curl is a command in linux (and a library in php). Curl typically makes an HTTP request.
What you really want to do is make an HTTP (or XHR) request from javascript.
Using this vocab you’ll find a bunch of examples, for starters:
Sending authorization headers with jquery and ajax
Essentially you will want to call $.ajax
with a few options for the header, etc.
$.ajax({
url: 'https://api.wit.ai/message?v=20140826&q=',
beforeSend: function(xhr) {
xhr.setRequestHeader("Authorization", "Bearer 6QXNMEMFHNY4FJ5ELNFMP5KRW52WFXN5")
}, success: function(data){
alert(data);
//process the JSON data etc
}
})