README

The framework-agnostic foundation: the application object, the contracts every other package depends on, environment loading, and a base service provider. Core defines interfaces and orchestration — it ships no concrete container, kernel, or HTTP layer. Those are bound by the application at runtime.

Contracts

The public API every other package codes against.

• KernelInterface — handle() runs the request lifecycle and emits the response (returns nothing); terminate() performs post-response clean-up.
• ServiceProviderInterface — register() binds services into the container; boot() runs once all providers are registered.
• ContainerInterface — extends PSR-11's ContainerInterface and adds singleton() (autowires a class-string or uses a callable factory; every entry is shared — there is no transient binding yet), instance() (register an already-constructed object), and bound() (does a binding exist). Core declares this interface only; the concrete container is supplied by the app.

Environment

Environment reads <basePath>/.env and exposes typed accessors: get(), has(), string(), int(), and bool(). A missing .env is tolerated; a present-but-non-integer value passed to int() throws rather than silently coercing to 0.

Providers

Providers\ServiceProvider is a concrete base class with empty register() and boot() methods. App and package providers extend it and override what they need; bindings are registered here.

Application

Application accepts a ContainerInterface and owns the boot sequence:

• register(ServiceProviderInterface) — registers a provider (and boots it immediately if the app has already booted).
• boot() — boots every registered provider exactly once.
• run() — boots, resolves the KernelInterface from the container, calls handle(), flushes the response with fastcgi_finish_request() when available, then calls terminate().