When you create a proxy for a WCF service, you can always add a
<system.serviceModel> section to the main assembly and
configure all the settings in there (including the URL of the service you
creates a proxy for).
If you add your proxy in a library assembly, you can still add
<system.serviceModel> to the main (executable/web
You need to copy the
<client> section from the
library config to the host application config (together with its binding
and possibly other elements).