722899700, 'last_updated': '2024-08-05 16:15', 'temp_c': 16.8, 'temp_f': 62.2, 'is_day': 1, 'condition': {'text': 'Partly Cloudy', 'icon': '//cdn.weatherapi.com/weather/64x64/day/116.png', 'code': 1003}, 'wind_mph': 13.2, 'wind_kph': 21.2, 'wind_degree': 261, 'wind_dir': 'W', 'pressure_mb': 1014.0, 'pressure_in': 29.94, 'precip_mm': 0.0, 'precip_in': 0.0, 'humidity': 74, 'cloud': 60, 'feelslike_c': 16.8, 'feelslike_f': 62.2, 'windchill_c': 16.8, 'windchill_f': 62.2, 'heatindex_c': 16.8, 'heatindex_f': 62.2, 'dewpoint_c': 12.3, 'dewpoint_f': 54.1, 'vis_km': 10.0, 'vis_miles': 6.0, 'uv': 5.0, 'gust_mph': 17.3, 'gust_kph': 27.8}}",
    metadata: {
      title: 'Weather in San Francisco',
      source: 'https://www.weatherapi.com/',
      score: 0.9947009,
      images: []
    },
    id: undefined
  },
  Document {
    pageContent: 'Current Weather for Popular Cities . San Francisco, CA 56 ° F Mostly Cloudy; Manhattan, NY warning 85 ° F Fair; Schiller Park, IL (60176) 71 ° F Mostly Cloudy; Boston, MA warning 84 ° F Partly ...',
    metadata: {
      title: 'San Francisco, CA Hourly Weather Forecast | Weather Underground',
      source: 'https://www.wunderground.com/hourly/us/ca/san-francisco/date/2024-08-02',
      score: 0.9859904,
      images: []
    },
    id: undefined
  },
  Document {
    pageContent: 'San Francisco CA 37.77°N 122.41°W (Elev. 131 ft) Last Update: 2:42 pm PDT Aug 4, 2024. Forecast Valid: 5pm PDT Aug 4, 2024-6pm PDT Aug 11, 2024 . Forecast Discussion . Additional Resources. Radar & Satellite Image. Hourly Weather Forecast. ... Severe Weather ; Current Outlook Maps ; Drought ; Fire Weather ; Fronts/Precipitation Maps ; Current ...',
    metadata: {
      title: 'National Weather Service',
      source: 'https://forecast.weather.gov/zipcity.php?inputstring=San+Francisco,CA',
      score: 0.98141783,
      images: []
    },
    id: undefined
  }
]

<ChatModelTabs customVarName="llm" />

// @lc-docs-hide-cell

import { ChatOpenAI } from "@langchain/openai";

const llm = new ChatOpenAI({
  model: "gpt-4o-mini",
  temperature: 0,
});

import { ChatPromptTemplate } from "@langchain/core/prompts";
import { RunnablePassthrough, RunnableSequence } from "@langchain/core/runnables";
import { StringOutputParser } from "@langchain/core/output_parsers";

import type { Document } from "@langchain/core/documents";

const prompt = ChatPromptTemplate.fromTemplate(`
Answer the question based only on the context provided.

Context: {context}

Question: {question}`);

const formatDocs = (docs: Document[]) => {
  return docs.map((doc) => doc.pageContent).join("\n\n");
}

// See https://js.langchain.com/docs/tutorials/rag
const ragChain = RunnableSequence.from([
  {
    context: retriever.pipe(formatDocs),
    question: new RunnablePassthrough(),
  },
  prompt,
  llm,
  new StringOutputParser(),
]);

await ragChain.invoke(query);

The current weather in San Francisco is partly cloudy with a temperature of 16.8°C (62.2°F). The wind is coming from the west at 13.2 mph (21.2 kph), and the humidity is at 74%. There is no precipitation, and visibility is 10 km (6 miles).