TFS Aggregator is a extension for TFS and VSTS that enables running custom script when Work Items change, allowing dynamic calculation of field values in TFS and more.
TFS Aggregator is an extension for Team Foundation Server (TFS) and Visual Studio Team Services (VSTS)
that enables running custom scripts when Work Items change, allowing dynamic calculation of field values and more.
It comes in two flavors sharing a common scripting language and configuration.
The Server Plugin, for TFS 2013 Update 2 up to TFS 2017 Update 1, runs in-process of your on-premise TFS and is the most performing option. TFS takes care of insulating from crashes in the plugin.
Another option is choosing for the Web Service version, for VSTS or TFS 2015 and later. You have to setup an hosting environment (basically an IIS Web Site) and it runs out-of the TFS process. The Web Service is the only option for Visual Studio Team Services (VSTS).