API Authentication-Authlogic

Hi all
            I am using Authlogic gem for authentication.I want an API
authentication for external API(XML) call.How to implement this in
authlogic .Thanks in advance...

Authlogic is not working well with my application.I want solution for
this..

Attachments:
http://www.ruby-forum.com/attachment/7204/error.htm

The error is saying you have an undefined variable or method "current_user".
Have you defined it? Authlogic doesn't provide it.

Cheers.