MinimalSample.csproj

<Project Sdk="Microsoft.NET.Sdk.Web">

  <PropertyGroup>
    <TargetFramework>$(DefaultNetCoreTargetFramework)</TargetFramework>
  </PropertyGroup>

  <ItemGroup>
    <Reference Include="Microsoft.AspNetCore" />
    <Reference Include="Microsoft.AspNetCore.Diagnostics" />
    <Reference Include="Microsoft.AspNetCore.Hosting" />
    <Reference Include="Microsoft.AspNetCore.Http" />
    <Reference Include="Microsoft.AspNetCore.Http.Results" />
    <!-- Mvc.Core is referenced only for its attributes -->
    <Reference Include="Microsoft.AspNetCore.Mvc.Core" />
    <Reference Include="Microsoft.AspNetCore.Server.Kestrel" />
  </ItemGroup>

</Project>