# RefSubject.Service

Defines the service state contract.

## Signatures

```ts
interface Service<Self, Id extends string, A, E> extends RefSubject<A, E, Self> {
    readonly id: Id;
    readonly service: Context.Service<Self, RefSubject<A, E>>;
    readonly make: <R = never>(value: A | Effect.Effect<A, E, R> | Fx<A, E, R>, options?: RefSubjectOptions<A> & {
        readonly skip?: number;
        readonly take?: number;
    }) => Layer.Layer<Self, never, Exclude<R, Scope.Scope>>;
    readonly layer: <E2, R2>(make: Effect.Effect<RefSubject<A, E>, E2, R2 | Scope.Scope>) => Layer.Layer<Self, E2, Exclude<R2, Scope.Scope>>;
}
```

## Why

Describes the class-like facade returned by `RefSubject.Service`: it is a Context tag whose
static members also implement current reads, Fx observation, and serialized writes.

## Ownership and lifetime

The contract itself acquires nothing. A matching Layer owns the underlying RefSubject; using
the facade requires `Self`, exposes the underlying `E` on reads and pushes, and forwards Scope
ownership to that installed subject.

## Property: id

Exposes id on the ref subject contract.

## Property: id: Why

Preserves the literal Context identifier used to construct and diagnose the service tag.

## Property: id: Ownership and lifetime

This declaration performs no acquisition and retains no resources. Implementations preserve
source errors, services, and lifetime.

## Property: layer

Exposes layer on the ref subject contract.

## Property: layer: Why

Converts a scoped Effect that produces a RefSubject into the exact Layer required by the
facade, preserving construction failures and non-Scope requirements.

## Property: layer: Ownership and lifetime

Layer acquisition runs `make` once per Layer instance. Its Scope owns the installed subject;
`E2` is a Layer-construction failure, while the subject's `E` remains on later state access.

## Property: make

Exposes make on the ref subject contract.

## Property: make: Why

Accepts values, Effects, Streams, and Fx through one renderer-independent state constructor
while retaining their typed failures and services.

## Property: make: Ownership and lifetime

The creation Effect requires Scope. It owns initializer acquisition, live source subscriptions,
and cleanup; source failures and services stay on reads and pushes.

## Property: service

Exposes service on the ref subject contract.

## Property: service: Why

Exposes the exact Effect Context tag used by `layer`, `make`, and every static operation on
the facade, so custom Layers can install an existing RefSubject without another wrapper.

## Property: service: Ownership and lifetime

The tag is pure metadata and owns no state. The Layer that provides it owns the installed
RefSubject and its scoped initializer; operations retrieving it require `Self`.