Microsoft.Extensions.Configuration
Microsoft.Extensions.Configuration is combined with a core configuration abstraction under Microsoft.Extensions.Configuration.Abstractions that allows for building different kinds of configuration providers to retrieve key/value pair configuration values from in the form of IConfiguration. There are a number of built-in configuration provider implementations to read from environment variables, in-memory collections, JSON, INI or XML files. Aside from the built-in variations, there are more shipped libraries shipped by community for integration with various configuration service and other data sources.