def _get_keywords():
    """Returns a list of the currently valid keywords for the AFLUX API.
    """
    from six.moves import urllib
    import json
    urlopen = urllib.request.urlopen
    url = 'http://aflowlib.duke.edu/search/API/?schema'
    r = urlopen(url).read().decode('utf-8')
    return json.loads(r)
