Hi @joostbos, thanks for raising this. Indeed, the openvr_api.cs is a file we require for using the examples in the Tobii XR SDK. This file will conflict when importing things such as SteamVR or other libraries which depend on OpenVR, but it is safe to delete this file if you have another one in your project, assuming they are both the same version.
Hopefully this clear up the situation, please do let us know if we can provide any further information. Best Wishes.