# documentation:2.0:servertoserver
Keywords: documentation,2.0,servertoserver

# Handling server webservice calls

In modern applications, web application may need to call some other web application on behalf of the connected users. There is three way to do it: the ugly and the smart.

The ugly consists to give the cookie value to the webapp 1 which use it in cookie header of its request. Since version 2.0, LLNG gives a better way to do it using tokens with limited scope.

## Webapp1 handler configuration

Insert a header containing this value:

    token( $_session_id, 'webapp2.example.com', 'webapp3.example.com' )

Webapp1 can read this header and use it in its requests in the `X-Llng-Token` header. The token is build using the session ID and the list of authorized virtualhosts. The token is available only 30 seconds and only the listed virtualhosts.

## Webapp2 handler configuration

Change handler type to “ServiceToken”. So it is able to manage both user and server connections. And that's all !