Zero ceremony configuration that updates itself. Define a class, add a rule, inject it — no IOptions<T> wrappers, no Configure<T>() calls.

dotnet add package Cocoar.Configuration              # Core library (console apps)
dotnet add package Cocoar.Configuration.DI            # + Microsoft.Extensions.DI
dotnet add package Cocoar.Configuration.AspNetCore     # + health endpoints, feature flags

You only need one — each includes everything above it. Requires .NET 9+.

Optional provider packages add only the integration you need:

dotnet add package Cocoar.Configuration.ConfigHub      # ConfigHub delivery and live invalidation
dotnet add package Cocoar.Configuration.Http           # Generic remote configuration via HTTP

var builder = WebApplication.CreateBuilder(args);

builder.AddCocoarConfiguration(c => c
    .UseConfiguration(rule => [
        rule.For<AppSettings>().FromFile("appsettings.json"),
        rule.For<AppSettings>().FromEnvironment("APP_"),
    ]));

var app = builder.Build();

// Inject directly — no wrapper
app.MapGet("/settings", (AppSettings settings) => new
{
    settings.AppName,
    settings.MaxRetries
});

app.Run();

• Zero Ceremony — Define a class, add a rule, inject it. Just your POCO.
• Reactive by Default — IReactiveConfig<T> updates automatically when sources change.
• Atomic Updates — IReactiveConfig<(T1, T2)> guarantees consistent snapshots across types.
• Explicit Layering — Rules execute in order, last write wins. File, environment, CLI, HTTP.
• Memory-Safe Secrets — Secret<T> with automatic zeroization and X.509 hybrid encryption.
• Feature Flags & Entitlements — Strongly-typed, source-generated, with expiry health monitoring.
• Multi-Tenant — The same config type resolves per tenant on a shared global base; .TenantScoped() rules, …ForTenant(id) access.
• DI-Aware Providers — Opt-in Layer-2 rules whose providers use IHttpClientFactory / Marten / EF, without giving up the no-DI core.
• Health Monitoring — Per-rule status tracking, OpenTelemetry metrics, ASP.NET Core health checks.
• Compile-Time Validation — Roslyn analyzers catch configuration errors in your IDE.
• First-Class Testing — CocoarTestConfiguration with AsyncLocal<T> isolation.

Explore real-world scenarios in the examples directory.

Contributions welcome! See CONTRIBUTING.md for guidelines.

Apache-2.0 — see NOTICE for details.