Project Server Interface (PSI) Overview
All Windows-based and Web-based client applications for Microsoft Project 2010 use the Project Server Interface (PSI), a set of Web services built on the Microsoft .NET Framework 3.5 and the Windows Communication Foundation (WCF). The PSI, with the Project Server Eventing Service, exposes the functionality and data that developers can use to extend Project Server and to integrate other applications with Project Server. Parameters of PSI methods typically include DataSet objects that provide many advantages in development. Datasets generally correspond to Project Server business object types. Each PSI Web service proxy includes the relevant datasets for public methods within that Web service.
The PSI in Project Server 2010 has a dual interface. The Web service (ASMX) interface operates similarly to the way it does in Microsoft Office Project Server 2007, with the following exceptions:
You must use the ?wsdl URL option when setting an ASMX reference. For example: http://ServerName/ProjectServerName/_vti_bin/PSI/Project.asmx?wsdl
An ASMX reference must be made through the Project Web App address. You cannot set an ASMX reference to the PSI through the back-end Project Server service application. For applications that must run on the local Project Server computer, you should use the WCF interface.
When you are developing on the Project Server computer, you cannot use localhost for the server name in the URL of an ASMX reference. Use the computer name.
The Project Professional 2010 and Project Web App clients use the new WCF service interface for improved performance, security, and scalability. Custom applications can use either interface; the ASMX and WCF interfaces have an identical object model for the public Web services. We recommend using the WCF interface for new applications.
The Project 2010 SDK download includes the WCF-based ProjectServerServices.dll proxy assembly and source code for the PSI services. We recommend that you use the proxy assembly or source code for programming with the WCF interface of the PSI. You can also build your own proxy assembly, for Project Server updates or service packs.