Are WCF services stateless by default?

Question

I\'ve got a simple WCF service that lets clients/consumer applications log in by providing a username and password. If both the username and password are correct, the WCF se

Answer 1

They are stateless by default and I would highly recommended keeping it that way if possible. However if for some reason you are unable to, you can enable state.

You have to use wsHttpBinding or wsDualHttpBinding and then set the SessionMode of the ServiceContract (MSDN link) to allowed or required. goes into much greater detail.