Recipe · Price monitor

Build a price monitor that tells you when prices drop.

Paste the prompt into Claude, Cursor, Replit, Lovable or Bolt with UnblockingAPI connected. Your agent reads the build guide, then writes the app; UnblockingAPI fetches the pages it needs.

Connect your AI first
prompt
Create a price monitor using UnblockingAPI: I paste product URLs and a target price, it checks each product twice a day from my country, keeps the price history and emails me when a price drops below the target. Read UnblockingAPI's build guide first (the get_build_guide tool, or https://github.com/unblockingapi/mcp/tree/main/guides) and call its REST API directly from the backend with plain fetch, my API key stored as a secret.

What your agent builds

  • A product list you add to by pasting a URL
  • A scheduled check that fetches each page through UnblockingAPI and reads the price
  • Price history per product, with changes highlighted
  • An alert when a price drops below your target

What it costs to run

1 credit per product per check: 50 products twice a day is about 3,000 credits a month.

Failed fetches are free. New accounts get 500 free credits; plans make credits cheaper at volume.

The API call at its heart

Plain fetch from the backend, no SDK. Your agent writes this for you - it's here so you know what your app does.

const res = await fetch("https://api.unblockingapi.com/unblock", {
  method: "POST",
  headers: { "X-Api-Key": process.env.UNBLOCKINGAPI_KEY, "Content-Type": "application/json" },
  body: JSON.stringify({
    url: product.url,
    location: "se",                                   // prices as your users see them
    wait_for: "[itemprop=price]", wait_state: "nonempty", // prices filled in by JavaScript
  }),
});
const { status, response: html } = await res.json(); // cleaned HTML: parse the price

The full recipe your agent reads - data model, scheduling, retries, UI - is on GitHub, and served to connected agents by get_build_guide.

Where it runs

Lovable
A Supabase Edge Function does the fetching on a schedule, with the key in Supabase secrets.
Replit
The backend reads the key from Replit Secrets; a Scheduled Deployment runs the checks.
Bolt, Next.js, Vercel
A route handler or server action, the key in environment variables, Vercel Cron for the schedule.
Claude Code, Cursor
Any stack you choose; ask for a cron job or a worker for the scheduled part.

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Build your price monitor today.

500 free credits, no credit card. Connect in under a minute.