[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/dd96d79f1dbe9a49fa12ce8e0aa7d3d0177795ca/packages/common/src/Types.ts#L467)

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