[API reference](https://evolu.dev/docs/api-reference) › [@evolu/common](https://evolu.dev/docs/api-reference/common) › [Types](https://evolu.dev/docs/api-reference/common/Types) › KeysOfUnion

```ts
type KeysOfUnion<T> = T extends T ? keyof T : never;
```

Defined in: [packages/common/src/Types.ts:467](https://github.com/evoluhq/evolu/blob/037c390af081e9944d616ff298a729515c5c5ab7/packages/common/src/Types.ts#L467)

Returns every property key present in any member of a union.