BTC API – GCF + Apps Script

btc_sheets.js

/**
 * Get's the bitcoin price at a date.
 *
 * @param {string} date The date in yyyy-MM-dd format. Defaults to today.
 * @return The value of BTC in USD at the date. From Coinbase's API
 * @customfunction
 */
function BTC_CF(date) {
  var dateString = Utilities.formatDate(new Date(date), "GMT", "yyyy-MM-dd");
  var res = UrlFetchApp.fetch("https://us-central1-new-project-as-test.cloudfunctions.net/btc?date=" + dateString);
  var json = JSON.parse(res.getContentText());
  return json.data.amount;
}