Get tax auction properties from King county WA

getKingCountyWATaxAuctions.js

// Run this function at the following url:
// https://kingcounty.gov/depts/finance-business-operations/treasury/foreclosure/current-foreclosure-action/foreclosure-properties.aspx
async function getAllProperties(copy) {
  const data = await fetch("https://data.kingcounty.gov/api/views/nx4x-daw6/rows.json", {
    "headers": {
      "accept": "application/json, text/javascript, */*; q=0.01",
      "sec-ch-ua": "\" Not A;Brand\";v=\"99\", \"Chromium\";v=\"90\", \"Google Chrome\";v=\"90\"",
      "sec-ch-ua-mobile": "?0"
    },
    "referrer": "https://kingcounty.gov/",
    "referrerPolicy": "strict-origin-when-cross-origin",
    "body": null,
    "method": "GET",
    "mode": "cors",
    "credentials": "omit"
  });
  
  const body = await data.json();
  
  const properties = body.data.map(property => property[8]);

  copy(properties);
}

// Pass in dev tools copy function
await getAllProperties(copy);

// Quotas exceeded
// https://i.imgur.com/LkU2Tuk.png

// Paste these into the following url:
// https://payment.kingcounty.gov/Home/Index?app=PropertyTaxes&Search=0012600030
async function getAllTaxes(startingIndex) {
    const formattedProperties = [];
    const end = startingIndex + 75;

    console.log('properties', properties.length);
    for (let i = startingIndex; i < end; i++) {
        const property = properties[i];        

        const taxData = await getTaxes(property);

        console.log('tax data', taxData.data[0].taxYears[0]);

        for (let taxYearIndex = 0; taxYearIndex < taxData.data[0].taxYears.length; taxYearIndex++) {
            const taxYear = taxData.data[0].taxYears[taxYearIndex];

            formattedProperties.push({
                name: taxData.data[0].accountName.trim(),
                address1: taxData.data[0].address1.trim(),
                address2: taxData.data[0].address2.trim(),
                address3: taxData.data[0].address3.trim(),
                taxYear: taxYear.year,
                amountDue: taxYear.amountDue,
                apn: property,
                assessorUrl: `https://blue.kingcounty.com/Assessor/eRealProperty/Dashboard.aspx?ParcelNbr=${property}`
            });
        }

        // Pause for a second between each request
        await timeout(1000);
    }

    return formattedProperties;
}

// Get tax data for an individual property
async function getTaxes(apn) {
  const data = await fetch("https://payment.kingcounty.gov/Home/TenantCall?app=PropertyTaxes", {
    "headers": {
      "accept": "application/json, text/plain, */*",
      "accept-language": "en-US,en;q=0.9,pt-BR;q=0.8,pt;q=0.7",
      "content-type": "application/json",
      "sec-ch-ua": "\" Not A;Brand\";v=\"99\", \"Chromium\";v=\"90\", \"Google Chrome\";v=\"90\"",
      "sec-ch-ua-mobile": "?0",
      "sec-fetch-dest": "empty",
      "sec-fetch-mode": "cors",
      "sec-fetch-site": "same-origin"
    },
    "referrer": "https://payment.kingcounty.gov/Home/Index?app=PropertyTaxes&Search=0012600030",
    "referrerPolicy": "no-referrer-when-downgrade",
    "body": `{\"path\":\"RealProperty/${apn}\",\"captchatoken\":\"\"}`,
    "method": "POST",
    "mode": "cors",
    "credentials": "include"
  });
  
  const body = await data.json();

  const json = JSON.parse(body);

  return json;
}

function timeout(ms) {
    return new Promise(res => setTimeout(res, ms));
}

copy(await getAllTaxes(0));

// Paste into json to csv converter
// https://json-csv.com/