Defining a Schema Equivalent for a Mapped Type in TypeScript

This might be asking too much. How would we define a Schema equivalent of the ff:

export type KV<R> = {
  [Key in keyof R]: {
    key: Key;
    value: R[Key];
  };
}[keyof R];

export type KV<R> = {
  [Key in keyof R]: {
    key: Key;
    value: R[Key];
  };
}[keyof R];

Defining a Schema Equivalent for a Mapped Type in TypeScript - Effect Community