UserScript - Loads Keepa price tracker for Amazon domains

keepa-price-history.user.js

// ==UserScript==
// @name        Keepa - Price History
// @description Loads Keepa price tracker for Amazon domains
// @version     2.0.1
// @namespace   https://gist.github.com/gperezmz
// @match       https://www.amazon.*/*/dp/*
// @match       https://www.amazon.*/dp/*
// @match       https://www.amazon.*/gp/product/*
// @author      gperezmz
// @license     bsd-3-clause
// @run-at      document-idle
// @grant       none
// ==/UserScript==

// User Settings: Modify these variables to customize the Amazon Historical Prices chart
const userSettings = {
  showAmazonPrice: 1, // Amazon price graph: 1 (draw), 0 (do not draw)
  showNewPrice: 1, // New price graph: 1 (draw), 0 (do not draw)
  showUsedPrice: 1, // Used price graph: 1 (draw), 0 (do not draw)
  chartRange: 90, // The range of the chart in days: Suggested values are 1, 2, 7, 31, 90, 365
};

(function () {
  'use strict';

  const style = document.createElement("style");
  style.innerHTML = `
      .historicalPriceContainer {
        margin-top: 20px;
        margin-bottom: 20px;
        text-align: center;
      }
      .historicalPriceChart {
        width: 100%;
        height: 100%;
        object-fit: contain;
        border-radius: 0!important;
      }
    `;
  document.head.appendChild(style);

  const memoize = (fn) => {
    const cache = new Map();
    return function (...args) {
      const key = JSON.stringify(args);
      if (cache.has(key)) return cache.get(key);
      const result = fn.apply(this, args);
      cache.set(key, result);
      return result;
    };
  };

  const getASIN = memoize(() => {
    const asinElement = document.getElementById("ASIN") || document.querySelector('input[name="ASIN"]');
    if (!asinElement) {
      console.error("Unable to find ASIN on the page.");
      return null;
    }
    return asinElement.value;
  });

  const insertPriceCharts = (asin, tld) => {
    const keepaCountryCode = {
      com: "1",
      uk: "2",
      de: "3",
      fr: "4",
      jp: "5",
      ca: "6",
      it: "8",
      es: "9",
      in: "10",
      mx: "11",
      br: "12",
    };

    const countryCode = keepaCountryCode[tld] || "unsupported";
    if (countryCode === "unsupported") {
      return console.error("This country is not supported by Keepa.");
    }

    const historicalPriceContainer = document.createElement("div");
    historicalPriceContainer.className = "historicalPriceContainer";

    const historicalPriceLink = document.createElement("a");
    const historicalPriceChart = new Image();
    historicalPriceChart.className = "historicalPriceChart";
    historicalPriceChart.loading = "lazy";

    const parentElement =
      document.getElementById("unifiedPrice_feature_div") ||
      document.querySelector("#MediaMatrix");
    if (!parentElement) {
      return console.error("Unable to find a suitable parent element for inserting the price charts.");
    }

    historicalPriceLink.target = "_blank";
    historicalPriceLink.href = `https://keepa.com/#!product/${countryCode}-${asin}`;
    historicalPriceChart.src = `https://graph.keepa.com/pricehistory.png?used=${userSettings.showUsedPrice}&asin=${asin}&domain=${tld}&amazon=${userSettings.showAmazonPrice}&new=${userSettings.showNewPrice}&range=${userSettings.chartRange}`;

    historicalPriceLink.appendChild(historicalPriceChart);
    historicalPriceContainer.appendChild(historicalPriceLink);

    parentElement.appendChild(historicalPriceContainer);
  };

  const asin = getASIN();
  if (asin) {
    const tld = document.location.hostname.match('.*\.amazon\.(.*)$')[1];
    insertPriceCharts(asin, tld);
  }
})();

hi @gperezmz
are you still using this thing? :)

it looks like keepa got rid of https://keepa.com/iframe_addon.html – it now says "You are using an outdated version of the Keepa extension."

e.g. https://keepa.com/iframe_addon.html#1-0-B0BNGVWL98

the keepa extension now injects https://keepa.com/keepaBox.html instead, but i can't get that to work.

with their extension installed, visiting this url works: https://keepa.com/keepaBox.html#1-0-B0BNGVWL98
however, without it installed, it errors: "Please make sure to exclusively utilize our latest browser extension."

either the ASIN and country code need to be specified some other way than a url fragment, or the browser extension check needs to be defeated somehow...

edit: i ended up fixing it via another method... 🥷

hi @gperezmz are you still using this thing? :)

it looks like keepa got rid of https://keepa.com/iframe_addon.html – it now says "You are using an outdated version of the Keepa extension."

e.g. https://keepa.com/iframe_addon.html#1-0-B0BNGVWL98

the keepa extension now injects https://keepa.com/keepaBox.html instead, but i can't get that to work.

with their extension installed, visiting this url works: https://keepa.com/keepaBox.html#1-0-B0BNGVWL98 however, without it installed, it errors: "Please make sure to exclusively utilize our latest browser extension."

either the ASIN and country code need to be specified some other way than a url fragment, or the browser extension check needs to be defeated somehow...

edit: i ended up fixing it via another method... 🥷

Hi there ! Same issue on my end.
How did you end up fixing the deprecated use of iframe_addon.html ?
Thanks for your help 🙃

i ended up just writing my own script, but i don't want to publicly share it because i'm greedy and paranoid about keepa defeating it. clearly, they want users to join their botnet (erm, i mean use their browser extension).

i'd share it with you but don't know how. i hate how github doesn't have PMs. lol
i also don't want to publicly share my contact info. i guess if you want it bad enough, leave me a way to contact you. discord preferred. sry

i ended up just writing my own script, but i don't want to publicly share it because i'm greedy and paranoid about keepa defeating it. clearly, they want users to join their botnet (erm, i mean use their browser extension).

i'd share it with you but don't know how. i hate how github doesn't have PMs. lol i also don't want to publicly share my contact info. i guess if you want it bad enough, leave me a way to contact you. discord preferred. sry

Hi there ! Quite late reply, but I'm still interested 🙃
You can DM me on Discord : _sgta_
Thanks !