Announcing the deprecation of the WIT and Test Client OM at Jan 1, 2020

Dan Hellem

Since the first version of Team Foundation Server (TFS) in 2005, we have provided a set of SOAP APIs for programmatic interaction with Work Items and Tests. In recent years, REST has replaced SOAP as the preferred method for building integrations offering a simpler and more flexible programming model, support for multiple data formats, and superior performance and scalability. As our REST APIs have matured we’ve reached a point where we feel it’s time to announce the deprecation of the Work Item and Test SOAP APIs. The plan is as follows:

  • TFS “2020” (shipping towards the end of the 2019 calendar year) will remove support for the Work Item Tracking (WIT) and Test SOAP APIs.
  • VSTS support will be removed on Jan 1, 2020.

If you are a consumer of these SOAP APIs we recommend to plan for a migration to REST. The table below outlines a support matrix of what you can expect across both SOAP and REST.


TFS 2018TFS “2019”1TFS “2020”2
and later

1 Code name from the TFS version which is expected end of 2018
2 Code name from the TFS version which is expected end of 2019


Before Jan 1 2020After Jan 1 2020

Additional resources

If you need help, or want to provide feedback, please reach out to this support alias.


Q: What happens to the Version Control SDK and its SOAP APIs?
A: We will keep supporting the Version Control SDK, but we will end-of-life the SDK at some point in the future. If you create a new application, we recommend you start with the REST APIs. If you have existing apps using the SOAP SDK, we recommend you migrate to the REST APIs.

Q: The SDK included an easy-to-use C# client library. Does REST API have an equivalent?
A: Yes, the REST APIs have a .NET library that abstract out the need to call REST APIs directly.

Q: I’m using TFS2017 or an earlier version. Can I migrate to REST APIs?
A: No, older versions of TFS don’t include the full set of Work Items and Test REST APIs

Q: Which assemblies are impacted?

Q: Which NuGet package is impacted?
A: These assemblies are part of the Microsoft.TeamFoundationServer.ExtendedClient NuGet Package. Please be aware that this package not only contains WIT assemblies, but also provide support for Build and Code. We will keep supporting the Build and Code assemblies. Only the WIT and Test assemblies in the NuGet package will be removed.

Dan Hellem
Dan Hellem


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