rss :: Parsing, generation, and caching system for xml news feeds

i am using rails 2.1.0
i installed feedtools gem
now i don't know how to use in my app
could you please help in that

i am clear about RSS
i tried with putting feed action in controller and also tried
with .rxml file
i am in confusion what to do
thats why i am asking

thank you for your response

but when i am calling the index action it is giving authorize error

in my app there are three controllers..
login, clients and users.

main controller is “clients” controller

now
i kept all controller code in clients controller
def index
@clients = Client.find(:all)
respond_to do |format|
format.atom
end
end

and all index.atom.builder code in views/clients/
require”feedtool”
require”feedreader”
require”feedupdate”

atom_feed do |feed|
feed.title(“My Atom Feed”)
feed.updated((@clients.first.created_at))

for post in @clients
feed.entry(client) do |entry|
entry.title(client.title)
entry.content(client.body, :type => ‘html’)

entry.author do |author|
author.name(“EMF”)
end
end
end

Now when i am running
it is giving Nomethoderror in clientcontroller#index

undefined method ‘authorize’ for #<clientcontroller::7658n>

could u plz help me solving this