Tavily is a search engine built specifically for AI agents (LLMs), delivering real-time, accurate, and factual results at speed. Tavily offers two key endpoints, one of which being Search, which provides search results tailored for LLMs and RAG. This guide provides a quick overview for getting started with the Tavily tool. For a complete breakdown of the Tavily tool, you can find more detailed documentation in the API reference.

Overview

Integration details

ClassPackagePY supportPackage latest
TavilySearch@langchain/tavilyNPM - Version

Setup

The integration lives in the @langchain/tavily package, which you can install as shown below:
import IntegrationInstallTooltip from "@mdx_components/integration_install_tooltip.mdx";
<IntegrationInstallTooltip></IntegrationInstallTooltip>

<Npm2Yarn>
  @langchain/tavily @langchain/core
</Npm2Yarn>

Credentials

Set up an API key here and set it as an environment variable named TAVILY_API_KEY.
process.env.TAVILY_API_KEY = "YOUR_API_KEY"
It’s also helpful (but not needed) to set up LangSmith for best-in-class observability:
process.env.LANGSMITH_TRACING="true"
process.env.LANGSMITH_API_KEY="your-api-key"

Instantiation

You can import and instantiate an instance of the TavilySearch tool like this:
import { TavilySearch } from "@langchain/tavily";

const tool = new TavilySearch({
  maxResults: 5,
  topic: "general",
  // includeAnswer: false,
  // includeRawContent: false,
  // includeImages: false,
  // includeImageDescriptions: false,
  // searchDepth: "basic",
  // timeRange: "day",
  // includeDomains: [],
  // excludeDomains: [],
});

Invocation

Invoke directly with args

The Tavily search tool accepts the following arguments during invocation:
  • query (required): A natural language search query
  • The following arguments can also be set during invocation : includeImages, searchDepth , timeRange, includeDomains, excludeDomains, includeImages.
  • For reliability and performance reasons, certain parameters that affect response size cannot be modified during invocation: includeAnswer and includeRawContent. These limitations prevent unexpected context window issues and ensure consistent results.
await tool.invoke({
  query: "what is the current weather in SF?"
});

Invoke with ToolCall

We can also invoke the tool with a model-generated ToolCall, in which case a ToolMessage will be returned:
// This is usually generated by a model, but we'll create a tool call directly for demo purposes.
const modelGeneratedToolCall = {
  args: {
    query: "what is the current weather in SF?"
  },
  id: "1",
  name: tool.name,
  type: "tool_call",
}

await tool.invoke(modelGeneratedToolCall)

Chaining

We can use our tool in a chain by first binding it to a tool-calling model and then calling it:
<ChatModelTabs customVarName="llm" />
// @lc-docs-hide-cell

import { ChatOpenAI } from "@langchain/openai"

const llm = new ChatOpenAI({
  model: "gpt-4o",
  temperature: 0,
})
import { HumanMessage } from "@langchain/core/messages";
import { ChatPromptTemplate } from "@langchain/core/prompts";
import { RunnableLambda } from "@langchain/core/runnables";

const prompt = ChatPromptTemplate.fromMessages(
  [
    ["system", "You are a helpful assistant."],
    ["placeholder", "{messages}"],
  ]
)

const llmWithTools = llm.bindTools([tool]);

const chain = prompt.pipe(llmWithTools);

const toolChain = RunnableLambda.from(
  async (userInput: string, config) => {
    const humanMessage = new HumanMessage(userInput,);
    const aiMsg = await chain.invoke({
      messages: [new HumanMessage(userInput)],
    }, config);
    const toolMsgs = await tool.batch(aiMsg.tool_calls, config);
    return chain.invoke({
      messages: [humanMessage, aiMsg, ...toolMsgs],
    }, config);
  }
);

const toolChainResult = await toolChain.invoke("what is the current weather in sf?");
const { tool_calls, content } = toolChainResult;

console.log("AIMessage", JSON.stringify({
  tool_calls,
  content,
}, null, 2));

Agents

For guides on how to use LangChain tools in agents, see the LangGraph.js docs.

API reference

For detailed documentation of all Tavily Search API features and configurations head to the API reference: https://docs.tavily.com/documentation/api-reference/endpoint/search