# RefTrie.keys

Get all keys from the Trie.

## Signatures

```ts
export declare const keys: <V, E, R>(ref: RefTrie<V, E, R>) => RefSubject.Computed<Array<string>, E, R>;
```

## Why

Projects trie state with keys for both current reads and future pushes, avoiding a second
mutable cache of the derived value.

## Ownership and lifetime

The keys view retains no independent state. An Effect read samples the source once; Fx
observation follows later pushes and its observing Scope owns subscription cleanup.