Shopify AJAX Form submit

ajax-submit-form.js

/* Build the Shopify Parameters
//---------------------------------------*/
var action  = '/contact?';
    action += encodeURIComponent('form_type') +'='+ encodeURIComponent('contact');
    action += '&'+ encodeURIComponent('utf8') +'='+ encodeURIComponent('✓');
    action += '&'+ encodeURIComponent('contact[email]') +'='+ encodeURIComponent(contact_email);
    action += '&'+ encodeURIComponent('contact[body]') +'='+ encodeURIComponent(contact_body);

/* Submit the form
//---------------------------------------*/
$.ajax({
    type: "POST",
    async: true,
    url: action,
    error: function(jqXHR, textStatus, errorThrown) {
        //  Request Failed. 
    },
    success: function(response) {
        // Assume Success. 'response' is the complete HTML page of the 
        // contact success form, so likely won't be helpful
        self.submit_thankyou();
    }
});

What does the '/contact?' action refer to?

@luukee the form's action value

/contact?form_type=customer&utf8=%E2%9C%93&contact%5Bemail%5D=&contact%5Btag%5D=new%20year%20subscribe
why Status Code: 429 ?