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 flagsYou 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 HTTPvarbuilder=WebApplication.CreateBuilder(args);builder.AddCocoarConfiguration(c =>c.UseConfiguration(rule =>[rule.For<AppSettings>().FromFile("appsettings.json"),rule.For<AppSettings>().FromEnvironment("APP_"),]));varapp=builder.Build();// Inject directly — no wrapperapp.MapGet("/settings",(AppSettingssettings)=>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 —
CocoarTestConfigurationwithAsyncLocal<T>isolation.
| Provider | Fluent API | Package |
|---|---|---|
| File (JSON) | .FromFile("path") | Core |
| Environment Variables | .FromEnvironment("PREFIX_") | Core |
| Command Line | .FromCommandLine("--prefix") | Core |
| Static / Observable | .FromStaticJson() / .FromObservable() | Core |
| WritableStore (writable overlay) | .FromStore() | Core |
| ConfigHub | .FromConfigHub(url, token) | ConfigHub |
| HTTP | .FromHttp(url) | Http |
| Microsoft IConfiguration | .FromIConfiguration(config) | MicrosoftAdapter |
Explore real-world scenarios in the examples directory.
Contributions welcome! See CONTRIBUTING.md for guidelines.
Apache-2.0 — see NOTICE for details.