superagent call in server side not happening

we are creating react flux app with superagent for api calls.
As per server side loading , all the html with api data rendered in component should be called from
server end only.
we are calling superagent from actioncreater.
as we are using react router and in server.js using below code

React.renderToString(
React.createElement(Router, i));

is it clear enough that we are rendering from server side on first call and other calls handled from client side.

But as all the html should call from server end on first call why my api xhr call in component showing in firebug NET call? and also api result is rendered client side. so not sure all the result on first call coming from server.
React-router is a module that can run both on the server and in the client also.
so does this called as server side rendering?
or anything need to done at superagent call?