Restock Monitor Proxies: Fast Stock Checks on Fixed IPs

Why restock monitors need proxies

A restock monitor asks the same pages the same question every few minutes. Retailers cap requests per IP and answer HTTP 429 when you go over, so one server IP watching hundreds of products ends up rate-limited at the moment a drop happens.

Ask for less. Many stores expose stock in small JSON: Shopify's product endpoint, /products/<handle>.js, returns available for the product and for each variant. If the server sends an ETag, a conditional request comes back 304 Not Modified with no body when nothing changed.

Stock can differ by region — Merchant Center lets sellers set availability per region — so check from the country whose stock you care about. Datacenter IPs keep polling cheap with a flat price per IP; move a store to rotating residential only if it blocks server IPs.

• MDN — 429 Too Many Requests
• Shopify Ajax API — Product (products/{handle}.js)
• MDN — 304 Not Modified
• Google Merchant Center Help — Regional availability and pricing

Recommended restock monitor setup

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The button below opens Static Datacenter Proxies with the AI and automation use case. Choose Region, Term, Protocol and Quantity (up to 100 IPs at a time) before you pay.

• Proxy302 console — Static Datacenter Proxies

Which Proxy302 proxy to buy

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Prices in US dollars. Top up your wallet once and pay any line from it. Nothing renews automatically — renew in My assets to keep an IP.

• Proxy302 pricing

Set up restock monitor proxies in 4 steps

1. Choose the region and term

   The button below opens Static Datacenter Proxies (Per IP and term) with the AI and automation use case. Under Connection settings pick the Region, choose a Term and set Protocol to HTTP. Set Quantity to the number of IPs you'll spread products over (up to 100 at a time), then click Review cost and generate.

2. Copy each IP

   In My assets, Copy gives host:port:user:password. Turn it into PROXY_URL = http://USER:PASS@HOST:PORT for each monitor worker.

3. Poll a small endpoint with ETags

   Use the code below: it asks for the product JSON, sends If-None-Match with the last ETag and treats only a 200 with available false as sold out.

   Expected result The first check prints the sizes in stock; unchanged checks print 304 and download no body.

4. Post alerts, not noise

   Send a message only when the in-stock list changes, and keep the last known state when a check errors.

Restock check with ETag through a proxy (Python)

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# pip install requests
import os
import time
import requests

PROXY = os.environ["PROXY_URL"]  # static datacenter IP from My assets: http://USER:PASS@HOST:PORT
PROXIES = {"http": PROXY, "https": PROXY}
URL = "https://store.example.com/products/limited-sneaker.js"  # Shopify product JSON

session = requests.Session()
etag, last = None, None

for _ in range(3):  # in production, let your scheduler run each check
    headers = {"If-None-Match": etag} if etag else {}
    try:
        r = session.get(URL, headers=headers, proxies=PROXIES, timeout=20)
        status = r.status_code
    except requests.RequestException as exc:  # proxy refused (407), timeout or connection error
        status = type(exc).__name__
    if status == 304:
        print("unchanged (304, no body downloaded)")
    elif status == 200:
        etag = r.headers.get("ETag")
        in_stock = [v["title"] for v in r.json()["variants"] if v["available"]]
        if in_stock != last:
            print("in stock:", in_stock or "none")
            last = in_stock
    else:
        print("unknown, keeping last state:", status)  # never turn an error into "sold out"
    time.sleep(30)

Checked on 2026-10-18 (requests 2.33.1) through a local password-protected proxy, against HTTP and HTTPS store endpoints that send an ETag: the first check printed the sizes in stock and the next two came back 304 with no body; with a wrong password every check printed 'unknown' and kept the last state.

• Local proxy fixture run
• Shopify Ajax API — Product (products/{handle}.js)
• MDN — 304 Not Modified

Quick fixes

Restock monitor proxy FAQ

Related setups

Price monitoring proxies

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