# Composite.typeaheadKey

Returns an unmodified one-character key exactly as provided; modified and multi-character keys
return null.

## Signatures

```ts
export declare function typeaheadKey(event: KeyboardEventLike): string | null;
```

## Why

Separating this deterministic policy from event wiring lets applications test it directly and
reuse it in custom composites.

## Ownership and lifetime

This is a synchronous calculation. It acquires no resources and does not mutate the input array,
state, event, or DOM.

## Examples

```ts
import * as Composite from "@typed/ui/Composite";

const key = Composite.typeaheadKey({ key: "A" });
```