Holiday Price Tracker API: Watch Gift Prices From Now Through Black Friday

Gift shoppers ask the same question every November: is this a good price, or will it be lower next week? A Holiday Price Tracker API answers it by keeping a daily record of what each product cost and comparing today with that record. The Affiliate.com Price History API provides the record for any product with a barcode, across every store that sells it, so one request gives a page enough to track a gift from now through Black Friday. The demo below uses prices last pulled November 10, 2026. You can pick a product, set a target price and watch an alert fire or not.

What a holiday price tracker has to answer

Strip away the interface and a tracker answers three questions. What is the lowest price a shopper can pay today? Is that low or high compared with recent weeks? And if the shopper had asked to be told about a price, would the alert have fired yet?

Each question needs a different slice of the same data. The first needs today’s price at every store that has the product in stock. The second needs the daily history, so a price can be placed between its low and its high. The third needs only a number from the shopper, a target, and a comparison against both. None of it needs a dedicated pricing team. It needs a daily series, which the Price History API returns for a barcode in a single response.

The word “lowest” matters here. A product is sold by many stores at many prices, and a shopper cares about the cheapest one that actually has it. The tracker below therefore takes, for every day, the lowest price among stores that listed the product as in stock. A cheaper listing that was out of stock that day is left out, because nobody could have bought it.

Who builds with a price tracker API

Publishers use a tracker on gift guides and deal pages, where a line such as “at its lowest price this season” gives a reader a reason to act now instead of a vague promise. Newsletter teams use the same figures to write the one-line summary above a product, and they can pull a fresh set before each send.

Wishlist and shopping apps are the most natural fit. A saved item needs a target price, a daily check and a message when the price is reached, which is the alert in the demo. Our walkthrough of building wishlists and collections covers the saved-list side. This article covers the watching side.

AI shopping assistants need the history for a different reason. An assistant that recommends a gift should be able to say whether the price is unusual, and that statement has to come from data rather than from the model’s memory. The history is a few kilobytes per store, small enough to place in a prompt.

Try the price tracker

This tracker runs on real results from the Price History API for popular gifts. The page holds a rotating set that is rebuilt every night, and it shows two of them, a different pair on most visits. Pick a product, choose a target price and read the result. The chart plots the lowest in-stock price for each of the last 90 days. The request below it is the exact call that returns the history, and the second tab shows the short check a page runs on the response.

How one request becomes a tracker

The request is one barcode. The response contains one entry for every store that sells that barcode, up to 25 per page, and each entry carries the same fields. A tracker needs only a handful of them.

One call covers up to 90 calendar days, and history reaches back 365 days. A missing day means the price was not observed that day, not that the product was free, so a tracker should skip it rather than draw a zero.

Turning daily history into an alert

The alert is two small functions. The first collapses every store’s series into one price per day. The second compares today with a target. The same pair powers the demo above.

// listings: the data array of the response, one entry per store
function lowestInStockPerDay(listings) {
  const best = {};
  for (const l of listings)
    for (const p of l.series)
      if (p.availability === "InStock" && (best[p.date] === undefined || p.final_price < best[p.date]))
        best[p.date] = p.final_price;
  return best; // { "2026-11-09": 124.99, ... }
}

function checkWatch(prices, target) {
  const today = prices[prices.length - 1];
  return {
    today,
    reached: today <= target,
    toGo: Math.max(0, +(today - target).toFixed(2)),
    daysAtTarget: prices.filter(p => p <= target).length
  };
}

Two choices in this code are worth making deliberately. It compares the target with the lowest in-stock price, so an alert never fires on a store that cannot ship the product. And it reports the number of days at or under the target as well as whether today qualifies. A target that was reached on 30 of the last 90 days is a common price. A target reached on two is rare, and the difference changes what a shopper should do.

Targets can also be relative. The demo offers five and ten percent below today’s price and the window’s lowest price. Relative targets suit a wishlist where shoppers rarely know what a product ought to cost, and the lowest price in the window is a sensible default for a deal page.

What the November 10, 2026 pull shows

We ran the same request for the six gifts in that day’s set on November 10, 2026, with the window set to the last 90 days. One of the six sat at the lowest in-stock price of the window that day, and five sat above it. The largest gap was on the Keurig K-Elite coffee maker, $30.00 above its low of $99.99. Measured from the window’s highest price, the Keurig K-Elite coffee maker had fallen furthest, by 38%, from $209.99 to $129.99.

This table is fixed to November 10, 2026. The demo above is rebuilt every night with a different set of gifts, so both its products and its numbers will change as Black Friday approaches. Treat the table as a record of what the data looked like on one day, and the demo as the live version of the same check.

A handful of products is a small sample and not a market study. Each figure describes one product across the stores that report history for it, in US dollars. It says nothing about products outside the list.

What to check before Black Friday

A tracker earns trust only if its statements are plain facts, so a few habits are worth building in before traffic arrives.

Know the window. One call returns at most 90 days. A shopper looking at a price on Black Friday sees roughly the 90 days before it, which begins in late August. Say “lowest in the last 90 days” rather than “lowest ever”, because history beyond the window is not in that response. You can page back through the 365 days of history with a second request when a longer claim is needed.

State what was observed. “Charged $199.99 on 31 of the last 90 days” is a fact from the series. Words such as fake or inflated are a judgment the data does not need. Our post on telling readers whether a Black Friday deal is real applies the same restraint to claimed discounts.

Confirm stock separately. The line already ignores out-of-stock days, but a page should check availability again before it sends a reader to a store. Handling out-of-stock and price-changed offers lays out how an agent can do that.

Match on the barcode. The tracker is only as good as the product match. Two colors or two bundles of the same model are different products with different barcodes, and mixing them makes a price look like it moved when it did not. Barcode search explains why the barcode comes first.

Getting started in three steps

Moving from the demo to a tracker of your own takes three steps, and the request panel above already contains the second one.

Keeping a holiday price page current

Prices move daily during the holidays, so a tracker that updates weekly will be wrong most of the time. The demo above is refreshed every night and shows the date it was last pulled, so readers can see how old the figures are. A page of your own can do the same: pull on a schedule, store the result and print the time beside it. How often product pages should be updated discusses how often is often enough.

The same history helps with planning. Before the season peaks, planning holiday content with product data lists what to check on a gift guide, and comparing regular price with final price shows how to test a discount claim against the list price. A tracker joins the two: it keeps a record all season so that a claim on Black Friday can be checked against it.

{
  "target_type": "barcode",
  "target_ids": [
    "195949121708"
  ],
  "currency": "USD",
  "include_series": true,
  "per_page": 25
}