PowerCSharp.BuiltInFeatures.md

PowerCSharp.BuiltInFeatures — API Reference

Bundle of lightweight, runtime-flag-toggled ASP.NET Core capabilities. Toggled via PowerFeatures:<Key>:Enabled. Any built-in can be disabled and replaced by a custom Pluggable Feature.

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Package Information

Property	Value
Package ID	PowerCSharp.BuiltInFeatures
Version	$(PowerCSharpFeaturesVersion)
Target Framework	net8.0
Dependencies	PowerCSharp.Features, Microsoft.AspNetCore.App
NuGet	PowerCSharp.BuiltInFeatures

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1. What Are Built-in Features?

Built-in Features (Group 1) are low-complexity ASP.NET Core / pipeline capabilities that:

• Ship together in a single bundle package.
• Carry no third-party dependencies — only ASP.NET Core framework references.
• Are gated by runtime flag only (no package-reference gating).
• Can each be disabled and replaced by a custom Pluggable Feature that provides the same FeatureKey.

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2. Host Integration

Step 1 — Register

builder.Services.AddPowerFeatures(builder.Configuration, options =>
{
    options.AddBuiltInFeatures(); // opts the bundle into auto-discovery
});

AddBuiltInFeatures() is an extension on PowerFeaturesOptions that calls ScanAssemblies(typeof(CorsFeatureModule).Assembly).

Step 2 — Apply

var app = builder.Build();
app.UsePowerFeatures(); // applies enabled built-ins' middleware in Order

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3. Included Built-in Features

CORS (PowerFeatures:Cors)

Property	Value
Feature Key	Cors
Module	CorsFeatureModule
Order	10
Default	Disabled

Registers and applies a named CORS policy using IApplicationBuilder.UseCors. When disabled, no policy is registered and no middleware is added.

Configuration

{
  "PowerFeatures": {
    "Cors": {
      "Enabled": true,
      "AllowedOrigins": [ "https://example.com", "https://app.example.com" ],
      "AllowedMethods": [ "GET", "POST", "PUT", "DELETE" ],
      "AllowedHeaders": [ "Authorization", "Content-Type" ],
      "AllowCredentials": false
    }
  }
}

Environment variable override

POWERFEATURES__CORS__ENABLED=true

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4. BuiltInFeaturesOptionsExtensions

public static PowerFeaturesOptions AddBuiltInFeatures(this PowerFeaturesOptions options)

Convenience method that opts the PowerCSharp.BuiltInFeatures assembly into auto-discovery. Equivalent to:

options.ScanAssemblies(typeof(CorsFeatureModule).Assembly);

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5. Replacing a Built-in with a Custom Feature

Disable the built-in via flag and register your own Pluggable Feature with the same FeatureKey:

{
  "PowerFeatures": {
    "Cors": { "Enabled": false }
  }
}

// Your custom CORS module
public class CustomCorsFeatureModule : IFeatureModule
{
    public string FeatureKey => "Cors";
    public int Order => 10;
    // ...
}

builder.Services.AddPowerFeatures(builder.Configuration, options =>
{
    options.AddBuiltInFeatures();
    options.AddModule(new CustomCorsFeatureModule()); // explicit registration
});

The built-in CORS module will be skipped (flag off); your custom module runs instead.

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6. Roadmap — Planned Built-in Features

The following are planned for future minor releases:

Feature Key	Description
CorrelationId	Injects/reads a correlation ID header for distributed tracing
SecurityHeaders	Adds security response headers (CSP, HSTS, X-Frame-Options, etc.)
ExceptionHandling	Global exception handler middleware with structured error responses
Sanitization	Request/response body sanitization
HealthChecks	Standard ASP.NET Core health check endpoint wiring

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7. Related Documents

• PowerCSharp.Features.md — Features engine API reference
• PowerCSharp.Features.Architecture.md — Two-tier system design
• PowerCSharp.Features.Authoring-Guide.md — How to build a new Built-in Feature
• PowerCSharp.Features.FlagReference.md — Flag schema and precedence rules