Scrape the Metaculus API

ScrapeMetaculus.js

let script = document.createElement('script');
script.src = 'https://cdnjs.cloudflare.com/ajax/libs/PapaParse/5.1.0/papaparse.min.js';
document.getElementsByTagName('body')[0].append(script);

function download(text, filename='data.txt', mime='text/plain'){
  let link = document.createElement('a');
  link.href = window.URL.createObjectURL(new Blob([text], {type: mime}));
  link.setAttribute('download', filename);
  link.click();
}

function downloadJSON(json){
  download(JSON.stringify(json), 'data.json', 'application/json');
}

function downloadCSV(json){
  download(Papa.unparse(json), 'data.csv', 'text/csv');
}

function getMyPredictions(){
  return new Promise((res, rej) => {
    fetch(`https://www.metaculus.com/api2/questions/?guessed_by=${metacData.user.id}&order_by=-activity&page=1`).then(data1 => data1.json().then(predictions => {
      let n = Math.ceil(predictions.count/20);
      let requests = [];
      for(let i = 2; i <= n; i++){
        requests.push(
          fetch(`https://www.metaculus.com/api2/questions/?guessed_by=${metacData.user.id}&order_by=-activity&page=${i}`).then(data2 => data2.json().then(page => {
            predictions.results = predictions.results.concat(page.results);
          }))
        );
      }
      Promise.all(requests).then(() => res(predictions.results));
    }));
  });
}

Use by copying/pasting into Dev Console while logged into Metaculus. Then:

getMyPredictions().then(downloadCSV);
# OR
getMyPredictions().then(downloadJSON);