To use AuthSub for Actionscript (or as we’re calling it, AuthSubAS), first ensure that the API you are accessing offers cross-domain support. To do this, simply check for a
crossdomain.xmlfile like those offered by the Picasa Web Albums Data API and the YouTube Data API. Then, if the API supports cross-domain scripting, you can simply point your Flash app to
Currently, cross-domain requests are only supported by the Picasa Web Albums Data API and the YouTube Data API. However, as more APIs offer cross-domain scripting through an open
crossdomain.xmlfile, the AuthSubAS authentication will work automatically. For questions about a specific API or to encourage your API to provide AuthSubAS support sooner, visit your API’s support group in Google Groups.