I am kind of new to Python, but I have had the same issue working with Node apps. I am making a pretty standard jQuery AJAX request to my local Python sever:

```
init: function(callback) {
            var token = _config.get_token();

            $.ajax({
                    url: 'http://localhost:5000/api/ia/v1/user_likes',
                    type: 'POST',
                    contentType: 'application/json',
                    datatype: 'json',
                    data: token
                })
                .done(function(data) {
                    callback(data);
                })
                .fail(function(err) {
                    callback(err);
                });

            callback(token);
        }

```

I can confirm that the variable token is confirming like this:

```
Object {access_token: "791415154.2c0a5f7.4d707361de394512a29682f9cb2d2846", campaign_id: "102"}

```

But I am getting this error from my javascript console:

```
XMLHttpRequest cannot load http://localhost:5000/api/ia/v1/user_likes. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://s3.amazonaws.com' is therefore not allowed access. The response had HTTP status code 500.

```

I have found that when I am building Node apps that this is a cors error. The page that I am running the jQuery AJAX request from is http. Here are the parts of my Python code that I believe I am configuring incorrectly:

```
from flask import Flask, request, redirect
from flask.ext.cors import CORS, cross_origin

app = Flask(__name__)
cors = CORS(app)
app.config['CORS_HEADERS'] = 'application/json'

```

And the route:

```
@app.route("/api/ia/v1/user_likes", methods=['POST', 'OPTIONS'])
def user_likes():
    validate = validate_request(request.data)

    return 'something'

```

My Python error is also returning an error because the request is never making it to this line of code:

```
def validate_request(object_from_user):
    load_object = json.loads(object_from_user)

```

I can fix that later. Anyway, does anyone have any suggestions for Cors configurations for Python?