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

```ts
type UnionInputType<Input, Error> = Type<
  "Union",
  Input,
  Input,
  Error,
  null,
  Error,
  never,
  Input
>;
```

Defined in: [packages/common/src/Type.ts:3845](https://github.com/evoluhq/evolu/blob/f0109fb501a593010e858e39248dde1200eeb2d7/packages/common/src/Type.ts#L3845)

A root [Type](https://evolu.dev/docs/api-reference/common/Type/interfaces/Type) validating the encoded Inputs accepted by [union](https://evolu.dev/docs/api-reference/common/Type/functions/union).