Making an ajax request using plain JavaScript

XMLHttpRequest.js

var data = {
    ids: [12, 18, 27, 35, 41, 53, 66, 68, 72, 85, 94, 103, 111, 120, 133]
}

var xhr = new XMLHttpRequest();
xhr.onreadystatechange = function(xhr) {
    if (xhr.readyState < 4 || xhr.status !== 200) {
        return;
    }

    // all is well
    if (xhr.readyState === 4) {
        console.log(xhr.responseText); // the list of tweets
        parseTweets(xhr.responseText)
    }
}

xhr.open('GET', 'https://your_awesome_url.com/tweet/', true);
xhr.setRequestHeader("Authorization", 'key=oNs3NZXPKF2_9NSAetkus');
xhr.setRequestHeader("Content-type", "application/json");
xhr.send(JSON.stringify(data));