microsoft-extensions-configuration

Validate .NET configuration at startup by implementing IValidateOptions<T> for complex rules or using Data Annotations on your strongly-typed classes. This ensures the application fails fast during initialization if any required settings are missing or invalid.

IOptions provides singleton configuration values, IOptionsSnapshot recalculates values per request scope, and IOptionsMonitor retrieves current values dynamically with change notifications. Choosing the right options lifetime ensures configuration behaves correctly across different application needs.

Bind appsettings.json sections to C# classes using the Options Pattern. By configuring the strongly-typed class in your Startup or Program file, the configuration system automatically maps the corresponding JSON section values to your class properties.

Yes, implement custom cross-property validation by creating a class that implements the IValidateOptions<T> interface. This allows you to define complex, environment-specific validation logic that runs automatically when the configuration is bound.

Named options in ASP.NET Core allow you to configure and retrieve multiple distinct instances of the same options class using different names. Use them when your application requires different configurations for the same settings structure across various environments or modules.

Handle configuration sources like database connection strings by binding them to strongly-typed C# classes using Microsoft.Extensions.Configuration. Apply validation at startup to ensure the application fails immediately if any connection strings are missing or formatted incorrectly.