# RequiredKeysOf

**Kind:** Type

**Source:** [`src/utils/types.ts`](https://github.com/honojs/hono/blob/main/src/utils/types.ts#L104)

**Part of:** [Utils](subsystem-src-utils)

## Definition

```ts
Exclude< { [Key in keyof BaseType]: BaseType extends Record<Key, BaseType[Key]> ? Key : never }[keyof BaseType], undefined >
```