Provides a base class for file-based configuration providers used with Microsoft.Extensions.Configuration and extension methods for configuring them.
Documentation can be found at https://learn.microsoft.com/dotnet/core/extensions/configuration
The APIs and functionality are mature, but do get extended occasionally.
Microsoft.Extensions.Configuration.FileExtensions is included in the ASP.NET Core shared framework. The package is deployed as out-of-band (OOB) too and can be referenced into projects directly.