# RefSubject.isHydrationRef

Tests whether a value carries callable hydration metadata.

## Signatures

```ts
export declare function isHydrationRef(value: unknown): value is HydrationRef<any, any>;
```

## Why

Detects hydration capability by its public TypeId instead of relying on a concrete class or
renderer.

## Ownership and lifetime

This declaration acquires no resources. Effects represented by the contract retain their own
services and Scope requirements.