AdsCrawl for LangChain

SETUP METHOD 01

Create a LangChain tool

Use the official AdsCrawl SDK with LangChain’s custom tool API. The first call works without configuring a language model.

1. 1

   Install dependencies

   Run this in your application directory.

   ShellCopy

   npm install adscrawl @langchain/core zod

2. 2

   Configure your API key

   Set the variables in your server environment or local shell. Replace the placeholders with your own keys; keep them out of browser bundles and source control.

   ShellCopy

   export ADSCRAWL_API_KEY="your_adscrawl_api_key"

3. 3

   Save langchain-web.mjs

   The tool validates the URL, reads the page and returns a JSON string containing source and markdown. The example invokes the tool directly.

   JavaScriptCopy

   import AdsCrawl from "adscrawl";
   import { tool } from "@langchain/core/tools";
   import { z } from "zod";
   
   const browser = new AdsCrawl({ apiKey: process.env.ADSCRAWL_API_KEY });
   
   export const readWebPage = tool(
     async ({ url }) => {
       const markdown = await browser.markdown({
         url, waitUntil: "domcontentloaded",
       });
       if (!markdown.trim()) throw new Error("The page returned no text");
       return JSON.stringify({ source: url, markdown });
     },
     {
       name: "read_web_page",
       description: "Read a public web page as browser-rendered Markdown, with its source URL.",
       schema: z.object({ url: z.string().url() }),
     },
   );
   
   const result = await readWebPage.invoke({ url: "https://example.com" });
   console.log(JSON.parse(result));

4. 4

   Run and connect the next step

   Expect a source URL and Markdown headed Example Domain. Register readWebPage in your LangChain agent’s tools list to let the agent call it. Configure your chosen model separately; ask the agent to cite source when using the result.

   ShellCopy

   node langchain-web.mjs