Autodesk.Revit.Sdk.Refs.2018 1.1.0
Install from the command line:
Learn more about NuGet packages
$ dotnet add package Autodesk.Revit.Sdk.Refs.2018 --version 1.1.0
About this version
The Software Development Toolkit (SDK) provides extensive .NET code samples and documentation to help you get started developing with the Revit API.