Competitor Price Monitoring: Track Any Marketplace in Real Time

If you sell on more than one marketplace, your margins are being decided by competitors who reprice several times a day. Manual checks can't keep up. This playbook shows how to stand up automated competitor price monitoring that scrapes rivals on a schedule, diffs every field, and pings you the instant something moves.

The short answer

Point a recurring scrape at the competitor listings you care about, let it run on an interval, and have it compare each run against the last one. When a watched field - price, MRP, discount, or stock - changes, a webhook fires with the before-and-after values. ArrowCrawl does all three (schedule, diff, alert) across 8 marketplaces behind one API call:

curl -X POST https://api.arrowcrawl.com/api/v1/monitors \
  -H "Authorization: Bearer ac_live_..." \
  -d '{
    "marketplaces": ["amazon_in", "flipkart", "meesho"],
    "product_ids": ["B0BGQR6QBR", "MOBGXYZ123"],
    "interval": "15m",
    "watch": ["price", "mrp", "stock"],
    "webhook_url": "https://yourapp.com/hooks/price"
  }'

Step 1: Schedule recurring scrapes

The core of monitoring is cadence. A monitor is just a scrape that repeats: you pick the listings and an interval, and ArrowCrawl re-runs it for you. Fast-moving hero SKUs might warrant a 5- or 15-minute cadence; a long tail of 10,000 products is fine on a daily sweep. Because every run routes through the same reputation-scored proxy pool, tightening the interval doesn't increase your block rate - blocked IPs are scored down and rotated out automatically. See the full list of what each run can pull on the features page.

Step 2: Field-level diffs, not full dumps

Re-downloading a product page tells you nothing on its own - you need to know what changed. After each run, ArrowCrawl compares the fresh scrape against the previous snapshot and produces a field-level diff: it knows that price went from ₹1,299 to ₹1,149, that the discount widened, or that stock flipped from in-stock to sold out. You watch only the fields that matter, so a competitor swapping a product image never wakes you up, but a price cut does.

Step 3: Webhook alerts on price and stock changes

When a watched field moves, the monitor fires a webhook to your endpoint with the old value, the new value, the marketplace, and a timestamp. That payload can drop straight into Slack, trigger an automatic reprice, or update a dashboard. Because the alert is diff-driven, you get signal, not noise - one message per real change instead of a firehose every interval. Teams typically wire this into a repricing rule so a competitor's cut is matched within minutes.

Step 4: Cover all 8 marketplaces at once

The same product often lives on Amazon, Flipkart, Meesho, and more, each with its own price. A single monitor can span all 8 supported marketplaces, normalizing fields so a diff on Flipkart looks identical to one on Amazon. That gives you one unified view of where you're being undercut and by whom. Explore the coverage on the marketplace page, and check the pricing tiers to size your credit budget against how many SKUs and how tight an interval you need.

Putting it together

Good competitor price monitoring is three moving parts working as one: a schedule that keeps data fresh, a diff engine that isolates real change, and a webhook that turns that change into action. Wire those together and repricing stops being a daily chore and becomes an automated reflex. You can stand the whole pipeline up with a single ArrowCrawl key - start free with 1,000 credits a month.