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Overview

In this example we’ll be using a number of different tools and features to:

  1. Scrape the content of the top 3 articles from Hacker News
  2. Summarize each article
  3. Email the summaries to yourself

And we’ll be using the following tools and features:

  • Schedules to run the task every weekday at 9 AM
  • Batch Triggering to run separate child tasks for each article while the parent task waits for them all to complete
  • idempotencyKey to prevent tasks being triggered multiple times
  • BrowserBase to proxy the scraping of the Hacker News articles
  • Puppeteer to scrape the articles linked from Hacker News
  • OpenAI to summarize the articles
  • Resend to send a nicely formatted email summary

WEB SCRAPING: When web scraping, you MUST use a proxy to comply with our terms of service. Direct scraping of third-party websites without the site owner’s permission using Trigger.dev Cloud is prohibited and will result in account suspension. See this example which uses a proxy.

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Prerequisites

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Build configuration

First up, add these build settings to your trigger.config.ts file:

trigger.config.ts
import { defineConfig } from "@trigger.dev/sdk/v3";
import { puppeteer } from "@trigger.dev/build/extensions/puppeteer";

export default defineConfig({
  project: "<project ref>",
  // Your other config settings...
  build: {
    // This is required to use the Puppeteer library
    extensions: [puppeteer()],
  },
});

Learn more about the trigger.config.ts file including setting default retry settings, customizing the build environment, and more.

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Environment variables

Set the following environment variable in your local .env file to run this task locally. And before deploying your task, set them in the Trigger.dev dashboard or using the SDK:

BROWSERBASE_API_KEY: "<your BrowserBase API key>"
OPENAI_API_KEY: "<your OpenAI API key>"
RESEND_API_KEY: "<your Resend API key>"

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Task code

trigger/scrape-hacker-news.ts
import { render } from "@react-email/render";
import { logger, schedules, task, wait } from "@trigger.dev/sdk/v3";
import { OpenAI } from "openai";
import puppeteer from "puppeteer-core";
import { Resend } from "resend";
import { HNSummaryEmail } from "./summarize-hn-email";

const openai = new OpenAI({ apiKey: process.env.OPENAI_API_KEY });
const resend = new Resend(process.env.RESEND_API_KEY);

// Parent task (scheduled to run 9AM every weekday)
export const summarizeHackerNews = schedules.task({
  id: "summarize-hacker-news",
  cron: {
    pattern: "0 9 * * 1-5",
    timezone: "Europe/London",
  }, // Run at 9 AM, Monday to Friday
  run: async () => {
    // Connect to BrowserBase to proxy the scraping of the Hacker News articles
    const browser = await puppeteer.connect({
      browserWSEndpoint: `wss://connect.browserbase.com?apiKey=${process.env.BROWSERBASE_API_KEY}`,
    });
    logger.info("Connected to Browserbase");

    const page = await browser.newPage();

    // Navigate to Hacker News and scrape top 3 articles
    await page.goto("https://news.ycombinator.com/news", {
      waitUntil: "networkidle0",
    });
    logger.info("Navigated to Hacker News");

    const articles = await page.evaluate(() => {
      const items = document.querySelectorAll(".athing");
      return Array.from(items)
        .slice(0, 3)
        .map((item) => {
          const titleElement = item.querySelector(".titleline > a");
          const link = titleElement?.getAttribute("href");
          const title = titleElement?.textContent;
          return { title, link };
        });
    });
    logger.info("Scraped top 3 articles", { articles });

    await browser.close();
    await wait.for({ seconds: 5 });

    // Use batchTriggerAndWait to process articles
    const summaries = await scrapeAndSummarizeArticle
      .batchTriggerAndWait(
        articles.map((article) => ({
          payload: { title: article.title!, link: article.link! },
        }))
      )
      .then((batch) => batch.runs.filter((run) => run.ok).map((run) => run.output));

    // Send email using Resend
    await resend.emails.send({
      from: "Hacker News Summary <hi@demo.tgr.dev>",
      to: ["james@trigger.dev"],
      subject: "Your morning HN summary",
      html: render(<HNSummaryEmail articles={summaries} />),
    });

    logger.info("Email sent successfully");
  },
});

// Child task for scraping and summarizing individual articles
export const scrapeAndSummarizeArticle = task({
  id: "scrape-and-summarize-articles",
  retry: {
    maxAttempts: 3,
    minTimeoutInMs: 5000,
    maxTimeoutInMs: 10000,
    factor: 2,
    randomize: true,
  },
  run: async ({ title, link }: { title: string; link: string }) => {
    logger.info(`Summarizing ${title}`);

    const browser = await puppeteer.connect({
      browserWSEndpoint: `wss://connect.browserbase.com?apiKey=${process.env.BROWSERBASE_API_KEY}`,
    });
    const page = await browser.newPage();

    // Prevent all assets from loading, images, stylesheets etc
    await page.setRequestInterception(true);
    page.on("request", (request) => {
      if (["script", "stylesheet", "image", "media", "font"].includes(request.resourceType())) {
        request.abort();
      } else {
        request.continue();
      }
    });

    await page.goto(link, { waitUntil: "networkidle0" });
    logger.info(`Navigated to article: ${title}`);

    // Extract the main content of the article
    const content = await page.evaluate(() => {
      const articleElement = document.querySelector("article") || document.body;
      return articleElement.innerText.trim().slice(0, 1500); // Limit to 1500 characters
    });

    await browser.close();

    logger.info(`Extracted content for article: ${title}`, { content });

    // Summarize the content using ChatGPT
    const response = await openai.chat.completions.create({
      model: "gpt-4o",
      messages: [
        {
          role: "user",
          content: `Summarize this article in 2-3 concise sentences:\n\n${content}`,
        },
      ],
    });

    logger.info(`Generated summary for article: ${title}`);

    return {
      title,
      link,
      summary: response.choices[0].message.content,
    };
  },
});

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Create your email template using React Email

To prevent the main example from becoming too cluttered, we’ll create a separate file for our email template. It’s formatted using React Email components so you’ll need to install the package to use it.

Notice how this file is imported into the main task code and passed to Resend to send the email.

summarize-hn-email.tsx
import { Html, Head, Body, Container, Section, Heading, Text, Link } from "@react-email/components";

interface Article {
  title: string;
  link: string;
  summary: string | null;
}

export const HNSummaryEmail: React.FC<{ articles: Article[] }> = ({ articles }) => (
  <Html>
    <Head />
    <Body style={{ fontFamily: "Arial, sans-serif", padding: "20px" }}>
      <Container>
        <Heading as="h1">Your Morning HN Summary</Heading>
        {articles.map((article, index) => (
          <Section key={index} style={{ marginBottom: "20px" }}>
            <Heading as="h3">
              <Link href={article.link}>{article.title}</Link>
            </Heading>
            <Text>{article.summary || "No summary available"}</Text>
          </Section>
        ))}
      </Container>
    </Body>
  </Html>
);

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Local development

To test this example task locally, be sure to install any packages from the build extensions you added to your trigger.config.ts file to your local machine. In this case, you need to install .

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Testing your task

To test this task in the dashboard, use the Test page and set the schedule date to “Now” to ensure the task triggers immediately. Then click “Run test” and wait for the task to complete.