# OptionalSchemaField

An optional schema record key paired with its Effect Schema.

## Signatures

```ts
export type OptionalSchemaField = readonly [
    Schema.Record.Key,
    Schema.Top
];
```

## Why

Optional route parameters preserve Effect Schema's optional-key semantics.

## Ownership and lifetime

`OptionalSchemaField` is a readonly structural contract. The concrete arrays, AST nodes, names, and Schemas remain owned by the caller that constructs them.