Monitoring Amazon ASINs daily for price changes, rating shifts, and stock availability is essential for e-commerce intelligence. Scraper-based solutions require constant maintenance as Amazon changes page layouts and tightens bot detection. This tutorial builds a stable monitoring pipeline using the Scavio API that checks a list of ASINs on a schedule, stores historical data, detects meaningful changes, and sends alerts. Each ASIN check costs $0.005 with zero maintenance overhead.
Prerequisites
- Python 3.9+ installed
- requests library installed
- A Scavio API key from scavio.dev
- A list of ASINs to monitor
Walkthrough
Step 1: Define the ASIN watchlist and storage
Set up the list of ASINs to monitor and a JSON-based storage system for historical tracking.
Python
import os, requests, json, time
from datetime import datetime
SCAVIO_KEY = os.environ['SCAVIO_API_KEY']
H = {'x-api-key': SCAVIO_KEY, 'Content-Type': 'application/json'}
URL = 'https://api.scavio.dev/api/v1/search'
WATCHLIST = ['B09G9FPHY6', 'B07FZ8S74R', 'B08N5WRWNW', 'B0BSHF7WHW']
HISTORY_FILE = 'asin_history.json'
def load_history() -> dict:
if os.path.exists(HISTORY_FILE):
with open(HISTORY_FILE) as f:
return json.load(f)
return {}
def save_history(history: dict):
with open(HISTORY_FILE, 'w') as f:
json.dump(history, f, indent=2)Step 2: Fetch current product data for each ASIN
Query the Scavio API for each ASIN and extract price, rating, review count, and availability.
Python
def fetch_asin(asin: str) -> dict:
resp = requests.post(URL, headers=H,
json={'platform': 'amazon', 'query': asin, 'marketplace': 'US'})
resp.raise_for_status()
data = resp.json()
product = data.get('product', data)
price_str = product.get('price', '')
price = None
if price_str:
price = float(price_str.replace('$', '').replace(',', ''))
return {
'asin': asin,
'title': product.get('title', ''),
'price': price,
'rating': product.get('rating', ''),
'reviews': product.get('reviews_count', 0),
'availability': product.get('availability', ''),
'timestamp': datetime.now().isoformat(),
}
for asin in WATCHLIST[:2]:
data = fetch_asin(asin)
print(f'{asin}: ${data["price"]} | {data["rating"]} stars | {data["title"][:40]}')
time.sleep(0.3)Step 3: Detect changes and generate alerts
Compare current data with previous snapshots to detect price drops, rating changes, and stock issues.
Python
def check_changes(asin: str, current: dict, history: dict) -> list:
alerts = []
prev_records = history.get(asin, [])
if not prev_records:
return alerts
prev = prev_records[-1]
# Price change
if current['price'] and prev.get('price'):
pct_change = (current['price'] - prev['price']) / prev['price'] * 100
if abs(pct_change) > 5:
direction = 'dropped' if pct_change < 0 else 'increased'
alerts.append(f'PRICE {direction} {abs(pct_change):.1f}%: ${prev["price"]} -> ${current["price"]}')
# Rating change
if current['rating'] and prev.get('rating') and current['rating'] != prev['rating']:
alerts.append(f'RATING changed: {prev["rating"]} -> {current["rating"]}')
# Stock status
if 'out of stock' in (current.get('availability', '') or '').lower():
alerts.append('OUT OF STOCK')
return alerts
def run_monitoring():
history = load_history()
for asin in WATCHLIST:
current = fetch_asin(asin)
alerts = check_changes(asin, current, history)
if asin not in history:
history[asin] = []
history[asin].append(current)
status = f'[ALERT] {", ".join(alerts)}' if alerts else '[OK]'
print(f'{status} {asin}: ${current["price"]} | {current["title"][:35]}')
time.sleep(0.3)
save_history(history)
print(f'\nMonitored {len(WATCHLIST)} ASINs | Cost: ${len(WATCHLIST) * 0.005:.3f}')
run_monitoring()Python Example
Python
import os, requests, json, time
from datetime import datetime
SCAVIO_KEY = os.environ['SCAVIO_API_KEY']
H = {'x-api-key': SCAVIO_KEY, 'Content-Type': 'application/json'}
def monitor_asins(asins):
for asin in asins:
resp = requests.post('https://api.scavio.dev/api/v1/search', headers=H,
json={'platform': 'amazon', 'query': asin, 'marketplace': 'US'})
p = resp.json().get('product', resp.json())
print(f'{asin}: {p.get("price", "N/A")} | {p.get("rating", "N/A")} | {p.get("title", "")[:40]}')
time.sleep(0.3)
print(f'Cost: ${len(asins) * 0.005:.3f}')
monitor_asins(['B09G9FPHY6', 'B07FZ8S74R'])JavaScript Example
JavaScript
const SCAVIO_KEY = process.env.SCAVIO_API_KEY;
async function monitorAsins(asins) {
for (const asin of asins) {
const resp = await fetch('https://api.scavio.dev/api/v1/search', {
method: 'POST',
headers: { 'x-api-key': SCAVIO_KEY, 'Content-Type': 'application/json' },
body: JSON.stringify({ platform: 'amazon', query: asin, marketplace: 'US' })
});
const p = (await resp.json()).product || {};
console.log(`${asin}: ${p.price || 'N/A'} | ${p.rating || 'N/A'} | ${(p.title || '').slice(0, 40)}`);
}
console.log(`Cost: $${(asins.length * 0.005).toFixed(3)}`);
}
monitorAsins(['B09G9FPHY6', 'B07FZ8S74R']);Expected Output
JSON
[OK] B09G9FPHY6: $29.99 | Echo Dot (5th Gen) | Smart speake
[ALERT] PRICE dropped 12.3%: $28.49 -> $24.99 B07FZ8S74R: $24.99 | Fire TV Stick 4K with Alexa
[OK] B08N5WRWNW: $89.99 | Kindle Paperwhite (11th Generatio
[OK] B0BSHF7WHW: $39.99 | Fire TV Stick 4K Max (2nd Gen)
Monitored 4 ASINs | Cost: $0.020