Dragonfire.Features 8.3.3

Dragonfire.Features

Feature toggle and release-gate library for .NET 8 — built for B2B2C platforms that need different tiers, early-access cohorts, and gradual rollouts without a roundtrip to a SaaS flag service.

Packages

Quick start

builder.Services.AddDragonfireFeatures(o =>
{
    o.RefreshInterval = TimeSpan.FromSeconds(30);
});
builder.Services.AddDragonfireFeaturesConfiguration(builder.Configuration);
builder.Services.AddDragonfireFeaturesAspNetCore();

// appsettings.json
{
  "Features": {
    "NewCheckout": {
      "DefaultEnabled": false,
      "Tenants": [ "acme", "globex" ],
      "Percentage": 25,
      "PercentageBucket": "TenantThenUser"
    }
  }
}

[FeatureGate("NewCheckout")]
public class CheckoutController : ControllerBase { ... }

app.MapPost("/orders", CreateOrder).RequireFeature("NewCheckout");

Rule semantics

Rules are evaluated in order; the first non-null verdict wins. If every rule abstains, FeatureDefinition.DefaultEnabled is the final answer.

• TenantAllowListRule — grants when the current tenant id is in the list, otherwise abstains.
• UserAllowListRule — grants when the current user id is in the list, otherwise abstains.
• PercentageRule — stable FNV-1a hash of (featureName, bucketKey) mod 100; grants when the bucket is below the threshold. Bucket key prefers tenant id, then user id; anonymous calls abstain so they don't randomly flip on every request.

Sources

IFeatureSource.LoadAllAsync() is called every refresh tick. When two sources advertise the same feature name, the source registered later in DI wins — register configuration first, EF Core second to let the database override appsettings.

The refresh service uses PeriodicTimer directly rather than the Dragonfire.Poller library: Poller targets request/response polling with retry/backoff, not "tick every N seconds forever". Refreshing a feature snapshot is the latter.

Audit log

Every refresh that produces a non-empty diff calls IFeatureAuditLog.RecordAsync with one entry per added / updated / removed feature. The default NoOpFeatureAuditLog discards entries; the EF Core integration persists them to features.FeatureAudit for B2B compliance.

Caching integration

AddDragonfireFeaturesCaching() decorates the resolver. Each decision is cached as features:{feature}:{tenantOrNone}:{userOrNone} with tags features:{feature} and features-tenant:{tenantId}. Flush a single tenant's slice with cacheService.InvalidateByTagAsync("features-tenant:acme").

TenantContext

The AspNetCore accessor reads tenant id from a configurable header (default X-Tenant-Id) or claim. Users on Dragonfire.TenantContext can swap in their own IFeatureContextAccessor that reads ITenantContextAccessor.Current — Dragonfire.Features deliberately avoids a hard dependency on TenantContext.