Each request to the Filr REST interface must be authenticated using basic authentication (see http://tools.ietf.org/html/rfc1945#section-11.1). If you enter your Filr REST URL in your browser address bar, it will prompt you to enter your Filr username and password.
Likewise, if you try to make an unauthenticated HTTP request using the curl command-line tool, the server responds with a 401 Unauthorized HTTP error:
[Request]
> curl -k -v https://amethyst.provo.novell.com:8443/rest > GET /rest HTTP/1.1 > User-Agent: curl/7.35.0 > Host: amethyst.provo.novell.com:8443 > Accept: */*
[Response]
< HTTP/1.1 401 Unauthorized < WWW-Authenticate: Basic realm="Novell Filr"
[Request]
> curl -k -v -u dlewis:novell https://amethyst.provo.novell.com:8443/rest > GET /rest HTTP/1.1 > Authorization: Basic ZGxld2lzOm5vdmVsbA== > User-Agent: curl/7.35.0 > Host: amethyst.provo.novell.com:8443 > Accept: */*
[Response]
< HTTP/1.1 200 OK
{...}