Once I was asked to develop a solution that was not to be installed on the SharePoint server neither I was allowed to create a webpart solution that could be deployed on SharePoint server. The best solution that I found was to create Desktop Application, and delivering it executable file. As it was a desktop application we need to use CSOM. In this blog I will show you a basic code demo to interact with SharePoint server. Validate User 1. When you are on same domain as SharePoint server and use windows credentials to login. using ( ClientContext ctx = new ClientContext (URL)) { } 2. When you are in different domain or want to login as different user. using ( ClientContext ctx = new ClientContext (URL)) { ctx.Credentials = new NetworkCredential (UserName,Password,Domain); } 3. When you want to login as FBA User using ( ClientContext ctx = new ClientContext (URL)) { ctx.AuthenticationMode = ClientAuthenticationMode .Form