Our TFS Customers who wish to extend or program against their Hosted TFS Server cannot use the TFS object model remotely. Instead they must use the web services that TFS exposes, much like Team Explorer does.
TFS web Services come in two flavors V1.0, and V2.0, perhaps for backward compatibility with Team Explorer 2005.
Find your various services at the following web addresses.
Build Service
V1.0
http://YOURServerNameHERE:8080/Build/V1.0/BuildController.asmx
http://YOURServerNameHERE:8080/Build/V1.0/BuildStore.asmx
http://YOURServerNameHERE:8080/Build/V1.0/Integration.asmx
http://YOURServerNameHERE:8080/Build/V1.0/PublishTestResultsBuildService.asmx
http://YOURServerNameHERE:8080/Build/V1.0/PublishTestResultsBuildService2.asmx
V2.0
http://YOURServerNameHERE:8080/Build/V2.0/BuildService.asmx
http://YOURServerNameHERE:8080/Build/V2.0/Integration.asmx
Services Service
V1.0
http://YOURServerNameHERE:8080/Services/v1.0/AuthorizationService.asmx
http://YOURServerNameHERE:8080/Services/v1.0/CommonStructureService.asmx
http://YOURServerNameHERE:8080/Services/v1.0/EventService.asmx
http://YOURServerNameHERE:8080/Services/v1.0/GroupSecurityService.asmx
http://YOURServerNameHERE:8080/Services/v1.0/ProcessTemplate.asmx
http://YOURServerNameHERE:8080/Services/v1.0/projectMaintenance.asmx
http://YOURServerNameHERE:8080/Services/v1.0/Registration.asmx
http://YOURServerNameHERE:8080/Services/v1.0/ServerStatus.asmx
V2.0
http://YOURServerNameHERE:8080/Services/v2.0/GroupSecurityService2.asmx
Version Control Service
V1.0
http://YOURServerNameHERE:8080/VersionControl/v1.0/Administration.asmx
http://YOURServerNameHERE:8080/VersionControl/v1.0/Integration.asmx
http://YOURServerNameHERE:8080/VersionControl/v1.0/ProxyStatistics.asmx
http://YOURServerNameHERE:8080/VersionControl/v1.0/Repository.asmx
Warehouse Service
V1.0
http://YOURServerNameHERE:8080/Warehouse/v1.0/warehousecontroller.asmx
WorkItem Tracking Service
V1.0
http://YOURServerNameHERE:8080/WorkItemTracking/v1.0/ClientService.asmx
http://YOURServerNameHERE:8080/WorkItemTracking/v1.0/ConfigurationSettingsService.asmx
http://YOURServerNameHERE:8080/WorkItemTracking/v1.0/ExternalServices.asmx
http://YOURServerNameHERE:8080/WorkItemTracking/v1.0/Integration.asmx
http://YOURServerNameHERE:8080/WorkItemTracking/v1.0/SyncEventsListener.asmx