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XSron Hou
XSron Hou

Posted on Originally published at scrapio.dev

Schedule a Weekly Price Monitor in 10 Minutes

#webscraping #api #ai #showdev

Originally posted on the Scrapio blog — sharing here too.

Price monitoring is a common automation need — whether you're tracking a competitor, waiting for a deal, or monitoring supplier costs. The traditional path involves a server, a cron job, a scraper, and a notification system. With Scrapio you only need the last two.

Scrapio now also has native Monitors — set the URL, the fields to extract, and which ones to watch from the dashboard, and Scrapio owns the schedule, the "last value" comparison, and the webhook delivery for you. The walkthrough below is still useful if you want the cron trigger and comparison logic running in your own infrastructure (e.g. to chain into other systems), but for most teams the native Monitor is the faster path — skip to Next steps to try it.

What you'll need

  • A Scrapio API key
  • A cron trigger (GitHub Actions, cron-job.org, or any scheduler)
  • A webhook URL to receive notifications (use webhook.site for testing)

The approach

The pattern is simple:

  1. A cron trigger fires on a schedule (e.g. every Monday at 9am)
  2. It calls Scrapio to extract the current price from the product page
  3. It compares against the last recorded price
  4. If the price dropped, it sends a notification

Step 1 — Fetch the price with Scrapio

Use the extract parameter to pull just the fields you care about:

import httpx

API_KEY = "sk-..."

def get_price(url: str) -> dict:
    resp = httpx.post(
        "https://api.scrapio.dev/v1/fetch",
        headers={"Authorization": f"Bearer {API_KEY}"},
        json={
            "url": url,
            "output": ["json"],
            "extract": {
                "mode": "schema",
                "schema": {
                    "price": "number",
                    "availability": "string",
                },
            },
            "render_js": True,
        },
        timeout=30,
    )
    resp.raise_for_status()
    return resp.json()["outputs"]["json"]
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Step 2 — Compare and notify 

import json
import os
import httpx

PRICE_FILE = "last_price.json"
WEBHOOK_URL = "https://your-webhook-url.com/price-alert"
PRODUCT_URL = "https://example.com/products/iphone-15"

def load_last_price() -> float | None:
    if os.path.exists(PRICE_FILE):
        return json.loads(open(PRICE_FILE).read()).get("price")
    return None

def save_price(price: float) -> None:
    open(PRICE_FILE, "w").write(json.dumps({"price": price}))

def run():
    current = get_price(PRODUCT_URL)
    price = current["price"]
    last = load_last_price()

    if last is not None and price < last:
        httpx.post(WEBHOOK_URL, json={
            "message": f"Price dropped from ${last:.2f} to ${price:.2f}",
            "url": PRODUCT_URL,
            "price": price,
        })

    save_price(price)

run()
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Step 3 — Schedule with GitHub Actions

Create .github/workflows/price-monitor.yml:

name: Price Monitor
on:
  schedule:
    - cron: "0 9 * * 1"  # Every Monday at 9am UTC
  workflow_dispatch:

jobs:
  check:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-python@v5
        with:
          python-version: "3.12"
      - run: pip install httpx
      - run: python monitor.py
        env:
          SCRAPIO_API_KEY: ${{ secrets.SCRAPIO_API_KEY }}
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GitHub Actions is free for public repos and the free tier covers hundreds of runs per month for private ones. No server required.

Cron expressions quick reference

Expression Meaning
0 9 * * 1 Every Monday at 9am UTC
0 */6 * * * Every 6 hours
0 8 * * * Every day at 8am UTC
*/30 * * * * Every 30 minutes

Next steps

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